Vapor-Phase and Particulate-Associated Pesticides and PCB Concentrations in Eastern North Dakota Air Samples

Vapor-phase and suspended particulate (<50 µm) samples were collected on polyurethane foam (PUF) and quartz fiber filters in rural North Dakota to determine the air concentrations of pesticides in an area where agriculture is a primary source of semivolatile pollutants. Samples were collected at two sites from 1992 to 1994 that were at least 0.4 km from the nearest farmed fields and known application of pesticides, and analyzed for 22 different organochlorine, triazine, and acid herbicide pesticides. Fourteen pesticides were found above the detection limits (typically <1 pg/m³). The most prevalent species found in the PUF extracts were endosulfan I and II (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin 3-oxide, exo- and endo-isomers, respectively) at <1 to 2200 pg/m³ and <1 to 500 pg/m³, respectively, trifluralin (2,6-dinitro-N,N-dipropyl-4-trifluoromethylaniline) at 3 to 700 pg/m³, and 4,4′-DDE (1,1-dichloro-2,2-bis-(4-(chlorophenyl)ethylene) at 6 to 200 pg/m³. The most prevalent pesticides in filter extracts included carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate) at <0.5 to 470 pg/m³, atrazine (2-chloro-4-ethylamino-6-isopropylamino-l,3,5-triazine) at <0.4 to 46 pg/m³, 2,4-D ((2,4-dichlorophenoxy)acetic acid) at <0.4 to 1800 pg/m³, and chlorothalonil (2,4,5,6-tetrachloro-1,3-benzenedicarbonitrile) at <13 to 7800 pg/m³. Concentrations of polychlorinated biphenyl (PCB) congeners were much lower (<50 pg/m³ in all cases) than many of the pesticides. These results demonstrate that pesticides are among the most prevalent chlorinated semivolatile pollutants present in rural North Dakota, that significant transport of pesticides occurs both in the vapor-phase and on suspended particulate matter, and that blown soil may be a significant mechanism for introducing pesticides into surface and ground waters.