The Impact of Pesticides - Academy Publish

Current Pesticide Loads in Dutch Surface WatersMartina G. Vijver, Geert R. De SnooKey words: measurements, pesticides, surface water, MPC exceedanceINTRODUCTIONThe Netherlands is one of the world’s foremost agricultural producers, with anestimated 22,900 km 2 of the total land mass of around 33,700 km 2 devoted toagriculture or horticulture. In international comparisons of the economicsignificance (export value) of the agricultural sector the Netherlands inevitablyranks in the top three (with the USA heading the list). Land use is consequentlyhighly intensive: in terms of output per hectare or head of livestock the Netherlandsranks among Europe’s leaders. To achieve such high outputs a vast range ofagricultural chemicals are used, including fertilisers, veterinary drugs, cropprotection agents and other biocides.At the same time the Netherlands is a country with a multitude of watercourses,characterised as it is as by its location in the delta of several major rivers like theRhine and Meuse that flow out to sea via numerous channels. Equally characteristicare the countless man-made ditches, canals and lakes created for the purposes ofwater management, quite a challenge as around half the country is below sea level.It is no wonder, then, that the Netherlands has a long tradition of managing waterquantity and water quality.The widespread and heavy use of agricultural chemicals begs many questions, oneof which is: to what extent do these practices pose a potential threat to theenvironment? Unsurprisingly, then, within both Europe and the Netherlands inrecent decades policies have been introduced that seek to reduce dependency onpesticides, reduce pesticide usage and reduce emissions of these chemicals to theenvironment. Market approval of pesticides is tightly regulated and application ofsuch compounds is also subject to stringent regulation, in agricultural settings aswell as elsewhere. Farmers must have a spraying diploma, equipment must beapproved, and agricultural plots must be separated from their surroundings by a(narrow) buffer zone.Thanks to these policies there have been major improvements in surface waterquality in Europe and specifically the Netherlands. The question, though, is whetherthese efforts have been sufficient. Pesticides are still frequently encountered in highconcentrations in surface waters (Vijver et al. 2008), at levels often exceeding waterquality standards, with potential damage to the aquatic ecosystem as a result. Thisimplies a substantial challenge for policymakers, and it is therefore of keyimportance to know exactly where and when what pesticides occur in Dutch surfacewaters and to what extent this leads to statutory limits being exceeded.AcademyPublish.org - The Impact of Pesticides191