Environmental Issues: Health
Coffee, Conservation, and Commerce in the Western Hemisphere
How Individuals and Institutions Can Promote Ecologically Sound Farming and Forest Management in Northern Latin America
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IV. ENVIRONMENTAL DIMENSIONS OF COFFEE PRODUCTION
The way coffee is grown and processed has profound environmental importance both locally and internationally. This section focuses on four themes intimately related to the coffee sector: biodiversity and conservation of forest ecosystems; agro-chemical use; water pollution from coffee processing; and soil quality. Each of these factors is critical to environmental quality in northern Latin America.
Deforestation trends are serious throughout the coffee-producing lands of Latin America. Seven of the ten countries in the world with the highest deforestation rates are in Latin America and the Caribbean; these seven countries include Jamaica, Haiti, Costa Rica, Paraguay, Ecuador, Guatemala and Mexico. In a number of areas, tropical forest ecosystems have disappeared or are on a path to elimination in the near-term. By the late 1980s, for example, only an estimated one-fourth of the primary moist tropical forest in Colombia remained.
Remarkable biodiversity values are at stake. Latin American tropical forests are critical ecologically for purposes of protection of atmospheric dynamics, water quality, and wildlife species, as well as economically as reservoirs of germplasm with multiple applications for food, medicine, and industrial products.
The region's threatened natural heritage transcends national boundaries. For instance, neotropical migratory birds that winter in northern Latin America constitute 60 to 80 percent of the bird species that inhabit forests throughout the eastern U.S. and Canada; neotropical migrants also constitute a large fraction of bird species in the forests of the Pacific Northwest. Birds numbering in the hundreds of millions and representing more than 120 species migrate annually through or to the part of the Central American isthmus composed of Costa Rica and Panama.
Traditional, shade coffee production has been shown to be highly beneficial to biodiversity conservation in tropical forest ecosystems. In northern Latin America, traditional coffee covers very significant areas with closed canopy, agro-forestry systems with high species diversity. Smithsonian Migratory Bird Center biologists conducting research in the southern Mexican state of Chiapas discovered that traditionally-managed coffee and cacao (chocolate) plantations support at least 180 species of birds, an amount significantly greater than bird numbers found on other agricultural lands and exceeded only by undisturbed tropical forest. The attraction of industrial sun coffee for birds falls well short of that seen in traditional shade systems. For example, studies in Colombia and Mexico have identified over 90 percent fewer bird species in sun-grown plantations than in shade coffee.
Shade coffee also provides essential habitat for diverse communities of other tropical forest species. Findings by University of Michigan biologist Ivette Perfecto and colleagues from research in Costa Rica suggest that local species diversity of beetles, ants, wasps and spiders on a single tree species (Erythrina poeppigiana) in shade coffee plantations approximates the arthropod diversity levels on single tree species sampled in undisturbed tropical forest.
Additional recent studies on tropical forest ecology have been conducted by scientists from Mexico's National University and Chicago's Lincoln Park Zoo. These researchers' work in Veracruz, Mexico, has shown that shaded agricultural plantations, as compared to unshaded agricultural landscapes, feature richer diversity of small mammals such as opossums, squirrels and mice. Bats, important dispersers of seeds and pollinators of many tree species, as well as natural predators of insects, also show a presence in such systems. Comparing forest habitat to several agricultural lands, these same researchers found that habitats designated as "mixed plantation" (cacao, coffee, bananas, and citrus) and "coffee" (coffee with shade trees) jointly contained 74% of the species richness.
Traditional coffee is often integral to agro-forestry systems in which tree species are cultivated together with the coffee and other agricultural commodities. Where geographic and market conditions are favorable, economic returns can be achieved through sustained-yield timber production in association with coffee. For example, research in Costa Rica has shown that timber from the precious hardwood species Cordia alliadora can occur with no significant damage to growing coffee crops. Agro-forestry systems, including those involving coffee, have potential to enhance the economic and ecological stability of poor rural areas in northern Latin America. By providing an alternative to deforestation, traditional coffee systems constitute an important check against greenhouse gas emissions that contribute to global warming.
Traditional shade coffee systems typically rely on much lower chemical inputs than industrial plantations. This is because planting coffee among natural vegetation, or among trees planted for shade, fruit or timber, can reduce susceptibility to pests. Moreover, because many traditional methods have been passed down to today's farmers by previous generations before synthetic pesticides and fertilizers were widely used in agriculture, a human-land use equilibrium has evolved in coffee production over time.
Intensive pesticide use within industrial coffee production often employs chemicals that present serious health and ecological concerns. Sampling of imported green coffee beans conducted by the U.S. Food and Drug Administration (FDA) in the late 1970s and early 1980s revealed frequent detections of DDT, BHC (benzine hexachloride) and other pesticides banned in the U.S. because of possible carcinogenicity or long-term persistence in the environment.
In 1983, the Natural Resources Defense Council retained the services of an outside contract laboratory to conduct independent testing on imported coffee beans. The analysis revealed multiple pesticide residues on all samples when green coffee beans were tested using detection methods many times more precise than the FDA procedures (see Table 6). The roasting process reduced detectable levels of pesticide residues on the bean samples; however, the test of one sample of the Brazilian coffee beans retained the original level of DDD (the toxic metabolite of DDT) that had been detected on the beans before roasting. It should be noted that while DDT is rarely used on coffee today, other chemicals are used to combat insect pests, weeds, and diseases.
Over the last decade, governments throughout the Western Hemisphere have taken steps to prohibit use of a number of pesticides banned in the U.S. Certain banned chemicals remain approved for agricultural use in some Latin American countries, however. For instance, a 1990 report from the General Accounting Office found that Costa Rica continues to permit use of chlordane, a highly toxic insecticide that persists for years in the environment. Attempts to restrict U.S. exports of banned pesticides have failed in recent years; for example, "circle of poison" legislation passed by the U.S. House and Senate fell short of final enactment in the 1990 farm bill.
Under-regulated pesticide use also threatens farmers and other rural residents with exposures to toxic substances in the workplace or in water supplies. For example, serious public health and water quality impacts have been linked to pesticide use in Mexico; in one documented case in 1987, more than 200 people became sick from drinking water contaminated with agricultural pesticides and fertilizers in the western Mexican state of Jalisco.
A recent World Resources Institute (WRI) report documented extensive human exposure to pesticides in Latin America and elsewhere in the developing world; for example, studies of farmworkers and their families in Nicaragua have revealed significant decreases in the activity of cholinesterase, an enzyme vital for normal neuro-muscular functioning. The WRI report notes that "inadequate safety and hygiene practices are the norm" in developing country pesticide use.
Recently, concerns have been raised about human health and environmental impacts associated with expanded use of the highly toxic insecticide, endosulfan, in Colombia to combat a coffee insect pest known as "la broca." According to official accounts compiled by Pesticide Action Network North America (PANNA), more than 100 human poisonings and one death were attributed to endosulfan use in coffee during 1993; more than 100 poisonings and three deaths were reported in 1994. Although the Colombian health ministry took steps to ban endosulfan use in January 1995, concerns continue to be raised that this move has not been implemented fully. The Colombian Coffee Growers' Federation and the country's National Center for Coffee Research have pointed out the availability of less-toxic chemicals, as well as biological methods for coffee pest management, and have prohibited their field technicians from recommending use of extremely or highly toxic pesticides on coffee.
Farmworkers historically unaccustomed to technified coffee production systems encounter an array of chemicals that are supposed to be applied with protective gear such as masks, long-sleeved shirts, long pants and boots -- clothing that frequently goes unused in the heat and humidity of tropical environments. Recent field research by the U.S. Environmental Protection Agency (EPA) documented widespread lapses in the use of protective clothing among pesticide applicators working in the Mississippi Delta. These EPA staff findings have important implications for farmworker health and safety in technified coffee production in northern Latin America. Current pesticide regulatory systems, including in the United States, take insufficient account of the practical limitations of wearing protective gear in hot weather.
Increased nitrogen fertilizer applications have gone hand in hand with the widespread removal of shade cover from Central American coffee plantations. Heavy synthetic fertilizer inputs in coffee have contributed to nitrate contamination of drinking water aquifers in Costa Rica, with the documented groundwater pollution in some cases exceeding World Health Organization levels. In high concentrations, nitrates can cause infant methemoglobinemia ("blue-baby syndrome"), a potentially fatal condition that impedes oxygen transport in infants' bloodstreams. Other human health concerns surrounding nitrate contamination of groundwater include suspected links between nitrates and certain cancers, birth defects, hypertension, and developmental problems in children.
Largely irrespective of how coffee is grown, discharges from coffee beneficios (processing plants) represent a major source of river pollution in northern Latin America. The process of separating the commercial product (the beans) from coffee cherries generates enormous volumes of waste material in the form of pulp, residual water and parchment. For example, the Guatemala-based Instituto Centroamericano de Investigación y Tecnología Industrial estimated that over a six month period during 1988, the processing of 547,000 tons of coffee in Central America generated 1.1 million tons of pulp and polluted 110,000 cubic meters of water per day, resulting in discharges to the region's waterways equivalent to raw sewage dumping from a city of four million people.
Coffee beneficios exist in a wide range of sizes. In Guatemala, for instance, where a total of some 4000 processing facilities are estimated to dot the landscape, the National Association of Coffee Growers divides them into micro-facilities (those with a capacity to process 500 to 5000 pounds of harvested coffee per day), medium facilities (5000 to 50,000 pounds per day), and large (greater than 50,000 pounds per day). The 100 beneficios belonging to this last category (3% of all Guatemala's beneficios ) process 60% of the coffee produced annually.
Ecological impacts result from the discharge of organic pollutants from beneficios to waterways, robbing aquatic plants and wildlife of essential oxygen. Costa Rican health officials have expressed concerns over harms to marine life along parts of the Pacific Coast where rivers contaminated by coffee processing wastes flow into the ocean. According to Costa Rican government estimates from the early 1980s, coffee processing residues account for two-thirds of the total biochemical oxygen demand (the principal measure of organic pollutant discharges) in the country's rivers. In 1992, Costa Rica instituted a plan to upgrade the nation's coffee processing systems, with the objective of cutting organic pollutant discharges to surface waters by 80 percent within five years.
Recent years have witnessed important progress in the development of pollution control technology in coffee processing. A small but growing number of beneficios are substantially reducing the volume of water used in "wet" processing of coffee; this in turn, reduces the amount of water requiring treatment before being discharged from the processing facilities. Additional environmentally sound measures include composting coffee husks mixed with farm animal manure to use as organic fertilizer on crops, as well as digesters that produce methane gas that can be used for practical applications like powering the processing plant. Success has been demonstrated with these measures in various parts of northern Latin America, including the major coffee areas of Mexico's Veracruz state. Without a concerted regional investment plan in improved technology, however, pollution prevention will remain the exception to the rule in this part of Latin America.
Soil quality benefits of traditional agricultural resource management in northern Latin America have been well documented by Colorado State University geographer Gene C. Wilken in his 1987 book, Good Farmers. Regarding soils, Wilken attributes the success of traditional systems to key factors such as the following:
- understanding of local resource characteristics and how they can be applied efficiently to particular soil and crop conditions to build organic matter through such practices as mulching and multiple cropping;
- careful, precise applications of inorganic nutrients to save on production costs and prevent damage to soil and water quality; and
- effective slope management techniques such as terracing that conserve moisture, control erosion and enable agricultural production in areas otherwise unsuited for farming.
Such practices are typical within shade coffee production systems, which demonstrate remarkable technical sophistication in soil management. Additional benefits derive from substantially reduced or foregone use of pesticides, whose over-application can eliminate insects and micro-organisms that play vital roles in the enhancement of soil productivity and plant nutrition.
Elimination of shade cover can cause significant impacts on various soil quality parameters. Research in Nicaragua in the late 1980s documented that, relative to traditional systems, significantly higher erosion rates occurred on renovated coffee plantations where shade had been reduced. This study also showed that shade coffee systems demonstrated higher levels of soil moisture and organic material.
Nutrient cycling also reacts to changes in the shade cover in coffee. In Costa Rica's Central Valley, where rainfall can reach up to 2.5 meters annually, the leaching of soil nutrients into the groundwater can be significant. Within these high-rainfall areas, unshaded coffee loses nearly three times more soil nitrogen than shaded plantations. In general, shade coffee systems have been shown to be more conservative recyclers of nitrogen than unshaded plantations.
27. The World Bank, The World Bank Atlas:1995 (Washington, D.C.:1994), 26-27.
28. Lester R. Brown et al., State of the World 1991: A Worldwatch Institute Report on Progress Toward a Sustainable Society (New York: W.W. Norton and Company, 1991), 75.
29. Russell Greenberg, Southern Mexico: Crossroads for Migratory Birds (Washington, D.C.: Smithsonian Migratory Bird Center, 1994), 16.
30. Russell Greenberg, Bridging the Americas: Migratory Birds in Costa Rica and Panama (Washington, D.C.: Smithsonian Migratory Bird Center, 1994), 4.
31. Russell Greenberg, "Phenomena, Comment and Notes," Smithsonian (Nov. 1994), 25.
32. Smithsonian Migratory Bird Center, "Why Migratory Birds are Crazy for Coffee" (Washington, D.C.: Fact Sheet No. 1, 1994).
33. Ivette Perfecto and R. Snelling, "Biodiversity and Tropical Ecosystem Transformation: Ant Diversity in the Coffee Agroecosystem in Costa Rica," Ecological Applications (in press); Ivette Perfecto, John Vandermeer, Paul Hanson, and Victor Cartín, 1996, Arthropod biodiversity loss and the transformation of a tropical agroecosystem, In review.
34. Alejandro Estrada, Rosamond Coates-Estrada and Dennis Meritt, Jr., "Non flying Mammals and Landscape Changes in the Tropical Rain Forest Region of Los Tuxtlas, Mexico," Ecography 17 (Copenhagen: 1994), 229-241.
35. Alejandro Estrada, Rosamond Coates-Estrada and Dennis Meritt, Jr., "Bat species richness and abundance in troipcal rain forest fragments and in agricultural habitats at Los Tuxtlas, Mexico," Ecography 16 (Copenhagen: 1993), 309-318.
36. R.K. Dixon, J. Winjum, K. Andrasko, J. Lee, and P. Schroeder, 1994 Integrated land-use systems: assessment of promising agroforest and alternative land-use practices to enhance carbon conservation and sequestration Climatic Change 27:71-92; Somarriba, E., 1990 Sustainable timber production from uneven-aged shade stands of Cordia alliodora in small coffee farms, Agroforestry Systems 10:253-263.
37. See National Research Council, 1993 Sustainable Agriculture and the Environment in the Humid Tropics (Washington, D.C.: National Academy Press) p. 92.
38. Patricia Moguel and Victor M. Toledo, El Café en México: Sustentabilidad y Resistencia Campesina e Indígena La Jornada del Campo 26 September 1995.
39. See Lori Ann Thrupp, 1995 Bittersweet Harvests for Global Supermarkets: Challenges in Latin America's Agricultural Export Boom (Washington, D.C.: World Resources Institute), p. 127.
40. Shelley A. Hearne, 1984 Harvest of Unknowns: Pesticide Contamination in Imported Foods (New York: Natural Resources Defense Council), pp. 16-17.
41. Ibid., p. 18.
42. Ibid., p. 19.
43. U.S. General Accounting Office, Food Safety and Quality: Five Countries' Efforts to Meet U.S. Requirements on Imported Produce (Washington, D.C.: GAO/RCED-90-55, March 1990), pp. 26-81.
44. Fred Powledge, 1991 Toxic Shame, The Amicus Journal 13(1):38-44.
45. Ivan Restrepo, 1992 Los Plaguicidas en México (México, D.F.:Comisión Nacional de Derechos Humanos), pp. 126-127, 130.
46. Robert Repetto and Sanjay S. Baliga, 1996 (March) Pesticides and the Immune system: The Public Health Risks (Washington, DC: World Resources Institute) pp. 9-13.
47. Ibid., p. 10.
48. Telephone conversation with Ellen Hickey, Information Coordinator, Pesticide Action Network, San Francisco, October 19, 1995.
49. Pesticide Action Network North America, Endosulfan to be Banned in Colombia? PANUPS (San Francisco, CA June 16, 1995).
50. Elsa Nivia, Red de Acción en Plaguicidas en America Latina (RAPAL), Palmira, Colombia, personal communication, December 14, 1995.
51. Steven Shapiro, "Pesticides, Agriculture, and Hot Weather in the Mississippi Delta" (Washington, D.C.: EPA Occupational Safety Branch, Office of Pesticide Programs, Field Report, October 1990).
52. Olman Segura B. and Jenny Reynolds, "Environmental Impact of Coffee Production and Processing in El Salvador and Costa Rica," (Geneva: UN Conference on Trade and Environment, UNCTAD/COM/20, August 27, 1993), pp. 15-16.
53. E.G. Nielson and L.K. Lee, 1987 The Magnitude and Costs of Groundwater Contamination from Agricultural Chemicals, (Washington, D.C.: USDA Economic Research Service), p. 22. See also Robbin S. Marks and Justin R. Ward, "Nutrient and Pesticide Threats to Water Quality," in Soil Specific Crop Management, ed. P.C. Robert, R.H. Rust and W.E. Larson (Madison, Wisconsin: American Society of Agronomy, 1993), pp. 293-294.
54. Gilberto Amaya H., Appropriate Technology International, personal communication, January 22, 1996.
55. Erick Guerrero, mechanical engineer at ANACAFE in Guatemala City, personal communication, March 13, 1995.
56. Jose Loria, "Coffee Poses Environmental Headache for Costa Rica," The Reuter Washington Report, 21 September 1992.
57. Segura B. and Reynolds, p. 16.
58. Ibid., pp. 30-31.
59. Gene C. Wilken, Good Farmers: Traditional Agricultural Resource Management in Mexico and Central America (Berkeley: University of California Press, 1987), 69, 93-95, 128. See also Gerardo Bocco, Traditional Knowledge for Soil Conservation in Central Mexico, 46 Journal of Soil and Water Conservation (September-October 1991):346-348.
60. World Resources Institute, World Resources: 1994-95, p. 114.
61. Robert A. Rice, 1991 Observaciones Sobre la Transicion en el Sector Cafetalero en Centroamerica, Agroecología Neotropical 2:1-6.
62. Liana Babbar and Donald Zak, 1995 Nitrogen loss from coffee agroecosystems in Costa Rica: leaching and denitrification in the presence and absence of shade trees, Journal of Environmental Quality 24:227-233; Liana Babbar and Donald Zak, 1993 Nitrogen cycling in coffee agroecosystems, net N mineralization and nitrification in the presence and absence of shade trees Agriculture, Ecosystems and Environment 48:107-113.