April Weber

April Weber

Thursday, 24 March 2011 19:13

Singers

The term singer applies to any person whose career, avocation or livelihood relies heavily on the use of his or her voice in a musical context rather than ordinary speech. Unlike percussionists, pianists or violinists, the singer is the instrument. Hence, the well-being of a singer depends not only on the health of his or her larynx (where the sound originates) or vocal tract (where the sound is modified), but also on proper functioning and maximal coordination of most mind and body systems.

Of the many styles of singing documented throughout the world, some reflect a unique liturgical, cultural, linguistic, ethnic or geo-political heritage, while others are more universal in nature. Among the common styles of singing in the United States and Western world are: traditional classical (including oratorio, opera, art songs and so on), barbershop, jazz, musical theatre (Broadway), choral, gospel, folk, country (and western), popular, rhythm and blues, rock ’n’ roll (including heavy metal, alternative rock and so on) and others. Each style of delivery has its typical settings, patterns, habits and associated risk factors.

Vocal Problems

Unlike non-singers, who may not be significantly hindered by vocal problems, for the classical singer, the effect of subtle vocal impairment can be devastating. Even within that category of trained singers, vocal impairment is much more debilitating for the higher voice classifications (sopranos and tenors) than for lower classifications (mezzo sopranos, altos, baritones and basses). On the other hand, some vocal performers (pop, gospel or rock, for example) go to great lengths to achieve a unique trademark and enhance their marketability by inducing vocal pathologies which often yield a breathy, husky, muffled diplophonic (simultaneous multiple pitches) quality. Owing, in part, to their impairment, they tend to sing with great effort, struggling particularly to produce the high notes. To many listeners, this struggle adds a dramatic effect, as if the singer is sacrificing his or her self while engaging in the artistic process.

The prevalence of occupation-related injuries in general, and voice disorders in particular, among singers is not well documented in the literature. This author estimates that on the average, between 10 and 20% of singers in the United States sustain some form of chronic voice disorder. However, the incidence of vocal injury varies significantly with many factors. Because many singers must adhere to specific artistic/aesthetic criteria, performance practices, popular (consumer) demands, financial constraints and social pressures, they often stretch their vocal capabilities and endurance to the limits. Furthermore, singers generally tend to deny, trivialize or ignore warning signs and even diagnoses of vocal injury (Bastian, Keidar and Verdolini-Marston 1990).

The most common problems among singers are benign mucosal disorders. The mucosa is the outer layer, or cover, of the vocal folds (commonly called vocal cords) (Zeitels 1995). Acute problems can include laryngitis and transient vocal fold swelling (oedema). Chronic mucosal lesions include vocal fold swellings, nodules (“calluses”), polyps, cysts, sub-mucosal haemorrhage (bleeding), capillary ectasia (widening), chronic laryngitis, leukoplakia (white spots or patches), mucosal tears and glottic sulci (deep furrows in the tissue). Although these disorders can be exacerbated by smoking and excessive alcohol consumption, it is important to note that these benign mucosal lesions are typically related to the amount and manner of voice use, and are the product of vibratory trauma (Bastian 1993).

Causes of Vocal Problems

In looking at the causes of vocal problems in singers, one should distinguish between intrinsic and extrinsic factors. Intrinsic factors are those related to personality, vocal behaviour (including speaking) on and off stage, vocal technique, and intake habits (primarily if substance abuse, improper medication, malnutrition and/or dehydration is involved). Extrinsic factors are related to environmental pollutants, allergies and so on. Based on clinical experience, intrinsic factors tend to be most important.

Vocal injury is usually a cumulative process of misuse and/or overuse during the singer’s productive (performance-related) and/or non-productive (domestic, social) activities. It is difficult to ascertain how much of the damage is attributable directly to the former versus the latter. Performance risk factors can include unreasonably long dress rehearsals requiring full-voice singing, performing with an upper-respiratory infection in the absence of a replacement and excessive singing. Most vocalists are advised not to sing for more than about 1.5 hours (net) per day. Unfortunately, many singers do not respect the limitations of their apparatus. Some tend to get caught up in the exploratory excitement of new technical skills, new means of artistic expression, new repertoire and so on, and practice 4, 5 or 6 hours daily. Even worse is the beating of the voice into shape when distress signals of injury (such as loss of high notes, inability to sing softly, breathy delay in sound initiation, unstable vibrato and increased phonatory effort) are manifested. The culpability of vocal overtaxing is shared with other taskmasters such as the booking agent who squeezes multiple performances into an impossible time frame, and the recording agent who leases the studio for 12 consecutive hours during which the singer is expected to record a complete CD sound track from start to finish.

Although every singer may encounter acute episodes of voice problems at some point in his or her career, it is generally believed that those singers who are musically literate and can adjust the musical score to their voice limitations, and those who have had proper voice training, are less likely to encounter severe problems of a chronic nature than their untrained peers, who often learn their repertoire by rote, repeatedly imitating or singing along with demo tapes or recordings of other performers. In doing so, they frequently sing in a key, range or style unsuitable for their voices. Singers who lend themselves to periodic tutelage and maintenance by proficient voice experts are less likely to resort to faulty compensatory vocal manoeuvres if confronted by physical impairment, and are more inclined to establish a reasonable balance between artistic demands and vocal longevity. A good teacher is aware of the normal (expected) capabilities of each instrument, can usually distinguish between technical and physical limitations, and often is the first to detect warning signs of vocal impairment.

Sound amplification can also create problems for singers. Many rock groups, for example, amplify not only the singer, but the entire band. When the noise level interferes with auditory feedback, the singer is often unaware that he or she is singing too loudly and using faulty technique. This may contribute significantly to the development and exacerbation of vocal pathology.

Non-performance factors can also be important. Singers must realize that they do not have separate laryngeal mechanisms for singing and speaking. Although most professional singers spend much more time talking than singing, speaking technique is commonly discarded or rejected, which can adversely affect their singing.

Many of today’s singers must travel regularly from one performance venue to another, on trains, tour buses or airplanes. Ongoing touring requires not only psychological adaptation, but also physical adjustments on many levels. In order for singers to function optimally, they must receive adequate quality and quantity of sleep. Radical rapid changes in time zones causes jet lag, which forces singers to remain awake and alert when their internal clock is cueing various body systems to shut down for sleep, and conversely, to sleep when their brain systems are aroused to plan and execute normal daytime activities. Such interruption may result in a host of debilitating symptoms, including chronic insomnia, headaches, sluggishness, dizziness, irritability and forgetfulness (Monk 1994). Aberrant sleep patterns are also a common problem among those singers who perform late at night. These abnormal sleep patterns are all too often mismanaged with alcohol or recreational, prescription or over-the-counter (OTC) drugs (most of which adversely affect the voice). Frequent and/or prolonged confinement to a closed cabin of a motor vehicle, train or aircraft may create additional problems. Inhalation of poorly filtered (often recycled), contaminated, dehumidified (dry) air (Feder 1984), according to many singers, can cause respiratory discomfort, tracheitis, bronchitis or laryngitis that may linger on for hours or even days following a trip.

Owing to environmental instability and hectic scheduling, many singers develop erratic, unhealthful eating habits. In addition to reliance on restaurant food and unpredictable changes in meal times, many singers eat the main meal of the day after their performance, usually late at night. Particularly for the overweight singer, and especially if spicy, greasy or acidic foods, alcohol or coffee were consumed, lying down soon after having filled the stomach is likely to result in gastroesophageal reflux. Reflux is the retrograde flow of acids from the stomach up the oesophagus and into the throat and larynx. The resulting symptoms can be devastating to the singer. Eating disorders are quite common among singers. In the operatic and classical realm, overeating and obesity are quite common. In the musical theatre and pop domain, particularly among young females, reportedly one-fifth of all singers have encountered some form of eating disorder, such as anorexia or bulimia. The latter involves various purging methods, of which vomiting is thought to be particularly hazardous to the voice.

A detrimental factor to voice production is exposure to pollutants, such as formaldehyde, solvents, paints and dusts, and allergens, such as tree, grass or weed pollens, dust, mould spores, animal danders and perfumes (Sataloff 1996). Such exposure may occur on and off stage. In their work milieu, singers can be exposed to these and other pollutants associated with vocal symptoms, including cigarette smoke and theatrical smoke and fog effects. Singers use a greater percentage of their vital capacity than ordinary speakers. Furthermore, during intense aerobic activity (such as dancing), the number of breathing cycles per minute increases, and mouth breathing prevails. This results in the inhalation of larger amounts of cigarette smoke and fogs during performances.

Treatment of Vocal Problems

Two major issues in the treatment of vocal problems of singers are self-medication and improper treatment by physicians who are not knowledgeable about the voice and its problems. Sataloff (1991, 1995) surveyed the potential side effects associated with medications commonly used by singers. Whether recreational, prescription, over the counter or food supplements, most drugs are likely to have some effect on phonatory function. In an attempt to control “allergies”, “phlegm” or “sinus congestion”, the self-medicating singer will ultimately ingest something that will damage the vocal system. Likewise, the physician who keeps prescribing steroids to reduce chronic inflammation caused by abusive vocal habits and ignores the underlying causes will eventually hurt the singer. Vocal dysfunction resulting from poorly indicated or ill-performed phonosurgery has been documented (Bastian 1996). To avoid injuries secondary to treatment, singers are advised to know their instruments, and consult only with health care professionals who understand and have experience and expertise managing the vocal problems of singers, and who possess the patience to educate and empower singers.

 

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Thursday, 24 March 2011 15:57

Musicians

The musician relies on the skilled use of the muscles, nerves and bones (neuromusculoskeletal system). Playing an instrument requires finely controlled repetitive motions and often entails working in unnatural postures for extended periods of practice and performance (figure 1). These demands on the body can result in specific types of health problems. In addition, adverse working conditions, such as excessive sound exposure levels, prolonged periods of performance without rest, and inadequate preparation for new and difficult repertoire or instruments may affect the health of musicians in all age groups and at all levels of performing ability. Recognition of these hazards, accurate diagnosis and early treatment will prevent occupational disabilities that may interfere with, interrupt or end careers.

Figure 1. Orchestra.

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Neuromusculoskeletal Problems

Studies from the United States, Australia and Canada suggest that around 60% of musicians will face career-threatening injuries during their working lifetime. Clinical cross-sectional studies have examined the prevalence of muscle-tendon disorders, of peripheral nerve entrapment syndromes and motor control problems. These studies have revealed several common diagnoses, which include various overuse syndromes, including strain of the muscles and connective tissue which control the bending and extending motions in the wrist and fingers. These syndromes result from the repetitive forceful movement of the muscle-tendon units. Other common diagnoses relate to pain in body parts which are involved in prolonged strain from awkward and imbalanced postures while playing musical instruments. Playing the instruments in the groups described below involves putting pressure on the branches of the nerves in the wrist and forearm, the shoulders, arm and neck. Occupational cramp or muscle spasms (focal dystonia) are also common problems which often can affect performers at the pinnacle of their careers.

String instruments: Violin, viola, cello, bass, harp, classical guitar and electric guitar

Health problems in musicians who play string instruments often are caused by the manner in which the musician supports the instrument and the posture assumed while sitting or standing and playing. For example, most violinists and violists support their instruments between the left shoulder and chin. Often the musician’s left shoulder will be elevated and the left chin and jaw will bear down in order to allow the left hand to move over the fingerboard. Elevating a joint and bearing down at the same time leads to a state of static contraction which promotes neck and shoulder pain, temporomandibular joint disorders involving the nerves and muscles of the jaw, and thoracic outlet syndrome, which can include pain or numbness in the neck, shoulder and upper chest area. Prolonged static sitting postures, particularly while assuming a bent posture, promote pain in the large muscle groups which support posture. Static twisting rotation of the spine is often required to play the string bass, harp and classical guitar. Heavy electric guitars are usually supported by a strap over the left neck and shoulder, contributing to pressure on the nerves of the shoulder and upper arm (the brachial plexus) and thus to pain. These problems of posture and support contribute to the development of strain and pressure of the nerves and muscles of the wrist and fingers by promoting their faulty alignment. For example, the left wrist may be used for excessive repetitive bending motions which result in strain of the extensor muscles of the wrist and fingers and the development of carpal tunnel syndrome. Pressure on the nerves of the shoulder and arm (lower trunks of the brachial plexus) may contribute to problems with the elbow, such as a double crush syndrome and ulnar neuropathy.

Keyboard instruments: Piano, harpsichord, organ, synthesizers and electronic keyboards

Playing a keyboard instrument requires assuming a similar posture to that of typing. Often the forward and downward orientation of the head to look at the keys and hands and repetitive upward movement to look at the music causes pain in the nerves and muscles of the neck and back. The shoulders will often be rounded, combined with a forward head poking posture and a shallow breathing pattern. A condition known as thoracic outlet syndrome can develop from chronic compression of the nerves and blood vessels that pass between the muscles in the neck, shoulder and rib cage. In addition, a musician’s tendency to bend the wrists and curl the fingers while keeping the hand/finger joints flat places excessive strain on the wrist and finger muscles in the forearm. Additionally, the repeated use of the thumb kept in a position under the hand strains the thumb muscles which extend and binds the finger extensor muscles across the back of the hand. The high repetitive force needed to play large chords or octaves may strain the capsule of the wrist joint and result in ganglion formation. Prolonged co-contraction of the muscles that turn and move the arms up and down can lead to nerve entrapment syndromes. Muscle spasms and cramps (focal dystonia) are common among this group of instrumentalists, sometimes requiring long periods of neuromuscular retraining to correct movement patterns which can lead to these difficulties.

Wind and brass instruments: Flute, clarinet, oboe, saxophone, bassoon, trumpet, french horn, trombone, tuba and bagpipes

A musician who plays one of these instruments will vary his or her posture according to the need to control airflow since posture will control the area from which diaphragmatic and intercostal breath is drawn. Playing these instruments depends on the way the mouthpiece is held (the embouchure) which is controlled by the facial and pharyngeal muscles. The embouchure controls sound production of vibrating reeds or the mouthpiece. Posture also affects how the musician supports the instrument while sitting or standing and in operating the keys or valves of the instrument that govern the pitch of the note played by the fingers. For example, the traditional French open-holed flute requires sustained adduction and flexion (bending forward) of the left shoulder, sustained abduction (drawing away) of the right shoulder and rotation of the head and neck to the left in slight movement. The left wrist is often held in an extremely bent position while the hand is also extended in order to support the instrument by the curled left index finger and both thumbs, counter balanced by the right little finger. This promotes strain of the forearm muscles and the muscles which permit extension of the fingers and thumbs. The tendency to project the head and neck forward and use shallow breathing increases the chances of developing thoracic outlet syndrome.

Percussion instruments: Drums, timpani, cymbals, xylophone, marimba, tabla and taiko

The use of sticks, mallets and bare hands to strike various percussion instruments results in rapid pulling back of the wrists and fingers at impact. The impulse vibration caused by striking the instrument is transmitted up the hand and arm and contributes to repetitive strain injuries of the muscle-tendon units and the peripheral nerves. Biomechanical factors, such as the amount of force used, the repetitive nature of the playing and static load placed on the muscles can add to the injuries. Carpal tunnel syndrome and nodule formation in tendon sheaths are common in this group of musicians.

Hearing Loss

The risk of hearing loss from music exposure depends on the intensity and duration of exposure. It is not uncommon to have exposure levels of 100 dB during a quiet passage of orchestral music, with peak values of 126 dB measured at the shoulder of an instrumentalist in the middle of the orchestra. At the position of the conductor or teacher, levels of 110 dB in an orchestra or band are common. Exposure levels for pop/rock and jazz musicians may be significantly higher, depending on the physical acoustics of the stage or pit, amplification system and placement of speakers or other instruments. The average duration of exposure may be approximately 40 hours per week, but many professional musicians will perform 60 to 80 hours per week on occasion. Hearing loss among musicians is far more common than expected, with approximately 89% of professional musicians who were found to have suffered musculoskeletal injuries also showing an abnormal hearing test result, with a hearing loss in the 3 to 6 KHz region.

Personal ear protection can be used but it must be adapted for each instrument type (Chasin and Chong 1992). By inserting an acoustic attenuator or filter into custom-moulded earplugs, the intensity of higher frequency sounds transmitted by ordinary earplugs is reduced to a flat attenuation as measured at the eardrum, which should be less damaging to the ear. The use of a tuned or adjustable vent in a custom earplug will allow the lower frequencies and some harmonic energy to pass through the earplug unattenuated. Earplugs can be designed to provide a slight amplification to alter perception of the singer’s voice, thus allowing the artist to reduce the risk of vocal strain. Depending on the psycho-acoustical nature of the instrument and surrounding music exposures, substantial reduction in risk for the development of hearing loss can be obtained. Improvement in the perception of the relative intensity of the musician’s own performance may reduce the risk of repetitive strain injuries by a relative reduction of the force of repetitive movements.

There are practical strategies for reducing the exposure of musicians that do not interfere with music production (Chasin and Chong 1995). Loudspeaker enclosures can be elevated above floor level, which results in minimal loss of low-frequency sound energy, while preserving sufficient loudness for the musician to perform at a lower intensity level. Musicians who play high-intensity, highly directional instruments such as trumpets and trombones should be on risers so that the sound passes above the other musicians, thereby lowering its impact. There should be 2 m of unobstructed floor space in front of the orchestra. Small stringed instruments should always have at least 2 m of unobstructed space above them.

 

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Thursday, 24 March 2011 15:54

History of Performing Arts Medicine

While interest in the physiology of music making dates back to antiquity, the first real summary of the occupational diseases of performing artists is Bernardino Ramazzini’s 1713 treatise Diseases of Workers. Sporadic interest in arts medicine continued through the eighteenth and nineteenth centuries. In 1932 the English translation of Kurt Singer’s Diseases of the Music Profession: A Systematic Presentation of Their Causes, Symptoms and Methods of Treatment appeared. This was the first textbook to bring together all the current knowledge on performing arts medicine. After World War II, the medical literature began to feature case reports of injured artists. The musical literature also began to carry short items and letters. There was a parallel growth of awareness among dancers.

One of the catalysts for the development of performing arts medicine as a cross-disciplinary field was the Danube Symposium on Neurology, held in Vienna in 1972. The conference focused on music and led to the publication of Music and the Brain: Studies in the Neurology of Music, by MacDonald Critchley and R.A. Henson. Also in 1972 the first Care of the Professional Voice Symposium was organized by the Voice Foundation. This has become an annual conference, with proceedings appearing in the Journal of Voice.

While injured performers and the health professionals serving them began to cooperate more closely, the general public was unaware of these developments. In 1981 a New York Times article described the hand problems suffered by pianists Gary Graffman and Leon Fleisher, and their treatment at Massachusetts General Hospital. These were virtually the first well-known musicians to admit to physical problems, so the publicity generated by their cases brought forth a large, previously unknown group of injured artists.

Since then, the field of performing arts medicine has advanced rapidly, with conferences, publications, clinics and associations. In 1983 the first Medical Problems of Musicians and Dancers symposium was held, in conjunction with the Aspen Music Festival, in Aspen, Colorado. This has become an annual conference and is perhaps the most important in the field. Meetings such as these usually include lectures by health professionals as well as demonstrations and master classes by artists.

In 1986 the journal Medical Problems of Performing Artists was launched. This is the only journal completely dedicated to arts medicine, and it publishes many of the Aspen symposium presentations. Related journals include the Journal of Voice, Kinesiology and Medicine for Dance, and the International Journal of Arts-Medicine. In 1991 the Textbook of Performing Arts Medicine, edited by Robert Sataloff, Alice Brandfonbrener and Richard Lederman, became the first modern, comprehensive text on the subject.

As publishing grew and conferences continued, clinics serving the performing arts community were organized. Generally these clinics are in large cities that support an orchestra or dance company, such as New York, San Francisco and Chicago. There are now more than twenty such centres in the United States and several in various other countries.

Those active in the field of performing arts medicine have also founded associations to further research and education. The Performing Arts Medicine Association, set up in 1989, now co-sponsors the Aspen symposiums. Other organizations include the International Association for Dance Medicine and Science, the International Arts-Medicine Association and the Association of Medical Advisors to British Orchestras.

Research in performing arts medicine has grown from case reports and prevalence studies to sophisticated projects using advanced technology. New treatments, more responsive to the artists’ specific needs, are being developed and the emphasis is beginning to shift to prevention and education.

 

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Thursday, 24 March 2011 15:52

Dancers

Dance involves patterned and rhythmic body movements, usually performed to music, that serve as a form of expression or communication. There are many different types of dances, including ceremonial, folk, ballroom, classical ballet, modern dance, jazz, flamenco, tap and so forth. Each of these has its unique movements and physical demands. Audiences associate dance with grace and enjoyment, yet very few people regard dance as one of the most demanding and strenuous athletic activities. Sixty-five to 80% of dance-related injuries are in the lower limbs, out of which about 50% are in the foot and ankle (Arheim 1986). Most of the injuries are due to over-use (about 70%) and the rest are of the acute type (ankle sprain, fractures and so on).

Dance medicine is a multidisciplinary profession because causes of injuries are multifactorial and hence treatment should be comprehensive and take into consideration the specific needs of dancers as artists. The goal of the treatment should be to prevent potentially dangerous specific stresses, allowing the dancer to keep active, acquiring and perfecting physical creativity and psychological well-being.

Training should preferably start at an early age in order to develop strength and flexibility. However, incorrect training results in injury to young dancers. Proper technique is the main concern, as incorrect posture and other bad dancing habits and methods will cause permanent deformities and over-use injuries (Hardaker 1987). One of the most basic movements is the turn-out—opening of the lower limbs outwards. This should take place in the hip joints; if it is forced more than the anatomic external rotation these joints will allow, compensations occur. The most common compensations are rolling-in of the feet, internal flexing of the knees and hyperlordosis of the lower back. These positions contribute to deformities such as hallux valgus (displacement of the great toe towards the other toes). Inflammations of tendons such as the flexor hallucis longus (the tendon for the great toe) and others may also result (Hamilton 1988; Sammarco 1982).

Being cognizant of individual anatomic differences in addition to the unusual biomechanical loads, such as in point position (standing on the tip of the toes), allows one to take actions to prevent some of these undesired outcomes (Teitz, Harrington and Wiley 1985).

The environment of dancers has great influence on their well-being. A proper floor should be resilient and absorb shock to prevent cumulative trauma to the feet, legs and spine (Seals 1987). Temperature and humidity also influence performance. Diet is a major issue as dancers are always under pressure to keep slim and look light and pleasing (Calabrese, Kirkendal and Floyd 1983). Psychological maladjustment may lead to anorexia or bulimia.

Psychological stress may contribute to some hormonal disturbances, which may present as amenorrhoea. The incidence of stress fractures and osteoporosis may increase in hormonally imbalanced dancers (Warren, Brooks-Gunn and Hamilton 1986). Emotional stress due to competition between peers, and direct pressure from choreographers, teachers and directors may enhance psychological problems (Schnitt and Schnitt 1987).

A good screening method for both students and professional dancers should detect psychological and physical risk factors and avoid problems.

Any change in activity levels (whether return from a holiday, sickness or pregnancy), intensity of work (rehearsals before a premiere tour), choreographer, style or technique, or environment (such as floors, stages or even type of dance shoes) makes the dancer more vulnerable.

 

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Thursday, 24 March 2011 15:48

Graphic Arts

The term graphic arts (also called graphic design, commercial art, visual design or visual communication) refers to the organization of ideas and concepts in a visual form that conveys a particular message to a target audience. Graphic designers work in a wide array of venues, including magazines, books, posters, packaging, film, video, exhibition design and, most recently, in digital forms such as computer screen design, multimedia presentations and pages on the World Wide Web. There are two types of visual communicators: graphic designers, who work with typography and page layout as well as photography and illustration; and illustrators, who work exclusively with visual images. Frequently the two roles overlap, but most commonly graphic designers hire illustrators to create visualizations of the ideas that will be used within a typographic context.

Graphic Design

The hazards of graphic design were very different in the late 1990s compared to only a few years earlier when some designers were still producing traditional mechanicals for offset printing (figure 1). Now, virtually all page layout and graphic design is produced in a digital format before it is printed on paper. Much graphic design is even created exclusively for a final digital form: a floppy disk, CD-ROM or a page on the Internet. Graphic designers use computers to create and store both text and images. These digitally created artworks are stored on floppy disks, removable storage cartridges or CD-ROMs, and then given to the client for the final presentation (package design, magazine, film titles, poster, business stationery or many other applications).

Figure 1. Hand lettering for graphic arts.

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Graphic designers must now be concerned with the potential hazards of prolonged work at a computer. Unfortunately, this technology is too new to know all the associated hazards. At present the hazards identified from working for extended periods at a visual display unit (VDU) (also called a video display terminal, or VDT) include eyestrain, headaches, backaches, stiff necks, sore hands and wrists, dizziness, nausea, irritability and stress. There have also been reports of skin rashes and dermatitis associated with VDU use. While the health effects of VDU use have been studied for a couple of decades, there are no proven links between long-term use of VDUs and long-term health problems. VDUs do emit comparatively low-level radiation, but there are no hard data to support any permanent adverse health effects from VDU use.

Ergonomic computer workstations, elimination of glare and frequent work breaks enable graphic designers to work more safely than most other artistic professions. Generally the digital revolution has greatly reduced the health hazards previously associated with the graphic design profession.

 

 

Illustration

Illustrators create images in a wide variety of media and techniques for use in various commercial venues. For example, an illustrator may create work for magazines, book jackets, packaging, movie posters, advertising and many other forms of promotion and publicity. Generally illustrators are freelancers who are hired by art directors for a particular project, though some illustrators work for publishing houses and greeting card companies. Since illustrators generally create their own workspaces, the burden for creating a safe working environment usually falls upon the individual.

The materials used by professional illustrators are as varied as the techniques and styles exhibited in contemporary illustration. Therefore, it is imperative that each individual artist be aware of any hazards associated with his or her particular medium. Among the materials commonly used by illustrators are drawing and painting materials such as markers, water colours, oil paints, coloured inks, coloured pencils, dry pastels, oil pastels, dyes, acrylic paints and gouache.

Many commonly used colours contain hazardous ingredients such as xylene and petroleum distillates; pigments may contain such dangerous ingredients as mercury, cadmium, cobalt and lead. Precautions include working in a well-ventilated studio, wearing gloves and a respirator when using oil-based materials (particularly from aerosols) and substituting safer materials (water- and alcohol-based colours) when possible. Materials such as pastels can be hazardous when they become airborne dust; good ventilation is particularly important when using any material that can be breathed into the lungs. A final general precaution is to avoid eating, drinking or smoking while working with any toxic artists’ materials.

The wide assortment of materials used by illustrators requires an individual approach to safe working conditions, since each artist has a personal technique and selection of materials. Manufacturers in some countries are required by law to provide information about product ingredients and hazards. Each individual artist should carefully scrutinize every material used, working in the safest possible manner with the available media.

Adhesives

Adhesives used include rubber cement, spray mount, contact cement, electric waxers, dry-mount tissues, glue sticks, hot-melt glue guns, adhesive transfer materials, double-coated tape and water-soluble glues. Associated hazards include: dangerous chemicals such as n-hexane (a neurotoxin) in some rubber cements and contact cement; cyanoacrylate instant-action glues; airborne toxic chemicals and fire hazards associated with spray adhesives; and possible burns from hot-melt glue gun use. Many of the commonly used adhesives (rubber cement in particular) can also cause skin irritation.

Proper ventilation and use of gloves can prevent many of the hazards associated with common adhesives. Substitution of non-toxic adhesives whenever possible, such as electric waxers, adhesive transfer materials, dry-mount tissues, double-coated tapes, and water-soluble glues is recommended. Heptane-containing rubber cements and spray adhesives are less toxic than hexane types, although they are still flammable.

Solvents

Solvents include rubber cement thinner, turpentine, acetone, correction fluid and mineral spirits.

Hazards include skin irritation, headaches, damage to respiratory and nervous systems, kidney and liver damage, and flammability. Primary precautions include substituting safer solvents whenever possible (for example, mineral spirits are less toxic than turpentine) or switching to water-based pigments that do not require solvents for cleanup. Excellent ventilation or respiratory protection, careful storage, use of gloves and chemical splash goggles are also important when using any solvents.

Aerosol sprays

Aerosol sprays include fixative spray, spray markers, varnish, texture sprays and airbrush colours.

Hazards include respiratory problems, skin irritation, headaches, dizziness and nausea from toxic chemicals such as toluene and xylene; long-term adverse effects include damage to kidneys, liver and central nervous system. Sprays are also frequently flammable; care must be exercised to use them away from heat or flames. Precautions include using a respirator or adequate studio ventilation (such as a spray booth), and working with non-toxic pigments when using an airbrush.

Cutting tools

The various types of cutting tools can include paper cutters, razor knives and mat cutters. The hazards can range from cuts and, in the case of large paper cutters, the severing of fingers. Precautions include careful use of knives and cutters, keeping hands away from blades, and maintaining blades in sharp condition.

 

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Thursday, 24 March 2011 15:29

Jewellery

Jewellery manufacturing can include working with a variety of materials, such as precious and semi-precious stones, synthetic stones, shells, coral, pearls, precious metals, metal enamels and newer materials such as epoxy resins and vinyl polymers. These can be used to make rings, earrings, necklaces, pendants and a variety of other personal decorative items. Jewellery manufacturing shops vary in size, and different manufacturing processes may be adopted. Thus, health hazards may vary from one workshop to another.

Processes, Hazards and Precautions

Precious stones and settings

Much jewellery manufacturing involves the setting of precious stones into bases of precious metals or alloys of precious metals. Stones are initially cut into desired sizes, then polished. Base metals are cast, then ground and polished. Traditionally, the metal settings were made using “injection” mouldings. Alloys of low melting point, including alloys of cadmium and mercury, have also been used for metal casting. Recently, “lost wax” methods have been used to achieve a better quality of casting. Stones are held on metal bases using adhesives, soldering or mechanical clamping by parts of the metal frame. Metal bases are usually plated with precious metals.

Health hazards may result from exposure to metal fumes, wax fumes or dust of stones and metals, and visual impairment from poor lighting. Working with fine parts of jewellery items generally requires proper ventilation, adequate illumination and the use of magnifying lenses. In addition, proper ergonomic design in the workplace is recommended.

Stone cutting and polishing

Precious, semi-precious and synthetic stones (including diamond, jade, ruby, garnet, jasper, agate, travertine, opal, turquoise and amethyst) are usually cut to the desired size with small saws before setting. Injury hazards include abrasions and lacerations of the skin or eyes; other health hazards include dust inhalation (e.g., silicosis from quartz stones).

Precautions include proper ventilation, dust collectors, using magnifying lenses, local illumination, eye protection and ergonomic design of tools and working environments.

Lost wax metal casting

Rubber or silicon moulds are made from original moulds that are custom-made or designed by artists. Wax is subsequently injected into these moulds. Moulds (called investments) of plaster of Paris and/or silica are made to enclose these wax moulds. The whole investment is then heated in the kiln or oven to drain the wax out of the block, then filled with molten metal with the aid of centrifugation. The mould is shattered to recover the metal piece. This is polished, and also may be electroplated with a thin layer of precious metal.

Precious metals and their alloys, including gold, silver, platinum and copper as well as zinc and tin, are commonly used in constructing metal pieces. Injury hazards include fire or explosion from flammable gas used for melting metals, and burns from heated plaster casts or blocks, molten metal spillage, oxyacetylene torches or ovens; other health hazards include inhalation of metal fumes or dusts of silver, gold, zinc, lead, tin and so on.

Precautions include using alternative casting methods to lower the level of exposures and toxicity, proper local exhaust ventilation for metal dust and fumes, dust collectors, personal protective equipment including goggles, insulating gloves and working gowns, and proper storage of flammable gas.

Enamelling

Enamelling involves the fusion of pre-ground, powdered lead or borosilicate glass particles mixed with various coloured oxides onto a base metal to form an enamelled surface. Base metals can include silver, gold or copper. Common colourants include antimony, cadmium, cobalt, chromium, manganese, nickel and uranium.

Cleaning

The metal surface must first be cleaned with a torch or in a kiln to burn off oils and grease; it is then pickled with dilute nitric or sulphuric acid, or the safer sodium bisulphate, to remove firescale. Hazards include thermal and acid burns. Precautions include protective gloves, goggles and apron.

Application

Some enamellists grind and sift their enamels to obtain desired particle sizes. Application techniques include brushing, spraying, stencilling and sifting or wet packing of the enamel onto the metal surface. Inhalation of enamel powder or spray mist is the greatest hazard, particularly with lead-based enamels. Precautions include use of lead-free enamels and respiratory protection. In cloisonné, different enamel colours are separated by metal wires that have been soldered onto the metal. (See the discussion on silver soldering below). In champleve, designs are etched with ferric chloride or nitric acid, and depressed areas filled with enamels. Another technique involves applying enamels mixed with resin in turpentine. Ventilation and precautions to prevent skin contact are required.

Firing

The enamelled metal is then fired in a small kiln. Ventilation is required to remove toxic metal fumes, fluorides and decomposition products (from gums and other organic materials in the enamel). Other hazards include thermal burns and infrared radiation. Infrared goggles and heat-protective gloves are recommended.

The enamel piece can then be finished by such methods as filing the edges and grinding and sanding the enamelled surface. Standard precautions against dust inhalation and eye contact are needed.

Metal jewellery

Metal jewellery can be made by cutting, bending and otherwise fabricating metals, electroplating, anodizing, soldering, gluing, finishing and so on. Many of these processes are discussed in “Metalworking”. Some specific applications are discussed below.

Electroplating

Gold, silver, copper and strong acid as well as cyanide are used in the electroplating process. Injury hazards include electrical shock and burns from acid or alkali spillage; other health hazards include the inhalation of metal, acid and cyanide mist, organic solvents, as well as hydrogen cyanide gas.

Precautions include substitution of non-cyanide plating solutions, avoidance of mixing cyanide solution with acids, local exhaust ventilation, using a tank cover to reduce mist production, proper storage of chemicals, electrical precautions and adequate personal protective equipment.

Soldering or gluing

Soldering involves metals such as tin, lead, antimony, silver, cadmium, zinc and bismuth. Safety hazards include burns; other health hazards include the inhalation of metal fumes, including lead and cadmium (Baker et al. 1979), and fluoride and acid fluxes.

Using epoxy resin and quick-drying agents with solvents to bind stones and metal pieces is a common practice. Injury hazards from gluing include fire and explosion; other health hazards include the inhalation of solvents and skin contact with epoxy resin, other adhesives and solvents.

Precautions include avoidance of lead and cadmium solders, adequate local exhaust ventilation, proper storage of chemicals, adequate illumination and personal protective equipment.

Metal grinding and polishing

Rotating wheels and linear actuators of varied sizes are used for grinding, polishing and cutting. Injury hazards include skin abrasions; other health hazards include the inhalation of metal dusts, as well as repetitive motion, vibration, awkward position and forces.

Precautions include adequate local exhaust ventilation, dust collectors, goggles for eye protection and ergonomic designs for workplaces and tools.

Shells

Mother-of-pearl (from oyster shells) and coral, as well as abalone and other shells, can be made into jewellery by cutting, drilling, sawing, shaving, grinding, polishing, finishing and so on. Hazards include hand and eye injuries from flying particles and sharp edges, respiratory irritation and allergic reactions from inhalation of fine shell dust, and, in the case of mother-of-pearl, possible hypersensitivity pneumonia and ossification with inflammation of tissues covering the bones, especially in young people.

Precautions include cleaning shells thoroughly to remove organic matter, wet grinding and polishing techniques, and local exhaust ventilation or respiratory protection. Goggles should be worn to prevent eye injury.

Beads

Beads can be made from a variety of materials, including glass, plastic, seed, bone, shells, pearls, gemstones and so on. A newer material used for beads and other jewellery is heat-cured polyvinyl chloride (polymer clays). Hazards include inhalation of dust from drilling the holes for the string or wire used to hold the beads, and possible eye injuries. Precautions include wet drilling, ventilation or respiratory protection and goggles. The polymer clays can release hydrogen chloride, a respiratory irritant, if heated above recommended temperatures. Using cooking ovens for heat curing is not recommended. There has also been concern about plasticizers such as diethylhexyl phthalate, a possible carcinogen and reproductive toxin, present in these polymer clays.

 

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Thursday, 24 March 2011 15:22

Woodworking

Woodworking is practised as an art form and utilitarian craft all over the world. It includes wood sculpture, furniture and cabinet making (figure 1), musical instrument making and so on. Techniques include carving (figure 2), laminating, joining, sawing, sanding, paint removing, painting and finishing. Woodworking uses a large number of different types of hard and soft woods, including many exotic tropical woods, plywood and composition boards, and sometimes woods treated with pesticides and wood preservatives.

Figure 1. Furniture making.

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Figure 2. Carving wood with hand tools.

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Hazards and Precautions

Woods

Many woods are hazardous, especially tropical hardwoods. Types of reactions can include skin allergies and irritation from the sap, wood dust or sometimes the wood, as well as conjunctivitis, respiratory allergies, hypersensitivity pneumonia and toxic reactions. Inhalation of hardwood dust is associated with a particular type of nasal and nasal sinus cancer (adenocarcinoma). See the chapter Woodworking industry.

Precautions include avoiding use of sensitizing woods for people who have a history of allergies, or for objects where people would be in frequent contact with the wood, and controlling dust levels by using local exhaust ventilation or wearing a toxic-dust respirator. When handling woods that can cause skin irritation or allergies, the artist should wear gloves or apply a barrier cream. Hands should be washed carefully after work.

Plywoods and composition board

Plywood and composition board (e.g., particle board) are made by gluing thin sheets of wood, or wood dust and chips, together with either urea-formaldehyde glues or phenol-formaldehyde glues. These materials can emit unreacted formaldehyde for some years after manufacture, with composition board emitting more formaldehyde. Heating these materials or machining them can cause decomposition of the glue to release formaldehyde. Formaldehyde is a skin, eye and respiratory irritant and strong sensitizer, and a probable human carcinogen.

Precautions include using low-formaldehyde products whenever possible, not storing large amounts of plywood or composition board in the shop, and using dust collectors connected to woodworking machines that are exhausted to the outside.

Wood preservatives and other treatments

Pesticides and preservatives are often applied to wood when it is being timbered, processed or shipped. Pentachlorophenol and its salts, creosote and chromated copper arsenate (CCA) have been banned for sale in the United States as wood preservatives because of possible carcinogenicity and reproductive hazards. They can, however, still be found in older woods, and chromated copper arsenate is still allowed as a commercial treatment (e.g., “green” lumber, playground equipment and other outdoor uses). A variety of other chemicals can be used in treating wood, including fire retardants and bleaches.

Precautions include not handling woods that have been treated with pentachlorophenol or creosote, using local exhaust ventilation when machining CCA-treated wood or wearing a respirator with high-efficiency filters. Wood that has been treated with creosote, pentachlorophenol or chromated copper arsenate should not be burned.

Carving and machining wood

Woods can be hand carved with chisels, rasps, hand saws, sandpaper and the like, or they can be machined with electric saws, sanders and other woodworking machines. Hazards include exposure to wood dusts, excessive noise levels from woodworking machines, accidents from using tools and machines, electrical shock or fire from faulty wiring, and wood fires. Vibrating tools—for example, chain saws—can cause “white fingers” (Raynaud’s phenomenon), involving numbness of the fingers and hands.

Precautions include equipping woodworking machines with dust collectors (figure 3) and machine guards, cleaning up sawdust to avoid fire hazards, wearing goggles (and sometimes face shields) and reducing noise. Using the appropriate machine for the desired operation, and repairing defective machines immediately; keeping hand tools sharpened, and using them safely; keeping all electrical equipment and wiring in good repair, and avoiding extension cords which can be tripped over; not wearing ties, long loose hair, loose sleeves or other items that could catch in machinery are some other precautions.

Figure 3. Woodworking machines with dust collector.

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Michael McCann

Gluing wood

A variety of glues are used for laminating and joining wood, including contact adhesives, casein glue, epoxy glues, formaldehyde-resin glues, hide glues, white glue (polyvinyl acetate emulsion) and the cyanoacrylate “instant” glues. Many of these contain toxic solvents or other chemicals, and can be skin, eye and respiratory hazards.

Precautions include avoiding formaldehyde resin glues; using water-based glues rather then solvent-type glues; wearing gloves or barrier creams when using epoxy glues, solvent-based adhesives or formaldehyde-resin glues; and having good ventilation when using epoxy glues, cyanoacrylate glues and solvent-based glues. Sources of ignition should be avoided when using flammable solvents.

Painting and finishing

Wood can be painted with most types of paint; can be stained, lacquered or varnished; and can be treated with linseed or other types of oil. Other materials that are used in finishing wood include shellacs, polyurethane coatings and waxes. Many materials are sprayed. Some woodworkers mix their own paints from dry pigments. Hazards include inhalation of toxic pigment powder (especially lead chromate pigments), skin and inhalation hazards from solvents, fire hazards from flammable solvents, and spontaneous combustion from rags soaked with oil or turpentine.

Precautions include using ready-made paints rather than mixing your own; avoiding eating, drinking or smoking in the work area; using water-based paints rather than solvent-based ones; and placing oil- and solvent-soaked rags in self-closing oily-waste cans, or even a pail of water.

Precautions with solvents include wearing gloves and goggles, as well as having adequate ventilation; doing the operation outside; or wearing a respirator with organic vapour cartridges. Materials should be brushed on whenever possible, to avoid the hazards of spraying. Spraying finishes inside an explosion-proof spray booth, or wearing a respirator with organic vapour cartridges and spray filters; avoiding open flames, lit cigarettes and other sources of ignition (e.g., lit pilot lights) in the area when applying flammable finishes, or when spraying, are other precautions to be taken.

Paint stripping

Stripping old paint and varnish from wood and furniture is done with paint and varnish removers containing a wide variety of toxic and often flammable solvents. “Non-flammable” paint strippers contain methylene chloride. Caustic soda (sodium hydroxide), acids, blowtorches and heat guns are also used to remove old paint. Old stains on wood are often removed with bleaches, which can contain corrosive alkalis and oxalic acid, hydrogen peroxide or hypochlorite. Heat guns and torches can vaporize the paint, possibly causing lead poisoning with lead-based paint, and are a fire hazard.

See the previous section for precautions with solvent-based paint strippers. Gloves and goggles should be worn when handling caustic soda, oxalic acid bleaches or chlorine-type bleaches. An eyewash fountain and emergency shower should be available. Avoid using torches or heat guns to remove lead-containing paint.

 

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Thursday, 24 March 2011 15:15

Ceramics

Foodware, sculpture, decorative tiles, dolls and other ceramic or clay items are made in both large and small professional studios and shops, classrooms in public schools, universities and trade schools, and in homes as a hobby or cottage industry. The methods can be divided into ceramics and pottery, although terminology can vary in different countries. In ceramics, objects are made by slip casting—pouring a slurry of water, clay and other ingredients into a mould. The clay objects are removed from the mould, trimmed and fired in a kiln. Some ware (bisque ware) is sold after this stage. Other types are decorated with glazes that are mixtures of silica and other substances which form a glass surface. In pottery, objects are formed from plastic clay, usually by hand-forming or wheel-throwing, after which they are dried and fired in a kiln. Objects may then be glazed. Slip cast ceramics usually are glazed with china paints, which are commercially produced in dry or liquid pre-packaged form (figure 1). Potters may glaze their ware with these commercial glazes or with glazes they compound themselves. All types of ware are produced, from terra cotta and earthenware, which are fired at low temperatures, to stoneware and porcelain, which are fired at high temperatures.

Figure 1.  Decorating a pot with China paints.

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Clay and Glaze Materials

All clays and glazes are mixtures of silica, aluminium and metallic minerals. These ingredients usually contain significant amounts of respirable-sized particles such as those in silica flour and ball clays. Clay bodies and glazes are composed of essentially the same types of minerals (see table 1, but glazes are formulated to melt at lower temperatures (have more flux) than the bodies on which they are applied. Lead is a common flux. Raw lead minerals such as galena and lead oxides derived from burning car battery plates and other scrap are used as fluxes, and have poisoned potters and their families in some developing countries. Commercially sold glazes for industrial and hobby use are more likely to contain lead and other chemicals which have been mixed and pre-fired into powdered frits. Glazes are formulated to mature in either oxidation or reduction firing (see below) and may contain metal compounds as colourants. Lead, cadmium, barium and other metals may leach into food when glazed ceramic wares are used.

Table 1. Ingredients of ceramic bodies and glazes.

Basic constituents

 

 

Clays (hydroaluminium silicates)

Alumina

Silica

Kaolins and other white clays

Red iron-rich clays

Fire clays

Ball clays

Bentonite

Aluminium oxide, corundum, usual source in glazes is from clays and feldspars

Quartz from flint, sand, diatomaceous earth; cristobalite from calcined silica or fired silica minerals

Other ingredients and some mineral sources

Fluxes

Opacifiers

Colourants

Sodium, potassium, lead, magnesium, lithium, barium, boron, calcium, strontium, bismuth

Tin, zinc, antimony, zirconium, titanium, fluorine, cerium, arsenic

Cobalt, copper, chrome, iron, manganese, cadmium, vanadium, nickel, uranium

Sources include oxides and carbonates of metals above, feldspars, talc, nepheline syenite, borax, colemanite, whiting, lead frits, lead silicates

Sources include oxides and carbonates of metals above, cryolite fluorspar, rutile, zirconium silicate

Sources include oxides, carbonates and sulphates of metals above, chromates, spinels and other metal complexes

 

Other special surface treatments include metallic lustre glazes containing tack oils and solvents such as chloroform, iridescent effects obtained by fuming metallic salts (usually chlorides of tin, iron, titanium or vanadium) onto surfaces during firing, and new paints containing plastic resins and solvents, which look like fired ceramic glazes when dry. Specially textured clay bodies may include fillers such as vermiculite, perlite and grog (ground fire brick).

Exposure to clay and glaze ingredients occurs during mixing, sanding and spray-applying glazes, and when grinding or chipping fired glaze imperfections from the bottoms of pottery or from kiln shelves (figure 2). Cleaning kiln shelves exposes workers to flint, kaolin and other kiln wash ingredients. Silica dust from fired kiln wash or bisque is more hazardous because it is in the cristobalite form. Hazards include: silicosis and other pneumoconioses from inhalation of minerals such as silica, kaolin, talc and fibrous amphibole asbestos in some talcs; toxicity from exposure to metals such as lead, barium and lithium; dermatitis from sensitizing metals such as chrome, nickel and cobalt; cumulative trauma disorders such as carpal tunnel syndrome (“potter’s thumb”) from wheel throwing; back injuries from digging clay, lifting 100-pound sacks of bulk minerals or from wedging (hand working clay to remove air bubbles); slips and falls on wet floors; shocks from electric pottery wheels and other equipment used in wet areas; allergies to moulds in clay; fungal and bacterial infections of nail beds and skin; and accidents with clay mixers, pug mills, blungers, slab rollers and the like.

Figure 2. Exposure to clay and glaze dusts while hand sanding a pot.

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Henry Dunsmore

Precautions: outlaw open lead burning; use substitutes for raw lead, lead frits, cadmium and asbestos-containing materials; isolate work from family areas and children; practice housekeeping and hygiene; control dust; use local exhaust ventilation for glaze spraying and dusty processes (figure 3); use respiratory protection; work with adequate rest periods; lift safely; guard machines; and use ground fault interrupters on wheels and all other electrical equipment.

Figure 3. Local exhaust ventilation for clay mixing.

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Michael McCann

Kiln Firing

Kilns vary from railroad-car size to a few cubic inches for firing test tiles and miniatures. They are heated with electricity or fuels such as gas, oil or wood. Electric kilns produce ware fired in primarily oxidizing atmospheres. Reduction firing is achieved by adjusting fuel/air ratios in fuel-fired kilns to create chemically reducing atmospheres. Firing methods include salt firing, raku (putting red-hot pots into organic matter such as damp hay to produce a smoky reduced clay body), climbing kilns (many-chambered wood or coal fired kilns built on hillsides), sawdust firing (kilns packed tight with pots and sawdust) and open-pit firing with many fuels including grass, wood and dung.

Primitive fuel-fired kilns are poorly insulated because they are usually made of fired clay, brick or mud. Such kilns can burn large amounts of wood and can contribute to fuel shortages in developing countries. Commercial kilns are insulated with refractory brick, castable refractory or ceramic fibre. Asbestos insulation is still found in older kilns. Refractory ceramic fibre is in very wide use in industry and hobby kilns. There are even small fibre kilns which are heated by putting them in home kitchen microwave ovens.

Kiln emissions include combustion products from fuels and from organic matter that contaminates clay and glaze minerals, sulphur oxides, fluorine and chlorine from minerals such as cryolite and sodalite, and metal fumes. Salt firing emits hydrochloric acid. Emissions are especially hazardous when fuels such as painted or treated wood and waste oils are burned. Hazards include: respiratory irritation or sensitization from aldehydes, sulphur oxides, halogens and other emissions; asphyxiation from carbon monoxide; cancer from inhalation of asbestos or ceramic fibre; eye damage from infrared radiation from glowing hot kilns; and thermal injury and burns.

Precautions: use clean-burning fuels; design fuel-efficient, well-insulated kilns; substitute refractory brick for asbestos or ceramic fibre; encapsulate or remove existing fibre insulation; locally vent indoor kilns; locate kilns in areas free of combustible materials; equip electric kilns with two automatic shut-offs; wear infrared-blocking goggles and gloves when handling hot objects.

 

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Thursday, 24 March 2011 15:10

Fibre and Textile Crafts

Contemporary fibre or textile artists use a wide range of processes, such as weaving, needlework, papermaking, leatherworking and so forth. These can be done by hand or aided by machines (see table 1). They may also use many processes for preparing fibres or finished textile, such as carding, spinning, dyeing, finishing and bleaching (see table 2). Finally the fibreworks or textiles may be painted, silk-screened, treated with photographic chemicals, scorched or otherwise modified. See separate articles in this chapter describing these techniques.

Table 1. Description of fibre and textile crafts.

Process

Description

Basketry

Basketry is the making of baskets, bags, mats, etc., by hand weaving, plaiting and coiling techniques using materials such as reeds, cane and sisal fibre. Knives and scissors are often used, and coiled baskets are often sewed together.

Batik

Batik involves the creating of dye patterns on fabric by applying molten wax to the fabric with a djanting to form a resist, dyeing the fabric and removing the wax with solvents or by ironing between newsprint.

Crocheting

Crocheting is similar to knitting except that a hook is used to loop threads into the fabric.

Embroidery

The embellishment of a fabric, leather, paper or other materials by sewing of designs worked in thread with a needle. Quilting comes under this category.

Knitting

Knitting is the craft of forming a fabric by interlocking of yarn in a series of connected loops using long hand or mechanized needles.

Lacemaking

Lacemaking involves the production of ornamental openwork of threads that have been twisted, looped and intertwined to form patterns. This can involve very fine and intricate hand stitching.

Leatherworking

Leather crafts involve two basic steps: cutting, carving, sewing and other physical processes; and cementing, dyeing and finishing the leather. The first can involve a variety of tools. The latter can involve the use of solvents, dyes, lacquers and such. For tanning, see the chapter Leather, fur and footwear.

Macrame

Macrame is the ornamental knotting of yarn into bags, wall hangings or similar materials.

Papermaking

Papermaking involves preparing the pulp and then making the paper. A variety of plants, wood, vegetables, used paper rags and so forth can be used. The fibres must be separated out, often by boiling in alkali. The fibres are washed and placed in a beater to complete preparation of the pulp. Then paper is made by trapping the pulp on a wire or fabric screen, and allowed to dry in the air or by being pressed between layers of felt. The paper can be treated with sizings, dyes, pigments and other materials.

Silk screen printing

See “Drawing, Painting and Printmaking”.

Weaving

Weaving uses a machine called a loom to combine two sets of yarn, the warp and the weft, to produce fabric. The warp is wound on large reels, called beams, which run the length of the loom. The warp yarns are threaded through the loom to form vertical parallel threads. The weft is fed from the side of the loom by bobbins. The loom shuttle carries the weft yarns across the loom horizontally under and above alternate warp threads. A starch sizing is used to protect warp threads from breaking during weaving. There are many types of looms, both hand-operated and mechanical.

 

Table 2. Description of fibre and textile processes.

Process      

Description

Carding

Process of cleaning and straightening fibres into parallel lines by combing it (by hand or by special machinery) and twisting the fibres into a rope-like form. This process can create large amounts of dust.

Spinning

A foot-pedal-operated spinning wheel is used to turn the spindle, which combines several fibres into twisted, elongated yarn.

Finishing

The woven fabric can be singed to remove projecting hairs, desized with enzymes, and scoured by boiling in alkali to remove fats and waxes.

Dyeing

Yarn or fabric can be dyed using a variety of types of dyes (natural, direct, acid, basic, disperse, fibre-reactive and more) depending upon the type of fabric. Many dyeing processes involve heating the dyebath to near boiling. Many dyeing assistants can be used, including acids, alkalis, salt, sodium hydrosulphite and, in the case of natural dyes, mordants such as urea, ammonium dichromate, ammonia, copper sulphate, and ferrous sulphate. Dyes are usually purchased in powder form. Some dyes may contain solvents.

Bleaching

Fabrics can be bleached with chlorine bleaches to remove colour.

 

No material is off limits for artists, who may use any of thousands of animal, vegetable or synthetic materials in their work. They gather materials such as weeds, vines or animal hair from the outdoors, or purchase products from suppliers who may have altered them by treating them with oils, fragrances, dyes, paints or pesticides (e.g., rat poison in twine or rope intended for agricultural use). Imported animal or vegetable materials that have been processed to eliminate disease carrying insects, spores or fungi are also used. Old rags, bones, feathers, wood, plastics or glass are among many other materials incorporated in fibre crafts.

Potential Sources of Health Hazards in the Fibre Arts

Chemicals

Health hazards in fibre or textile arts, as in any workplace, include air pollutants such as dusts, gases, fumes and vapours that are inherent in the materials or are produced in the work process, and can be inhaled or affect the skin. In addition to chemical hazards of dyes, paints, acids, alkalis, mothproofing agents and so on, fibre or textile materials may be contaminated with biological materials that can cause disease.

Vegetable dusts

Workers heavily exposed to dusts of raw cotton, sisal, jute and other vegetable fibres in industrial workplaces have developed various chronic lung problems such as “brown lung” (byssinosis), which begins with chest tightness and shortness of breath, and can be disabling after many years. Exposure to vegetable dusts in general may cause lung irritation or other effects such as asthma, hay fever, bronchitis and emphysema. Other materials associated with vegetable fibres, such as moulds, mildew, sizing materials and dyes, may also cause allergic or other reactions.

Animal dusts

Animal products used by fibre artists such as wool, hair, hides and feathers may be contaminated with bacteria, moulds, lice or mites that are capable of causing “Q” fever, mange, respiratory symptoms, skin rashes, anthrax, allergies and so on, if they are not treated or fumigated before use. Fatal cases of inhalation anthrax have occurred in craft weavers, including the 1976 death of a California weaver.

Synthetic materials

The effects of dusts of polyesters, nylon, acrylic, rayon and acetates are not well known. Some plastic fibres may release gas or components or residues which are left in the fabric after processing, as in the case of formaldehyde released by polyesters or permanent-press fabrics. Sensitive individuals have reported allergic responses in rooms or stores where these materials were present, and some have developed skin rashes after wearing clothing of these fabrics, even after repeated washings.

Heating, scorching or otherwise altering synthetic materials chemically may release potentially hazardous gases or fumes.

Physical Effects of Working with Fibres and Textiles

The physical characteristics of materials may affect the user. Rough, thorny or abrasive materials can cut or abrade skin. Glass fibres or stiff grasses or rattan can penetrate the skin and cause infections or rashes.

Much of fibre or fabric work is done while the worker is seated for prolonged periods, and involves repetitious motion of arms, wrists, hands and fingers, and often the entire body. This may produce pain and eventual repetitive strain injuries. Weavers, for example, can develop back problems, carpal tunnel syndrome, skeletal deformation from weaving in a squatting position on older types of looms (particularly in young children), hand and finger disorders (e.g., swollen joints, arthritis, neuralgia) from threading and tying knots, and eyestrain from poor lighting (figure 1). Many of the same problems can occur in other fibre crafts involving sewing, tying knots, knitting and so forth. Needlework crafts can also involve hazards of needle pricks.

Figure 1. Weaving with a hand loom.

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Lifting of large papermaking screens containing water-saturated pulp can cause possible back injuries due to the weight of the water and pulp.

Precautions

As with all work, the adverse effects depend upon the amount of time spent working on a project each day, the number of workdays, weeks or years, the quantity of work and the nature of the workplace, and the type of work itself. Other factors such as ventilation and lighting also affect the health of the artist or craftsperson. One or two hours a week spent at a loom in a dusty environment may not affect a person seriously, unless that person is highly allergic to dusts, but a prolonged period of work in the same environment over months or years may result in some health effects. However, even one episode of untrained lifting of a heavy object can cause injury to the spine.

Generally, for prolonged or regular work in fibre art or textiles:

  • Obtain and use only treated or fumigated animal or vegetable materials. Other materials should be cleaned or washed, and stored in closed containers to minimize dusts.
  • Damp mop or wipe work area surfaces frequently.
  • In many countries, manufacturers are required to provide information that describes the hazardous aspects of chemicals such as dyes, adhesives, paints or solvents in any product purchased, such as a manufacturer’s Material Safety Data Sheet (MSDS). Request such information.
  • Avoid eating, drinking or smoking in the work area.
  • Take frequent rest and exercise periods when work involves repetitive motion.
  • Modify work processes to reduce the need for excessive lifting or straining. For example, in papermaking use smaller screens or have another person assist in lifting the screen with the pulp.
  • Use exhaust ventilation for regular or prolonged use of dusty materials, spray painting, heating of wax or work with solvent-containing materials such as oil-based paints or permanent ink markers.
  • Avoid boiling acids and alkalis if possible. Wear gloves, goggles, face shield and protective apron.
  • Remember that dusts, gases and vapours travel throughout buildings and may affect others present, particularly infants, children, the aged and the chronically ill.
  • Consult an industrial hygienist or safety and health professional when planning a production workshop.

 

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Thursday, 24 March 2011 15:07

New Technology in Art

This article describes the basic health and safety concerns associated with the use of lasers, neon sculpture and computers in the arts. Creative artists often work very intimately with the technology, and in experimental ways. This scenario too often increases the risk of injury. The primary concerns are for eye and skin protection, for reducing the possibilities of electrical shock and for preventing exposure to toxic chemicals.

Lasers

Laser radiation may be hazardous to the eyes and skin of artists and audiences by both direct viewing and reflection. The degree of laser injury is a function of power. Higher-power lasers are more likely to cause serious injury and more hazardous reflections. Lasers are classified and labelled by their manufacturer in classes I to IV. Class I lasers exhibit no laser radiation hazard and Class IV are very dangerous.

Artists have used all laser classes in their work, and most use visible wavelengths. Besides the safety controls required of any laser system, artistic applications require special considerations.

In laser exhibits, it is important to isolate the audience from direct beam contact and scattered radiation, using plastic or glass enclosures and opaque beam stops. For planetariums and other indoor light shows, it is critical to maintain direct beam or reflected laser radiation at Class I levels where the audience is exposed. Class III or IV laser radiation levels must be kept at safe distances from performers and the audience. Typical distances are 3 m away when an operator controls the laser and 6 m away without continuous operator control. Written procedures are needed for set-up, alignment and testing of Class III and IV lasers. Required safety controls include warning in advance of energizing these lasers, key controls, fail-safe safety interlocks and manual reset buttons for Class IV lasers. For Class IV lasers, appropriate laser goggles should be worn.

Scanning laser art displays often used in the performing arts use rapidly moving beams that are generally safer since the duration of inadvertent eye or skin contact with the beam is short. Still, operators must employ safeguards to ensure exposure limits will not be exceeded if the scanning equipment fails. Outdoor displays cannot allow aircraft to fly through hazardous beam levels, or the illumination with greater than Class I levels of radiation of tall buildings or personnel in high-reach equipment.

Holography is the process of producing a three-dimensional photograph of an object using lasers. Most images are displayed off-axis from the laser beam, and intrabeam viewing is typically not a hazard. A transparent display case around the hologram can help reduce the possibilities of injury. Some artists create permanent images from their holograms, and many chemicals used in the development process are toxic and must be managed for accident prevention. These include pyrogallic acid, alkalis, sulphuric and hydrobromic acids, bromine, parabenzoquinone and dichromate salts. Safer substitutes are available for most of these chemicals.

Lasers also have serious non-radiological hazards. Most performance-level lasers use high voltages and amperage, creating significant risks of electrocution, particularly during design stages and maintenance. Dye lasers use toxic chemicals for the active lasing medium, and high-powered lasers may generate toxic aerosols, especially when the beam strikes a target.

Neon Art

Neon art uses neon tubes to produce lighted sculptures. Neon signage for advertising is one application. Producing a neon sculpture involves bending leaded glass to the desired shape, bombarding the evacuated glass tube at a high voltage to remove impurities from the glass tube, and adding small amounts of neon gas or mercury. A high voltage is applied across electrodes sealed into each end of the tube to give the luminous effect by exciting the gases trapped in the tube. To obtain a wider range of colours, the glass tube can be coated with fluorescent phosphors, which convert the ultraviolet radiation from the mercury or neon into visible light. The high voltages are achieved by using step-up transformers.

Electrical shock is a threat mostly when the sculpture is connected to its bombarding transformer to remove impurities from the glass tube, or to its electrical power source for testing or display (figure 1). The electrical current passing through the glass tube also causes the emission of ultraviolet light that in turn interacts with the phosphor-covered glass to form colours. Some near-ultraviolet radiation (UVA) may pass through the glass and present an eye hazard to those nearby; therefore, eyewear that blocks UVA should be worn.

Figure 1. Neon sculpture manufacture showing an artist behind a protective barrier.

ENT070F1

Fred Tschida

Some phosphors that coat the neon tube are potentially toxic (e.g., cadmium compounds). Sometimes mercury is added to the neon gas to create a particularly vivid blue colour. Mercury is highly toxic by inhalation and is volatile at room temperature.

Mercury should be added to the neon tube with great care and stored in unbreakable sealed containers. The artist should use trays to contain spillage, and mercury spill kits should be available. Mercury should not be vacuumed up, as this may disperse a mist of mercury through the vacuum cleaner’s exhaust.

Computer Art

Computers are used in art for a variety of purposes, including painting, displaying scanned photographic images, producing graphics for printing and television (e.g., on-screen credits), and for a variety of animated and other special effects for motion pictures and television. The latter is a rapidly expanding use of computer art. This can bring about ergonomic problems, typically due to repetitive tasks and uncomfortably arranged components. The predominant complaints are discomfort in the wrists, arms, shoulders and neck, and vision problems. Most complaints are of a minor nature, but disabling injuries such as chronic tendinitis or carpal tunnel syndrome are possible.

Creating with computers often involves long periods manipulating the keyboard or mouse, designing or fine tuning the product. It is important that computer users take a break away from the screen periodically. Short, frequent breaks are more effective than long breaks every couple of hours.

Regarding the proper arrangement of components and the user, design solutions for correct posture and visual comfort are the key. Computer work station components should be easy to adjust for the variety of tasks and people involved.

Eye strain may be prevented by taking periodic visual breaks, preventing glare and reflection and by placing the top of the monitor so that it is at eye level. Vision problems may also be avoided if the monitor has a refresh rate of 70 Hz, so that image flicker is reduced.

Many kinds of radiation effects are possible. Ultraviolet, visible, infrared, radio frequency and microwave radiation emissions from computer hardware are generally at or below normal background levels. The possible health effects of lower-frequency waves from the electrical circuitry and electronic components are not well understood. To date, however, no solid evidence identifies a health risk from exposure to the electromagnetic fields associated with computer monitors. Computer monitors do not emit hazardous levels of x rays.

 

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Contents

Preface
Part I. The Body
Part II. Health Care
Part III. Management & Policy
Part IV. Tools and Approaches
Part V. Psychosocial and Organizational Factors
Part VI. General Hazards
Part VII. The Environment
Part VIII. Accidents and Safety Management
Part IX. Chemicals
Part X. Industries Based on Biological Resources
Part XI. Industries Based on Natural Resources
Part XII. Chemical Industries
Part XIII. Manufacturing Industries
Part XIV. Textile and Apparel Industries
Part XV. Transport Industries
Part XVI. Construction
Part XVII. Services and Trade
Part XVIII. Guides