NIOSH study confirms pesticide drift dangers

A new study by The National Institute for Occupational Safety and Health (NIOSH) and state agency partners confirms the risk faced by agricultural workers who are exposed to airborne drifts of pesticides. "Acute pesticide illnesses associated with off-target pesticide drift from agricultural applications — 11 States, 1998–2006," posted online by Environmental Health Perspectives, is the first comprehensive report to be done of multistate surveillance data on drift-related pesticide poisoning in the United States, according to its authors.

Pesticide poisoning can irritate the eyes and skin, as well as cause dizziness, vomiting, diarrhea, cough, respiratory irritation and pain, chest pain, fatigue, and fever. Pesticide drift is the term for unintended airborne movement of pesticide spray, vapor, or odor from a target application site "and is recognized as a major cause of pesticide exposure affecting people, wildlife, and the environment," according to NIOSH, which said the study found that "small" drifts -– those associated with fewer than five cases of pesticide poisoning per incident –- decreased during the study period. Overall incidence remained constant, however, mainly driven by "large" drifts involving more than five cases each.

The findings should assist in regulatory, enforcement, and education efforts, the researchers said, and NIOSH Director Dr. John Howard agreed.

"These findings underscore the importance of identifying factors that can result in unintended pesticide exposures, recognizing that any health effects from exposures are cause for concern, and adhering to safe application practices and policies at all times," Howard said. "The study also illustrates the value of federal and state partnerships in collecting and using data that are vital for informing occupational and public health initiatives."

The data came from NIOSH's Sentinel Event Notification System for Occupational Risks (SENSOR) program, which provides federal funding or technical support for occupational health surveillance in 12 states, and California's Pesticide Illness Surveillance Program. Of 2,945 pesticide poisoning cases associated with drift in 11 states during 1996-2008, agricultural workers had the highest incidence rate of drift-related pesticide illness (114.3 cases per 1 million people). This was 145 times greater than the rate for non-agricultural workers; the rate for residents in five agricultural-intensive counties in California was 42.2 cases per million, still 69 times higher than the rate in other California counties.

In addition, 53 percent of the 2,945 cases involved non-occupational exposures while 47 percent were work-related exposures. Soil applications with fumigants caused 45 percent of the cases and aerial applications caused 24 percent.

"Common factors contributing to pesticide drift included weather conditions such as high winds or temperature inversions, improper seal of the fumigation site such as a tear in the tarp used to cover the site after application or premature removal of a tarp, and carelessness by the applicator, such as flying over houses or failing to turn off a nozzle at the end of a row of crops," according to NIOSH. "The findings show the need to reinforce compliance with regulatory requirements for applications, and suggest that the practice of establishing buffer zones around application sites, as applicators are required now to do, may not be sufficient independent of other safety measures. Other measures may include reducing maximum application rates, using new, validated drift-reduction technologies as they become available, improving training of pesticide applicators, and improving pesticide labels so that directions for use are clear, flexible, practical and enforceable."

Source: OHS online