DBPapers

ECOTOXICOLOGICAL ASSESSMENT OF ORGANOPHOSPHORUS PESTICIDES AND THEIR OZONATION BYPRODUCTS

AUTHOR/S: M. E. AYDIN, S. OZCAN, F. BEDUK
Sunday 1 August 2010 by Libadmin2010

10th International Multidisciplinary Scientific GeoConference - SGEM2010, www.sgem.org, SGEM2010 Conference Proceedings/ ISBN 10: 954-91818-1-2, June 20-26, 2010, Vol. 2, 545-552 pp

ABSTRACT

Partial decomposition of an organic compound can lead to the formation of products,
which are more toxic than the parent compound. Organophosphorus pesticides (OPPs)
are transformed into metabolites of lesser molecular weight in ozone application
Toxicity assessments of both organophosphorus pesticides (OPPs) and their ozonation
byproducts (OPPs-oxons) are necessary for safety consideration of ozonation treatment.
The widespread use of OPPs, such as chlorpyrifos and diazinon for pest control in urban
and rural environments poses a risk of contamination to aquatic environments. The
objective of this study is to investigate the acute toxicity of OPPs and their main
ozonation byproducts; oxon derivatives by using Daphnia magna and Vibrio fischeri.
For the trophic level, the crustacea Daphnia magna was selected as representative for
the consumers while representative for the decomposer was Vibrio fischeri. By
comparing the results of the toxicological responses of test organisms, Daphnia magnatest organism is much more sensitive to OPPs and OPPs-oxons than Vibrio fischeri.
According to Daphnia magna test results EC50 values are 0.37 μg L-1 and 0.78 μg L-1
for chlorpyrifos and diazinon respectively while these values are 23190 μg L-1 and
15340 μg L-1 for Vibrio fischeri. Chlorpyrifosoxon is five times more toxic than its parental form on Vibrio fischeri.

Keywords: organophosphorus pesticides, ozonation, byproducts, toxicity