Tree bark as a biomonitor for the determination of polychlorinated biphenyls and polybrominated diphenyl ethers from Southern Jiangsu, China: levels, distribution, and possible sources.

Tree bark was used as the passive air sampler to evaluate polychlorinated biphenyl (PCB) and polybrominated diphenyl ether (PBDE) pollution and possible sources in Southern Jiangsu. The concentrations of PCBs and Σ7PBDEs were in the range of 0.58-5.19 ng/g dry weight (dw; mean 1.79 ng/g dw) and 17.9-243 pg/g dw (mean 74.7 pg/g dw), respectively. Tri-PCBs were the major PCB homologs, and technical PCB product Ar1242 was identified as the main source. BDE209 concentrations (4.29-456 ng/g dw) were relatively high, indicating that BDE209 pollution was serious in this region. The deca-BDE commercial mixture was the predominant commercial PBDE product used in this region. A good correlation was found between tree bark and polyurethane foam (PUF) disks in Σ6PCB monitoring, suggesting that both of them respond well to the gas-phase PCB monitoring.

Levels and spatial distribution of polybrominated diphenyl ethers (PBDEs) in surface soil from the Yangtze River Delta, China.

Surface soil samples were collected from Suzhou, Wuxi and Nantong in the Yangtze River Delta (YRD), China. Eight BDE congeners (BDE-28, 47, 99, 100, 153, 154, 183 and 209) were measured to determine the levels and compositional profiles in the samples. The concentrations of Σ7PBDEs and BDE-209 ranged from 0.04 to 2.23 µg/kg dw and 1.48 to 41.7 µg/kg dw in the samples, respectively. BDE-209 was the predominant congener (contributing to 69.2 %-99.8 % of Σ8PBDEs) in all samples. It was found that small towns and rural economic development zones in this region had also become sources of polybrominated diphenyl ethers pollutants to surrounding areas. Investigation of the pattern of BDE congener profiles showed that deca- and octa- technical formulations as emission sources were identified in the samples collected from the YRD.

Tree barks for retrospective measurement and source appointment of airborne perfluoroalkyl and polyfluoroalkyl substances.

Tree bark is a useful bioindicator of atmospheric pollution. It is specially suitable for airborne perfluoroalkyl and polyfluoroalkyl substances (PFASs) investigation due to persistence of ionic PFASs. The present work firstly systematically studied tree barks as a bioindicator of airborne PFASs. Comparison with the regular active and passive samplers found barks could produce long-term measurement of airborne PFASs, and could record the historical emission of PFASs with retrospective time frame as long as decades. Factors, e.g. tree type, trunk diameter, and sampling depth, can affect PFAS accumulation in barks, and these factors should be kept consistent during sampling. In a study area spatial distribution of airborne PFASs can be obtained by interpolation of bark results, and the concerned region can be located. Properties of the emission sources can be characterized, and the potential sources can be tracked based on the bark results. Their contributions can be further estimated by the source appointment strategies. In the economically and industrially developed study area of the present study, eight cities of southern Jiangsu Province of China, total ionic PFAS concentration of camphor bark samples collected in 34 sites was 0.44-359 ng/g dw (dry weight), dominated by perfluoroalkyl carboxylic acids (PFCAs). Two types of possible sources were characterized as with long-chained PFCAs and PFOA (perfluorooctanoic acid) as the main components respectively. The sources were appointed as fluoropolymer manufacturing and textile industries, the important PFAS application fields, and their relative contribution was estimated as 32.5% and 67.5% respectively. The present study can provide useful advice to the method framework of using barks for long-term occurrence investigation, concerned region location, and emission source appointment of airborne PFASs in a study area. Based on the bark results, effective strategies can be further made for PFAS pollution elimination and risk control.

An immobilized composite microbial material combined with slow release agents enhances oil-contaminated groundwater remediation.

Microbial remediation of oil-contaminated groundwater is often limited by the low temperature and lack of nutrients in the groundwater environment, resulting in low degradation efficiency and a short duration of effectiveness. In order to overcome this problem, an immobilized composite microbial material and two types of slow release agents (SRA) were creatively prepared. Three oil-degrading bacteria, Serratia marcescens X, Serratia sp. BZ-L I1 and Klebsiella pneumoniae M3, were isolated from oil-contaminated groundwater, enriched and compounded, after which the biodegradation rate of the Venezuelan crude oil and diesel in groundwater at 15 °C reached 63 % and 79 %, respectively. The composite microbial agent was immobilized on a mixed material of silver nitrate-modified zeolite and activated carbon with a mass ratio of 1:5, which achieved excellent oil adsorption and water permeability performance. The slow release processes of spherical and tablet SRAs (SSRA, TSRA) all fit well with the Korsmeyer-Peppas kinetic model, and the nitrogen release mechanism of SSRA N2 followed Fick's law of diffusion. The highest oil removal rates by the immobilized microbial material combined with SSRA N2 and oxygen SRA reached 94.9 % (sand column experiment) and 75.1 % (sand tank experiment) during the 45 days of remediation. Moreover, the addition of SRAs promoted the growth of oil-degrading bacteria based on microbial community analysis. This study demonstrates the effectiveness of using immobilized microbial material combined with SRAs to achieve a high efficiency and long-term microbial remediation of oil contaminated shallow groundwater.

A preliminary investigation of BDE-209, OCPs, and PAHs in urban road dust from Yangtze River Delta, China.

Urban road dust samples were collected from different land use areas in Suzhou, Wuxi, and Nantong, Yangtze River Delta, China. The dust samples were analyzed for the levels and compositional profiles of deca-polybrominated diphenyl ethers (Deca-BDE), 22 organochlorine pesticides (OCPs), and 16 polycyclic aromatic hydrocarbons (PAHs). The levels of BDE-209, ∑OCPs, and ∑PAHs in samples ranged from 4.01-1,439 µg/kg, 3.15-615 µg/kg, and 2.24-58.2 mg/kg, respectively. PAHs were the predominant target compounds in road dust samples, comprising on average 97.7 % of total compounds. The spatial gradient of the pollutants (commercial/residential area> industrial area > urban park concentrations) was observed in the present study. The results indicated that the levels of BDE-209, OCPs, and PAHs observed in road dust were usually linked to anthropogenic activities in the urban environment. In addition, there might be a reflection of current usage or emissions of OCPs in urban environment.

Levels and seasonal variations of polybrominated diphenyl ethers in the urban atmosphere of Beijing, China.

Year-round air samples were collected at Beijing on a weekly basis from 2009 to 2010, to determine the levels, gas-particle distribution, seasonal variations and compositional profiles of 8 polybrominated diphenyl ether congeners. The annual mean atmospheric concentrations of ∑7PBDEs and BDE-209 were 6.16 pg/m(3)(N.D-23.6 pg/m(3)) and 164 pg/m(3) (30.7-454 pg/m(3)), respectively. The results showed wide consumption of industrial products containing commercial deca-BDE mixtures in Beijing. The seasonal variations showed that lower brominated congeners had higher levels and greater proportions in the gaseous phase at warm sampling periods than the higher brominated counterparts.

Concentration and source identification of polycyclic aromatic hydrocarbons and phthalic acid esters in the surface water of the Yangtze River Delta, China.

The pollution from polycyclic aromatic hydrocarbons (PAHs) and phthalic acid esters (PAEs) in the surface water of the rapidly urbanized Yangtze River Delta region was investigated. Fourteen surface water samples were collected in June 2010. Water samples were liquid-liquid extracted using methylene chloride and analyzed by gas chromatography-mass spectrometry. Concentrations of PAHs and PAEs ranged 12.9-638.1 ng/L and 61-28550 ng/L, respectively. Fluoranthene, naphthalene, pyrene, phenanthrene, di-2-ethylhexyl phthalate, and di-n-butyl phthalate were the most abundant compounds in the samples. The water samples were moderately polluted with benzo[a]pyrene according to China's environmental quality standard for surface water. The two highest concentrations of PAHs and PAEs occurred in samples from Taihu Lake, Wuxi City and the western section of Yangchenghu Lake. Potential sources of pollution at S7 were petroleum combustion and the plastics industry, and at Yangchenghu Lake were petroleum combustion and domestic waste. Pollution in samples from the Beijing-Hangzhou Grand Canal originated from diesel engines. There were no obvious sources of pollution for the other water samples. These results can be used as reference levels for future monitoring programs of pollution from PAHs and PAEs.

Levels, seasonal patterns, and potential sources of organochlorine pesticides in the urban atmosphere of Beijing, China.

Air samples collected monthly on the roof of a building in Beijing were analyzed for the levels, seasonal patterns, and potential sources of organochlorine pesticides (OCPs). A high-volume air sampler with polyurethane foam and quartz fiber filters was used to collect monthly samples from November 2005 to April 2009. Hexachlorobenzene (HCB) and DDT isomers were the most abundant organochlorinated pesticides in the Beijing atmosphere. Higher OCP concentrations were generally found in summer, except for HCB. Coal combustion, waste incineration, and fuel combustion were assumed to be the potential HCB emission sources. Significant input of either of these OCPs during our study period was considered very unlikely.

Organochlorine pesticides in muscle of wild seabass and Chinese prawn from the Bohai Sea and Yellow Sea, China.

Muscle samples from wild seabass and Chinese prawn collected from the Bohai Sea and the Yellow Sea, China were analyzed for 22 organochlorine pesticides. DDTs were the predominant contaminants in all samples. The concentration of DDTs in seabass was 247 µg kg(-1) wet wt (from 4.30 to 2,089 µg kg(-1) wet wt). Significantly, concentration of DDTs in seabass was much higher than that in prawn (6.51 µg kg(-1) wet wt). Very high concentrations of DDTs and high DDT/DDTs ratio were found in seabass samples from some locations, which imply there might be new inputs of DDT into the marine environment.

Concentration and gas-particle partitioning of hexachlorobenzene in the ambient air before and after the Beijing Olympic Games.

Systematic studies of hexachlorobenzene in the ambient air before and after the Beijing Olympic Games were carried out during July 2007 to March 2009. Air samples were collected around 20th monthly on the roof of a building near the Olympic center. The average concentration of hexachlorobenzene was 264 pg x m(-3), which was higher in winter than other seasons. However, hexachlorobenzene concentration was decreased clearly in winter in 2008 compare with in 2007 due to the implementation of a series of "Green Olympic" policies. Gas-particle partitioning shows that the increase of hexachlorobenzene levels in winter time was mainly contributed by the high total suspended particulate from combustion processes such as coal-burning and traffic emission.

Seasonality in polybrominated diphenyl ether concentrations in the atmosphere of the Yangtze River Delta, China.

Polybrominated diphenyl ether (PBDE) concentrations in the atmosphere in rapidly developing parts of China have been studied little. In this study, polyurethane foam disk passive air samplers were used to comprehensively investigate PBDE concentrations in the atmosphere of the Yangtze River Delta in different seasons in 2010 and 2011. The mean sum of the concentrations of 13 PBDE congeners was 3.3 pg/m(3) in spring, 7.3 pg/m(3) in summer, 1.0 pg/m(3) in autumn, and 12 pg/m(3) in winter. Higher PBDE concentrations were found in urban areas than in rural areas. The PBDE concentrations were comparable to concentrations that have been found in cities around the world. BDE28, BDE47, BDE99, BDE153, and BDE183 were the dominant PBDE congeners in all seasons. High PBDE concentrations were found in satellite cities, such as Changshu, Wujiang, and Zhangjiagang, suggesting that commercial PBDEs (including pentabromodiphenyl ether products) are produced and/or used in those cities. The PBDE concentrations in the atmosphere were used to estimate daily doses through the inhalation of outdoor air. The most severe risks posed by exposure to PBDEs were found to occur in winter, for both adults and children, but the PBDE concentrations were found not to pose appreciable risks to human health.

Changes of polybrominated diphenyl ethers and polychlorinated biphenyls in surface soils from urban agglomeration of the Yangtze River Delta, in China between 2003 and 2012.

Surface soil samples were collected from urban agglomeration of the Yangtze River Delta (YRD), China in 2003 and 2012, respectively. Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were analyzed to determine if there were any changes in their levels and compositional profiles between the two sampling years. The concentrations of Σ8PBDEs ranged from 0.553 to 13.0 µg kg(-1)(with the mean of 3.31 µg kg(-1)) in the 2003 samples and from 1.01 to 43.2 µg/kg (with the mean of 10.0 µg kg(-1)) in the 2012 samples. The concentrations of Σ32PCBs ranged from 0.301 to 3.29 µg kg(-1)(with the mean of 1.01 µg kg(-1)) in the 2003 samples and from 0.205 to 3.96 µg/kg (with the mean of 0.991 µg kg(-1)) in the 2012 samples. The comparisons between the 2012 and 2003 data showed that PBDEs concentrations increased over the years, but PCB concentrations did not change much. BDE-209 was the major BDE congener in both the 2003 and 2012 samples, indicating that the dominant PBDE mixture production and usage in the YRD had been the commercial deca-BDE mixture. Investigation of the PBDE congener profiles indicated that there had been new input of octa-BDEs in this region in recent years. Little change was found for the pattern of PCBs congener profiles between 2 years' samples. As such, spatial distributions of PBDEs or PCBs in surface soil samples reflected a gradient (from high to low) from the central cities out to rural areas in both the 2003 and 2012 data. In addition, high concentrations of PBDEs were observed in the industrial and residential areas, whereas high concentrations of PCBs were only observed in the industrial areas.

[Determination of kepone in water by liquid chromatography-tandem mass spectrometry].

An analytical procedure for the determination of kepone in water was described. Water samples were extracted by liquid-liquid extraction, and then cleaned-up. Chromatographic separation was performed on an Eclipse plus C18 column (100 mm x 2.1 mm, 3.5 microm) with gradient elution using acetonitrile and water at a flow rate of 0.3 mL/min. The target compounds were determined in multiple reaction monitoring (MRM) mode via negative electrospray ionization (ESI(-)) and quantified by isotopic-dilution technique. Results showed that kepone existed as diol form and hemiacetal in acetone/acetonitrile and methanol respectively, the structures of which were confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Due to the polar nature of kepone, it was difficult to be eluted during clean-up procedure and it may be decomposed during sulfuric acid washing. Therefore, it could not be analyzed together with the other organochlorine pesticides. The calibration curve showed good linearity in the range of 5-100 microg/L with correlation coefficient (r2) of 0.999. The limit of detection was 0.70 ng/L and the limit of quantification was 2.8 ng/L in water. The average recoveries when spiked at 5, 40 and 100 ng/L in water were 95.1%-98.9%, and the relative standard deviations (RSDs) were 3.85%-4.72%. The method can be used to the determination of kepone in water due to its high sensitivity, good recovery and reproducibility.

Spatial distribution and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in Camphor (Cinnamomum camphora) tree bark from Southern Jiangsu, China.

The concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) were investigated in Camphor tree bark from Southern Jiangsu, China. Tree bark samples were collected in August 2012. The Σ15PAHs concentrations were ranged from 6.18 to 1560 ng g(-1)dry weight (dw), with an average value of 407 ng g(-1)dw. Generally, the concentrations of PAHs in the suburban areas were the highest, followed by urban and rural areas. Principal component analysis and diagnostic ratios results showed that vehicle emission, biomass and coal combustion and industrial emission were the major sources of PAHs in tree bark from Southern Jiangsu. Good correlation was found between tree bark and polyurethane foam (PUF) samplers, indicating that both of them respond well to the gas-phase PAHs monitoring.

[Levels and possible sources of organochlorine pesticides (OCPs) in camphor (Cinnamomum camphora) tree bark from Southern Jiangsu, China].

Thirty-three camphor tree bark samples were collected from Southern Jiangsu in August 2012. They were analyzed for organochlorine pesticides (OCPs), including hexachlorobenzene (HCB), DDTs (o,p'-DDE, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT and p,p'-DDT), trans-chlordane and cis-chlordane. The concentrations of HCB, sigma6 DDTs and sigma Chlordanes ranged (dw) from 0.31 ng x g(-1) to 1.81 ng x g(-1), 0.40 ng x g(-1) to 17.3 ng x g(-1) and n. d. to 1.03 ng x g(-1), respectively. Due to the high volatility, the spatial distribution of HCB in Southern Jiangsu was uniform. Compared to the other results, the HCB concentration in Southern Jiangsu was lower. The historical usage of technical DDT mixture and the dicofol-type DDT were the major sources of DDTs in southern Jiangsu. The TC/CC ratio is usually used to distinguish between aged and fresh chlordane. According to the ratio of TC/CC, the chlordane in the urban area was derived from the fresh application of technical chlordane, and that in the rural area was attributed to the historical usage.

Assessment of halogenated POPs and PAHs in three cities in the Yangtze River Delta using high-volume samplers.

The objective of this study was to quantify organic chlorinated pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs) in air samples collected from July 2009 to April 2010 in Suzhou, Wuxi and Nantong in the Yangtze River Delta (YRD) and to identify potential sources of these pollutants during the period. Gas- and particle-phase concentrations of these species were determined using gas chromatography-mass spectrometry on samples collected using high volume samplers. Phenanthrene, fluoranthene, hexachlorobenzene (HCB), p,p'-DDE, tri-CB (#18), tri-CB (#28) and deca-BDE (#209) were the most abundant compounds in the YRD. Average concentrations of these pollutants in Suzhou, Wuxi and Nantong, respectively, were 88.4, 105 and 69.5 ng/m(3) for PAHs, 162, 237 and 136 pg/m(3) for HCB, 35.7, 41.7 and 34.7 pg/m(3) for hexachlorocyclohexane, 131, 83.1 and 229 pg/m(3) for DDTs, 63.4, 52.4 and 31.7 pg/m(3) for chlordanes, 80.5, 51.8 and 65.1 pg/m(3) for PCBs, 30.4, 32.0 and 54.6 pg/m(3) for PBDEs (tri- to hepta-BDE) and 882, 807 and 1200 pg/m(3) for deca-BDE (#209). Concentrations of the emerging persistent organic pollutant, deca-BDE (#209), in the three cities were greater than those of other countries. Massive production and/or the use of commercialized deca-BDE (#209) may occur in metropolitan areas and development zones in the YRD.

Passive air sampling of organochlorine pesticides and polychlorinated biphenyls in the Yangtze River Delta, China: concentrations, distributions, and cancer risk assessment.

The Yangtze River Delta (YRD) has been quickly industrialized and urbanized. Passive air sampling of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) was carried out in the YRD in 2010-2011 to investigate their spatiotemporal distributions and estimate the risk of cancer from their inhalation. Annual concentrations were 151, 168, 18.8, 110, 17.9, and 35.0 pg m(-3) for HCB, ∑DDTs, ∑HCHs, ∑chlordane, mirex, and PCBs, respectively. The highest OCP and PCB concentrations were generally detected in the autumn and winter. The average concentrations of OCPs and PCBs for the different site groups followed the order urban ≈ urban-rural transition > rural. The lifetime excess cancer risks from the inhalation of OCPs and PCBs were <1.0 × 10(-6). The predicted cancer cases per lifetime associated with the inhalation of OCPs and PCBs are 12, 7, and 4 per ten thousand people for urban, urban-rural transition, and rural areas, respectively.

[Polybrominated diphenyl ethers and polychlorinated biphenyls in road dust from Suzhou, Wuxi and Nantong].

Fifty-eight urban road dust samples were collected in June of 2009 from Suzhou, Wuxi and Nantong, South Jiangsu Province. Eight polybrominated diphenyl ether (PBDE) congeners and thirty-two polychlorinated biphenyl (PCB) congeners were measured using the gas chromatography-mass spectrometry. Concentrations of Sigma8PBDEs and Sigma32PCBs ranged from 4. 21 to 1 471 microg.kg-1 and ND was 14. 1 microg.kg-1 in the road dust samples, respectively. On the average, levels of PBDEs were much higher than PCBs in samples. Compared with the levels of PBDEs and PCBs in urban soil samples, results indicated that PBDEs levels observed in road dust samples were much higher than urban soil samples collected from other cities. Road dust PBDEs from combustion sources and vehicle emission should be attracted concerns. No significant difference was found between the levels of PBDEs or PCBs in the industrial areas and the urban center area, but was higher than landscape area. The results showed that there were exited unintentional emissions of PCBs in industrial areas. Investigation of compositional pattern of PBDEs indicated that BDE209 was the predominant congener in all samples, contributed 96.7% (64. 1% -99.8% ) of Sigma8 PBDEs . The dominant congeners in the Sigma32PCBs were tetra-PCBs and hexa-PCBs. The compositional pattern of PCBs congeners found in the road dust was not consistent with that of the commercial PCBs product and other environmental matrix.

[PUF passive air sampling of polycyclic aromatic hydrocarbons in atmosphere of the Yangtze River Delta, China: spatio-temporal distribution and potential sources].

Atmosphere is regarded to be an important media in the environmental pollution research area. Passive air sampling was one of the effective complementary sampling techniques for the active high volume air sampler in recent decades. A regional scale investigation on the atmospheric polycyclic aromatic hydrocarbons (PAHs) was conducted in the Yangtze River Delta (YRD). Polyurethane foam based passive air samplers were used to collect the atmospheric PAHs from 31 sampling sites in this area. PAHs concentrations ranged from 10.1 ng x m(-1) to 367 ng x m(-3) in this study. The annual average concentration of benzo [a] pyrene (BaP) reached 2.25 ng x m(-3), which was two times higher exceeding the national standard, GB 3095-2012. The atmospheric PAHs during four seasons decreased in the following order: autumn > winter > spring > summer. Larger BaP excessive areas were found in autumn and winter than other seasons. Moreover, an obvious emission of BaP was confirmed during the winter time. Traffic related petroleum combustion, coal and biomass burning, and coke oven were identified as potential sources of atmospheric PAHs, contributing 38.1%, 42.4%, and 19.5%, respectively.

Concentrations and possible sources of polychlorinated biphenyls in the surface water of the Yangtze River Delta, China.

In this study, polychlorinated biphenyls (PCBs) pollution in the surface water of the Yangtze River Delta (YRD) was investigated. A total of 26 samples were collected from water bodies in three cities within the YRD during the dry season from October to November of 2009. The total PCBs (dissolved plus particulate) ranged from 1.23 to 16.6 ng L(-1) and were dominated by tri-, tetra-, and penta-chlorinated biphenyls. The mean PCBs in the Beijing-Hangzhou Grand Canal and the Yangtze River were 8.84 and 3.36 ng L(-1), respectively. A t-test showed that there were no significant differences in the concentration of samples from the metropolitan area and the development zone. According to the Chinese national environmental quality standards for surface water (GB 3838-2002), the concentrations of PCBs observed in this study do not pose a hazard to aquatic or human health. Overall, this study described the PCB concentration and homolog distribution patterns in one of the most rapidly developing areas in China, and the results can be used as reference levels for future PCB monitoring programs.