Organochlorine pesticide contents of tributaries into Blanca Bay,Argentina

Thirteen 1-L replicate water samples from streams emptying into Blanca Bay, Argentina, were taken to study the environmental quality of the surface waters. Out of tests for eleven chlorinated pesticides, five were detected in all the sampling places as both dissolved and adsorbed species: alpha-HCH, gamma-HCH (lindane), heptachlor, delta-HCH, and aldrin. The concentrations were in the following ranges: alpha-HCH = 3 to 68 ng L^?1 and 9 to 239 ng g^?1, lindane = 2 to 42 ng L^?1 and 10 to 542 ng g^?1, heptachlor = 5 to 32 ng L^?1 and 9 to 390 ng g^?1, delta-HCH = 1 to 10 ng L^?1 and n.d. to 87 ng g^?1, and aldrin = 1 to 7 ng L^?1 and n.d. to 33 ng g^?1 for filtered water and suspended matter samples, respectively. Heptachlor epoxide, dieldrin, o-p′ DDD, and p-p′ DDT were found to be present in solution at only one sampling site whereas p-p′ DDD and o-p′DDT were not detected. The analyses revealed a non-uniform distribution of these compounds over the studied area. The higher concentrations of organochlorines were detected downstream urban areas.