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Beekeeping, Insect Raising and Silk Production

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Some information on the silk industry was adapted from the article by J. Kubota in the 3rd edition of this Encyclopaedia.

More than a million species of insects exist in the world, and the global mass of insects exceeds the total mass of all other terrestrial animals. Insects such as crickets, grasshoppers, locusts, termites, beetle larvae, wasps, bees and moth caterpillars are among about 500 species that form part of the regular diet of people around the world. Usually humans hunt or gather insects for food rather than intentionally rearing and harvesting them.

In addition to food, humans use insects as sources of pollination, biological controls of pests and fibre. Different uses depend on the four stages of the insect’s life cycle, which consist of egg, larva, pupa and adult. Examples of commercial uses of insects include beekeeping (nearly 1 billion tonnes of honey produced annually and pollination of fruit and seed crops), insect rearing (more than 500 species in culture, including those used for insect biological control), shellac production (36,000 tonnes annually) and silk production (180,000 tonnes annually).

Beekeeping

Beekeepers raise the honey-bee in apiaries, a collection of hives that house bee colonies. The honey-bee is a source of flower pollination, honey and wax. Bees are important pollinators, making more than 46,430 foraging trips per bee for each kilogram of honey that they produce. During each foraging trip, the honey-bee will visit 500 flowers within a 25-minute period. The honey-bee’s source of honey is flower nectar. The bee uses the enzyme invertase to convert sucrose in the nectar into glucose and fructose and, with water evaporation, honey is produced. In addition, bumble-bees and cutter bees are grown for pollinating, respectively, tomato plants and alfalfa.

The honey-bee colony collects around a single queen bee, and they will colonize in boxes—artificial hives. Beekeepers establish an infant colony of about 10,000 bees in the bottom box of the hive, called a brood chamber. Each chamber contains ten panels with cells that are used for either storing honey or laying eggs. The queen lays about 1,500 eggs per day. The beekeeper then adds a food chamber super (a box placed on top of the brood box), which becomes the storage chamber for honey, on which the bees will survive through the winter. The colony continues to multiply, becoming mature at about 60,000 bees. The beekeeper adds a queen excluder (a flat panel that the larger queen cannot enter) on top of the food super to prevent the queen from laying eggs in additional shallow supers that will be stacked on top of the excluder. These additional supers are designed for harvesting only honey without the eggs.

The beekeeper moves the hives to where flowers are budding. A honey-bee colony can forage over an area of 48 hectares, and 1 hectare can support about two hives. The honey is harvested during the summer from the shallow supers, which can be stacked seven high as the colony grows and the bees fill the panels with honey. The supers with honey-laden panels are transported to the honey “house” for extraction. A sharp, warm knife, called an uncapping knife, is used to remove the wax caps that the bees have placed over the honeycombs within the panels. The honey is then extracted from the panels with a centrifugal force machine. The honey is collected and bottled for sale (Vivian 1986).

At the end of the season, the beekeeper winterizes the hives, wrapping them in tar paper to protect the colonies from the winter wind and to absorb the solar heat. The beekeeper also provides the bees with medicated sugar syrup for their winter consumption. In the spring, the hives are opened to begin production as mature honeybee colonies. If the colony becomes crowded, the colony will create another queen through special feeding, and the old queen will swarm with about half of the colony to find another accommodation. The beekeeper may capture the swarm and treat it as an infant colony.

Beekeepers are exposed to two related hazards from honey-bee stings. One hazard is sting envenomation. The other is venom hypersensitivity reaction and possible anaphylactic shock. Males at 40 years of age and older are at highest risk of fatal reactions. About 2% of the general population is thought to be allergic to venom, but systemic reactions in beekeepers and their immediate family members are estimated at 8.9%. The reaction incidence varies inversely to the numbers of stings received. Anaphylactic reactions to bumble-bee venom are rare except among bumble bee keepers, and their risk is greater if they have been sensitized to honey bee venom.

If a honey-bee stings the beekeeper, the stinger should be removed, and the sting site should be washed. Ice or a paste of baking soda and water should be applied to the site of envenomation. The victim should be watched for signs of systemic reaction, which can be a medical emergency. For anaphylactic reactions, epinephrine is administered subcutaneously at the first sign of symptoms. To assure safe beekeeping, the beekeeper should use smoke at the beehive to neutralize the bees’ protective behaviour and should wear a protective hood and veil, thin gloves and log sleeves or coveralls. Bees are attracted to sweat for the moisture, so beekeepers should not wear watch bands or belts where sweat collects. In extracting the honey, the beekeeper should keep his or her thumb and fingers clear of the cutting motion of the uncapping knife.

Mass Insect Raising

More than 500 species of arthropods are reared in the laboratory, including ants, beetles, mites, flies, moths, spiders and ticks. An important use of these arthropods is as biological controls for other animal species. For example, 2,000 years ago, markets in China sold nests of weaver ants to place in citrus orchards to prey on crop pests. Today, more than 5,000 species of insects have been identified worldwide as possible biological controls for crop pests, and 300 are successfully used regularly in 60 countries. Disease vectors have also become targets for biological control. As an example, the carnivorous mosquito from Southeast Asia, Toxorhynchites spp., also called the “tox” mosquito, has a larva that feeds on the larvae of the tiger mosquito, Aedesspp., which transmits diseases such as dengue fever to humans (O’Toole 1995).

Mass rearing facilities have been developed to raise sterile insects as a non-chemical pest-suppression tool. One such facility in Egypt rears a billion fruit flies (about 7 tonnes) each week. This rearing industry has two major cycles. One is the feed conversion or larval incubation cycle, and the other is the propagation or egg-production cycle. The sterile insect technique was first used to eliminate the screw worm, which preyed on cattle. Sterilization is accomplished by irradiating the pupae just prior to adult emergence from the cocoon with either x rays or gamma rays. This technique takes mass quantities of reared, sterile insects and releases them into infested areas where the sterile males mate with the wild, fertile females. Breaking the insect’s life cycle has dramatically reduced the fertility rate of these pests. This technique is used on screw worms, gypsy moths, boll weevils and fruit flies (Kok, Lomaliza and Shivhara 1988).

A typical sterile insect facility has an airlock system to restrict unwanted insect entry and fertile insect escape. Rearing tasks include mopping and sweeping, egg stacking, tray washing, diet preparation, inoculation (placing eggs into agar), pupae dyeing, emergence tending, packing, quarantining, irradiating, screening and weighing. In the pupae room, vermiculite is mixed with water and placed in trays. The trays are stacked, and the vermiculite dust is swept with a broom. The pupae are separated from the vermiculite with a sieve. The insect pupae chosen for the sterile insect technique are transported in trays stacked on racks to the irradiation chamber in a different area or facility, where they are irradiated and rendered sterile (Froehlich 1995; Kiefer 1996).

Insect workers, including silkworm workers, may have an allergic reaction to arthropod allergens (scales, hairs, other body parts). Initial symptoms are itchy eyes and irritation of the nose followed by intermittent episodes of wheezing, coughing and breathlessness. Subsequent asthma attacks are triggered by re-exposure to the allergen.

Entomologists and workers in sterile fly facilities are exposed to a variety of potentially hazardous, flammable agents. These agents include: in entomology laboratories, isopropyl alcohol, ethyl alcohol and xylene; in the diet preparation room, isopropyl alcohol is used in water solution to sterilize walls and ceilings with a sprayer. Vermiculite dust poses respiratory concerns. Some vermiculites are contaminated with asbestos. Air-handling units in these facilities emit noise that may be damaging to employee hearing. Proper exhaust ventilation and personal respiratory protection can be used in facilities to control exposure to airborne allergens and dusts. Non-dusty working materials should be used. Air conditioning and frequent changes of filters may help reduce airborne levels of spines and hairs. X rays or gamma rays (ionizing radiation) can damage genetic material. Protection is needed against x rays or gamma rays and their sources in the irradiation facilities (Froehlich 1995; Kiefer 1996).

Silkworm Raising

Vermiculture, the raising of worms, has a long history in some cultures. Worms, especially the meal worm (which is a larva rather than a true worm) from the darkling beetle, are raised by the billions as animal fodder for laboratory animals and pets. Worms are also used in composting operations (vermi-composting).

Sericulture is the term used for silkworm cocoon production, which includes silkworm feeding and cocoon formation. Cultivation of the silkworm and the silk moth caterpillar dates back to 3000 BC in China. Silkworm farmers have domesticated the silkworm moth; there are no remaining wild populations. Silkworms eat only white mulberry leaves. Fibre production thus has historically depended upon the leafing season of the mulberry tree. Artificial foods have been developed for the silkworm so that production can extend the year around. Silkworms are raised on trays sometimes mounted on racks. The worms take about 42 days of feeding at a constant temperature of 25 °C. Artificial heating may be required. Silk is a secretion from the silkworm’s mouth that solidifies upon contact with air. The silkworm secretes about 2 km of silk fibre to form a cocoon during the pupal stage (Johnson 1982). After the cocoon is formed, the silkworm farmer kills the pupa in a hot oven, and ships the cocoon to a factory. At the factory, silk is harvested from the cocoon and spun into thread and yarn.

Nine per cent of silkworm workers manifest asthma in response to silkworm moth scales, although most asthma in silkworm workers is attributed to inhalation of silkworm faeces. In addition, contact of the skin with silkworm caterpillar hairs may produce a primary irritant contact-dermatitis. Contact with raw silk may also produce allergic skin reactions. For silk moth production, hyposensitization therapy (for moth scales and faeces) provides improvement for 79.4% of recipients. Corticosteroids may reverse the effects of inhaled antigens. Skin lesions may respond to topical corticosteroid lotions and creams. Oral antihistamines relieve itching and burning. Carbon monoxide poisoning has been identified among some silkworm farmers in their homes, where they are maintaining warmth with charcoal fires as they raise the silkworms. Charcoal fires and kerosene heaters should be replaced with electric heaters to avoid carbon monoxide exposures.

 

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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
Agriculture and Natural Resources Based Industries
Beverage Industry
Fishing
Food Industry
Forestry
Hunting
Livestock Rearing
Lumber
Paper and Pulp Industry
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

Livestock Rearing References

Aldhous, P. 1996. Scrapie theory fed BSE complacency, now fears grow for unborn babies. New Scientist 150:4-5.

Ahlgren, GH. 1956. Forage Crops. New York: McGraw-Hill Book Co.

American Conference of Governmental Industrial Hygienists (ACGIH). 1994. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH: ACGIH.

Auty, JH. 1983. Draught animal power in Australia. Asian Livestock VIII:83-84.

Banwart, WC and JM Brenner. 1975. Identification of sulfur gases evolved from animal manures. J Environ Qual 4:363-366.

Baxter, PJ. 1991. Toxic marine and freshwater algae: An occupational hazard? Br J Ind Med 48(8):505-506.

Bell, RG, DB Wilson, and EJ Dew. 1976. Feedlot manure top dressing for irrigated pasture: Good agricultural practice or a health hazard? B Environ Contam Tox 16:536-540.

Benenson, AS. 1990. Control of Communicable Diseases in Man. Washington, DC: American Public Health Association.

—. 1995. Control of Communicable Diseases Manual. Washington, DC: American Public Health Association.

Brown, LR. 1995. Meat production takes a leap. In Vital Signs 1995: The Trends that are Shaping our Future, edited by LR Brown, N Lenssen, and H Kane. New York: WW Norton & Company.

Bursey, RG. 1992. New uses of dairy products. In New Crops, New Uses, New Markets: Industrial and Commercial Products from U.S. Agriculture: 1992 Yearbook of Agriculture. Washington, DC: USDA.

Calandruccio, RA and JH Powers. 1949. Farm accidents: A clinical and statistical study covering twenty years. Am Surg (November):652-660.

Cameron, D and C Bishop. 1992. Farm accidents in adults. Br Med J 305:25-26.

Caras, RA. 1996. A Perfect Harmony: The Intertwining Lives of Animals and Humans throughout History. New York: Simon & Schuster.

Carstensen, O, J Lauritsen, and K Rasmussen. 1995. The West-Justland study on prevention of farm accidens, Phase 1: A study of work specific factors in 257 hospital-treated agricultural injuries. Journal of Agricultural Safety and Health 1:231-239.

Chatterjee, A, D Chattopadhyay, D Bhattacharya, Ak Dutta, and DN Sen Gupta. 1980. Some epidemiologic aspects of zoophilic dermatophytosis. International Journal of Zoonoses 7(1):19-33.

Cherry, JP, SH Fearirheller, TA Foglis, GJ Piazza, G Maerker, JH Woychik, and M Komanowski. 1992. Innovative uses of animal byproducts. In New Crops, New Uses, New Markets: Industrial and Commercial Products from U.S. Agriculture: 1992 Yearbook of Agriculture. Washington, DC: USDA.

Crowley, M. 1995. Aquaculture trends and technology. National Fisherman 76:18-19.

Deere & Co. 1994. Farm and Ranch Safety Management. Moline, IL: Deere & Co.

DeFoliart, GR. 1992. Insects as human foods. Crop Protection 11:395-399.

Donham, KJ. 1985. Zoonotic diseases of occupational significance in agriculture: A review. International Journal of Zoonoses 12:163-191.

—. 1986. Hazardous agents in agricultural dusts and methods of evaluation. Am J Ind Med 10:205-220.

Donham, KJ and LW Knapp. 1982. Acute toxic exposure to gases from liquid manure. J Occup Med 24:142-145

Donham, KJ and SJ Reynolds. 1995. Respiratory dysfunction in swine production workers: Dose-response relationship of environmental exposures and pulmonary function. Am J Ind Med 27:405-418.

Donham, KJ and L Scallon. 1985. Characterization of dusts collected from swine confinement buildings. Am Ind Hyg Assoc J 46:658-661.

Donham, KJ and KM Thu. 1995. Agriculture medicine and enivronmental health: The missing component of the sustainable agricultural movement. In Agricultural health and safety: Workplace, Environment, Sustainability, edited by HH McDuffie, JA Dosman, KM Semchuk, SA Olenchock, and A Senthilselvan. Boca Raton, FL: CRC Press.

Donham, KJ, MJ Rubino, TD Thedell and J Kammenmeyer. 1977. Potential health hazards of workers in swine confinement buildings. J Occup Med 19:383-387.

Donham, KJ, J Yeggy, and RR Dauge. 1985. Chemical and physical parameters of liquid manure from swine confinement facilities: Health implications for workers, swine and the environment. Agricultural Wastes 14:97-113.

—. 1988. Production rates of toxic gases from liquid manure: Health implications for workers and animals in swine buildings. Bio Wastes 24:161-173.

Donham, KJ, DC Zavala, and JA Merchant. 1984. Acute effects of work environment on pulmonary functions of swine confinement workers. Am J Ind Med 5:367-375.

Dosman, JA, BL Graham, D Hall, P Pahwa, H McDuffie, M Lucewicz, and T To. 1988. Respiratory symptoms and alterations in pulmonary function tests in swine producers in Saskatchewan: Results of a survey of farmers. J Occ Med 30:715-720.

Douglas, JDM. 1995. Salmon farming: Occupational health in a new rural industry. Occup Med 45:89-92.

Douglas, JDM and AH Milne. 1991. Decompression sickness in fish farm workers: A new occupational hazard. Br Med J 302:1244-1245.

Durning, AT and HB Brough. 1992. Reforming the livestock economy. In State of the World, edited by LR Brown. London: WW Norton & Company.

Erlich, SM, TR Driscoll, JE Harrison, MS Frommer, and J Leight. 1993. Work-related agricultural fatalities in Australia, 1982-1984. Scand J Work Environ Health 19:162-167.

Feddes, JJR and EM Barber. 1994. Agricultural engineering solutions to problems of air contaminants in farm silos and animal buildings. In Agricultural Health and Safety: Workplace, Environment, Sustainability, edited by HH McDuffie, JA Dosman, KM Semchuk, SA Olenchock and A Senthilselvan. Boca Raton, FL: CRC Press.

Ferguson, IR and LRC Path. 1993. Rats, fish and Weil’s disease. Safety and Health Practitioner :12-16.

Food and Agriculture Organization (FAO) of the United Nations. 1965. Farm Implements for Arid and Tropical Regions. Rome: FAO.

—. 1995. The State of the World Fisheries and Aquaculture. Rome: FAO.

Fretz, P. 1989. Injuries from farm animals. In Principles of Health and Safety in Agriculture, edited by JA Dosman and DW Crockcroft. Boca Raton, FL: CRC Press.

Froehlich, PA. 1995. Engineering Control Observations and Recommendations for Insect Rearing Facilities. Cincinnati, OH: NIOSH.

Gillespie, JR. 1997. Modern Livestock and Poultry Production. New York: Delmar Publishers.

Gorhe, DS. 1983. Draught animal power vs mechanization. Asian Livestock VIII:90-91.

Haglind, M and R Rylander. 1987. Occupational exposure and lung function measurements among workers in swine confinement buildings. J Occup Med 29:904-907.

Harries, MG and O Cromwell. 1982.Occupational allergy caused by allergy to pig’s urine. Br Med J 284:867.

Heederick, D, R Brouwer, K Biersteker, and J. Boleij. Relationship of airborne endotoxin and bacteria levels in pig farms with lung function and respiratory symptoms of farmers. Intl Arch Occup Health 62:595-601.

Hogan, DJ and P Lane. 1986. Dermatologic disorders in agriculture. Occup Med: State Art Rev 1:285-300.

Holness, DL, EL O’Glenis, A Sass-Kortsak, C Pilger, and J Nethercott. 1987. Respiratory effects and dust exposures in hog confinement farming. Am J Ind Med 11:571-580.

Holness, DL and JR Nethercott. 1994. Acute and chronic trauma in hog farmers. In Agricultural Health and Safety: Workplace, Environment, Sustainability, edited by HH McDuffie, JA Dosman, KM Semchuk, SA Olenchock, and A Senthilselvan. Boca Raton, FL: CRC Press.

Iowa Department of Public Health. 1995. Sentinel Project Research Agricultural Injury Notification System. Des Moines, IA: Iowa Department of Public Health.

Iverson, M, R Dahl, J. Korsgaard, T Hallas, and EJ Jensen. 1988. Respiratory symptoms in Danish farmers: An epidemiological study of risk factors. Thorax 48:872-877.

Johnson, SA. 1982. Silkworms. Minneapolis, MN: Lerner Publications.

Jones, W, K Morring, SA Olenchock, T Williams, and J. Hickey. 1984. Environmental study of poultry confinement buildings. Am Ind Hyg Assoc J 45:760-766.

Joshi, DD. 1983. Draught animal power for food production in Nepal. Asian Livestock VIII:86-87.

Ker, A. 1995. Farming Systems in the African Savanna. Ottawa,Canada: IDRC Books.

Khan, MH. 1983. Animal as power source in Asian agriculture. Asian Livestock VIII:78-79.

Kiefer, M. 1996. Florida Department of Agriculture and Consumer Services Division of Plant Industry, Gainesville, Florida. Cincinnati, OH: NIOSH.

Knoblauch, A, B Steiner, S Bachmann, G Trachsler, R Burgheer, and J Osterwalder. 1996. Accidents related to manure in eastern Switzerland: An epidemiological study. Occup Environ Med 53:577-582.

Kok, R, K Lomaliza, and US Shivhare. 1988. The design and performance of an insect farm/chemical reactor for human food production. Canadian Agricultural Engineering 30:307-317.

Kuo, C and MCM Beveridge. 1990. Mariculture: Biological and management problems, and possible engineering solutions. In Engineering for Offshore Fish Farming. London: Thomas Telford.

Layde, PM, DL Nordstrom, D Stueland, LB Wittman, MA Follen, and KA Olsen. 1996. Animal-related occupational injuries in farm residents. Journal of Agricultural Safety and Health 2:27-37.

Leistikow, B Donham, JA Merchant, and S Leonard. 1989. Assessment of U.S. poultry worker respiratory risk. Am J Ind Med 17:73-74.

Lenhart, SW. 1984. Sources of respiratory insult in the poultry processing industry. Am J Ind Med 6:89-96.

Lincoln, JM and ML Klatt. 1994. Preventing Drownings of Commercial Fishermen. Anchorage, AK: NIOSH.

MacDiarmid, SC. 1993. Risk analysis and the importation of animals and animal products. Rev Sci Tech 12:1093-1107.

Marx, J, J Twiggs, B Ault, J Merchant, and E Fernandez-Caldas. 1993. Inhaled aeroallergen and storage mite reactivity in a Wisconsin farmer nested case-control study. Am Rev Respir Dis 147:354-358.

Mathias, CGT. 1989. Epidemiology of occupational skin disease in agriculture. In Principles of Health and Safety in Aagriculture, edited by JA Dosman and DW Cockroft. Boca Raton, FL: CRC Press.

Meadows, R. 1995. Livestock legacy. Environ Health Persp 103:1096-1100.

Meyers, JR. 1997. Injuries among Farm Workers in the United States, 1993. DHHS (NIOSH) Publication No. 97-115. Cincinnati, OH: NIOSH.

Mullan, RJ and LI Murthy. 1991. Occupational sentinel health events: An up-dated list for physician recognition and public health surveillance. Am J Ind Med 19:775-799.

National Institute for Occupational Safety and Health (NIOSH). 1993. Injuries among Farm Workers in the United states. Cincinnati, OH: NIOSH.

—. 1994. Request for Assistance in Preventing Organic Dust Toxic Syndrome. Washington, DC: GPO.

National Institutes of Health (NIH). 1988. Institutional Administrator’s Manual for Laboratory Animal Care and Use. Washington, DC: GPO.

National Research Council (NRC). 1989. Alternative Agriculture: Committee on the Role of Alternative Farming Methods in Modern Production Agriculture. Washington, DC: National Academy Press.

National Safety Council. 1982. Accident Facts. Chicago, IL: National Safety Council.

—. 1985. Electrofishing. NSC data sheet I-696-85. Chicago, IL: National Safety Council.

Nesheim, MC, RE Austic, and LE Card. 1979. Poultry Production. Philadelphia, PA: Lea and Febiger.

Olenchock, S, J May, D Pratt, L Piacitelli, and J Parker. 1990. Presence of endotoxins in different agricultural environments. Am J Ind Med 18:279-284.

O’Toole, C. 1995. Alien Empire. New York: Harper Collins Publishers.

Orlic, M and RA Leng. 1992. Prelimenary Proposal to Assist Bangladesh to Improve Ruminant Livestock Productivity and Reduce Methane Emissions. Washington, DC: US Environmental Protection Agency, Global Change Division.

Panti, NK and SP Clark. 1991. Transient hazardous conditions in animal building due to manure gas release during slurry mixing. Applied Engineering in Agriculture 7:478-484.

Platt, AE. 1995. Aquaculture boosts fish catch. In Vital Signs 1995: The Trends that Are Shaping our Future, edited by LR Brown, N Lenssen, and H Kane. New York: WW Norton & Company.

Pursel, VG, CE Rexroad, and RJ Wall. 1992. Barnyard biotchnology may soon produce new medical therapeutics. In New Crops, New Uses, New Markets: Industrial and Commercial Products from U.S. Agriculture: 1992 Yearbook of Agriculture Washington, DC: USDA.

Ramaswami, NS and GL Narasimhan. 1982. A case for building up draught animal power. Kurushetra (India’s Journal for Rural Development) 30:4.

Reynolds, SJ, KJ Donham, P Whitten, JA Merchant, LF Burmeister, and WJ Popendorf. 1996. A longitudinal evaluation of dose-response relationships for environmental exposures and pulmonary function in swine production workers. Am J Ind Med 29:33-40.

Robertson, MH, IR Clarke, JD Coghlan, and ON Gill. 1981. Leptospirosis in trout farmers. Lancet: 2(8247)626-627.

Robertson, TD, SA Ribeiro, S Zodrow, and JV Breman. 1994. Assessment of Strategic Livestock Feed Supplementation as an Opportunity for Generating Income for Small Scale Dairy Producers and Reducing Methane Emissions in Bangladesh. Washington, DC: US Environmental Protection Agency.

Rylander, R. 1994. Symptoms and mechanisms: Inflammation of the lung. Am J Ind Med 25:19-24.

Rylander, R, KJ Donham, C Hjort, R Brouwer, and D Heederik. 1989. Effects of exposure to dust in swine confinement buildings: A working group report. Scand J Work Environ Health 15:309-312.

Rylander, R and N Essle. 1990. Bronchial hyperactivity among pig and dairy farmers. Am J Ind Med 17:66-69.

Rylander, R, Y Peterson, and KJ Donman. 1990. Questionnaire evaluating organic dust exposure. Am J Ind Med 17:121-128.

Rylander, R and R Jacobs. 1994. Organic Dusts: Exposure, Effects and Prevention. Chicago, IL: Lewis Publishing.
Safina, C. 1995. The world’s imperiled fish. Sci Am 272:46-53.

Scherf, BD. 1995. World Watch List for Domestic Animal Diversity. Rome: FAO.

Schmidt, MJ. 1997. Working elephants. Sci Am 279:82-87.

Schmidt, JO. 1992. Allergy to venomous insects. In The Hive and the Honey Bee, edited by JM Graham. Hamilton: DaDant & Sons.

Shumacher, MJ and NB Egen. 1995. Significance of Africanized bees on public health. Arch Int Med 155:2038-2043.

Sherson, D, I Hansen, and T Sigsgaard. 1989. Occupationally related respiratory symptoms in trout-processing workers. Allergy 44:336-341.

Stem, C, DD Joshi, and M Orlic. 1995. Reducing Methane Emissions from Ruminant Livestock: Nepal prefeasibility Study. Washington, DC: US Environmental Protection Agency, Global Change Division.

Sweeten, JM. 1995. Odor measurement technology and applications: A state-of-the-art review. In Seventh International Symposium on Agricultural and Food Processing Wastes: Proceedings of the 7th International Symposium, edited by CC Ross. American Society of Agricultural Engineering.

Tannahill, R. 1973. Food in History. New York: Stein and Day.

Thorne, PS, KJ Donham, J Dosman, P Jagielo, JA Merchant, and S Von Essen. 1996. Occupational health. In Understanding the Impacts of Large-scale Swine Production, edited by KM Thu, D Mcmillan, and J Venzke. Iowa City, IA: University of Iowa.

Turner, F and PJ Nichols. 1995. Role of the epithelium in the response of the airways. Abstract for the 19th Cotton and Other Organic Dust Research Conference, 6-7 January, San antonio, TX.

United Nations Development Programme (UNDP). 1996. Urban Agriculture: Food, Jobs, and Sustainable Cities. New York: UNDP.

US Department of Agriculture (USDA). 1992. Agricultural Waste Management Field Handbook. Washington, DC: USDA Soil Conservation Service.

—. 1996a. Livestock and Poultry: World Markets and Trade. Circular Series FL&P 1-96. Washington DC: USDA Foreign Agricultural Service.

—. 1996b. Dairy: World Markets and Trade. Circular Series FD 1-96. Washington DC: USDA Foreign Agricultural Service.

—. 1997. Poultry Production and Value, 1996 Summary. Washington, DC: National Agricultural Statistics Service.

van Hage-Hamsten, M, S Johansson, and S Hogland. 1985. Storage mite allergy is common in a farming population. Clin Allergy 15:555-564.

Vivian, J. 1986. Keeping Bees. Charlotte, VT: Williamson Publishing.

Waller, JA. 1992. Injuries to farmers and farm families in a dairy state. J Occup Med 34:414-421.

Yang, N. 1995. Research and development of buffalo draught power for farming in China. Asian Livestock XX:20-24.

Zhou, C and JM Roseman. 1995. Agriculture-related residual injuries: Prevalence, type, and associated factors among Alabama farm operators, 1990. Journal of Rural Health 11:251-258.

Zuehlke, RL, CF Mutel, and KJ Donham. 1980. Diseases of Agricultural Workers. Iowa City, IA: Department of Preventive Medicine and Environmental Health, University of Iowa.