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C Kempenaar

Publications and source records attributed to C Kempenaar.

3 recordsLinked to original sources

Contribution of agricultural and non-agricultural use of pesticides to the environmental impact on aquatic life in regional surface water systems.

By means of a modelling tool an analysis was made of the local variation in the use of pesticides in the province of Utrecht in The Netherlands, and the potential environmental impact of pesticide emissions on the aquatic ecosystems. The aim of this study was to identify and quantify the major sources of pesticide use and environmental impact, taking the regional variation of pesticide use into account. The analysis was targeted at different levels: detailed (individual active substances, individual agricultural crops, civil land-use types, hydrological catchment basins) and globally covering agricultural use, non-agricultural use (some civil sectors) and recreational shipping. The results can be used for the (re)design of environmental monitoring programmes of pesticides in surface waters and for the development of region based policies towards sustainable pesticide use. The analysis tool that was developed is considered to be applicable for other regions as well.

Agriculture↗

Effects of vapours of chlorpropham and ethofumesate on wild plant species.

Effects of vapours of two herbicides on plantlets of fourteen wild higher plant species and two bryophytes were screened in fumigation experiments using foliar injury, chlorophyll fluorescence and growth as response parameters. After vaporisation of the herbicides for 48 h, concentrations in the chambers reached 77 micrograms m-3 in the chlorpropham treatments and 184 ng m-3 in the ethofumesate treatments. Despite the higher concentrations of the volatile chlorpropham (vapour pressure, VP: 1.3 mP), plants showed no foliar injury, but vapours of this herbicide caused leaf crinkling in the agriophyte Agrostemma githago. The less volatile ethofumesate (VP: 0.56 mP) caused foliar injury in all higher species, with lowest no observed effect concentrations (NOECs) of 75 ng m-3. Chlorpropham affected growth only in Agrostemma, while ethofumesate reduced growth in one third of the higher plant species. Chlorophyll fluorescence proved to be a less suitable response parameter compared to foliar injury and growth. No adverse effects were observed in mosses, probably due to the slow growth and hence small doses of herbicides taken up. The extent of foliar injury due to ethofumesate showed a weak positive relationship to relative growth rates and specific leaf area in the tested higher plant species.

Benzofurans↗