|
(M/EH073) Biodegradation of propetamphos in three contrasting estuarine sediments: Impact of aerobic and anaerobic conditions. Garcia-Ortega, Susana1, Jones, Davy1, Holliman, Peter1, 1 ABSTRACT- Propetamphos (1-methylethyl (E)-3-{{(ethylamino)methoxyphosphinothioyl}oxy}-2-+butenoate), is an organophosphate pesticide that is used primarily in sheep dips. Although, organophosphate pesticides were once temporarily banned by the UK Ministry of Agriculture, Fisheries an Food (MAFF) because of a possible link with health human problems, their use is still permitted so long as additional precautions are taken to minimise direct contac with dip concentrate. This particular organic pesticide (propetamphos) has been detected in some rivers in the UK (>0.1 Key words: pesticide, organophosphate, biodegradation, sediments |
g L-1), however, little is known about its environmental fate. It is known that invertebrates are extremely sensitive to propetamphos at very low concentrations and below those values reported for UK rivers. The bioavailability of a xenobiotic depends on chemical interactions under different conditions. The present study was designed to establish the degradation kinetics of propetamphos under aerobic and anaerobic conditions in three contrasting estuarine sediments of the river Conwy, North Wales. In the present paper the influence of organic carbon content, microbial activity, and sediment characteristics on the degradation kinetics of propetamphos in superficial sediments are described alongside estimate of total volatilization. The kinetics and the basic statistics used to characterise propetamphos degradation are discussed.