The effects of prosperity indices and land use indicators of an urban conurbation on the occurrence of hexabromocyclododecanes and tetrabromobisphenol A in surface soil in South China.

Hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) are legacy brominated flame retardants which are still produced and used in China. In this study, 187 surface soils from the Pearl River Delta (PRD) urban conurbation in China were collected, and the effects of urban conurbation development on the concentrations, distributions and human exposure risk of HBCDs and TBBPA were investigated. The concentration ranges of Σ 3 HBCD (sum of α-, β-, and γ-HBCD) and TBBPA in soil were below the limit of quantification (<LOQ) to 300 ng g⁻¹ dry weight (dw) and < LOQ to 53.1 ng g⁻¹ dw, respectively. Concentration levels of HBCDs and TBBPA in the PRD were affected both by distributions of land-use type and by the location of the city. Soils from residential areas contained the highest concentrations of Σ 3 HBCD (median: 1.75 ng g⁻¹ dw) and TBBPA (1.92 ng g⁻¹ dw) among all land-use types. In addition, soils from the central PRD had higher Σ 3 HBCD and TBBPA levels (0.46 and 0.90 ng g⁻¹ dw) than those from the surrounding areas (0.17 and 0.07 ng g⁻¹ dw). The concentrations of Σ 3 HBCD and TBBPA were highly correlated with urbanization level, population density, regional GDP and per capita income in all cities studied (p < 0.01), which indicates that the prosperity of the urban conurbation may play an important role in soil contamination of HBCDs and TBBPA in the PRD. Children living in residential areas had the highest estimated daily intakes of Σ 3 HBCD (7.09 pg kg⁻¹ d⁻¹) and TBBPA (7.76 pg kg⁻¹ d⁻¹), suggesting that people living in residential areas have a relatively higher exposure risk of HBCDs and TBBPA. This is a comprehensive study to report the effects of prosperity indices and land use indicators of an urban conurbation on the occurrence of HBCDs and TBBPA in soil in China. Image 1 • Conc. of HBCDs and TBBPA in soils were affected by land-use type and city location. • Urban prosperity may play an important role in soil contamination of HBCDs and TBBPA. • People living in the residential areas were exposure to relative higher levels of HBCDs and TBBPA, especially for children. Urban conurbation development affects contamination of HBCDs and TBBPA in soil. [ABSTRACT FROM AUTHOR]