Multimedia modeling of the fate of triclosan and triclocarban in the Dongjiang River Basin, South China and comparison with field data.

Triclosan (TCS) and triclocarban (TCC) are two active ingredients widely used in many home and personal care products. Multimedia fate of TCS and TCC in the Dongjiang River basin, South China were addressed by the developed level III fugacity model based on their usage. Under the assumption of steady state, the concentrations in air, water, soil, sediment, suspended particulate matter (SPM) and fish as well as transfer flux across the interface between the compartments were simulated.

Hexachlorocyclohexane and dichlorodiphenyltrichloroethane residues in the dustfall of Tianjin, China.

Heating and nonheating season dustfall samples were collected from 23 sites in Tianjin, China during 2002-2003 to determine residues of hexachlorocyclohexane isomers (a-HCH, beta-HCH, gamma-HCH, and beta-HCH) and dichlorodiphenyltrichloroethane and metabolites (p,p'-DDE, p,p'-DDD, and p,p'-DDT). Concentrations of sumHCH (sum of alpha-, beta-, gamma-, and delta-HCH) and sumDDT (sum of p,p'-DDE, p,p'-DDD, and p,p'-DDT) varied in ranges of 10.9-3.

[Population exposure to HCH in Tianjin area].

The population exposure to HCH in Tianjin area is estimated based on field data on media concentration and other data from the literature. A multimedia /multipathway human exposure model is employed to calculate the population' s Chronic Daily Intake (CDI) of HCH. The population's lifetime CDI was 0.

[PAHs in airborne particles from Tianjin in winter season].

Total suspended particles (TSP) samples from 13 stations in Tianjin were collected and analyzed for polycyclic aromatic hydrocarbons (PAHs) during 2002 winter. There was significant difference in total PAH concentration among 13 samples. TSP samples from the east Economic Development Area and mid-north districts had the highest contents of PAHs, while Dagang Oil Field had the lowest PAH content.

System-level responses of lake ecosystems to chemical stresses using exergy and structural exergy as ecological indicators.

This paper presents the system-level responses of experimental lake ecosystems to three chemical stresses (acidification, copper and pesticide contamination) using exergy and structural exergy as ecological indicators. The results indicate that the doses or toxicity of the three chemical stressors contributed to changes in both exergy and structural exergy. Remarkable changes in exergy and structural exergy occurred under acidic conditions and in the presence of Dursban, 24D-DMA, permethrin, bifenthrin, Carbaryl, TCP, PCP, trichlorethylene, benzene, and high doses of Cu, oil, and hexazinone.