Occurrence differences of hexachlorobutadiene and chlorobenzenes in road dust and roadside soil media in an industrial and residential mixed area in Eastern China.

The road dust and roadside soil can act as both sinks and sources of hexachlorobutadiene (HCBD) and chlorobenzenes (CBzs), but comparative research on these two adjacent media is extremely limited. In this study, HCBD and CBzs were simultaneously analyzed in road dust and roadside soil samples from an area containing both industrial factories and residential communities in Eastern China. The road dust there was found to have 2–6 times higher contents of HCBD (mean 1.14 ng/g, maximum 6.44 ng/g) and ∑ Cl3-Cl6 CBzs (22.8 ng/g, 90.6 ng/g) than those in the roadside soil. The spatial distributions of HCBD and CBzs in road dusts were affected by various types of sources, showing no significant discrepancy among the sites. On the contrast, HCBD and CBzs contamination in roadside soils occurring near several factories were strongly correlated to their industrial point sources. Risk assessments showed, at current contamination levels in the road dust and roadside soil, HCBD and CBzs are not likely to induce carcinogenic or non-carcinogenic risks to residents in the studied area. Nevertheless, road dust ingestion, as the major exposure pathway of HCBD and CBzs, should be avoided to reduce the exposure risk. These findings based on the contamination differences between two media provide a new perspective and evidence for screening important sources and exposure pathway of HCBD and CBzs, which would be helpful to their source identification and risk control. HCBD and CBzs in road dust and roadside soil in an industrial and residential mixed area. [Display omitted] • Pioneering study on HCBD and CBzs in road dust/soil from multifunctional area in China. • HCBD and CBz occurrences were significantly different between two media. • Roadside soil could reveal sources of HCBD and CBzs, but road dust couldn't. • Road dust was more contaminated by HCBD and CBzs than roadside soil. • HCBD and CBzs exposure via ingesting road dust posed highest risks among pathways. [ABSTRACT FROM AUTHOR]