Occurrence of Hexabromocyclododecane in soil and road dust from mixed-land-use areas of Shanghai, China, and its implications for human exposure

•HBCDDs in soil and road dust from mixed-land-use areas were investigated.•Distribution of HBCDDs in soil and road dust was affected by the land use.•HBCDDs in soil and road dust exhibited correlations in some mixed-land-use areas.•Human exposure to HBCDDs via road dust and soil should not be overlooked.

Herein, the occurrence of three Hexabromocyclododecane (HBCDD) diastereoisomers in soil and road dust from the mixed-land-use areas in Shanghai was investigated. The total concentrations of HBCDDs (∑ HBCDDs) in soil ranged from 0.30 to 249 ng g− 1 dw, with a median level of 5.14 ng g− 1 dw. For the road dust samples, the ΣHBCDD concentrations varied from 4.11 to 508 ng g− 1 dw, with a median level of 23.4 ng g− 1 dw. The levels of HBCDDs varied in different mixed-land-use areas. In soil, the levels of HBCDDs increased in the following sequence: residential area & agricultural area (R&A) < agricultural area & industrial area (A&I) < residential area & commercial area (R&C) < residential area & industrial area (R&I); the levels for the road dust were A&I < R&A < R&C < R&I. The proportions of α-HBCDD in road dust samples were significantly higher than those of α-HBCDD in the soil. For soil, the portion of α-HBCDD increased in the following sequence: R&I < A&I ≈ R&A < R&C, while that for the road dust was R&C < R&A < R&I < A&I. Significant correlations in the concentrations of HBCDDs between soil and road dust from R&C and R&I were found, which suggested that they may share similar sources in these regions. On the basis of the HBCDD concentrations of road dust and soil, the contributions of ingestion, dermal contact absorption and inhalation intake to total estimated daily intakes (EDIs) were estimated. The highest total EDIs of ∑ HBCDDs (sum of ingestion, dermal contact absorption and inhalation intake) were 0.154, 7.5 × 10− 2 ng kg− 1 d− 1 for infants from road dust and soil in R&I, respectively.

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