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

Abstract

The goal of the present work was to investigate the seasonal variations of organochlorine pesticide (OCP) levels in Bursa, Turkey. The sampling site was a campus and considered as a semi-rural site. Atmospheric OCPs in the particulate and gas phases were measured separately during night and day time periods. The average of the total concentrations was determined as 599 +/- 194 pg/m(3) and on average 65% of the total OCP concentration was in the 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, Gammaand Delta-HCH, and Methoxychlor concentrations for night samples, yet it was not statistically significant for the day samples. The maximum annual average gas phase OCP concentration was measured for Beta-HCH species as 176 pg/m(3). The maximum value was 67 pg/m(3) in the particle phase and it belonged to Beta-Endosulfan. The partitioning of OCPs between particle and gas phases was studied. They were compared to the P-L(o) (supercooled vapor pressure) and KOA (octanol/air partition coefficient) models. OCP concentrations measured during the day 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 of OCPs were calculated and they indicated low cancer risk.