IOSH Study Confirms Pesticide Drift Hazards Posed by Conventional Agriculture


(Beyond Pesticides, June 7, 2011)

A study by the Centers for Disease Control and Prevention’s (CDC) National Institute for Occupational Safety and Health (NIOSH) and state agency partners finds that pesticide drift from conventional, chemical-intensive farming has poisoned thousands of farmworkers and rural residents in recent years. According to the authors, agricultural workers and residents in agricultural regions were found to have the highest rate of pesticide poisoning from drift exposure, and soil fumigations were a major hazard causing large drift incidents. The study, “Acute Pesticide Illnesses Associated with Off-Target Pesticide Drift from Agricultural Applications =97 11 States, 1998‚ 2006,” was published June 6, 2011 in the online edition of the journal Environmental Health Perspectives.

Using data from NIOSH’s Sentinel Event Notification System for Occupational Risks (SENSOR) – Pesticides Program and the California Department of Pesticide Regulation, the study identifies 2,945 cases of pesticide poisoning associated with agricultural pesticide drift in 11 states. While the study focuses on top agriculture producing states, it provides only a snapshot of the poisoning of farmworkers and other rural residents nationally and around the world. Advocates also point out that pesticide poisoning is often underreported by farmworkers. According to the Cesar E. Chavez Foundation, only one percent of California pesticide illness or injury is reported.

Of the cases attributed to pesticide drift examined in this study, 47% had exposures at work and 14% were children (<15 years). Most experienced “low severity” illness. The overall incidence (in million person-years) is 114.3 for agricultural workers, 0.79 for other workers, 1.56 for non-occupational cases, and 42.2 for residents in five agriculture-intensive counties in California. Soil applications with fumigants are responsible for the largest proportion (45%) of cases. Aerial applications account for 24% of cases. Study findings show that the risk of illness resulting from drift exposure is largely borne by agricultural workers, and the incidence (114.3/million worker-years) was 145 times greater than that for all other workers.

While this study focuses only on acute poisoning due to pesticide drift, an increasing number of studies are linking low level agricultural pesticide exposure to chronic health impacts. Beyond Pesticides’ Pesticide-Induced Diseases Database features dozens of studies linking common diseases, from asthma and autism to Parkinson’s disease and cancer, to pesticide drift and other agricultural exposures.

Pesticide spray drift is typically the result of small spray droplets being carried off-site by air movement. The main weather factors that cause drift are wind, humidity and temperature changes. Aside from poisoning people and animals, drift can injure foliage, shoots, flowers and fruits resulting in reduced yields, economic loss and illegal residues on exposed crops.