TY - JOUR
T1 - Toxicology and fate of Pestanal® and commercial propetamphos formulations in river and estuarine sediment
AU - García-Ortega, Susana
AU - Holliman, Peter J.
AU - Jones, Davey L.
PY - 2006/8/1
Y1 - 2006/8/1
N2 - To quantify the impact of organophosphate pesticides on aquatic ecosystems requires a mechanistic understanding of their behaviour in a range of environmental matrices. The objective of this study was to compare the sorption/desorption, biodegradation and toxic effects of the Pestanal® grade and commercial formulation (Ectomort Centenary) of the organophosphate insecticide propetamphos in river and estuarine sediments. For both formulations, the sorption of propetamphos onto sediment was initially very rapid followed by a slower sorption phase. Similarly, the initial rate of desorption was rapid, followed by a much slower rate. In both sorption and desorption experiments, the level of sorbed propetamphos was considerably higher for the commercial formulation of propetamphos (Kd = 7-11) than for the Pestanal® grade (Kd = 4-10). The rate of propetamphos biodegradation was sediment dependent but was most rapid where microbial activity and nutrients were the highest and sorption was the lowest. Propetamphos was more rapidly degraded in sediments under aerobic (t1 / 2 = 15 d) compared to anaerobic conditions (t1 / 2 = 19 d). However, no significant difference in the biodegradation rates of the Pestanal® grade and commercial formulations of propetamphos were observed. The toxic effect of propetamphos on sediment microbial communities was significantly greater for the commercial formulation than for the Pestanal® grade of propetamphos based on EC50 (21 versus 236 μg g- 1) and EC10 values (0.3 versus 54 μg g- 1). In conclusion, our results highlight the importance of using commercial pesticide formulations when carrying out ecotoxicological testing.
AB - To quantify the impact of organophosphate pesticides on aquatic ecosystems requires a mechanistic understanding of their behaviour in a range of environmental matrices. The objective of this study was to compare the sorption/desorption, biodegradation and toxic effects of the Pestanal® grade and commercial formulation (Ectomort Centenary) of the organophosphate insecticide propetamphos in river and estuarine sediments. For both formulations, the sorption of propetamphos onto sediment was initially very rapid followed by a slower sorption phase. Similarly, the initial rate of desorption was rapid, followed by a much slower rate. In both sorption and desorption experiments, the level of sorbed propetamphos was considerably higher for the commercial formulation of propetamphos (Kd = 7-11) than for the Pestanal® grade (Kd = 4-10). The rate of propetamphos biodegradation was sediment dependent but was most rapid where microbial activity and nutrients were the highest and sorption was the lowest. Propetamphos was more rapidly degraded in sediments under aerobic (t1 / 2 = 15 d) compared to anaerobic conditions (t1 / 2 = 19 d). However, no significant difference in the biodegradation rates of the Pestanal® grade and commercial formulations of propetamphos were observed. The toxic effect of propetamphos on sediment microbial communities was significantly greater for the commercial formulation than for the Pestanal® grade of propetamphos based on EC50 (21 versus 236 μg g- 1) and EC10 values (0.3 versus 54 μg g- 1). In conclusion, our results highlight the importance of using commercial pesticide formulations when carrying out ecotoxicological testing.
KW - Bioavailability
KW - Fate
KW - Pesticide formulation
KW - Safrotin
KW - Sheep dip
KW - Toxicology
UR - http://www.scopus.com/inward/record.url?scp=33745834793&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2005.08.008
DO - 10.1016/j.scitotenv.2005.08.008
M3 - Article
C2 - 16171848
AN - SCOPUS:33745834793
VL - 366
SP - 826
EP - 836
JO - Science of the Total Environment
JF - Science of the Total Environment
SN - 0048-9697
IS - 2-3
ER -