Gas-Phase Concentrations of Current-Use Pesticides in Iowa

Abstract

Local and regional atmospheric transport of current-use pesticides is an important source of these compounds to nontarget plants and ecosystems. Current-use pesticides were measured at urban, rural, and suburban sites in eastern Iowa during 2000-2002. The most detected compounds were hexachlorobenzene and trifluralin, which were found in 89% and 78% of the samples, respectively. As expected, many pesticides showed a strong seasonal trend with the most detections and highest concentrations occurring during the spring and early summer. The average detected concentrations of five heavily used herbicides were 0.52 ng/ m3 for trifluralin, 4.6 ng/m3 for acetochlor, 2.3 ng/m3 for metolachlor, 1.1 ng/m3 for alachlor, 1.7 ng/m3 for pendimethalin, and 1.2 ng/m3 for atrazine. The most frequently detected insecticides were phorate and chlorpyrifos, which were found in 20% and 19% of the samples, respectively. The average phorate and chlorpyrifos concentrations were 25 ng/m3 and 1.0 ng/m3, respectively. The maximum phorate concentration, the highest measured for all pesticides, was 91.2 ng/m3. The most frequently detected current-use fungicides were chloroneb and etridiazole, which were found in 14% and 10% of the samples, respectively.

Gas-phase pesticide measurement using iodide ionization time-of-flight mass spectrometry

“…The resulting atmospheric concentrations vary, and these currentuse pesticides have been detected hundreds of meters to kilometers away from application sites in both gas and particle phases (Coscollà et al, 2010(Coscollà et al, , 2008LeNoir et al, 1999). Atrazine, trifluralin, and metolachlor have been observed near application areas in concentrations ranging from < 1 ng m −3 to as high as 61 µg m −3 , and in urban and remote locations that are far from sources with concentrations < 2 ng m −3 (Foreman et al, 2000;Majewski et al, 2014;Peck A.M, 2005;Bedos et al, 2006;Coscollà et al, 2010).…”

“…For detection of pesticides in the atmosphere, air samples are typically collected on solid-phase micro-extraction (SPME) fibers or other adsorbent materials with sampling times of 2 h-1 week (Bedos et al, 2006;Glotfelty et al, 1989;LeNoir et al, 1999;Majewski et al, 2014;Peck A.M, 2005). These solid adsorbents are analyzed by offline techniques, typically gas chromatography coupled to mass spectrometry (GC-MS) or electron capture detection (GC-ECD) (Bedos et al, 2006;Coscollà et al, 2010;Foreman et al, 2000;Glotfelty et al, 1989;LeNoir et al, 1999;Majewski et al, 2014;Peck A.M, 2005;Rice et al, 2002).…”

“…These solid adsorbents are analyzed by offline techniques, typically gas chromatography coupled to mass spectrometry (GC-MS) or electron capture detection (GC-ECD) (Bedos et al, 2006;Coscollà et al, 2010;Foreman et al, 2000;Glotfelty et al, 1989;LeNoir et al, 1999;Majewski et al, 2014;Peck A.M, 2005;Rice et al, 2002). These measurement approaches are adequate for offline quantitation of airborne pesticides, with detection limits for trifluralin ranging from 1.3 pg m −3 (GC-MS) to 0.4 µg m −3 (GC-ECD) with sample collection times of 24 and 2 h, respectively (Peck A.M, 2005;Bedos et al, 2006). These techniques have proven successful in quantifying atmospheric pesticide concentrations, although offline analysis introduces steps that can alter a compound's structure and reduce sampling efficiency (Coscollà et al, 2010;LeNoir et al, 1999;Peck A.M, 2005;Rice et al, 2002), and it is inadequate for rapid ambient measurement.…”

“…While the ecological implications of these observations have been the focus of much research, little work has focused on their atmospheric chemistry, despite the fact that many of these pesticides are transported through the atmosphere (Bedos et al, 2006;Coscollà et al, 2008;LeNoir et al, 1999;Majewski et al, 2014;Peck A.M, 2005;Rice et al, 2002;Sauret et al, 2000;Tabor, 1965;White et al, 2006). The chemical fate of compounds in the atmosphere -including oxidation, gas-particle partitioning, and surface deposition -ultimately controls their chemical identities and concentrations, and thus their impact on ecosystems and human health.…”

Phenoxyacid Herbicides in Stormwater Retention Ponds: Urban Inputs

“…Numerous other surface waters worldwide impacted by agricultural lands have reporting 2,4-D, mecoprop, or dichlorprop [7][8][9][10][11][12][13][14]. Pesticides can move in the environment by atmospheric transport, wet deposition, or be transported by surface rain-generated runoff from soils or surfaces [2,5,[14][15][16][17][18]. As phenoxyacid herbicides have high water solubility ranging from 44 mg·L -1 to 4500 mg·L -1 ( Table 1) surface water runoff is the major transport pathway.…”