Assessing dicofol concentrations in air: Retrospective analysis of global atmospheric passive sampling network samples from agricultural sites in India

Abstract

Risk assessment of the pesticide dicofol is hampered by the lack of information about its levels, which is largely attributed to its instability during instrumental analysis. In this study, dicofol was assessed in air through a novel approach by tracking the ratio of the two isomers (p,p′ and o,p′) of its stable degradation product dichlorobenzophenone (DCBP), while considering other potential precursors. Twenty-three samples were collected using polyurethane foam (PUF) disk passive air samplers deployed across agricultural, urban, and rural sites throughout India in 2006 under the Global Atmospheric Passive Sampling Network. The retrospective analysis focused on agricultural sites in the Indo-Gangentic Plain region where dicofol is used. Yearly mean concentrations for p,p′- and o,p′-DCBP (breakdown products of p,p′- and o,p′-dicofol, respectively) were 1.1 and 0.29 ng/m3, respectively, for agricultural sites, 1.6 and 0.31 ng/m3, respectively, at an urban site, and 0.36 and 0.039 ng/m3, respectively, at a background site.