Organochlorine pesticides in agricultural soils and associated biota.

LUPI L; BEDMAR F; WUNDERLIN D.A.; MIGLIORANZA, K.

Environmental Earth Sciences

Springer Verlag

Año: 2016 vol. 75 p. 519 - 519

1866-6280

The behavior of organochlorine pesticides (OCPs), such as DDTs, endosulfans, HCHs,heptachlors, drins and chlordanes, have been evaluated in the agricultural watershedof Rio Quequén Grande involving different matrices. Soil profiles from field dedicated tosoybean cultures, associated terrestrial biota (earthworms, coleopteran larvae,collembolan and mites), stream water, suspended particle matter and surface sedimentwere sampled during pre-application pesticide period. Pesticide analyses wereperformed using a gas chromatography with electron capture detector. Soils samplesshowed a differential pesticide pattern along the profile. Control soils, settled 200 mtsfrom agricultural plots presented similar pesticide levels with higher variety ofcompounds, denoting the historical use of OCPs in the zone. However in agriculturalplots DDTs and endosulfans constituted the 90% of pesticides found with anenrichment of endosulfan sulfate with depth. The relative high p,p´-DDT levels insurface agricultural soil would be a consequence of impurities of this pesticide intechnical acaricide Dicofol widely used in the region; and it represent a fresh p,p´-DDTinput in the environment despite its forbidden use. Terrestrial biota, mainly mesofaunademonstrated high capacity to accumulate OCPs, being these organisms a goodoption for monitoring trace pesticides. Moreover the high OCPs levels found constitutea hazard to food web since these organisms are one of the first steps in the food chainand the biomagnification is a common process with these compounds. As a result ofrunoff and volatilization the occurrence of OCPs in aquatic environment was observed,reaching the river a load of 21.5 kg of pesticides daily delivered. As a whole, theseresults suggest the importance of using terrestrial biota for studying recalcitrantpesticides and a continual monitoring is strongly recommended as a first preventivemeasure to minimize environmental risks.