Seasonal variations of organochlorine pesticides (OCPs) in air samplesduring day and night periods in Bursa, Turkey

Özet

The goal of the present work was to investigate the seasonal variations of organochlorine pesticide (OCP) levelsin Bursa, Turkey. The sampling site was a campus and considered as a semi-rural site. Atmospheric OCPs in theparticulate and gas phases were measured separately during night and day time periods. The average of the totalconcentrations was determined as 599 ± 194 pg/m3and on average 65% of the total OCP concentration was inthe gas phase. Measured OCP level were comparatively greater in the warmer months of June, July, and August.The temperature dependence of gas-phase atmospheric concentrations of OCPs was examined using the Clausius-Clapeyron approach. The temperature effect was statistically significant (p < 0.05) on the Alpha, Gamma- andDelta-HCH, and Methoxychlor concentrations for night samples, yet it was not statistically significant for the daysamples. The maximum annual average gas phase OCP concentration was measured for Beta-HCH species as176 pg/m3. The maximum value was 67 pg/m3in the particle phase and it belonged to Beta-Endosulfan. Thepartitioning of OCPs between particle and gas phases was studied. They were compared to the PoL(supercooledvapor pressure) and KOA (octanol/air partition coefficient) models. OCP concentrations measured during theday and night-time periods were found to be close to each other. The absence of a significant difference in night-day concentrations has shown that the impact of local sources were similar. Inhalation carcinogenic risks ofOCPs were calculated and they indicated low cancer risk.