House dust levels of selected insecticides and a herbicide measured by the EL and LWW samplers and comparisons to hand rinses and urine metabolites

Abstract

During the Minnesota Children's Pesticide Exposure Study ( MNCPES ) , comparisons were made between the insecticide / herbicide loadings obtained with two household dust / insecticide or herbicide samplers: the Edwards and Lioy ( EL ) press sampler ( used for dust collection from carpets or other surfaces ) and the Lioy, Wainman and Weisel ( LWW ) surface wipe sampler. The results were compared with hand rinse levels, and urine metabolite levels obtained from 102 children ( ages 3 ± 13 ) . All measurements were made during a 1 -week sampling period, and information was obtained on household pesticide use and each child's activities. Of the homes, < 5% had recent spot uses of a pesticide but none had recent general applications. The analyses focused primarily on atrazine ( a herbicide ) , and malathion, diazinon, and chlorpyrifos ( insecticides ) . Metabolites were measured for atrazine, malathion and chlorpyrifos. The atrazine levels obtained using the EL indicate that this compound was transported into the home by an unquantified transport mechanism ( e.g. tracking of soil ) . Two malathion hand rinse values exceeded > 170 ng / cm 2 , suggesting that since indoor surface levels were low, these children had other sources of exposure. Atrazine, chlorpyrifos and malathion were detectable in > 30% of the homes by the EL, LWW or hand rinse. Only chlorpyrifos had detectable levels in !50% of the samples for all types, i.e. compound or metabolite, which is consistent with it being a common household pesticide. The median ( and maximum ) chlorpyrifos levels for the EL surface, EL carpet, LWW surface ( two rooms ) , hand rinse, and urine metabolites were: 0.07 ( 32.6 ) ng / cm 2 ; 0.07 ( 44.5 ) ng / cm 2 ; 0.34 ( 3.64 ) ng / cm 2 ; 0.42 ( 14.4 ) ng / cm 2 ; 0.03 ( 2.14 ) ng / hand and 6.9 ( 59.0 ) g / g, respectively. A strong correlation was found for chlorpyrifos between the EL surface and carpet samples. Chlorpyrifos levels detected by LWW had a different distribution and concentration range than the EL, indicating that it collected more than the surface dislodgeable insecticide. EL was directly comparable to the hand rinse or urine levels, but only the LWW had a weak correlation with hand rinse levels, suggesting that the children had other sources of chlorpyrifos exposure. Thus, mechanistic exposure studies are needed to more accurately establish exposure ± dose relationships in residential settings.

Analysis of aggregate exposure to chlorpyrifos in the NHEXAS-Maryland investigation.

“…The chlorpyrifos detection frequency and concentrations in our study for indoor air, carpet dust, and soil were in the same range as those from NHEXAS-Arizona (15) and the Minnesota Children's Pesticide Exposure Study (MNCPES) (16). Chlorpyrifos concentrations in settled dust and indoor air following indoor broadcast and other application methods may be 10-fold greater than the corresponding concentrations in the present study (17)(18)(19)).…”

“…Additional data are needed to evaluate the spatial variability of chlorpyrifos in settled dust indoors including carpet and hard surfaces in the household. However, data from the MNCPES indicate that chlorpyrifos loading (nanograms per square centimeter) on carpet and smooth indoors surface may be similar (16); thus, we did not quantify a potentially significant pathway of dermal and incidental ingestion exposure. We did not detect chlorpyrifos residues in duplicate beverage and drinking water samples (9,22); thus, omitting these media from the assessment had no impact on estimates of aggregate exposure.…”

Quantitative analysis of children's microactivity patterns: The Minnesota Children's Pesticide Exposure Study

“…The metabolites were atrazine mercapturate, monocarboxylic acid, and 3,5,6 trichloro -2 -pyridinol ( TCPY ). Report of the relationship between pesticides found in hand rinses and dust samples, and urinary metabolites was reported by Lioy et al ( 2000 ).…”

“…Hand rinse and dust samples were analyzed for chlorpyrifos, malathion, diazinon, and atrazine at EOHSI (Edwards and Lioy, 1999;Lioy et al, 2000 ). Pesticide metabolites were analyzed in urine samples for three pesticides: atrazine, malathion, and chlorpyrifos, by the CDC ( Hsu et al, 1988;Adgate et al, 2001).…”

Seasonal pesticide use in a rural community on the US/Mexico border

“…Communities adjacent to agricultural fields have the potential for exposure to pesticides greater than for the general population due to drift and track-in from farm fields and orchards (Simcox et al, 1995;Fenske et al, 2000;Lu et al, 2000;Shalat et al, 2002). The Minnesota National Human Exposure Assessment Survey (NHEXAS) Children's Pesticide Exposure Study evaluated residential use patterns of pesticides in an area of the country with a fairly narrow period of insect activity and a single agricultural season (Lioy et al, 2000), while the studies from Fenske's group in Washington (Simcox et al, 1995;Fenske et al, 2000;Lu et al, 2000) dealt specifically with agricultural pesticides among agricultural families. This study evaluates multiple sources of pesticide exposure with a group of families with young children.…”