Environ. Sci. Technol. 2010, 44, 3035–3040
Spatial and Seasonal Distribution of Polychlorinated Biphenyls (PCBs) in the Vicinity of an Iron and Steel Making Plant SONG-YEE BAEK,† SUNG-DEUK CHOI,‡ HYOKEUN PARK,† JUNG-HO KANG,† AND Y O O N - S E O K C H A N G * ,† School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang 790-784, Republic of Korea, and School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), 100 Banyeon-ri, Eonyang-eup, Ulsan 689-798, Republic of Korea
Received October 25, 2009. Revised manuscript received January 17, 2010. Accepted February 9, 2010.
Four consecutive passive air samplings (September 2006-July 2007) were conducted at 15 sites around an iron and steel making plant in Pohang, Korea to investigate the spatial and seasonal distributions of polychlorinated biphenyls (PCBs) and ultimately the source-receptor relationships. Annual mean values of Σ8PCBs (IUPAC number 8, 28, 52, 101, 118, 138, 153, 180) were in the range of 15.1-166 pg/m3 with an average of 53.0 pg/m3. The spatial distribution of PCBs for each sampling period clearly suggests that the steel complex is a major source of PCBs in this area, and the prevailing winds facilitated the atmospheric transport and dispersion of PCBs from the steel complex to the surrounding areas. Seasonal patterns of PCBs were observed clearly, which were influenced by meteorological conditions; the highest levels of PCBs were observed with the highest average air temperature, and the influence of rainfall (i.e., wet scavenging) was also observed. In addition, PCB 11, a non-Aroclor congener, was detected in high concentrations at all sites, implying that the sources of PCB 11 are both unique and ubiquitous. This study confirms that passive air sampling is a useful tool to obtain seasonal and spatial distributions of time-averaged POPs data at a local scale.
Introduction Polychlorinated biphenyls (PCBs) have been commercially produced for use in dielectric fluids and insulators. It is estimated that more than 1.3 million tons of PCBs were produced in the world between 1929 and 1989 (1). The high toxicity of PCBs was confirmed in the 1970s, and the production of PCBs is now prohibited in most countries. However, PCB products manufactured before the prohibition are still in use and can contaminate the environment by evaporation and leakage from products and landfills. Hence, PCBs continue to be detected in environments such as air, soil, sediments, and even in human blood (2-5) although they are no longer manufactured. * Corresponding author phone: (82)-54-279-2281; fax: (82)-54279-8299; e-mail:
[email protected]. † Pohang University of Science and Technology (POSTECH). ‡ Ulsan National Institute of Science and Technology (UNIST). 10.1021/es903251h
2010 American Chemical Society
Published on Web 03/03/2010
PCBs exhibited an urban-rural gradient in large cities such as Toronto, Seoul, and Rome (3, 6-8) In the Global Atmospheric Passive Sampling (GAPS) study (9), high levels of PCBs were detected at urban sites or sites near urban centers. This result implies that urban areas are the most important source of PCBs. Industrial complexes also release many kinds of chemicals including PCBs by various thermal processes and their uses. Recently, the iron and steel industry has been recognized as an important source of dioxin-like PCBs (10). Odabasi et al. reported that stack gases from scrapmetal plants with electric arc furnaces were a significant source of PCBs (11). Heavy industrial activities were also reported to cause high levels of PCBs (12, 13). Moreover, municipal waste incinerators are a source of PCBs (14). In addition, a PCB congener, which is not commercially produced or thermally synthesized, such as PCB 11 has been also detected in various environmental compartments: in water and mussels throughout the Halifax Harbor (15), in the wastewater of the New York/New Jersey Harbor (16), in the Delaware river (17), in the Arctic and Antarctic air (18), and in the Chicago air (19). This congener was identified to be produced as a byproduct during the production of paints and pigments. Passive air samplers (PAS) are simple devices and do not require electric power; therefore, it is easy to install them at many sites for an extended period of time (a couple of weeks to a year). Because of these advantages, passive air sampling has been used for various monitoring studies from a local to a global scale to investigate sources and distributions of persistent organic pollutants (POPs) since the early 2000s (7, 9, 18, 20-22). PAS were used for investigating urban-rural gradients and continental and global distributions of POPs such as PCBs, organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs) (7, 9, 22, 23). Furthermore, they were installed in polar regions and high mountains (18, 24) to assess the long-range atmospheric transport (LRAT) of POPs. In Korea, PAS have been installed to identify the source-receptor relationships in urban and industrial areas (25). Our study area, Pohang, is a city located on the east coast of South Korea and is surrounded by mountains (∼500 m). An iron and steel making plant is located at the center of this city. This steel complex is one of the largest steel making plants in the world. As this plant is close to a residential area (
