Isomer-Specific Analysis and Toxic Evaluation of Polychlorinated Naphthalenes in Soil, Sediment, and Biota Collected near the Site of a Former Chlor-Alkali Plant

Abstract

Concentrations and composition of polychlorinated naphthalene (PCN) congeners were determined in soil, sediments, blue crab, striped mullet, and boat-tailed grackle collected near a chlor-alkali plant to determine their congener profile, bioaccumulation properties, and toxic potential. Concentrations of total PCNs as high as 23 µg/ g, dry wt, were found in sediments collected at the marsh contaminated by disposal of wastes from the chloralkali process. The spatial distribution of sediment-PCN concentrations was not related with those observed for polychlorinated biphenyls (PCBs). The PCN congener profile did not resemble those of any technical mixtures. Hepta-and octa-chloronaphthalenes were the most abundant congeners accounting for greater than 50% of the total PCN concentrations in soil and sediments. A characteristic profile of PCNs in samples collected at the chlor-alkali site suggests the formation of chloronaphthalene congeners during chlor-alkali process, as has been suggested for polychlorinated dibenzofurans (PCDFs). Concentrations of total PCNs in biota were 3-5 orders of magnitude less than in sediments. The profile of PCN congeners in biota was predominated by tetra-or penta-chloronaphthalenes, while hepta-and octa-chloronaphthalenes were not detected. Affinity of more chlorinated naphthalene congeners to sediment organic carbon and steric factors that affect membrane permeability have contributed to less bioavailability. The 2,3,7,8-TCDD equivalents (TEQs) estimated for PCNs in sediments and biota were greater than those reported for PCBs, PCDDs, or PCDFs. Our results suggest that the chloralkali process has been an important source of PCNs due to their formation in the process. The contribution of PCNs to dioxin-like toxicity in environmental media near the chlor-alkali process may overwhelm those due to PCBs, PCDDs, or PCDFs.

Concentration and distribution of PCNs in ambient soil of a municipal solid waste incinerator

“…Also, comparing to a recent study in soil samples from South China, which featured a total PCN concentration range from 59.9 to 86.7 pg g −1 (Wang et al, 2012), soil samples in current study showed higher PCN concentrations. However, the total PCN concentrations in the current study were much lower than those (from TrCNs to OCN) in soil contaminated by emissions from a chlor-alkali plant (17,900 ng g −1 ) (Kannan et al, 1998).…”

“…The PCN homologue patterns in soil samples were different from patterns that have been reported in seafood from Guangzhou and Zhoushan, China, which were dominated by TrCNs and PeCNs (over 60% in mass) (Jiang et al, 2007). The similar research conducted by Kannan et al(1998) in soil, sediment, and biota collected near the site of a former chlor-alkali plant in Japan also found different distribution of homologues. The PCN profiles in soil and sediment samples were dominated by HxCNs and HpCNs, contributing 70% of the total PCN concentrations.…”

“…Studies have suggested that PCNs contribute a greater proportion of the dioxin-like activity than PCBs and PCDD/Fs in some cases (Kannan et al, 1998;Kannan et al, 2001). PCNs have bioaccumulation potential, and a number of congeners have been detected in the atmosphere, soils and sediments (Zhao et al, 2011).…”

Identification and characterization of the atmospheric emission of polychlorinated naphthalenes from electric arc furnaces

“…PCNs have attracted increasing attention due to their ubiquitous occurrence in environmental matrices and biota (Harner et al 2006;Bidleman et al 2010). Several investigations on PCN levels in some typical areas have been carried out, and some of the results show that the toxic equivalents (TEQs) of PCNs are comparable to or even higher than that of dioxins (Kannan et al 1998(Kannan et al , 2001. PCN TEQs in some human serum samples have also been studied (Park et al 2010), and results show that the levels are comparable to those of dioxins.…”

Polychlorinated naphthalenes (PCNs) in riverine and marine sediments of the Laizhou Bay area, North China

“…PCNs can be released into the environment from various pathways. Although the production and usage of technical PCN formulations has declined since early 1980s, products containing these formulations are still present in the environment (Kannan et al, 1998). In addition to the release from historical usage of technical formulations, PCNs are also leaked out from impurities of technical PCB preparations and from unlawfully usage in recent years (Falandysz, 1998;Yamashita et al, 2000a).…”