Jianfang Feng

Polychlorinated organic compounds in Yangtse River sediments

Polychlorinated organic compounds (PCOCs) were analyzed in Yangtse River sediments. The results show that the concentrations of PCOCs in Yangtse River sediments followed the order of DDTs > HCB > HCHs > PCBs. High PCOCs concentrations were detected in sediments from station Y02a and Y02b, which are located in the main input of the Yangtse River (Nanjing section). Results also show that the PCOCs values were highly correlated with organic carbon content and heavy metal contamination.

Polybrominated diphenyl ethers (PBDEs) in aquatic biota from the lower reach of the Yangtze River, East China

Sixteen species of aquatic biota from the lower reach of the Yangtze River including fishes, crabs and shrimps were collected and analyzed for 13 polybrominated diphenyl ethers (PBDEs) congeners. All the PBDEs congeners except BDE-17 were detectable in the samples indicating that the aquatic biota from the lower reach of the Yangtze River are widely exposed to these pollutants. The Sigma(12)PBDEs ranged from 3.52 to 603.69 ng/g lipid (0.032-62.69 ng/g wet wt), with a mean of 44.04 ng/g lipid (2.69 ng/g wet wt). The PBDEs levels in the Yangtze River aquatic biota were low to average compared to PBDEs levels in aquatic biota around the world. The predominant congeners were BDE-47, BDE-28, BDE-154, BDE-100 and BDE-153. The proportion of BDE-28 seemed to be relatively high which was different from the result in other studies around the world but consistent with the results in China. The congener pattern of the sample was similar to the pattern in the sediment from the Yangtze River which implies that sediment may be an important PBDEs source for aquatic biota in the lower reach of the Yangtze River. Although the PBDEs levels in aquatic biota this area is comparable to or even lower than that in other areas in China, such as the Pearl River Delta and the Laizhou Bay, the increasing textiles, chemical and electronic industry may bring more and more PBDEs contamination to the Yangtze River Delta. The fact that PBDEs were detectable in all the biota samples from the lower reach of the Yangtze River should be an alarm for increasing risk in the Yangtze River Delta, East China.

Levels and distribution of polybrominated diphenyl ethers (PBDEs) in the freshwater environment surrounding a PBDE manufacturing plant in China.

Polybrominated diphenyl ethers (PBDEs) were determined in muscle, liver and eggs of freshwater fishes and surface sediments from the Nongkang River in Jinhu, Jiangsu Province, China. The present study is the first to report PBDE concentrations in the freshwater environment surrounding a PBDE manufacturing plant in China. The concentrations of 13 PBDE congeners in muscle, liver and eggs of freshwater fishes ranged from <LOD to 130, <LOD to 252 and <LOD to 33.3 ng/g lipid wt, respectively, while the concentrations of 13 PBDE congeners in surface sediments from sewage outfall, upstream and downstream of the river were 52, 9.2, 7.1 ng/g organic carbon wt, respectively. Contamination by PBDEs in this area was not serious when compared with other regions of the world. A relatively high proportion of BDE-183 was found, consistent with the octa-BDE technical mixtures from the manufacturing plant by the side of the river.

Prediction of mixture toxicity with its total hydrophobicity

Based on the C18 Empore disk/water partition coefficient of a mixture, quantitative structure-activity relationships (QSARs) are presented, which are used to predict the toxicity of mixed halogenated benzenes to P. phosphoreum. The predicted toxicity of 10 other related mixtures based on the QSAR model, agree well with the observed data with r2 = 0.973, SE = 0.113 and F = 287.785 at a level of significance P < 0.0001. The joint effect of these chemicals is simple similar action and the toxicity of the mixtures can be predicted from total hydrophobicity and is independent of hydrophobicity of the components or the ratio of the individual chemicals.

Inhibitory effects of carbon nanotubes on the degradation of 14C-2,4-dichlorophenol in soil.

Concerns on the potential risks of engineered nanoparticles to the environment are increasing; however, little is known about the effects of carbon nanotubes (CNTs) on the environmental fate of hydrophobic organic pollutants in soil. We incubated radioactive labeled 2,4-dichlorophenol ((14)C-2,4-DCP) in a soil in the presence of various concentrations (0, 2, 20, and 2000 mg kg(-1) dry soil) of single-walled (SWCNTs) and multi-walled (MWCNTs) carbon nanotubes, and determined the mineralization, degradation, and residue distribution of 2,4-DCP in the soil. CNTs were added to the soil either after the spiking of (14)C-2,4-DCP or together with (14)C-2,4-DCP as a mixture. CNTs at the concentration of 2000 mg kg(-1) significantly (P<0.05) inhibited the mineralization of (14)C-2,4-DCP and induced a 2.3- to 3.9-fold increase in the amounts of the non-degraded (14)C-2,4-DCP in the soil after 90 d of incubation. Pre-adsorption of (14)C-2,4-DCP on CNTs showed stronger inhibitory effects on the degradation of (14)C-2,4-DCP, already significant with CNTs at 20 mg kg(-1). In general, SWCNTs had a higher effect on the degradation and residue distribution of 2,4-DCP in the soil than MWCNTs. The inhibitory effects are supposed to be owing to limited activities of soil endogenous microorganisms, potential toxicities of CNTs to the microorganisms, and reduced bioavailability of 2,4-DCP in the presence of CNTs, even though a desorption hysteresis of 2,4-DCP on CNTs was not observed. Our results indicate that CNTs have more significant impacts on the environmental fate of the hydrophobic pollutants entering soil together with CNTs via strong sorption than the pollutants already present in soil.

Polar organic and inorganic markers in PM10 aerosols from an inland city of China — Seasonal trends and sources

Polar organic compounds and elements were quantified in PM(10) aerosols collected in urban and rural areas of Baoji, an inland city of China, during winter and spring 2008. Concentrations of biomass burning markers and high molecular weight n-alkanoic acids (HMW, >C(22:0)) were heavily increased in winter. In contrast, sugars presented in higher levels in the spring, among which sucrose was the most abundant with an average of 219ngm(-3) in winter and 473ngm(-3) in spring respectively. This suggests enhanced biotic activity in the warm season, whereas no obvious trend was observed for sugar alcohols, concentrations of the three sugar alcohols in spring were only 0.94-2.3 times as those in winter, indicating a second pathway of their formation other than fungal spores in cold season. Major crustal elements (i.e., Fe, K, Mn and Ti) in PM(10) aerosols were also observed in larger concentrations in spring samples than those in winter due to an enhancement of coarse particles from soil minerals. By using principal component analysis (PCA) and positive matrix factorization (PMF), sources and their contributions to the PM components were also investigated in this study. Four factors were extracted with both models, and the sources represented by different factors were based on the highest loaded marker species as follows: factor 1, soil and road dust (Fe, Sr and Ti); factor 2, biomass burning (levoglucosan, galactosan and syringic acid); factor 3, microbial emissions (fructose and sucrose); and factor 4, fossil fuel combustion and fungal spores influence (Pb, Zn, arabitol and mannitol). The high correlation between PM(10) and factor 1 suggested that PM(10) pollution in Baoji was dominated by soil and dust re-suspension.

Occurrence of estrogenic activities in second-grade surface water and ground water in the Yangtze River Delta, China.

Second-grade surface water and ground water are considered as the commonly used cleanest water in the Yangtze River Delta, which supplies centralized drinking water and contains rare species. However, some synthetic chemicals with estrogenic disrupting activities are detectable. Estrogenic activities in the second-grade surface water and ground water were surveyed by a green monkey kidney fibroblast (CV-1) cell line based ER reporter gene assay. Qualitative and quantitative analysis were further conducted to identify the responsible compounds. Estrogen receptor (ER) agonist activities were present in 7 out of 16 surface water and all the ground water samples. Huaihe River and Yangtze River posed the highest toxicity potential. The highest equivalent (2.2 ng E2/L) is higher than the predicted no-effect-concentration (PNEC). Bisphenol A (BPA) contributes to greater than 50% of the total derived equivalents in surface water, and the risk potential in this region deserves more attention and further research.

Partitioning regularity of non- ionic organic mixtures in organic phase/water system

The partitioning regularity of nonionic organic mixtures in organic phase/water system is revealed. The equation for calculating the partition coefficients of mixtures (KMD), together with the determination model, is derived from the equilibrium partitioning models (EPMs). Based on these derived equations, the KMD values of 20 mixtures containing halogenated benzenes are obtained. The results show that stronger hydrophobicity of an individual chemical in the mixture results in the stronger hydrophobicity of the mixture and the greater the proportion of this chemical, the stronger the hydrophobicity of the mixture will be. This partitioning regularity is helpful to the study of the toxicity for mixtures and the environmental behavior, such as transfer or accumulation, for mixed organic pollutants.