Abstract
This study investigated the spatiotemporal variations in the occurrence of polychlorinated biphenyl (PCB) congeners both in soil and ambient air. Soil and air samples were taken simultaneously for three seasons (spring, summer, and autumn) from industrial, urban, and semi-rural areas in Bursa, Turkey. Light and medium PCB homologous groups were dominant in all samples. Total PCB (∑25 PCBs) concentrations in the air were 0.12 ± 0.13, 0.06 ± 0.07, and 0.08 ± 0.11 ng/m3 and in soil were 4.01.±2.38, 5.44 ± 3.14, and 3.66 ± 1.56 ng/g DM for summer, spring, and winter, respectively. Moreover, the samples were taken from different sites to determine the spatial fluctuations. The average ∑25 PCBs in the air were 0.22 ± 0.06, 0.03 ± 0.01, and 0.03 ± 0.02 ng/m3 and in soil were 7.08 ± 1.84, 2.98 ± 0.52, and 3.06 ± 0.70 ng/g DM for industrial, urban and semi-rural sites, respectively. Maximum air and soil PCB concentrations were determined in the industrial region. The spatiotemporal changes in the fugacity fractions and net fluxes were also examined. The direction of the PCB movement was assessed and the results indicated that soil was a diffusive source for PCBs. The calculated fugacity fractions (ff) were above 0.7 while average flux values were calculated as 0.65 ± 0.33 ng/m2-d, 0.21 ± 0.19 ng/m2-d, and 0.26 ± 0.27 ng/m2-day for industrial, urban and semi-rural regions, respectively.
Acknowledgements
This study was supported by the Scientific and Technological Research Council of Turkey (TÜBİTAK) project number 114Y577. We would like to thank Burak ÇALIŞKAN and Berfu BÜKLER for their selfless laboratory work and we thank Ahmet Egemen SAKIN for his effort during PCB analysis.
Disclosure statement
No potential competing interest was reported by the authors.