Short- and medium-chain chlorinated paraffins in urban road dust of Shanghai, China: concentrations, source apportionment and human exposure assessment.

Chlorinated paraffins (CPs) are ubiquitous anthropogenic contaminants that have been found in various environmental media. The objective of this study was to determine concentrations, spatial distribution, possible sources and potential health risk of SCCPs and MCCPs in urban road dust collected from Shanghai, China. The concentrations ranged from 9.74 to 11,400 ng g-1 for ΣSCCPs, 44.1 to 49,900 ng g-1 for ΣMCCPs and 53.9 to 61,400 ng g-1 for total CPs, respectively. MCCPs were the dominant component in all road dust, averagely accounting for 82.8% of total CPs. The concentrations of CPs in dust collected from traffic and commercial areas were significantly higher than those from campus, industrial, park and residential areas (p < 0.01), which could be attributed to tire wear in heavy traffic. All dust samples were divided into two groups by hierarchical cluster analysis for both SCCPs and MCCPs, and the most abundant homologue groups in most samples were C10Cl7-10 and C13Cl7-9 for SCCPs, and C14Cl7-9 and C15Cl8-9 for MCCPs. Correlation analysis showed that all carbon homologues in road dusts were highly correlated each other, suggesting SCCPs and MCCPs in dust maybe came from similar sources. Three sources for CPs in dust samples were apportioned by the PMF model; their relative contributions to the total CPs burden in dust were 25.6% for factor 1 (commercial CP mixture), 13.7% for factor 2 (long-distance transport) and 60.7% for factor 3 (commercial CP mixture). The median estimated daily intakes of total CPs via road dust were 1.78 × 10-5 for children and 3.0 × 10-6 mg kg-1 day-1 for adults, respectively. Quantitative risk assessment using non-cancer hazard index and total margin of exposure of total CPs indicated that total CPs at the present level in road dust pose no significant risk for both children and adults in Shanghai.

Occurrence, source apportionment, and carcinogenic risk assessment of polycyclic aromatic hydrocarbons in urban road dusts in Shanghai.

Polycyclic aromatic hydrocarbons (PAHs), as a class of important environmental pollutants, have received considerable concern due to their widespread existence and biological toxicity. The main purpose of this study was to determine concentrations, spatial distribution, possible sources, and potential health risk of PAHs in urban road dust in Shanghai, China. The concentration of Σ26PAHs ranged from 53.0 to 28,700 ng g-1 in road dust samples from Shanghai, which is at the low to medium level compared with other areas around the world. PAHs with 4-5 rings were predominant components in road dust. The level of PAHs in road dust was significantly higher than those in soil and river sediment in Shanghai. Six possible sources of PAHs were apportioned by PMF model. The contribution of pyrogenic PAHs accounted for 91.3% of the total PAHs in road dusts. The motor vehicular emission, natural gas, and coal combustion were main sources for urban road dust PAHs from Shanghai. Four dibenzopyrene (DBP) isomers were contributed averagely 75% of total TEQBaP concentration. DBalP, BaP, DBaiP, BbF, and DBA were main contributors to total carcinogenic potency, which totally contributed from 69.6 to 91.8% (median 89.1%) to total TEQBaP in urban road dusts of Shanghai. The results of incremental lifetime carcinogenic risk (ILCR) assessment showed that the total risk values exposed to 24 PAHs in road dust were lower than 10-4 at all sampling sites, indicating that exposure to dust-bound PAHs at present level was unlikely to result in high carcinogenic risk for both children and adults in Shanghai.

Spatial variations, source apportionment and potential ecological risks of polycyclic aromatic hydrocarbons and synthetic musks in river sediments in Shanghai, China.

The aims of this study were to investigate the levels, possible sources and potential ecological risks of 26 polycyclic aromatic hydrocarbons (PAHs) including highly carcinogenic dibenzopyrene (DBP) isomers and 4 synthetic musks (SMs) in river sediments from Shanghai. 74 sediment samples were collected from the Huangpu River and its main tributaries. The total concentrations ranged from 52.0 to 11400 ng g-1 for Σ26PAHs, 25.1-9910 ng g-1 for 16 USEPA priority PAHs (Σ16PAHs), 0.769-384 ng g-1 for Σ4DBPs, and 0.080-63.3 ng g-1 for Σ4SMs, respectively. Seven sources of PAHs in river sediments were identified by positive matrix factorization (PMF) model. Coal combustion, vehicle and creosote were the major emission sources for PAHs. SMs came mainly from domestic and industrial wastewaters. The toxic equivalent quantities of the benzo[a]pyrene (TEQBaP) ranged from 7.64 to 3920 ng g-1 for Σ24PAHs, 2.07-1150 ng g-1 for Σ16PAHs, and 5.53-3150 ng g-1 for Σ4DBPs. The TEQBaP of Σ4DBPs made up 73.9% of Σ24PAHs, which indicated that DBPs were the major carcinogenic contributors to total PAHs in sediments. According to sediment quality guidelines (SQGs) and mean PEL-Q values, the risks posed by PAHs in sediments were at medium level at most sampling sites, and SMs posed a low ecological risk to sediment-dwelling organisms in Shanghai.

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.

Polycyclic aromatic hydrocarbons (PAHs) in urban soils of the megacity Shanghai: occurrence, source apportionment and potential human health risk.

A comprehensive investigation was conducted to the urban soil in the megacity Shanghai in order to assess the levels of PAHs and potential risks to human health, to identify and quantitatively assess source contributions to the soil PAHs. A total of 57 soil samples collected in main urban areas of Shanghai, China were analyzed for 26 PAHs including highly carcinogenic dibenzopyrene isomers. The total concentrations ranged from 133 to 8,650 ng g for ΣPAHs and 83.3 to 7,220 ng g for ΣPAHs, with mean values of 2420 and 1,970 ng g, respectively. DBalP and DBaeP may serve as markers for diesel vehicle emission, while DBahP is a probable marker of coke tar as distinct from diesel emissions. Six sources in Shanghai urban area were identified by PMF model; their relative contributions to the total soil PAH burden were 6% for petrogenic sources, 21% for coal combustion, 13% for biomass burning, 16% for creosote, 23% for coke tar related sources and 21% for vehicular emissions, respectively. The benzo[a]pyrene equivalent (BaP) concentrations ranged from 48.9-2,580 ng g for ΣPAHs, 7.02-869 ng g for ΣPAHs and 35.7-1,990 ng g for ΣDBPs. The BaP concentrations of ΣDBPs made up 72% of ΣPAHs. Nearly half of the soil samples showed concentrations above the safe BaP value of 600 ng g. Exposure to these soils through direct contact probably poses a significant risk to human health from carcinogenic effects of soil PAHs. The index of additive cancer risk (IACR) values in almost one third of urban soil samples were more than the safe value of 1.0, indicating these urban soil PAHs in the study area may pose a potential threat to potable groundwater water quality from leaching of carcinogenic PAH mixtures from soil.

Internal carotid artery in the operative plane of endoscopic endonasal transsphenoidal surgery.

The objective of this study was to measure the related parameters of intercarotid artery (ICA) in the operative plane of endonasal transsphenoidal approach for hypophyseal surgeries. Nine parameters of the ICA were examined in the computed tomographic angiographic (CTA) scan of 101 patients. The shortest distance between the middle point of the nasal columella and the projective point of the ICA (D(3)) was 85.50 (5.79) mm. The shortest distance between the anterior wall of the sphenoid sinus and the projective point of the ICA (D(4)) was 16.93 (3.50) mm. The distance between the bilateral projective points of the ICA (D(5)) was 21.60 (3.45) mm. The shortest distance from the anterior wall of the sphenoid sinus to the line between the bilateral projective points of the ICA (D(6)) was 12.1 (3.91) mm. The shortest distance between the middle point of nasal columella and the anterior wall of the sphenoid sinus (D(7)) was 72.67 (5.99) mm. The width of the angle between the bilateral ICA projective point from the middle point of the nasal columella (A(1)) was 14.9 (2.32) degrees. The width of the angle between the bilateral ICA projective points from the anterior-most point of sphenoid sinus (A(2)) was 85.49 (18.12) degrees. Clinically, it is relatively safe to work within the distances and angles measured in this research, and these results may provide information for clinical surgery of pituitary tumor.

[Level, distribution, and source identification of polychlorinated naphthalenes in surface agricultural soils from an electronic waste recycling area].

The concentration of 46 polychlorinated naphthalenes (PCNs) in the agricultural soils from Luqiao was analyzed by GC-NCI-MS. The objectives of this study were to investigate the contents, spatial distribution and sources of PCNs. The total concentrations of PCNs (sigma PCNs) in soil samples were in the range of 0.062 to 2.92 ng x g(-1), with a mean of 0.630 ng x g(-1). Tetra-CNs and penta-CNs were the predominant homologues in most of the samples, accounting for 18.4% - 88.8% and 8.40% - 53.1%, with average values of 46.7% and 30.7%, respectively, followed by tri-CNs, accounting for 0 - 47.3%, with a mean of 10.6%. Cluster analysis and combustion marker analysis showed that the sampling sites were mainly polluted by Halowax 1014 and Halowax 1013, also possibly polluted by PCBs mixtures and e-waste combustion process. Compared to other studies, the PCNs concentration in this study was at a medium level.

[Levels, distribution and possible sources of polybrominated diphenyl ethers in river sediments from an electronic waste recycling area].

The concentrations of 41 polybrominated diphenyl ethers (PBDEs) in the river sediments from Luqiao were analyzed by GC-NCI-MS. The objectives of this study were to understand the contents, spatial distribution and sources. The Sigma40 PBDEs (excluding BDE209) concentrations in sediments sampled were in the range of 0.177 to 161 ng x g(-1), with a mean of 22.5 ng x g(-1), and the concentrations of BDE209 were from 0.36 to 958 ng x g(-1), with a mean of 148 ng x g(-1). Deca-BDE was the most predominant in 9 PBDE homologues in most of samples, accounting for 38.4%-96.0%, with an average of 74.4% nona-BDEs and hepta-BDEs, accounting for 3.3%-25.8% and 0.01%-14.1%, respectively. Significant correlations were observed among all of PBDEs congeners, which suggested these PBDEs might have the similar sources. The homologue composition of PBDEs and hierarchical cluster analysis (HCA) showed that most of sampling sites were mainly polluted by deca-BDE formulation, and others polluted by deca-BDE and octa-BDE formulations. Compared to other studies from different countries and regions, the PBDEs concentrations in the present study were at a medium-to-low level. But it should be concerned that a few of sampling sites were highly contaminated by point sources.

[Residues of organochlorine pesticides in urban soil of Shanghai].

The 55 soil samples were collected from Shanghai urban areas in March 2007. The residues and distribution characteristics of organochlorine pesticides (OCPs) in the soil samples were investigated with gas chromatography. The results showed that HCHs, DDTs, and HCB were in the ranges of nd-38.58 microg x kg(-1), 1.81-79.61 microg x kg(-1) and 0.16-40.25 microg x kg(-1), respectively. The total OCPs concentrations in urban soil of Shanghai ranged from 3.12 microg x kg(-1) to 91.07 microg x kg(-1) with a mean of 22.33 microg x kg(-1), and the p,p'-DDE took over 60% of the total OCPs. The main contaminated areas were distributed in the park and greenbelts. The composition of OCPs indicated that OCPs in soil samples mainly came from historical application. Compared to the reference data, the pollution burden in soil of Shanghai was lower than those in other areas of China and in German, Argentina and Poland.

[Distribution, possible source and ecological risk assessment of polycyclic aromatic hydrocarbons in river sediments from a typical contaminated area].

The concentrations of 16 US EPA PAHs in 37 sediment samples collected from Luqiao were analyzed by isotope dilution gas chromatograph/mass spectrometer (GC/MS), and their distribution characters,sources and ecological risk were further investigated. Each of the 16 PAHs could be detected in all of the sediment samples, the total concentrations of the 16 PAHs in the sediments ranged from 59.3 microg/kg to 3 180 microg/kg,with a mean of 722 microg/kg. The pollution level of PAHs can be categorized as low to moderate when compared with other studies around the world. SigmaPAHs were significantly correlated with TOC (r = 0.699, p < 0.001), indicating that TOC was a key soil property affecting the level and fate of PAHs in sediments. The isomeric ratios and factor analysis revealed that PAHs in the Luqiao sediments were originated from mixed sources, and combustion source was dominant. Six sampling sites had the mean PAH ERL quotient > 1, indicating that some sediments in Luqiao may have potential ecological risk. The toxic benzo[a]pyrene equivalents (TEQ(BaP)) of the 16 PAHs ranged from 3.41 microg/kg to 485 microg/kg, 98.4% of which was contributed by 7 carcinogenic PAHs, indicating that 7 PAHs were the main influential factors to the ecological risk.

Occurrence, distribution and possible sources of organochlorine pesticides in agricultural soil of Shanghai, China.

Surface soil samples from agricultural soil of Shanghai were collected and analyzed for 24 organochlorine pesticides (OCPs). The concentrations were in the ranges of nd-10.38 n gg(-1) for HCHs (sum of alpha-, beta-, gamma- and delta-HCH), 0.77-247.45 ng g(-1) for DDTs (sum of p,p'-DDT, p,p'-DDD, p,p'-DDE, and o,p'-DDT), 0.84-10.08 ng g(-1) for CHLs (sum of heptachlor, heptachlor epoxide, cis-chlordane, trans-chlordane, and trans-nonachlor), nd-3.68 ng g(-1) for endosulfan (sum of alpha- and beta-endosulfan), 0.10-3.62 ng g(-1) for HCB and nd-5.69 ng g(-1) for other OCPs (sum of aldrin, dieldrin and endrin). The total OCPs concentrations ranged from 3.16 to 265.24 ng g(-1) and the main contaminated areas were distributed in the south regions of Shanghai (including Fengxian, Nanhui and Jinshan districts). According to the measured concentrations and detection frequencies, HCHs, DDTs, HCB and heptachlor epoxide were the most dominant compounds among the 24 OCPs. The different compositions of DDT, HCH, chlordane and endosulfan indicated that the residues of these compounds in most soil samples originated from historical application, besides slight recent introduction at some sampling locations. The correlation analysis showed no significant relationship between TOC and OCPs. The quality of Shanghai agricultural soil was classified as low pollution by OCPs.

Levels, composition profiles and sources of polycyclic aromatic hydrocarbons in urban soil of Shanghai, China.

Levels, composition profiles and sources of polycyclic aromatic hydrocarbons (PAHs) were analyzed in 55 surface soil samples collected from Shanghai urban districts. The total concentrations of 22 PAHs (SigmaPAHs) ranged from 442 to 19,700 microgkg(-1), with a mean of 3780 microgkg(-1), and the sum of 16 priority PAHs (Sigma16PAHs) varied from 347 to 17,900 microgkg(-1), with a mean of 3290 microgkg(-1), and the seven possible carcinogenic PAHs (Sigma7CarPAHs) accounted for 36-58% of Sigma16PAHs. Among different functional areas, the higher level of PAHs was found in the roadside, followed by greenbelt, commercial district, park, and residential district. The composition of PAHs was characterized by the high molecular weight PAHs, among which fluoranthene, pyrene, benzo[b]fluoranthene and chrysene were most dominant components. A correlation analysis showed that there was relatively good correlation among the individual PAHs, but the contents of PAHs were poorly correlated with soil total organic carbon (TOC). A principal component analysis and PAHs isomeric ratios indicate that PAHs in Shanghai urban soil mainly originated from combustion. The toxic assessment suggested that soil PAHs exposure is medium carcinogenic at present level.

Distribution of persistent organochlorine pesticides in tissue/organ of silver carp (Hypophthalmichthys molitrix) from Guanting Reservoir, China.

The concentration of organochlorine pesticides (OCPs) in tissues and organs of silver carp (Hypophthalmichthys molitrix) from Guanting Reservoir were investigated to evaluate the pollution potential and distribution of OCPs. A total of 16 OCPs were measured and the concentrations were in the range of 1.61-69.01 ng/g wet weight (ww) for total OCPs, 0.16-0.75 ng/g ww for. HCB, 0.75-26.80 ng/g ww for sigmaHCH (sum of alpha-, beta-, gamma- and delta-HCH) and 0.68-35.94 ng/g ww for sigmaDDT( sum of p, p'-DDE, p, p'-DDD, o, p'-DDT and p, p'-DDT). The mean concentrations of total OCPs, HCB, sigmaHCH, and sigmaDDT were 18.04, 0.96, 7.14 and 9.28 ng/g ww, respectively. Among the organochlorine pesticides, beta-HCH and p, p'-DDE were the most dominant compounds in tissue and organ with the average concentrations of 4.42 and 8.14 ng/g, respectively. The results obtained in this study show that the levels of 16 OCP residues found in silver carps are low and pose no threat to human health and wildlife fed upon them on the basis of existing related quality guidelines. However, recent input of lindane and DDT might still exist in the area investigated and further investigation should be carried on.