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The distribution and ecosystem risk of 16 polycyclic aromatic hydrocarbons (PAHs) in the Luan River, China, has been investigated. summation operatorPAHs levels ranged from 37.3 to 234 ng L(-1) in water, from 20.9 to 287 ng g(-1) in sediment and from 36.9 to 378 ng g(-1) in bank soil, respectively. A method based on toxic equivalency factors (TEFs) and risk quotient (RQ) which can be used to assess the ecosystem risk of summation operatorPAHs sensitively and accurately was invented and a new ecosystem risk classification of summation operatorPAHs was suggested. The results indicated that the PAHs in aquatic environment of the Luan River resulted in low ecosystem risk and at S9 the ecosystem risk of PAHs in water was moderate. Low and moderate molecular PAHs presented much more ecosystem risk than high molecular PAHs in the Luan River basin and the mean ecosystem risk in water was higher than that in sediment and bank soil.

Dust samples were collected in Beijing, China, from four different indoor microenvironments (office, hotel, kindergarten, and student dormitory) and one outdoor (road dust) microenvironment. These five composite samples were fractionated into 13 sequential size fractions and an individual fraction of <50 μm for further analysis. In the fractions of <50 μm, nine phosphorus flame retardants (∑PFRs), four novel brominated flame retardants (∑NBFRs), and two Dechlorane Plus isomers (DPs) showed the highest concentrations in hotel dust (124,000 ng g(-1)), dormitory dust (14,200 ng g(-1)), and kindergarten dust (231 ng g(-1)), respectively. Nevertheless, nine polybrominated diphenyl ethers (∑PBDEs) were the dominant flame retardants (FRs) (96% of total FRs) in road dust, with the maximum concentration of 23,700 ng g(-1), higher than in any indoor dust. The FR contamination varied strongly among different types of microenvironments, leading to high human exposure to various FRs. Concentrations of FRs did not increase constantly with a particle size decrease. Fractions with a particle size around 900, 100, and 10 μm could represent peak values, while valley values were commonly detected around fractions with a particle size around 40 μm. Large differences were found between indoor dust and road dust. In road dust, FRs were mainly enriched in fractions of <50 μm. The organic content of dust, FR application, and consequent abrasion processes of FR-containing materials might be the determinants of the FR concentrations. Volatilization and abrasion were considered to be important migration pathways for FRs. DPs and BDE-209 were sought to be mainly applied in abrasion-proof materials, while most phosphorus flame retardants (PFRs) were probably added in a large proportion in materials easy to wear.