Gaps in Pesticide Reporting Lead to Underestimates of Risk

The "Spheres of Influence" article on pesticide safety for farm workers (1) raises important issues, including the likelihood that reports of pesticide illness and injury currently underestimate the real impacts on farmworker health. The discussion of this underreporting misses, however, what may be the most serious deficiency in estimating pesticide impacts on health--that no reporting system is ever likely to fully accommodate pesticide-related health impacts that are not pesticide-specific and that are often delayed. For example, in clinical practice, even when they occur, adverse impacts on immune system function are unlikely ever to be definitively linked to pesticide exposures, except in rare cases.

Many studies now establish that a diverse number of pesticides and other contaminants can alter immune system function, potentially rendering people more susceptible to infectious agents, allergies, or autoimmune diseases (2-4). These illnesses, if reported at all, are assigned to disease categories that fail to reflect causes of this increased vulnerability. Few physicians who treat patients with these conditions are likely to consider the possible contributory role of pesticide exposures. For research purposes, only rigorous, prospective epidemiologic studies with accurate exposure assessments are likely to uncover this potential link.

These limits to a pesticide-illness reporting system profoundly restrict efforts to gauge the real health costs of pesticide exposure, not just for farming families but for all people who are exposed. Increased research and screening for impacts of pesticide exposure on the immune system are needed to ensure that our understanding of the costs and benefits of pesticide use is not biased by limited disease surveillance systems in which certain types of harm predictably will not be documented.

REFERENCES AND NOTES

(1.) Taylor DA. Spheres of Influence: A new crop of concerns: Congress investigates pesticide safety. Environ Health Perspect 108:A408-A411 (2000).

(2.) Repetto R, Baliga S. Pesticides and the Immune System: The Public Health Risks. Washington, DC:World Resources Institute, 1996.

(3.) Chemically-induced Alterations in the Developing Immune System: The Wildlife/Human Connection. Environ Health Perspect 104 (suppl 4):805-842 (1996).

(4.) Rothman N, Cantor KP, Blair A, Bush D, Brock JW, Helzlsouer K, Zahm SH, Needham LL, Pearson GR, Hoover RN, et al. A nested case-control study of non-Hodgkin lymphoma and serum organochlorine residues. The Lancet 350:240-244 (1997).

John Peterson Myers W. Alton Jones Foundation Charlottesville, Virginia E-mail: jpmyers@wajones.org

Ted Schettler Science and Environmental Health Network Boston, Massachusetts E-mail: tschettler@igc.org

COPYRIGHT 2001 National Institute of Environmental Health Sciences
COPYRIGHT 2004 Gale Group