(Beyond Pesticides, May 28, 2013) A recent report by the Oregon Health Authority (OHA) found that residents that live in the Highway 36 corridor of Western Oregon were exposed to toxic pesticides in the spring and fall of 2011. OHA collected urine and environmental samples in August and September of 2011 and found levels of 2,4-D and atrazine in residents’ urine. 2,4-D and atrazine have been detected in residents’ urine previously after they had sent samples to be analyzed by Emory University in 2011. Residents continue to argue that herbicides being aerially sprayed on private forests are drifting on their land and causing dangerous levels of exposure. Even though this report by OHA has been delayed several times, it still contains serious data gaps.
According to the report, “The urine samples tested had levels of 2,4-D higher than the general U.S. population.” Though the report found that urine samples also had detectable levels of atrazine, there are no national reference values for atrazine available for the general population, so the study could not conclude that the levels of atrazine exposure were higher than the national average. The report also found other pesticide residues in the environmental samples besides 2,4-D and atrazine. Three of the 36 drinking water samples collected had detectable amounts of DEET, flouridone, or hexazione. Three of the 29 soil samples collected had detectable amounts of 2,4-D and/or glyphosate. The report also found that residents may have been exposed to low levels of clopyralid in the air.
Despite chemical detections in these samples, the report concludes that it was unlikely that residents were exposed to 2,4-D and atrazine through drinking water or through soil contamination, but did not determine whether air was a pathway of exposure. OHA was not able to determine this because it did not have, according to the report, “the capacity to monitor air for the pesticides used in the area.” However the report did find that, “available evidence suggests it is possible that reported [forestry] applications may have contributed to the [pesticide] levels detected in participants’ urine,” and “Urine samples collected after known atrazine applications contained statistically higher levels of atrazine metabolites than samples collected before any known atrazine applications.” Previous allegations have been made that 2,4-D and atrazine have drifted on to schools and homes after they were sprayed in Western Oregon forest areas.
In forest management, pesticides are often aerially sprayed after an area is clear-cut. This process of clear-cutting and aerial spraying for lumber production is ubiquitous on private forest land in Oregon’s $13 billion timber industry. In practice, pesticides are sprayed twice a year, usually in the fall and spring, and the spraying can last for several hours. Aerial spraying in forest management is a risky management technique. In the area of Oregon where the study was conducted, the mountainous terrain forces pilots to fly at heights that would not be tolerated in crop agriculture. Regular cropdusters typically fly at 10 feet above the field, but in this case the planes have flown at 50, 70, or even 80 feet above the trees, which increases the likelihood of pesticide drift.
The dangers associated with the use of 2,4-D and atrazine are very well known. Atrazine is a widespread contaminant in drinking water and is linked to various birth defects, endocrine disruption and cancer, even at concentrations below EPA standards. Although it has been excluded from re-registration in the European Union because it is found above allowable thresholds in groundwater, it is still one of the most widely used herbicides in the U.S. and around the world. A 2009 study found that atrazine upped the risk of nine birth defects in babies born to mothers who conceived between April and July, when surface water levels of the pesticide are highest.
2,4-D has been linked to cancer, reproductive effects, endocrine disruption, kidney and liver damage, is neurotoxic and toxic to beneficial insects (such as bees), earthworms, birds, and fish. Scientific studies have confirmed significantly higher rates of non-Hodgkin’s lymphoma for farmers who use 2,4-D than those who don’t. Despite the known health and environmental effects of 2,4-D, it is the top selling herbicides and total annual usage in the U.S. tops 40 million pounds.
This recent report has been long delayed and questions of industry’s lack of cooperation have been raised. According to a 2012 report by the Center for Investigative Reporting, “This spring , the Oregon Health Authority tabled a follow-up effort to test residents during the spray season. The agency’s plan depended on close collaboration with industry to let the health authority know where atrazine and 2,4-D would be sprayed. But the notifications never came.”
Though this new report helps shed light on the fact that residents in Western Oregon have been exposed to pesticides, the report acknowledges it contains several problematic data gaps. First, the OHA did not have the resources to collect air samples. The report suggests, “monitoring over several application seasons appears to be the best option to collect community wide air data”, however this will take several years to collect the necessary data. Second, these urine samples only represent a snap shot in time. According to the report, “Because 2,4-D and atrazine rapidly clear from the body the levels of these chemicals in urine can only be used to asses recent (within 24-48 hours) exposures.” This means it is unknown if residents have experienced chronic exposure over long periods of time, and even if these samples represent the peak of their exposure. Third, the report states that the urine samples were only tested for 2,4-D and atrazine, so it is unknown if residents were exposed to other types of pesticides. A wide range of pesticides are used in forest management and, given the detections found in soil and water, it is unlikely that forest companies in the area only used 2,4-D and atrazine as management tools.
For more information on effects of these harmful chemicals watch presentations, such as Tyrone Hayes, PhD talk on atrazine, from the recent 31st National Pesticide Forum, “Sustainable Families, Farms and Food Resilient Communities through Organic Practices.”
All unattributed positions and opinions in this piece are those of Beyond Pesticides.