Pesticide residues on the external surfaces of field crop sprayers: occupational exposure

There is a general perception, amongst farmers and researchers, that post-application residues on the external surfaces of sprayers are negligible compared with residues remaining on the internal surfaces, although there have been few attempts to verify this assumption. The aim of this study was to investigate, using cotton glove sampling, operator exposure resulting from three typical operations: entering and working in the cab, general handling of the sprayer and maintenance practices. Samples were analysed for azoxystrobin, carbendazim, chlorothalonil, cyanazine, cypermethrin, epoxiconazole, flusilazole, isoproturon, kresoxim-methyl, metazachlor, pendimethalin, pirimicarb and tebuconazole. Isoproturon, pendimethalin, chlorothalonil and carbendazim were detected >1 mg per glove pair on the cotton gloves, but on the whole there was variability in residue levels between and within compounds. Comparison of results with occupational exposure limits indicated that residues were such that they may not necessarily be considered insignificant. It may therefore be prudent to develop more efficient methods for the external decontamination of sprayers and/or raise awareness of the findings.