Distribution of organochlorine pesticides in surface water and sediments in Lake Volvi (northern Greece)

Abstract

The objective of the study was to monitor the occurrence of a wide range of OCPs and sediments of the Lake Volvi in northern Greece and to determine their temporal and spatial variations. The samples have been collected seasonally for a period of one year. Solid-phase extraction followed by gas-chromatographic techniques with electron-capture detection was used for the determination of the compounds. The compounds detected were HCB, lindane, β-HCH, heptachlor, methoxychlor, α-endosulphan, and 2,4-DDT, while α-HCH, aldrin, heptachlorperoxide, 4,4-DDE, dieldrin, endrin, 4,4-DDD, β-endosulphan, and 4,4-DDT could not be observed (detection limits ≥1 ng L⁻¹). The frequencies of the compounds detected in the samples varied between 10 and 83% and between 6 and 88% in the water and sediment samples, respectively. Among the 16 OCPs pesticides monitored, only 2,4-DDT and methoxychlor were found in detectable concentrations in sediments throughout the whole sampling period. The water–sediment distribution pattern of the detected compounds reflects the great capacity of the lake sediments to adsorb and accumulate such compounds.

Keywords:

• Distribution
• Monitoring
• Organochlorine pesticides
• Water and sediments
• Lake