Organochlorine pesticides in soils of Mexico and the potential for soil-air exchange.

Fiona Wong, Henry A. Alegria, Terry F. Bidleman

Research output: Contribution to journalArticlepeer-review

Abstract

The spatial distribution of organochlorine pesticides (OCs) in soils and their potential for soil–air exchange was examined. The most prominent OCs were the DDTs (Geometric Mean, GM = 1.6 ng g −1 ), endosulfans (0.16 ng g −1 ), and toxaphenes (0.64 ng g −1 ). DDTs in soils of southern Mexico showed fresher signatures with higher F DDTe = p , p ′-DDT/( p , p ′-DDT + p , p ′-DDE) and more racemic o , p ′-DDT, while the signatures in the central and northern part of Mexico were more indicative of aged residues. Soil–air fugacity fractions showed that some soils are net recipients of DDTs from the atmosphere, while other soils are net sources. Toxaphene profiles in soils and air showed depletion of Parlar 39 and 42 which suggests that soil is the source to the atmosphere. Endosulfan was undergoing net deposition at most sites as it is a currently used pesticide. Other OCs showed wide variability in fugacity, suggesting a mix of net deposition and volatilization.

Original languageAmerican English
JournalDefault journal
StatePublished - Jan 1 2010

Keywords

  • Organochlorine pesticides
  • Mexico
  • Soil

Disciplines

  • Chemistry

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