High concentrations of pesticide drift in the air can cause immediate (or “acute”) poisonings, resulting in serious illness and, in rare cases, death. Exposure to pesticide drift may cause birth defects, cancer, asthma, developmental disabilities and other long-term (or “chronic”)
. Pesticide drift can also harm the local environment by contaminating water ways, air, and soil, killing fish, birds and other wildlife.
Measuring Pesticide Drift at South Woods Elementary
Many methods are available for measuring pesticide drift. At South Woods Elementary School pesticide drift was measured using a "Drift Catcher
": an affordable, easy to use, and accurate air monitoring instrument developed by the Pesticide Action Network of North America and operated by concerned area residents. The preliminary air monitoring study conducted from December 6 to 14, 2006 found organochlorine
, and dinitroaniline
in drift. From these initial results
, a more detailed follow up study was conducted the following year.
From October 1 to December 6, 2008 four different pesticides were found in the thirty-nine air samples collected from the drift catchers: the insecticides endosulfan
, the herbicide trifluralin
, and the fungicide chlorothalonil
. Of the samples collected, 56% contained three of the four pesticides, and 18% contained all four pesticides. These pesticides were detected as long as several days to a week after an application indicating that the entry of contaminants into the atmosphere is primarily by volatilization drift, although application-related drift may have also contributed on the days on which applications took place.
Endosulfan Results, click image to enlarge
The following are tables summarizing the results of the 39 samples collected between October 1, 2008 to December 6, 2008.
Endosulfan is acutely neurotoxic to both insects and mammals and a suspected endocrine disruptor. Symptoms of acute poisoning include hyperactivity, tremors, convulsions, lack of coordination, staggering, difficulty breathing, nausea/vomiting, and diarrhea. Studies have found associations between chronic exposure and delayed sexual maturity (in males) and increased incidence of birth defects of the male reproductive system. Maternal endosulfan exposure during pregnancy has been associated with an increased incidence of autism in the children born to these mothers. Brain damage and skin irritation have been noted among adults exposed to endosulfan occupationally.
Endosulfan is an organochlorine insecticide that is applied in the US in greatest quantities to cotton, potatoes, and apples, and used in lesser amounts on a variety of vegetable and fruit crops. Residential uses of endosulfan were terminated in 2000. Nationwide from 1987–1997, U.S. EPA estimated that average annual use of endosulfan was 1.38 million pounds.
Of the 39 samples collected (spikes and blanks excluded) between October 1 and December 6 in Hastings, Fl, 87% were found to be above the limit of quantitation (LOQ) of 51 nanograms (ng) of α-endosulfan per sample. The LOQ is equivalent to an air concentration of 18 ng/m3 for the sampling method used. 69% of samples were found to be above the LOQ of 25 ng of β-endosulfan per sample (equivalent to an air concentration of 8.7 ng/m3). None of the samples contained endosulfan sulfate above the LOQ of 124 ng per sample (equivalent to an air concentration of 43 ng/m3); however, 38% did have concentrations above the MDL of 25 ng/sample (equivalent to an air concentration of 9 ng/m3).
Nine endosulfan samples (23%) were above the 24-hour acute and sub-chronic one-year-old child REL of 340 ng/m3
, calculated from U.S. EPA's inhalation No Observed Adverse Effect Level (NOAEL). Twenty-one percent of the samples were above the seven-year-old REL of 500 ng/m3
. The highest concentration of total endosulfan observed for a 24-hour period was 1,376 ng/m3
(4.0 times the 24-hour acute one-year-old REL and 2.8 times the seven-year-old REL) on October 13, 2007. The average concentration for the 39 days sampled was 248 ng/m3
Diazinon is neurotoxic to both insects and mammals, inhibiting cholinesterase, an enzyme essential for the proper transmission of nerve impulses. Citing unacceptable risks to children and the environment, the U.S. EPA banned all residential uses of diazinon effective in 2004; however, agricultural use continues.
Symptoms of acute poisoning range from headache, nausea and vomiting, dizziness, weakness, drowsiness, and agitation to difficulty breathing, twitching, excessive salvation and sweating, watery eyes, pinpoint pupils, confusion, inability to concentrate, and memory loss. Asthma, gestational diabetes, and certain types of cancer have been linked to chronic exposure to diazinon.
Diazinon is an organophosphorus insecticide applied in the United States to a wide variety of fruits, nuts, and vegetables. Nationwide in 2001, U.S. EPA estimated that 4–7 million pounds of diazinon were used, third behind malathion and chlorpyrifos for US organophosphorus insecticide use.
Exposures calculated from the measured air concentrations should be viewed as estimates that may or may not represent worst-case exposure scenarios, and do not necessarily represent the precise exposure individuals may experience. Variability in actual exposures and the effects that may be experienced by individuals are governed by breathing rates and activity levels, time spent in areas where pesticide exposure can occur, and individuals' ability to detoxify chemicals. Inhalation may not be the sole exposure source, and total exposures from all routes (air, skin, diet) may be higher.