Chiral Pesticides in Soils of the Fraser Valley, British Columbia

Abstract

Chiral organochlorine pesticides were examined in soils collected in 1989 from six farms in the Fraser Valley, British Columbia. Concentrations of pesticide residues were 1-2 orders of magnitude higher in muck soils (27-56% organic matter) than in silt loams (3-7% organic matter). Enantiomeric composition of R-hexachlorocyclohexane residues in muck soils indicated preferential breakdown of the (-) enantiomer, whereas R-hexachlorocyclohexane in the silt loams was racemic. Five of the soils contained racemic o,p′-DDT, but the (+) enantiomer was selectively lost in one silt loam soil. No enantioselective breakdown of cis-or trans-chlordane was found in any of the soils, but nonracemic traces of oxychlordane were found in one silt loam and three muck soils. Enantiomeric composition of heptachlor and heptachlor exo-epoxide in muck soils indicated loss of (-)-heptachlor and production of (+)-heptachlor exo-epoxide, suggesting that the metabolism of these two compounds in soil may be more complex than a simple conversion of heptachlor to heptachlor exo-epoxide.

DDT and its metabolites alter gene expression in human uterine cell lines through estrogen receptor-independent mechanisms.

“…The concentration of ICI 182,780 used inhibits E 2 -stimulated gene expression (66). In our results we have shown the data from treatments using 10-50 µM DDT and its metabolites, which gave significant activity and are environmentally relevant concentrations (59)(60)(61). Cells were then harvested and luciferase activity was measured using 30 µL of cell extract and 100 µL of luciferase assay substrate (Promega, Madison, WI) in a monolight 2010 luminometer.…”

“…Here, we show that the persistent pesticide DDT, along with its metabolites, activates AP-1-mediated gene expression at environmentally relevant concentrations (i.e., 10-50 µM) (59)(60)(61). Using a novel, stablereporter gene-cell system developed in our laboratory that includes the use of estrogenresponsive and estrogen-unresponsive cell variants, we show the activation is independent of classic ER-mediated mechanisms.…”

Levels and Chiral Signatures of Organochlorine Pesticides in Urban Soils of Yinchuan, China

“…Samples (2 lL) were injected splitless (split opened after 1.5 min) at 90°C, held for 1 min, 15°C/ min to 140°C, 2°C/min to 210°C, held for 5 min, 20°C/min to 240°C, held for 10 min. The elution orders for a-HCH and o,p 0 -DDT were determined from previously published work using the same column type (Fakconer et al 1997;Ridal 1997;Wiberg et al 2001).…”

“…Until now, there have been numerous studies of chiral OCPs in agricultural soils (Wiberg et al 2001;Li et al 2006;Fakconer et al 1997;Leone et al 2001), but there are very few reports in urban soils. Because of intense influence of industry, trade, traffic, human activity and so on, organic pollutants in urban soil not only have various species but high residual levels, in addition, the urban population is crowded, so the citizens health would be faced with potential threat.…”

Phytoestrogen signaling and symbiotic gene activation are disrupted by endocrine-disrupting chemicals.

“…Endocrinedisrupting pesticides routinely sprayed on agricultural crops are present in high concentrations (Aigner et al 1998;Falconer et al 1997). Quantities of DDT and other EDCs measured and reported by various U. S. government agencies are shown in Table 2.…”