Distribution characteristics and health risk assessment of volatile organic compounds in the groundwater of Lanzhou City, China.

Volatile organic compounds (VOCs) typically exist in the aqueous environment due to global anthropogenic activities. The distribution and contaminated profile (or characteristics) of VOCs in the groundwater of Lanzhou, China, were investigated in this study. Groundwater samples were collected from 30 sampling points in December 2015, and a total of 17 VOCs were analyzed by purge and trap gas chromatography-mass spectrometry. Thirteen types of VOCs were detected at 29 sampling points in the study area. Of these, dichloromethane and toluene, which were found at 22 sampling points, had the highest detection frequency (73.3%), followed by benzene (66.7%), 1,2-dichloroethane (50%), and xylenes (50%). The highest average concentration among the detected VOCs was found for chloroform (5151.5 µg/L). The spatial distribution of VOC contamination in four major urban areas of Lanzhou and the variation in VOC concentration caused by land use transitions were also analyzed. The results showed that Xigu district was the most polluted area in Lanzhou, mainly due to land use for industrial proposes. On the contrary, the samples for Anning district showed lower VOC concentrations because of better groundwater quality, which is associated with the absence of manufacturing industries in this region. The health risk assessment model developed by the United States Environmental Protection Agency was employed in this study to evaluate safety for drinking water use. This study found that despite considering the volatilization of VOCs from water due to heating, six sampling points (G05 in Qilihe district; G07 and G09 in Xigu district; G16, G17, and G15 in Chengguan district) showed non-carcinogenic risks, ranging from 1.63 to 14.2, while three points (G16 in Chengguan district, and G10 and G07 in Xigu district) exhibited high carcinogenic risks for human health, ranging from 2.94 × 10-4 to 6.85 × 10-4. Trichloroethylene, tetrachloroethylene, and 1,2-dichloroethylene were identified as the dominant VOCs, presenting high non-carcinogenic risk. 1,2-dichloroethane and vinyl chloride were the primary factors for high carcinogenic risk. The high-risk areas were concentrated in Xigu and Chengguan districts, suggesting the need to alert the relevant local government departments.

Removal of 1,2-Dichloroethane from real industrial wastewater using a sub-surface batch system with Typha angustifolia L.

1,2-Dichloroethane (1,2-DCA) is widely present in urban wastewaters and can be remediated by green technology. Subsurface batch system constructed wetlands (SSCWs) using macrophyte species of T. angustifolia L. were examined to remove 1,2-DCA using real wastewater from a petrochemical industry with a 1,2-DCA concentration of 390mg/L. We conducted an experiment with four pilot-scale constructed wetlands (0.81m2) in a greenhouse. Three SSCWs (T2, T3 and T4) were fed with real wastewater, and another one (T1) was fed with tap water (as plant control) to assess the role of T. angustifolia L. and their associated rhizobacteria to remediate 1,2-DCA. Tank T2 contained only sand without plants acting as contaminant control, tank T3 contained sand with plants and finally tank T4 contained plants with mixture of sand, soil and compost (3:2:1). The results show that the green technology has improved the removal of 1,2-DCA from the contaminated water through biodegradation with a remediation efficiency of 100% in T4 within 42 days. The removal efficiency was enhanced in T4 with 18% more than in T3 due to the compost addition, giving evidence for the potential application of SSCWs to treat chlorinated hydrocarbon in real field.

Co-occurrence of genes for aerobic and anaerobic biodegradation of dichloroethane in organochlorine-contaminated groundwater.

1,2-Dichloroethane (DCA) is a problematic groundwater pollutant. Factors influencing the distribution and activities of DCA-degrading bacteria are not well understood, which has hampered their application for bioremediation. Here, we used quantitative PCR to investigate the distribution of putative DCA-dehalogenating bacteria at a DCA-impacted site in Sydney (Australia). The dehalogenase genes dhlA, tceA and bvcA were detected in all groundwater samples (n = 15), while vcrA was found in 11/15 samples. The 16S rRNA gene sequences specific to the dehalogenating genera Dehalobacter, Desulfitobacterium and Dehalogenimonas were detected in 15/15, 13/15 and 13/15 samples, respectively, while Dehalococcoides sequences were found in 9/15 samples. The tceA, bvcA and vcrA genes occurred in the same samples as Dehalococcoides and Dehalobacter. Microcosm experiments confirmed the presence of bacteria capable of dechlorination under anoxic conditions. The abundance of the dhlA gene, which is found in hydrolytic DCA degraders, was positively correlated to the DCA concentration, and was unexpectedly most abundant in samples with low oxygen conditions. A dhlA-containing bacterium isolated from the site (Xanthobacter EL8) was capable of anaerobic growth on DCA under denitrifying conditions. The presence of diverse DCA-dehalogenating bacteria at this site indicates that natural attenuation or biostimulation could be valid approaches for site cleanup.

Vapor intrusion risk of lead scavengers 1,2-dibromoethane (EDB) and 1,2-dichloroethane (DCA).

Vapor intrusion of synthetic fuel additives represented a critical yet still neglected problem at sites impacted by petroleum fuel releases. This study used an advanced numerical model to simulate the vapor intrusion risk of lead scavengers 1,2-dibromoethane (ethylene dibromide, EDB) and 1,2-dichloroethane (DCA) under different site conditions. We found that simulated EDB and DCA indoor air concentrations can exceed USEPA screening level (4.7 × 10(-3) µg/m(3) for EDB and 1.1 × 10(-1) µg/m(3) for DCA) if the source concentration is high enough (is still within the concentration range found at leaking UST site). To evaluate the chance that vapor intrusion of EDB might exceed the USEPA screening levels for indoor air, the simulation results were compared to the distribution of EDB at leaking UST sites in the US. If there is no degradation of EDB or only abiotic degradation of EDB, from 15% to 37% of leaking UST sites might exceed the USEPA screening level. This study supports the statements made by USEPA in the Petroleum Vapor Intrusion (PVI) Guidance that the screening criteria for petroleum hydrocarbon may not provide sufficient protectiveness for fuel releases containing EDB and DCA. Based on a thorough literature review, we also compiled previous published data on the EDB and DCA groundwater source concentrations and their degradation rates. These data are valuable in evaluating EDB and DCA vapor intrusion risk. In addition, a set of refined attenuation factors based on site-specific information (e.g., soil types, source depths, and degradation rates) were provided for establishing site-specific screening criteria for EDB and DCA. Overall, this study points out that lead scavengers EDB and DCA may cause vapor intrusion problems. As more field data of EDB and DCA become available, we recommend that USEPA consider including these data in the existing PVI database and possibly revising the PVI Guidance as necessary.

Are Biometric Parameters Helpful to Assess the Health Risk of Consuming Organochlorine Compounds Contaminated Silver European Eel (Anguilla anguilla)?

Several organochlorine compounds (OCs) were measured in European eels from the Tevere river (Italy). It followed that some of them are still important chemical contaminants. Concentrations of dichlorodiphenyltrichloroethanes (DDTs) are hazardous for the consumer health; those of the 6 indicator polychlorinated biphenyls (PCBs) are often close to the current European maximum residue limit and always higher than the former limit. The relationship between OC concentrations, biometric parameters and the lipid content was then investigated. A strong positive correlation with eel size emerged for the indicator PCBs and DDTs concentrations expressed on wet weight basis. This is explained by the corresponding higher lipid percentage that characterizes bigger eels and the absence of a dilution effect for compounds of main concerns. On the basis of the PCB-TDI threshold for a 70 kg person, we suggest that 1 should consume no more than 2 eels per week each weighing about 100 g. Thus, we conclude that eel consumption should be limited and restricted to eels relatively shorter and lighter.

Correlation between DNAPL distribution area and dissolved concentration in surfactant enhanced aquifer remediation effluent: A two-dimensional flow cell study.

During the process of surfactant enhanced aquifer remediation (SEAR), free phase dense non-aqueous phase liquid (DNAPL) may be mobilized and spread. The understanding of the impact of DNAPL spreading on the SEAR remediation is not sufficient with its positive effect infrequently mentioned. To evaluate the correlation between DNAPL spreading and remediation efficiency, a two-dimensional sandbox apparatus was used to simulate the migration and dissolution process of 1,2-DCA (1,2-dichloroethane) DNAPL in SEAR. Distribution area of DNAPL in the sandbox was determined by digital image analysis and correlated with effluent DNAPL concentration. The results showed that the effluent DNAPL concentration has significant positive linear correlation with the DNAPL distribution area, indicating the mobilization of DNAPL could improve remediation efficiency by enlarging total NAPL-water interfacial area for mass transfer. Meanwhile, the vertical migration of 1,2-DCA was limited within the boundary of aquifer in all experiments, implying that by manipulating injection parameters in SEAR, optimal remediation efficiency can be reached while the risk of DNAPL vertical migration is minimized. This study provides a convenient visible and quantitative method for the optimization of parameters for SEAR project, and an approach of rapid predicting the extent of DNAPL contaminant distribution based on the dissolved DNAPL concentration in the extraction well.

Predictor-Response Analysis of Fiber Optic Enzymatic Biosensors Constructed with Nonmodified E. coli BL21 (DE3) pGELAF+ Sensing 1,2-Dichloroethane.

Biosensor technology can lack methods to iteratively validate system outputs (i.e., signals) concomitantly with the development of mathematical models. We evaluated a nonmodified fiber optic enzymatic biosensor (FOEB-Escherichia coli BL21 (DE3) pGELAF+) sensing dichloroethane with a predictor-response statistical form. The linear regression technique applied with MATLAB functions correlated FOEB parameters to sensing responses that could be used to identify system characteristics and interactions. A FOEB specific metric (i.e. normalized sensitivity) is shown to be significant as a mixed sensing correlation metric suggesting that similar development parameters could be related to engineering design paradigms for biosensor (or whole cell biosensor) systems.

C and Cl isotope fractionation of 1,2-dichloroethane displays unique δ¹³C/δ³7Cl patterns for pathway identification and reveals surprising C-Cl bond involvement in microbial oxidation.

This study investigates dual element isotope fractionation during aerobic biodegradation of 1,2-dichloroethane (1,2-DCA) via oxidative cleavage of a C-H bond (Pseudomonas sp. strain DCA1) versus C-Cl bond cleavage by S(N)2 reaction (Xanthobacter autotrophicus GJ10 and Ancylobacter aquaticus AD20). Compound-specific chlorine isotope analysis of 1,2-DCA was performed for the first time, and isotope fractionation (ε(bulk)(Cl)) was determined by measurements of the same samples in three different laboratories using two gas chromatography-isotope ratio mass spectrometry systems and one gas chromatography-quadrupole mass spectrometry system. Strongly pathway-dependent slopes (Δδ13C/Δδ37Cl), 0.78 ± 0.03 (oxidation) and 7.7 ± 0.2 (S(N)2), delineate the potential of the dual isotope approach to identify 1,2-DCA degradation pathways in the field. In contrast to different ε(bulk)(C) values [-3.5 ± 0.1‰ (oxidation) and -31.9 ± 0.7 and -32.0 ± 0.9‰ (S(N)2)], the obtained ε(bulk)(Cl) values were surprisingly similar for the two pathways: -3.8 ± 0.2‰ (oxidation) and -4.2 ± 0.1 and -4.4 ± 0.2‰ (S(N)2). Apparent kinetic isotope effects (AKIEs) of 1.0070 ± 0.0002 (13C-AKIE, oxidation), 1.068 ± 0.001 (13C-AKIE, S(N)2), and 1.0087 ± 0.0002 (37Cl-AKIE, S(N)2) fell within expected ranges. In contrast, an unexpectedly large secondary 37Cl-AKIE of 1.0038 ± 0.0002 reveals a hitherto unrecognized involvement of C-Cl bonds in microbial C-H bond oxidation. Our two-dimensional isotope fractionation patterns allow for the first time reliable 1,2-DCA degradation pathway identification in the field, which unlocks the full potential of isotope applications for this important groundwater contaminant.

Surgical smoke may be a biohazard to surgeons performing laparoscopic surgery.

BACKGROUND: Surgical smoke production is inevitable during surgical procedures. Although many workplaces have adopted smoke-free environments, healthcare workers, especially surgeons, continue to be exposed to surgical smoke. METHODS: From February 2013 to March 2013, a total of 20 patients underwent transperitoneal laparoscopic nephrectomy for renal cell carcinoma. A 5-L gas sample was collected 30 min after the electrocautery device was first used and was analyzed by gas chromatography and mass spectrometry. Cancer risk was calculated for carcinogenic compounds and hazard quotient was calculated for noncarcinogenic compounds using US Environmental Protection Agency guidelines. RESULTS: Twenty patients with a median age of 57.5 years were enrolled in the study. Eighteen volatile organic compounds were detected by Japanese indoor air standards mix analysis. The cancer risks were ethanol, 5.10 × 10(-5) ± 6.35 × 10(-5); 1,2-dichloroethane, 4.75 × 10(-3) ± 7.42 × 10(-4); benzene, 1.09 × 10(-3) ± 4.33 × 10(-4); ethylbenzene, 2.87 × 10(-5) ± 1.32 × 10(-5); and styrene, 2.94 × 10(-6) ± 1.16 × 10(-6). The hazard quotients were acetone, 1.88 × 10(-2) ± 7.63 × 10(-3); hexane, 1.48 × 10(-1) ± 8.70 × 10(-2); benzene, 4.66 ± 1.85; toluene, 2.61 × 10(-2) ± 7.23 × 10(-3); p-xylene, 1.81 × 10(-1) ± 6.45 × 10(-2); o-xylene, 2.40 × 10(-2) ± 3.33 × 10(-2); and styrene, 5.15 × 10(-3) ± 2.03 × 10(-3). CONCLUSIONS: For five carcinogenic compounds detected, the cancer risk was greater than negligible. For 1,2-dichloroethane and benzene, the risk was classified as unacceptable. Analysis of noncarcinogenic compounds showed that risk reduction measures are needed for benzene. Even though surgical smoke is not an immediate health hazard, operating room personnel should be aware of the potential long-term health risks associated with exposure.

Comprehensive screening and priority ranking of volatile organic compounds in Daliao River, China.

An analytical strategy for comprehensive screening of target and non-target volatile organic compounds (VOCs) in surface water was developed, and it was applied to the analysis of VOCs in water samples from Daliao River. The target VOCs were quantified using purge and trap-gas chromatography-mass spectrometry (P&T-GC/MS). Among 20 water samples, 34 VOCs were detected at least once. For the screening of non-target VOCs, the double distillation apparatus was used for the pre-concentration of VOCs prior to P&T-GC/MS analysis. Subsequently, deconvolution software and NIST mass spectral library were applied for the identification of the non-target compounds. A total of 17 non-target VOCs were identified. The most frequently detected VOCs (detection frequencies >80 %) included toluene, benzene, naphthalene, 1,2-dichloroethane, 1,1,2-trichloroethane, and methyl tert-butyl ether. The distribution of VOCs obviously varied according to the sampling sites. The total concentrations of VOCs in water samples collected from the heavily industrialized cities (Anshan and Liaoyang) and the busy port city (Yingkou) were relatively high. The top ten priority VOCs, including naphthalene, 1,2-dichloroethane, o-xylene, 1,3-dichlorobenzene, tetrachloroethene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, ethylbenzene, m-xylene, and p-xylene, were obtained by the ranking of the detected VOCs according to their occurrence and ecological effects. These compounds should be given more attention in monitoring and drainage control strategies.

[To the question of the optimization of methods for detection of vinyl chloride and 1,2-dichloroethane, and their metabolites in biological fluids in workers involved in production of polyvinyl chloride].

There is considered the improvement of methodological approaches to the gas chromatographic methods- of the detection of vinyl chloride and 1,2-dichloroethane and their metabolites--chloroethanol and monochloroacetic acid in biological fluids. There were evaluated such metrological characteristics of methods, as repeatability, interlaboratoty precision, relevance and accuracy. The value of relative expanded uncertainty does not exceed 30%. There are reported optimal regimes of gas chromatographic analysis, conditions for sample preparation. The results of the contents ofthese chemical compounds and their metabolites in biological fluids from persons working in contact with chlorinated hydrocarbons are presented These techniques can be used for the detection ofthe fact of exposure to toxic substances, assessment of the level of exposure and biomonitoring.

Enhanced 1,2-dichloroethane degradation in heavy metal co-contaminated wastewater undergoing biostimulation and bioaugmentation.

Biostimulation, bioaugmentation and dual-bioaugmentation strategies were investigated in this study for efficient bioremediation of water co-contaminated with 1,2-dichloroethane (1,2-DCA) and heavy metals, in a microcosm set-up. 1,2-DCA concentration was periodically measured in the microcosms by gas chromatographic analysis of the headspace samples, while bacterial population and diversity were determined by standard plate count technique and Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) analysis, respectively. Dual-bioaugmentation, proved to be most effective exhibiting 22.43%, 26.54%, 19.58% and 30.49% increase in 1,2-DCA degradation in microcosms co-contaminated with As(3+), Cd(2+), Hg(2+) and Pb(2+), respectively, followed by bioaugmentation and biostimulation. Dual-bioaugmented microcosms also exhibited the highest increase in the biodegradation rate constant (k1) resulting in 1.76-, 2-, 1.7- and 2.1-fold increase in As(3+), Cd(2+), Hg(2+) and Pb(2+) co-contaminated microcosms respectively, compared to the untreated microcosms. Dominant bacterial strains obtained from the co-contaminated microcosms were found to belong to the genera Burkholderia, Pseudomonas, Bacillus, Enterobacter and Bradyrhizobium, previously reported for 1,2-DCA and other chlorinated compounds degradation. PCR-DGGE analysis revealed variation in microbial diversity over time in the different co-contaminated microcosms. Results obtained in this study have significant implications for developing innovative bioremediation strategies for treating water co-contaminated with chlorinated organics and heavy metals.

[Sand box study on fingering front morphology for NAPLs infiltrated in homogeneous porous media].

Abstract: 1,2-dichloroethane and tetrachlorethylene were studied in four different unsaturated porous media to determine the impact of the properties of media and fluids on the infiltration aided by digital image analysis technique. The results indicated that the whole process of NAPLs migration can be recorded dynamically using the digital image analysis technique. The unstable flow "fingering" occurred in the process of infiltration. Fingering mechanisms such as splitting, coalescing, and shielding were observed in the process of fingering. Front morphology of the infiltration was influenced by the properties of porous media and fluids. The vertical migration rates and the growth rates of area development were positively correlated to the size of medium particle and the density of the NAPLs (except for toluene) in the process of infiltrating. The number of fingers and the wavelength of fingering were also closely correlated with the properties of media and fluid. DNAPLs infiltrated faster compared with LNAPLs, which resulted in larger pollution area within the same infiltration time. It can be concluded that the environmental risk of DNAPLs is significantly greater than the LNAPLs.

[Case study on health risk assessment based on site-specific conceptual model].

Site investigation was carried out on an area to be redeveloped as a subway station, which is right downstream of the groundwater of a former chemical plant. The results indicate the subsurface soil and groundwater in the area are both polluted heavily by 1,2-dichloroethane, which was caused by the chemical plant upstream with the highest concentration was 104.08 mg.kg-1 for soil sample at 8.6 m below ground and the highest concentration was 18500 microg.L-1 for groundwater. Further, a site-specific contamination conceptual model, giving consideration to the specific structure configuration of the station, was developed, and the corresponding risk calculation equation was derived. The carcinogenic risks calculated with models developed on the generic site conceptual model and derived herein on the site-specific conceptual model were compared. Both models indicate that the carcinogenic risk is significantly higher than the acceptable level which is 1 x 10(-6). The comparison result reveals that the risk calculated with the former models for soil and groundwater are higher than the one calculated with the latter models by 2 times and 1.5 times, respectively. The finding in this paper indicates that the generic risk assessment model may underestimate the risk if specific site conditions and structure configuration are not considered.

Effects of soil temperature and agitation on the removal of 1,2-dichloroethane from contaminated soil.

Mechanical soil aeration is an effective and low cost ex-situ remediation technique suitable for large sites contaminated by volatile organic compounds. However, this technique is still in the testing and development phase. To understand the effectiveness of this remediation technique and the main factors influencing its efficacy, an abandoned typical chlor-alkali chemical industry site was remediated using this technology on a pilot-scale. The results showed that this technology is effective for the remediation of volatile organic compounds, with a removal efficiency of greater than 99%. During the experiment, a better result was observed in the first 120 h than the last 120 h. Both temperature and agitation affected the remediation. Higher environmental or soil temperatures resulted in more rapid attenuation of 1,2-dichloroethane (1,2-DCA). Agitation had an obvious effect during the first 120 h. A preliminary dynamic characteristic study showed that the volatilization process can be described by a function similar to y=a+be((-kt)). Temperature (both environmental and soil temperature) had a greater effect on the reaction rate constant and the half-life of 1,2-DCA compared with agitation. This study aims to improve the remediation of contaminated sites, especially large areas contaminated by volatile organic contaminants.

Catalytic hydrodechlorination of 1,2-dichloroethane using copper nanoparticles under reduction conditions of sodium borohydride.

1,2-Dichloroethane (1,2-DCA) is a raw material used for the manufacture of vinyl chloride monomer (VCM) and therefore has very often been detected in the groundwater nearby the VCM manufacturing plant. Zero-valent iron (ZVI) is capable of degrading a wide array of highly chlorinated contaminants; however, the reactivity of ZVI towards 1,2-DCA is very low. In this study, zero-valent copper nanoparticles have been synthesized for effective dechlorination of 1,2-DCA under reduction conditions of sodium borohydride. Copper nanoparticles consisted of mainly metallic copper (Cu(0)) with small amounts of cuprous oxide (Cu(2)O). They have surface areas of about 19.0 m(2) g(-1) and an average diameter of 15 nm. Batch experiments were conducted to test the effectiveness of copper nanoparticles for 1,2-DCA degradation using sodium borohydride as electron donors where the ORP was measured as -1100 mV. More than 80% of 1,2-DCA (30 mg L(-1)) was rapidly degraded within 2 h in the presence of both copper nanoparticles (2.5 g L(-1)) and borohydride (25 mM). No reduction of 1,2-DCA was observed when the system contained either copper nanoparticles alone or borohydride alone. The degradation intermediates included ethane and ethylene accounting for 79% and ∼1.5% of the 1,2-DCA lost, respectively. Potential environmental applications can be achieved by immobilizing copper nanoparticles onto the surface of reducing metals to form a reactive bimetallic structure.

Surprises perilous: toxic health hazards for employees unloading fumigated shipping containers.

The fumigation of freight containers to protect transported goods from fungal and pest infestation has increased worldwide in the last five years due to international regulations requiring fumigation or heat treatment of wooden packaging material and dunnage. We have found in 2008 that every sixth container and its contents do retain harmful concentrations of various fumigants and chemicals, representing a significant health risk for port and transport workers, customs officials, warehousemen, store employees and consumers. The shipping documents of these containers did not provide any information about the fumigation procedure or the used fumigant. We report here the cases of 26 patients introduced to our outpatient clinic with presumed intoxication to fumigants, or with symptoms due to inhaling the air out of fumigated containers. All patients were examined from 2007 to 2010 according to a standardized comprehensive diagnostic program. We were able to confirm the diagnosis based on typical symptoms and extensive clinical examination; by laboratory analysis we identified ethylene dichloride, methyl bromide, phosphine and methylene chloride. The predominant symptoms were headaches, concentration and memory problems, dizziness and nausea, irritation of the skin and mucous membranes and a reduced ability to do exercise. In addition to the neurological and neuropsychological impairments our analyses verified the development of reactive airways dysfunction syndrome (RADS) in 14 of 26 patients with long lasting symptoms due to their contact with fumigants. Intoxications with fumigants are serious and could be avoided. These systematical explored cases show the sustainable impact for health and socio-economic wellbeing. These findings also emphasize the necessity for international standards on permitted fumigants, appropriate labeling in the shipping documents and handling of fumigated containers.

Characterization of hydrophobic hypercrosslinked polymer as an adsorbent for removal of chlorinated volatile organic compounds.

A hydrophobic hypercrosslinked polymer with poly (4-tert-butylstyrene-styrene-divinylbenzene) matrix (LC-1) was prepared as adsorbent for the removal of volatile organic compounds from gas streams. The content of oxygen-containing functional groups of LC-1 was about one-fourth that of commercial hypercrosslinked polymeric adsorbent (NDA-201). The results of the water vapor adsorption experiment indicated that LC-1 had a more hydrophobic surface than NDA-201. Three chlorinated volatile organic compounds (trichloroethylene, trichloromethane, and 1, 2-dichloroethane) were used to investigate the adsorption characteristics of LC-1 under dry and humid conditions. Equilibrium adsorption data in dry streams showed that LC-1 had good adsorption abilities for three chlorinated VOCs due to its abundant micropore structure. Moreover, the presence of water vapor in the gas stream had negligible effect on breakthrough time of three chlorinated VOCs adsorption onto LC-1 when values of relative humidity were equal to or below 50%; the breakthrough time of three chlorinated VOCs decreased less than 11% even if the relative humidity was 90%. Taken together, it is expected that LC-1 would be a promising adsorbent for the removal of VOCs vapor from the humid gas streams.

Cancer incidence in a petrochemical industry area in Sweden.

Emissions from petrochemical industries may contain suspected or established carcinogens. As increased incidence of cancer in residential areas close to petrochemical industries has been reported in the literature, we conducted a study of cancer incidence in Stenungsund, Sweden, where petrochemical industries were established in the mid 1960s. A number of cancer cases in the central parts of Stenungsund were collected from the regional cancer registry for each year between 1974 and 2005. In addition to the total number of cases, the numbers of leukemia, lymphoma, liver cancer, lung cancer, and brain cancer were also collected. Expected numbers for each year were calculated based on age- and sex-specific incidence rates in reference areas. Levels of carcinogenic volatile hydrocarbons (VOC) were estimated from measurements and emission data. A dispersion model was used to classify Stenungsund into a "low" and "high" ethylene level area. Standardized Incidence Ratio (SIR) for all cancer for the entire period was 1.02 (95% CI 0.97-1.08). The occurrence of leukemia, lymphoma, and cancer in the central nervous system was slightly lower than expected for the entire period. SIR for lung cancer was 1.37 (95% CI 1.10-1.69), and SIR for liver cancer was 1.50 (0.82-2.53). VOC levels were low. Taking estimated exposure and demographic factors into account, our assessment is that occurrence of cancer was not affected by industrial emissions in any of the studied sites.

Stability of the total and functional microbial communities in river sediment mesocosms exposed to anthropogenic disturbances.

River systems are exposed to anthropogenic disturbances, including chemical pollution and eutrophication. This may affect the phylogenetic diversity as well as the abundance of various functional groups within sediment-associated microbial communities. To address such potential effects, mesocosms filled with Ebro delta sediment covered with river water were exposed to chlorinated organic compounds or to a high nutrient concentration as used for fertilization. Changes in the abundance of selected functional microbial groups, i.e. total aerobes, nitrate, sulfate and iron reducers, organohalide-respiring microorganisms as well as methanogens, were examined using culture-dependent most probable number and culture-independent PCR methods targeting phylogenetic as well as functional gene markers. It was concluded that the abundance of functional groups was neither affected by pollution with 1,2-dichloroethane and tetrachloroethene nor by elevated nutrient loads, although changes in the bacterial community composition were observed using 16S rRNA gene-targeted fingerprint techniques. This study reinforced the notion that complementary culture-dependent and molecular methods, focusing on different fractions of the microbial community (cultivable, active or total), should be used in combination for a comprehensive description of phylogenetic diversity and functional potential.