Agri-Chemical Impacts: People, Wildlife, Water, Soil, and Air III
n 1962, Rachel Carson's Silent Spring penetrated the enthusiastic and carefree use of highly hazardous chemicals in all aspects of our lives and spawned the high level of citizen concern felt today. "If we are going to live so intimately with these chemicals — eating and drinking them, taking them into the very marrow of our bones — we had better know something about their nature and their power." —Rachel Carson, 196299 Since that fateful, ground-breaking book was written, we are reminded, time and time again, by the countless scientifically-based government and private sector reports, studies, and hearings of the negative consequences of our heavy reliance on agri-chemicals to the water, air, ozone layer, wildlife, and our personal health. More than 35 years later, the EPA states that "of the 3,000 chemicals that the U.S. imports or produces at more than one million pounds per year, a new EPA analysis finds that 43 % of these high production volume chemicals have no testing data on basic toxicity and only 7 % have a full set of basic test data".100 Time and again, new chemical tools and other magic bullets — such as the current huge industry push for genetically-engineered products — are used without adequate testing as to their health and environmental implications. Time and again, the burden of proof rests with the public to document the harm, press for accountability, and encourage more research.   Health Effects: Humans Pesticides are poisons intended to kill living things - weeds, insects, and fungi. Not surprisingly, these poisons can harm organisms other than the ones for which they are intended. They can harm birds, fish, wildlife, domestic animals, livestock, and humans — including children. The most vulnerable populations are children and fetuses because their brain, organs, and major systems are still developing and because of their small size relative to adults; the elderly due to their increasingly frail health; and people with respiratory problems, such as asthma or allergies.101 The impacts of agricultural chemicals on human health, like any human health effects, can be broadly categorized as acute and chronic. Acute effects occur relatively quickly upon exposure to elevated levels of pesticides. These can encompass adverse effects ranging from headaches, dizziness, irritability, and nausea to significant nervous system impairment and death. Chronic effects include the development of long-term illnesses, such as cancer. Acute Exposure According to the American Association of Poison Control Centers, an estimated 79,000 children were involved in common household pesticide-related poisonings or exposures in the U.S. in 1995.102 Looking into similar statistics for 1989, Stanley Schuman notes that of the total number of cases in that year alone (about 65,000 for 1989), more than 18,500 cases resulted in a visit to a health care facility.103 There is little argument that pesticide poisoning remains a commonly under-diagnosed and under-reported illness, and that definitive statistics are not readily available. EPA also estimates that there are approximately 250 to 500 physician-diagnosed cases of pesticide poisoning for every 100,000 agricultural workers, and many believe that the number of cases is actually twice that figure.104 Additionally, heavily nitrate-contaminated water has caused a rare condition called Blue Baby Syndrome (methemoglobinemia) — a condition in which the body's ability to absorb and hold oxygen is inhibited.105 Chronic or Long-Term Exposure Other health impacts from agri-chemical exposure, particularly those that relate to long-term exposures to relatively low doses, are even more difficult to track and fully understand. In looking at the impacts of chronic exposures to chemicals, scientists and policy-makers rely on two primary sources of information: animal studies and human epidemiological studies. More often than not, it takes a significant number of studies of both types over many years to build a clear case against a given chemical or product, such as tobacco. Also, there may be significant scientific and/or policy disagreement as to the validity or relevancy of certain animal studies for human health effects.106 In one study seeking to document the pesticide exposure of farmers and their families, the researchers sampled indoor and outdoor air in and around six farms in Iowa and North Carolina. Spouses and children in their homes showed far greater exposure to pesticides due to lack of ventilation compared to those who were outdoors — even on the day of application. Their exposure was comparable to the exposure experienced by the pesticide applicators as measured in their breathing zone at the time of application.107 A Natural Resources Defense Council (NRDC) report also indicates that there is a high risk of exposure experienced by children in rural communities.108 That study notes that there are more than 10 million people employed directly in farming109 of which 5 million are farmworkers, along with more than 320,000 children actually living on farms. In 1998, the California Public Interest Research Group (CALPIRG) cited the increasingly close proximity of growing residential communities to farms as exposing nearly four million Californians to harmful pesticides every year.110 Carcinogens and Cancer — For purposes of regulatory decisions, many chemicals, including those used in pesticides, have been placed into one of several categories dealing with carcinogenicity or the capacity to cause cancer in humans. As reported recently by former EPA Assistant Administrator Lynn Goldman,111 EPA and other national and international bodies have classified nearly 165 pesticidal chemicals as known, probable, or possible carcinogens.112 Of those, five are listed as known human carcinogens — a categorization that requires a very significant body of evidence from both animal and human studies. Sixty-eight pesticidal chemicals were classed as probable human carcinogens, with animal as well as limited human data on a portion of these. While the use of some of these chemicals has been restricted or canceled, others remain in common use. Among those chemicals that fall in the larger grouping of possible human carcinogens, there may be a paucity of data or study results may conflict or confound. In 1995, Dr. Aaron Blair of the National Institutes of Health summarized the literature on agricultural exposures and cancer. According to Blair, "farmers, despite a generally favorable mortality, appear to experience elevated rates for several cancers, including leukemia, non-Hodgkin's lymphoma, multiple myelmoa, soft-tissue sarcoma, and cancers of the skin, lip, stomach, brain, and prostate." As Blair explains, the studies do not pinpoint a definitive cause but show an association with either naturally occurring or induced immunodeficiencies. This, in turn, suggests a linkage to agriculturally related exposures to pesticides, solvents, dusts, engine exhausts, or other contaminants.113 Much of the literature behind this report implicates agricultural chemicals in the incidence of a variety of cancers. A more recent epidemiological study, published in March of 1999, looked at cancer mortality in Minnesota. That study found elevated mortality ratios for seven cancers in four regions of the state. The statistical significance of the findings was greatest in those areas with the most intensive use of pesticides.114 Parental occupational exposures to pesticides and home use of pesticides have also been implicated in elevated rates of childhood brain cancers and childhood leukemia.115 Other Health Effects — Several studies report increased incidence of miscarriages and stillbirths among women agricultural workers, and at least one study in India found similar problems in women whose husbands were employed in pesticide application.116 A Minnesota study found an association between pesticide exposure and birth defects in agricultural workers and in the general population.117 Another study of those who drink rural well water suggests a possible link between exposure to agricultural chemicals in drinking water and Parkinson's disease.118   CONTINUE TO: < < PREVIOUS Page NEXT Page > >     [  Back to Top  ]   Home  |  Credits  |  Table of Contents  |  Footnotes  |  State Profiles  |  Contact