Getting the Drift on Chemical Trespass Pesticide drift hits homes, schools and other sensitive sites throughout communities By Kagan Owens and Jay Feldman s suburban sprawl extends further into the countryside, the numbers of people who live, play and work near What Is pesticide drift? Aagricultural land is increasing. Due to pesticides drift- Pesticide drift is an inevitable problem in pest management ing, thousands of individuals are directly affected by adjacent or strategies that rely on spray and dust pesticide formulations. surrounding agricultural fields where pesticide use totals nearly There are essentially two types of drift: particle drift (off-tar- a million pounds a year. Pesticides used on lawns, ornamentals get movement during application) and vapor drift (off-target and trees also drift on to neighboring property. Both scenarios movement when a pesticide evaporates from a sprayed surface). result in chemical trespass causing involuntary exposure. Gov- EPA does not fully regulate particle drift, and it altogether ernment and independent studies show that drifting pesticides ignores vapor drift in its regulatory definition of drift.7 Vapor pose serious environmental drift is known to travel much and human health risks miles further than particle drift.8 away from the treated fields.1 Although pesticides can drift With 77% of all pesticides in the when applied from a truck or U.S. being used in agriculture,2 hand held applicator, of greatest people, especially vulnerable concern is the aerial application high risk population groups of pesticides, where up to 40% like children, the elderly and of the pesticide is lost to drift.9 infirm, are directly exposed to It is estimated that less than pesticides drifting on to homes, 0.1% of an insecticide reaches schools, health care facilities and the target pests. Therefore, other sensitive sites throughout more than 99% of the applied communities. pesticide is released and left to According to the U.S. Envi- impact the surrounding envi- ronmental Protection Agency ronment.10 Even the newer ultra (EPA), “Each year, states receive low volume technology (ULV) about 2,500 complaints of drift under ideal weather conditions from individuals.”3 In 2002, results in only approximately nearly half of the reported pes- 25% of an herbicide reaching ticide illness cases in California the target area.11 were individuals who were exposed as a result of pesticide drift.4 Researchers believe that Pesticides drift reported occurrences are a frac- for miles tion of actual incidents.5 A 2001 study by Texas A&M While EPA has proposed University researchers shows changes to product labels that that pesticides can volatilize will instruct users to “not allow Photo by LSU Ag Center into the gaseous state and be spray to drift from the applica- transported over long distances tion site...,”6 the health effects associated with drift exposure fairly rapidly through wind and rain.12 A U.S. Geological Survey are not calculated or incorporated into agency risk assessments. report reached similar conclusions, finding, “After they are Could EPA allow pesticides to be used if it had to calculate the applied, many pesticides volatilize into the lower atmosphere, real world impacts of drifting chemicals on people suffering a process that can continue for days, weeks, or months after cancer, neurological disease, asthma, etc.? Are there require- the application, depending on the compound. In addition, ments EPA could impose on users to prohibit drift under pesticides can become airborne attached to wind-blown dust.” penalty of law? Are drift reduction or mitigation strategies The report also documents that pesticides in rainfall collected effective? Should the need to stop drift require the adoption in Modesto, California exceeded state guidelines for the protec- of feasible non-toxic alternatives (e.g. organic)? tion of aquatic life in most samples.13 Page 16 Pesticides and You Vol. 24, No. 2, 2004 Beyond Pesticides/National Coalition Against the Misuse of Pesticides In Every Breathe You Take, Environmental Working Group such as nausea, dizziness, respiratory problems, headaches, reports on independent scientific monitoring that finds danger- rashes, and mental disorientation, may appear even when a ously high concentrations of the neurotoxin chlorpyrifos in pesticide is applied according to label directions. Pesticide the air that many residents breathe every day. Chlorpyrifos is exposure can adversely affect the neurological, respiratory, an organophosphate pesticide whose residential uses are being immune, and endocrine systems, even at low levels. A recent phased out, but continues to be used in agriculture, for public study found organophosphate pesticides cause genetic dam- health mosquito control and on golf courses. The report finds age linked to neurological disorders such as attention deficit that more than 22,000 children in three counties attend school hyperactivity disorder and Parkinson’s disease.19 Several near sites of heavy use of toxic pesticides, such as pyrethrins pesticides.14 and pyrethroids, organophos- Another report, Secondhand phates and carbamates, are also Pesticides, summarizes data known to cause or exacerbate collected throughout California asthma symptoms.20 Because and finds that airborne pesticide most of the symptoms of pes- levels routinely exceed accept- ticide exposure, from respira- able health standards miles tory distress to difficulty in from where they are used. More concentration, are common than 90% of pesticides used in in children and may also have California are prone to drift, and other causes, pesticide-related 34% of the 188 million pounds illnesses often go unrecognized of pesticides used in 2000 in and unreported.21 the state are considered highly Studies show that children toxic to humans, according to exposed to pesticides suffer el- the report. Concentrations of evated rates of leukemia, brain the pesticides chlorpyrifos and cancer, and soft tissue sarcoma.22 diazinon, another organophos- According to EPA’s Guidelines phate pesticide whose residen- for Carcinogen Risk Assessment, tial uses are being phased out, children receive 50 percent of were found near spray areas in their lifetime cancer risks in the concentrations that exceeded first two years of life.23 acceptable health levels by 184 A National Cancer Institute and 39 times, respectively. The researcher who matched pesti- report also reveals that for 45% cide data and medical records in of pesticides applied in Califor- ten California agricultural coun- nia, the concentrations of pes- Photo by U.S. Department of Agriculture ties recently reported that preg- ticides in air peak long after the nant women living within nine application is complete-between miles of farms where pesticides eight and 24 hours after an application starts. 15 are sprayed have an increased risk of losing an unborn baby to Studies also show that pesticides drift indoors. For ex- birth defects.24 A 1996 study found that living within 2600 feet ample, a 1991 EPA indoor pesticide study on children’s ex- of an agricultural area increased the risk of developing brain posure shows that for newer and older homes alike, “residues cancer by two-fold, with astrocytoma increased by 6.7-fold.25 of many pesticides are found in and around the home even when there has been no known use of them on the prem- ises.”16 In a 2003 study published in Environmental Science State preemption and Technology on indoor toxins in homes, researchers found grew out of drift varying and alarming levels of some of the most commonly In 1979, Mendocino County, California was among the first lo- used pesticides in dust concentrations in sampled homes. cal jurisdiction in the country to pass an ordinance prohibiting Most concerning is that 63% of the homes tested contain the the aerial application of phenoxy herbicides because of drift. commonly used herbicide 2,4-D,17 showing that pesticides The measure was passed after an incident in 1977 that resulted can be tracked indoors18 or drift in through poorly sealed or in herbicide drift on school buses nearly three miles away from open windows and doors. the application site. After a California State Supreme Court decision upheld the right of citizens to adopt more protective standards than the state and federal government (The People v. Cause for concern County of Mendocino, 1984), the California legislature passed Because of documented exposure patterns resulting from legislation taking away that right. The constitutionality of the drift, advocates for children and other sensitive population law was upheld in the Court of Appeals for the Third Appel- groups are particularly concerned. Adverse health effects, late District (1986). Vol. 24, No. 2, 2004 Pesticides and You Page 17 Beyond Pesticides/National Coalition Against the Misuse of Pesticides Table 1. State Buffer Zone Requirements For Agricultural Pesticide Applications32 STATE APPLICATION Type DIMENSIONS SITES Alabama Aerial application. 400 ft. Schools, hospitals, nursing homes, places of worship. Arizona Certain odoriferous 1/4 m. Schools, daycares, health care institutions, pesticides. 25+ residences adjoining field. Certain highly toxic pesticides. 400 ft. Health care institutions. Certain highly toxic liquid pesticides. 100 ft (aircraft) or 25+ residences adjoining field. 50 ft (ground). Aerial application, certain highly 300 ft. 25+ residences adjoining field. toxic pesticides. Certain highly toxic pesticides. 1/4 m. Schools, daycare centers. Connecticut