Contamination of rural surface and ground water by endosulfan in farming areas of the Western Cape, South Africa.

Mohamed A Dalvie,Eugene Cairncross,Abdullah Solomon,Leslie London

doi:10.1186/1476-069x-2-1

Mohamed A Dalvie, Eugene Cairncross + Show 2 more

Open Access

https://doi.org/10.1186/1476-069x-2-1

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Abstract

BackgroundIn South Africa there is little data on environmental pollution of rural water sources by agrochemicals.MethodsThis study investigated pesticide contamination of ground and surface water in three intensive agricultural areas in the Western Cape: the Hex River Valley, Grabouw and Piketberg. Monitoring for endosulfan and chlorpyrifos at low levels was conducted as well as screening for other pesticides.ResultsThe quantification limit for endosulfan was 0.1 μg/L. Endosulfan was found to be widespread in ground water, surface water and drinking water. The contamination was mostly at low levels, but regularly exceeded the European Drinking Water Standard of 0.1 μg/L. The two most contaminated sites were a sub-surface drain in the Hex River Valley and a dam in Grabouw, with 0.83 ± 1.0 μg/L (n = 21) and 3.16 ± 3.5 μg/L (n = 13) average endosulfan levels respectively. Other pesticides including chlorpyrifos, azinphos-methyl, fenarimol, iprodione, deltamethrin, penconazole and prothiofos were detected. Endosulfan was most frequently detected in Grabouw (69%) followed by Hex River (46%) and Piketberg (39%). Detections were more frequent in surface water (47%) than in groundwater (32%) and coincided with irrigation, and to a lesser extent, to spraying and trigger rains. Total dietary endosulfan intake calculated from levels found in drinking water did not exceed the Joint WHO/FAO Meeting on Pesticide Residues (JMPR) criteria.ConclusionThe study has shown the need for monitoring of pesticide contamination in surface and groundwater, and the development of drinking water quality standards for specific pesticides in South Africa.

Highlights

In South Africa there is little data on environmental pollution of rural water sources by agrochemicals
Endosulfan data are quoted as the sum of isomers I and II plus endosulfan sulphate, unless otherwise specified
Endosulfan concentrations are expressed as μg/L, because of the different molecular weights of the isomers and endosulfan sulphate

Summary

Introduction

In South Africa there is little data on environmental pollution of rural water sources by agrochemicals. While concern for water pollution by pesticides has mobilised considerable resources in other countries, in the developed world, little research has been undertaken in South Africa [11]. No contamination was found in a study undertaken in the Hex River Valley, [17] probably due to the use of monitoring equipment with high detection limits. The aim of this study was to investigate pesticide pollution of water supplies in agricultural areas of the Western Cape, South Africa. The objectives were to identify rural water sources in the Western Cape at high risk of agrochemical contamination, to identify and quantify the presence of agrochemicals at these selected sites and to explore the implications for human health

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