The bioavailability of chemicals is increasingly recognized as an important research area for scientific investigation of environmental risk assessment and contaminant mitigation. Despite this, most of the assessments are based on the total extractable chemical concentration alone, neglecting bioavailable fraction. The freely dissolved concentration of hydrophobic organic chemicals is considered the driving force behind their chemical bioavailability in the environmental matrices. The present study aims to quantify the chemical bioavailability of 5 pesticides (cyprodinil, cyproconazole, atrazine, mandipropamid, and isoproturon) in soil. The freely dissolved concentration and bioaccessibility (the fraction of contaminant which can become available over a period of time) of pesticides were assessed using passive samplers (Polyurethane and Silicone rubber) and mild solvent extraction through Tenax resins. The film water partition coefficient (Kfilm-water) was calculated for all the pesticides and the results indicate that the adsorption of pesticides follows a first-order model. The Cfree values derived using passive samplers and F24 h (single time interval desorption) from bioaccessibility assays ranged widely for the extracted pesticides. The results of the study demonstrate the feasibility of using chemical availability-based methods to derive pesticide persistence data over a substantially reduced time scale than conventional methods and in turn may facilitate the inclusion of bioavailability within the risk assessment framework.

To evaluate the persistence of pesticides in soil based on their biochemical availability

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.