Accumulation of organochlorine insecticide residues in food chain of fish at Khlong 7, Rangsit agricultural area, Pathum Thani province

Abstract

Fifty species of fish were collected during June 2004 to May 2005 at Khlong 7, Rangsit, Pathum Thani Province. Forty-two species were analyzed for accumulation and biomagnification of organochlorine (OC) insecticide residues. The compounds were [Sigma]BHC (alpha, beta, gamma and delta-BHC) [Sigma]Heptachlor (heptachlor and heptachlor epoxide), [Sigma]Endrin (endrin and endrin aldehyde), [Sigma]DDT (p,p'-DDE, p,p'-DDD and p,p'-DDT), [Sigma]Endosulfan (endosulfan I, endosulfan II and endosulfan sulfate), aldrin, dieldrin and methoxychlor. The major compounds detected in the fillets were [Sigma]DDT (<0.04-48.26 ppb) and [Sigma]Endosulfan (0.44-49.18 ppb), followed by [Sigma]Heptachlor (<0.02-26.51 ppb), [Sigma]BHC (<0.05-20.76 ppb), [Sigma]Endrin (<0.02-14.73 ppb), Dieldrin (<0.03-13.22 ppb), Methoxychlor (<0.02-13.18 ppb) and Aldrin (<0.02-9.88 ppb), respectively. [Sigma]DDT and [Sigma]Endosulfan concentrations in fillets increased with fish total bodylength. Biomagnification factor (BMF) values were 1.61-2.27 for [Sigma]DDT and 4.19-8.80 for [Sigma]Endosulfan from primary consumers, herbivorous and detritivorous fish to the top predatory fish. Based on the Thai and FAO/WHO maximum residue limits (MRLs), all OC residue concentrations were beloow the levels that have been suggested to cause the adverse effects on human and wildlife.