Atmospheric occurrence, homologue patterns and source apportionment of short- and medium-chain chlorinated paraffins in Shanghai, China: Biomonitoring with Masson pine (Pinus massoniana L.) needles.

A comprehensive survey was conducted to Masson pine (Pinus massoniana L.) needles widely distributed in Shanghai in order to investigate the levels and homologue group patterns of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs), to identify and quantitatively assess source contributions to the total CPs in pine needle samples. The concentration ranged from not detected (ND) to 13,600ngg(-1) with a geometric mean (GM) value of 63.7ngg(-1) for ΣSCCPs, from 12.4 to 33,500ngg(-1) with a GM value of 677ngg(-1) for ΣMCCPs, and from 14.0 to 45,700ngg(-1) with a GM value of 768ngg(-1) for total CPs. For different sampling units, the pollution levels both for SCCPs and MCCPs in pine needles were in the same orders: Pudong>suburbs>Puxi>Chongming. These significant differences in SCCPs and MCCPs among four sampling units could be associated with difference in industrial activities and to some extent also in population density. All pine needle samples (n=131) were divided into 2 groups by hierarchical cluster analysis (HCA) for SCCPs and MCCPs, the most abundant homologue groups in the bulk of pine needle samples were C11Cl5-7 and C13Cl5-7 for SCCPs, and C14Cl7-8 and C15Cl7-8 for MCCPs. Correlation analysis suggested that SCCPs and MCCPs in pine needles in the studied area may be derived from different sources. Four sources for pine needles were identified by the FA-MLR model; their relative contributions to the total CP burden in pine needles were 18.0% for F1 (attributed to commercial SCCP mixture), 42.2% for F2 (attributed to commercial MCCP mixture), 29.3% for F3 (attributed to LRAT), and 10.5% for F4 (unknown source). CP contamination of atmospheric air by point sources and long-range atmospheric transport in Shanghai should receive more attention by local government.

Occurrence, sources and health risk assessment of polycyclic aromatic hydrocarbons in urban (Pudong) and suburban soils from Shanghai in China.

A comprehensive investigation was conducted to the urban (Pudong) and suburban soils in Shanghai. A total of 154 soil samples were analyzed for 26 PAHs including highly carcinogenic dibenzopyrenes (DBPs). The total concentrations ranged from 25.8 to 7380 µg kg(-1) for Σ26PAHs and 18.8 to 6320 µg kg(-1) for 16 USEPA priority PAHs (Σ16PAHs), respectively. The BaP toxic equivalent (BaPeq) concentrations were between 6.41 and 2880 µg kg(-1) for Σ24PAHs, 1.11 and 620 µg kg(-1) for Σ16PAHs and 2.72 and 2250 µg kg(-1) for Σ4DBPs. The high PAH contamination in green land soils might originate mainly from local road traffic and industrial activities, and sewage sludge application or waste water irrigation for soil. Seven sources of soil PAHs in Shanghai were identified by positive matrix factorization (PMF) model. The mean risk quotient (m-RQ) values indicated that there were medium to high ecological risks in 9.10% of soil samples, pyrene (Pyr), benzo[b]fluoranthene (BbF) and benz[a]anthracene (BaA) were the major ecological risk drivers under agricultural use. The cancer risk (CR) values were within the acceptable range at 35.7%, 35.1% and 31.2% of sampling sites for children, youths and adults, respectively. The total lifetime carcinogenic risk (TLCR) values at 57.8% of sampling sites were within the acceptable range. Overall, cancer risks of soil PAHs in all sampling sites in the studied area were below the highest acceptable risk, suggesting that soil PAHs are unlikely to pose a significant cancer risk for population based on ingestion, dermal contact and inhalation exposure pathways.

[Study of combined effects of DES and EV on the proliferation of MCF-7 cells by two experimental designs].

The single toxicity of diethylstilbestrol (DES) and beta-estradiol 17-valerate (EV) and the joint toxicity of their binary mixtures in equiconcentration to the proliferation of MCF-7 cells were investigated, respectively. Additive index (AI) method was adopted to evaluate the joint toxicity effect. At the same time, 3 x 3 factorial experimental design was used to verify the joint toxiciy types derived from equiconcentration of DES and EV. The results show that the EC50 values of single EV and DES for 24, 48 and 72 h are 6.02, 0.40 and 0.33 nmol x L(-1) and 5.90, 6.98 and 2.90 nmol x L(-1), respectively. The EC50 values of the binary mixtures of DES and EV for 24, 48 and 72 h are 2.33, 0.71 and 0.39 nmol x L(-1). The binary joint effects of DES and EV for 24 h were synergistic, and the joint effects of DES and EV for 48 and 72 h were antagonistic. But synergistic and antagonistic effects are not strong; their values can be found close to the values of additive effects. Factorial experiment results show that combined effects of DES and EV to proliferation of MCF-7 cells for 24, 48 and 72 h three exposure periods are additive effect types. The consistent joint combined effect types can be drawn from both factorial experimental design and equiconcentration ratio of DES and EV to the proliferation of MCF-7 cells. However, the factorial experimental design is simpler and more convenient, and can avoid unnecessary mistakes due to the derivation of EC50 values.

[Comparison of aquatic predicted no-effect concentrations (PNECs) pentachlorophenol derived from different assessment approaches].

Predicted no-effect concentration (PNEC) is the key for ecological risk assessment and has become a focus of the study. Generally, extrapolation was used to derive PNEC values by different evaluation approaches according to results of single species toxicity test. However, PNEC values were different for the same toxicity data for the same chemicals if extrapolation methods were different. To evaluate PNEC values derived by different assessment methods, PNEC values of pentachlorophenol (PCP) were calculated using three different approaches, i. e. point estimation, statistical evaluation as well as interval evaluation. At the same time, the main factors controlling PNEC values were analyzed. The results showed that PNEC values for PCP by different assessment factors were 0.420 microg x L(-1) for acute toxicity data and 0.500 microg x L(-1) for chronic toxicity data, respectively. The PNEC values for PCP by statistical evaluation were 10.1 microg x L(-1) for probit unit and 8.10 microg x L(-1) for logit unit. The values derived by interval evaluation were 6.00 microg x L(-1) for PNEC-L95% and 11.8 microg x L(-1) for PNEC-L50%, respectively. PNECs obtained by the point estimation were the lowest and lower one order of magnitude than the PNEC values obtained by the other two methods. The PNEC values derived by the statistical assessment and interval evaluation were very similar. In addition, toxicity data type and statistical models have little effect on PNEC value for PCP with a great body of toxicity data. The results indicated that statistical evaluation and interval evaluation methods should be selected to derive PNEC values for well-studied substances like PCP, while point estimation should be used in preliminary screening assessment of chemicals to determine whether the effect is of concern.

[Method of ecological risk assessment for risk pollutants under short-term and high dose exposure in water pollution accident].

In recent years, water pollution accidents resulting in acute aquatic ecological risk and security issues become a research focus. However, in our country, the surface water quality standards and drinking water health standards were used to determine the safety of waters or not in pollution incidents due to lacking safety effect threshold or risk value for protection of aquatic life. In foreign countries, although predicted no effect concentration (PNEC) or risk value (R) of pollutants were provided for protection of aquatic organisms, the PNECs or risk values were derived based on long-term exposure toxicity data NOECs (no observed effect concentrations) and lack of short-term exposure risk or threshold values. For the short-term and high dose exposure in pollution incident, ecological risk assessment methods were discussed according to the procedures of the conventional ecological risk assessment and the water quality criteria establishment of the U.S. EPA for the protection of aquatic organisms in short-term exposure, and had a case study. At the same time, we provide some suggestions for the establishment of ecological risk assessment system in water pollution incidents.

[Present state of six estrogens in the sediment of Wenyuhe River].

To investigate the pollution levels, occurrence and distribution of estrogens, six estrogens in the surface sediments of Wenyuhe River were analyzed quantitatively by GC/MS following ultrasonicated extraction including diethylstilbestrol (DES), estrone (E1), beta-estradiol(E2), 17alpha-ethynylestradiol(EE2), estriol(E3), and beta-estradiol 17-valerate (EV). Six estrogen concentrations ranged from 0.39-36.6 ng/g and the mean concentration was 10.2 ng/g. E1 and E2 were detected in all samples while other four estrogens were only detected in a few samples, and the concentrations of El was higher than those of E2 in all samples. There were significant correlation relationships between the concentrations of six estrogens and the concentrations of total organic carbon (TOC), total phosphorus (TP) and total nitrogen (TN) in sediments. Considering also the characteristics of the sampling locations and pollution sources, six estrogens should come from wastewater discharges along the river and the contaminated tributaries. The contents of estrogens in this area are medium or slightly higher level compared with other areas abroad.

[Joint toxicity on multi-component mixtures of SDS and substituted aromatic compounds].

The toxicity to Photobacterium phosphoreum of different mixture systems of sodium dodecyl sulfate (SDS) and three substituted aromatic compounds according to equiconcentration ratio of 1 : 1, as well as individual toxicity, were determined respectively. The joint toxicity was evaluated by toxicity unit (TU), additive index (AI), similarity parameter (lambda), and mixtures toxicity index (MTI). Four evaluating methods were compared and the modes of joint action of different systems were analyzed primarily. The coherent results were obtained from four different evaluating methods. Conclusions can be drawn that the binary joint effects of phenol and toluene mixed with SDS showed weak synergistic, while the other joint effects of SDS and substituted aromatic compounds were antagonistic. Of the evaluating methods, Toxic Unit is most sensitive with higher value of its parameter. Mechanisms of joint toxicity action could be discussed according to luminescence principle of Photobacterium phosphoreum and molecule structures of the mixture components.