Dataset Information

Influence of Asian and Western United states agricultural areas and fires on the atmospheric transport of pesticides in the Western United States.

ABSTRACT: Historic and current use pesticides (HUPs and CUPs), with respect to use in the United States and Canada, were identified in trans-Pacific and regional air masses at Mt. Bachelor Observatory (MBO), a remote high elevation mountain in Oregon's Cascade Range located in the United States, during the sampling period of April 2004 to May 2006 (n = 69), including NASA's INTEX-B campaign (spring 2006). Elevated hexachlorobenzene (HCB) and alpha-hexachlorocyclohexane (alpha-HCH) concentrations were measured during trans-Pacific atmospheric transport events at MBO, suggesting that Asia is an important source region for these HUPs. Regional atmospheric transport events at MBO resulted in elevated dacthal, endosulfan, metribuzin, triallate, trifluralin, and chlorpyrifos concentrations, with episodic increases in concentration during some spring application periods, suggesting that the Western U.S. is a significant source region for these CUPs. Endosulfan I, gamma-HCH, and dacthal concentrations were significantly positively correlated (p-value < 0.05) with increased air mass time in Western U.S. agricultural areas. Elevated gamma-HCH concentrations were measured at MBO during both trans-Pacific and regional atmospheric transport events, including regional fire events. In addition to gamma-HCH, elevated sigmachlordane, alpha-HCH, HCB, and trifluralin concentrations were associated with fires in Western North America due to revolatilization of these pesticides from soils and vegetation. Trans-chlordane/cis-chlordane and alpha-HCH/gamma-HCH ratios were calculated and may be used to distinguish between free tropospheric and regional and/or Asian air masses.

SUBMITTER: Primbs T

PROVIDER: S-EPMC4145850 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature

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Influence of Asian and Western United states agricultural areas and fires on the atmospheric transport of pesticides in the Western United States.

Primbs Toby T Wilson Glenn G Schmedding David D Higginbotham Carol C Simonich Staci Massey SM

Environmental science & technology 20080901 17

Historic and current use pesticides (HUPs and CUPs), with respect to use in the United States and Canada, were identified in trans-Pacific and regional air masses at Mt. Bachelor Observatory (MBO), a remote high elevation mountain in Oregon's Cascade Range located in the United States, during the sampling period of April 2004 to May 2006 (n = 69), including NASA's INTEX-B campaign (spring 2006). Elevated hexachlorobenzene (HCB) and alpha-hexachlorocyclohexane (alpha-HCH) concentrations were meas ...[more]

PMID: 18800524

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Project description:We present a method for calculating the Acute Insecticide Toxicity Loading (AITL) on US agricultural lands and surrounding areas and an assessment of the changes in AITL from 1992 through 2014. The AITL method accounts for the total mass of insecticides used in the US, acute toxicity to insects using honey bee contact and oral LD50 as reference values for arthropod toxicity, and the environmental persistence of the pesticides. This screening analysis shows that the types of synthetic insecticides applied to agricultural lands have fundamentally shifted over the last two decades from predominantly organophosphorus and N-methyl carbamate pesticides to a mix dominated by neonicotinoids and pyrethroids. The neonicotinoids are generally applied to US agricultural land at lower application rates per acre; however, they are considerably more toxic to insects and generally persist longer in the environment. We found a 48- and 4-fold increase in AITL from 1992 to 2014 for oral and contact toxicity, respectively. Neonicotinoids are primarily responsible for this increase, representing between 61 to nearly 99 percent of the total toxicity loading in 2014. The crops most responsible for the increase in AITL are corn and soybeans, with particularly large increases in relative soybean contributions to AITL between 2010 and 2014. Oral exposures are of potentially greater concern because of the relatively higher toxicity (low LD50s) and greater likelihood of exposure from residues in pollen, nectar, guttation water, and other environmental media. Using AITL to assess oral toxicity by class of pesticide, the neonicotinoids accounted for nearly 92 percent of total AITL from 1992 to 2014. Chlorpyrifos, the fifth most widely used insecticide during this time contributed just 1.4 percent of total AITL based on oral LD50s. Although we use some simplifying assumptions, our screening analysis demonstrates an increase in pesticide toxicity loading over the past 26 years, which potentially threatens the health of honey bees and other pollinators and may contribute to declines in beneficial insect populations as well as insectivorous birds and other insect consumers.

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Dataset Information

Influence of Asian and Western United states agricultural areas and fires on the atmospheric transport of pesticides in the Western United States.

Publications

Influence of Asian and Western United states agricultural areas and fires on the atmospheric transport of pesticides in the Western United States.

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