Isotope Dilution High-resolution Gas Research Articles

Body burden and influencing factors of polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) in male workers from a municipal waste incineration plant in China

Emissions of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) from municipal solid waste incinerators (MSWIs) have aroused public concern around the world. However, biomonitoring evidence regarding the influence of MSWIs on the human body burden of PCDD/Fs is scarce. The aim of this study is to investigate the human body burden levels of PCDD/Fs in MSWI workers and to further explore the potential influencing factors, including duration of occupation and dietary habits, on the PCDD/F levels. A total of 98 paired serum samples from MSWI workers and non-MSWI workers were collected. Seventeen 2,3,7,8-chlorine substituted PCDD/Fs in the serums were analyzed using an isotope dilution high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS). The results showed that the mean levels of toxic equivalent (TEQ)-PCDD/Fs for the MSWI workers and the control group were 18.28 pg TEQ g−1 lipid and 5.81 pg TEQ g−1 lipid, respectively. Significantly higher concentrations of PCDD/Fs existed in the incinerator workers compared with the control subjects after adjustment of the confounding factors. OCDD was the most abundant congener in both the MSWI workers and the control subjects, accounting for 82.2% and 89.4% of the ∑17PCDD/Fs, respectively. The serum levels of PCDFs in the MSWI workers increased with the duration of occupation (β = 0.498, P = 0.031), and a higher total concentration of PCDD/Fs were present in senior workers classified as production supervisors than routine operation staff (β = 8.809, P = 0.008). No significant relationship was found between the PCDD/F concentrations and dietary habits. This study was the first to explore the associations between the body burden of PCDD/Fs and occupational exposure as well as dietary intake of MSWI workers in China. The findings provide scientific information for health risk assessments of human exposure to PCDD/Fs.

Determination of atmospheric organochlorine pesticides using isotope dilution high-resolution gas chromatography/high-resolution mass spectrometry

建立了测定大气中25种有机氯农药(OCPs)的同位素稀释-高分辨气相色谱/高分辨质谱法(ID-HRGC/HRMS)。样品用正己烷/二氯甲烷(1:1, v/v)进行加速溶剂萃取(ASE)。通过柱洗脱实验、单柱和组合柱净化实验,最终确定样品的净化方案为弗罗里硅土固相萃取柱和石墨化炭黑固相萃取柱组合净化。样品萃取液净化后进行HRGC/HRMS分析。采用平均相对响应因子(RRF)法对样品中目标物进行定量,6点校准溶液RRF的相对标准偏差(RSD)均≤20%。线性范围为0.4~800 μg/L,相关系数R2均>0.992。对空白样品依次进行100 pg、400 pg和15 ng水平下的加标试验,各添加水平下OCPs测定值的RSD为0.64%~16%,加标回收率为67.2%~135%。穿透试验表明,滤膜+聚氨酯泡沫/聚氨酯泡沫作为吸附介质的大体积主动大气采样器(AAS)在采集环境空气时,五氯苯极易发生穿透,有效采样模式待进一步研究。在上述采样模式下,六氯苯的有效采样体积较小,标准状态(101.325 kPa, 273 K)采样体积应≤30 m3,其他OCPs应≤1200 m3。以上述体积计算,25种目标化合物的检出限为0.002~0.7 pg/m3。对北京环境空气样品分析测定,结果显示除反式-环氧七氯、异狄氏剂、顺式-九氯和4,4'-滴滴滴在部分样品中未检出外,其他OCPs均为100%检出;六氯苯浓度在514~563 pg/m3之间,其他OCPs的浓度在0.01~18.9 pg/m3之间;替代标回收率为33.9%~155%。由于现有相关监测标准的仪器灵敏度较低、方法检出限较高,已无法满足目前空气中痕量OCPs的测定需求,因此亟待修订新的高灵敏度监测方法标准。该方法适用于目前大气中OCPs的超痕量水平分析,为新标准的制订奠定基础,也为国家履行相关国际公约提供有力技术指导。

Characterizing the emissions of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) from electric arc furnaces during steel-making

The amount of steel produced using electric arc furnaces (EAFs) has been increasing in recent years. In this study, stack gases from EAFs in steelmaking plants were analyzed to determine if they are also dominant sources of polybrominated dibenzo-p-dioxin and dibenzofuran (PBDD/F) emissions in China. Isotope dilution high-resolution gas chromatography high-resolution mass spectrometry for qualitative and quantitative analysis of PBDD/F congeners revealed that the mean PBDD/F mass concentrations were 271.1–9467.8 pg Nm−3 for the preheating stages (PS) of three EAF plants and that the corresponding toxic equivalents (TEQs) were 10.8–971.2 pg TEQ Nm−3. The PBDD/F mass concentration from the smelting stage (SS) at plant E3 was 261.9 pg Nm−3 (4.5 pg TEQ Nm−3). The PBDD/F emission factors (EF) during the preheating stage for the three plants were 0.0356–1.51 μg TEQ t−1, and the EF was 0.0359 μg TEQ t−1 during the E3 smelting stage. PBDD/Fs were found to contribute 2.39–67.85% to the total mass and 2.84–57.68% to the total dioxin TEQ. These wide fluctuations were caused by differences in the composition of feeding materials and the working temperature of bag filters. Overall, the results indicate that PBDD/F emissions from EAF steelmaking should receive increased attention. The PBDD/F congener patterns among the three EAF plants were variable, possibly because of differences in raw materials. The results presented herein will facilitate assessment of the contribution of EAFs to total PBDD/F emissions in China and investigations of PBDD/F emissions at different stages of steelmaking processes using EAFs.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) emissions from electric arc furnaces for steelmaking

The proportion of steel produced using electric arc furnaces (EAFs) is increasing. In this study, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) concentrations and patterns in stack gas samples from three typical EAFs in steelmaking plants were determined to allow the contributions of EAFs in steelmaking plants to PCDD/Fs emissions in China to be assessed. Samples collection was accomplished by adopting the automatic isokinetic sampling technique, then the PCDD/Fs congeners concentrations were analyzed qualitatively and quantitatively by isotope dilution high-resolution gas chromatography high-resolution mass spectrometry (HRGC-HRMS). The mean PCDD/Fs mass concentrations in stack gases emitted during the scrap preheating phase of plants E1, E2, and E3 were 0.48, 385.55, and 0.34 ng Nm−3, respectively, and the total toxic equivalent (WHO2005-TEQ) concentrations were 0.05, 33.16, and 0.03 ng Nm−3, respectively. The PCDD/Fs mass concentration in stack gases emitted during the melting phase at plant E3 was 0.12 ng Nm−3 (0.02 ng WHO2005-TEQ Nm−3). The operational temperature of the bag filter of the preheating in the E2 EAF was as high as 230 °C, which is conducive to the generation of PCDD/Fs, whether the temperature in the bag filter of E1 (150 °C) and E3 (120 °C) are not. Moreover, the bag filter temperature is suggested to be best controlled to below 150 °C. The emission factors (EF) for PCDD/Fs released into the air during the scrap preheating phase for plants E1, E2, and E3 were 0.13, 52, and 0.10 μg WHO2005-TEQ t−1, respectively, and the EF for the smelting phase from plant E3 was 0.14 μg WHO2005-TEQ t−1. The emission factor in E2 is 5 times higher than the highest current UNEP toolkit factor for EAFs (10 μg TEQ/tonne steel). Therefore, an update for the UNEP toolkit emission factor for a few case plants is suggested. Several congeners, including 2,3,7,8-TeCDF, 1,2,3,4,6,7,8-HpCDF, and 1,2,3,4,6,7,8-HpCDD, were dominant during the preheating phase, while 2,3,7,8-TeCDF, 1,2,3,7,8-PeCDF, and 2,3,4,7,8-PeCDF were dominant during the smelting phase. The monitoring data from the case plants helps to better understand the PCDD/Fs emissions of EAFs using preheating process stages. However, a more complete emission inventory requires more case investigations on the PCDD/Fs emissions from representative EAFs steelmaking plants.

Spatiotemporal variability of polybrominated diphenyl ether concentration in atmospheric fine particles in Shenzhen, China

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants for various products and have become ubiquitous pollutants in environmental media. However, little is known about PBDE levels in Shenzhen, a manufacturing center of electronic products. This study aimed to investigate spatiotemporal variability of PBDE concentration in atmospheric fine particles (PM2.5) and to estimate the daily inhalation exposure doses for local residents in Shenzhen, China. A total of 36 samples were collected and 8 PBDE compounds (BDE-28, 47, 99, 100, 153, 154, 183 and 209) were analyzed by isotope dilution high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS). Mean concentrations of Σ8PBDEs and BDE-209 in PM2.5 in Shenzhen were 33.47 pg/m3 and 24.75 pg/m3, respectively, which were lower than those for other reported cities from China. The mean concentration of Σ8PBDEs was higher in the winter + spring than that in summer + autumn, and both concentrations of BDE-28 and BDE-47 in PM2.5 were significantly higher in winter + spring than those in summer + autumn. Among the 8 congeners, BDE-209 was predominant, accounting for 73.9% of the Σ8PBDEs concentrations. Traffic area, industrial area, residential area and discharge of electronic industries had significant positive influences on PBDE concentrations in PM2.5. Both vegetation area and water area were significantly negatively correlated with PBDE levels in PM2.5. Significantly negative correlation was also found between PBDE concentrations in PM2.5 and the relative humidity. The ranking of estimated inhalation exposure doses of PBDEs via PM2.5 inhalation were toddlers (1.74 pg/kg b.w./day) > children (1.33 pg/kg b.w./day) > adults (1.26 pg/kg b.w./day) > teenagers (0.64 pg/kg b.w./day), and toddlers had a highest risk to expose to PBDEs by PM2.5. To our knowledge, the present study is the first to reveal the spatiotemporal variability of PBDEs in PM2.5 of Shenzhen, China.

Polychlorinated dibenzo‐p‐dioxins and dibenzofurans levels in piglet liver with various diseases

This study deals with the levels of toxic polychlorinated dibenzo-p-dioxin and furan congeners (PCDD/Fs) in the livers of piglets affected by infectious diseases using isotope dilution high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). Seventeen toxic congeners in the liver samples infected with bacterial and viral diseases were compared. For porcine reproductive and respiratory syndrome virus (PRRSV) samples, the North American- and European-type PRRS diseases were observed. This study shows that there are significantly different levels of PCDD/Fs, present, which vary according to the types of diseases as evidenced by our analysis of the piglet liver samples.

Congener-specific levels and patterns of polychlorinated biphenyls in edible fish tissue from the central Red Sea coast of Saudi Arabia

All 209 congeners of polychlorinated biphenyls (PCBs) in edible fish tissue from the central Red Sea coast (Jeddah region) of Saudi Arabia were analyzed by isotope dilution high-resolution gas chromatography–mass spectrometry. The upper-bound total PCB (ΣPCB) levels in nine commonly consumed fish species from three areas were 0.2–82.5ng/g wet weight (17–8450ng/g lipid weight), which were at the lower end of reported global range and far below international tolerance limits (500–3000ng/g ww). Dioxin-like congeners contributed up to 12.8% (mean 6.5%) to ΣPCB in tissue samples, with the total PCB toxic equivalencies (TEQs) at a tolerable range (0.05–2.6pgTEQ/g ww or 2–238pgTEQ/g lw) for all species. PCB profiles were dominated by moderately chlorinated homologs, mainly hexachlorobiphenyls, but less chlorinated congeners were also consistently elevated, notably in Siganus rivulatus (Area III) and Mugil cephalus (Area I). It remains to be ascertained if the latter were breakdown products or due to fresh inputs. The top congeners based on dominance by both occurrence and abundance were identified as potential markers of ΣPCB in fish tissue, which can be used for future selective biomonitoring in case of reasonable constraints on full congener approach.

Toxaphene levels in retail food from the Pearl River Delta area of South China and an assessment of dietary intake

Limited literature exists on toxaphene contamination in food worldwide, particularly in mainland China. In this study, three toxaphene congeners, Parlar 26 (B8-1413), Parlar 50 (B9-1679) and Parlar 62 (B9-1025), were analyzed in five different food categories from the Pearl River Delta Area in China using isotope dilution high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS), and toxaphene levels in food were reported and toxaphene dietary intake by local residents estimated. The results showed that fish contained the highest toxaphene level with a median of 12.87 pg/g wet weight (ww), followed by poultry meat, egg products, livestock meat and vegetable, which had median levels of 5.8, 2.2, 1.89 and 0.67 pg/g ww, respectively. Parlar 50 and Parlar 26 were the predominant characteristic congeners in fish, and Parlar 26 was the predominant congener not only in poultry products and eggs, but also in livestock and vegetable. The estimated average daily intake found by local residents was 35.57 pg/kg body weight/day. Overall toxaphene levels and estimated dietary intake in the Pearl River Delta Area of South China are far lower than the European Maximum Residue Limits (EU MRLs), the German MRL for fish, and other international literature data. Therefore, the risk of adverse health effects from dietary intakes of toxaphene for the local residents is not considerable at the current time, but follow-ups are warranted to study dynamic changes of toxaphene in food in this area.

The effect of a vegetarian versus conventional hypocaloric diet on serum concentrations of persistent organic pollutants in patients with type 2 diabetes

Background and aimsThe aim of this study was to explore the effect of a vegetarian versus conventional diet on the serum levels of persistent organic pollutants (POPs) in patients with T2D after 12 weeks of dietary intervention and to assess their relationships with metabolic parameters. Methods and resultsMen and women with T2D were randomly assigned to follow either a vegetarian diet without fish or meat (n = 37) or an isocaloric conventional antidiabetic diet (n = 37). Both diets were energy restricted (minus 500 kcal/day). All foods were provided to the participants. At randomization (week 0) and 12 weeks, the meal test was performed to assess the β-cell function and serum levels of 24 POPs. Dioxins and dioxin-like POPs were analyzed by isotope dilution high-resolution gas chromatography (HRGC) and mass spectrometry after cleanup of the silica and carbon columns. Non-dioxin-like POPs were analyzed by gas chromatography with an electron capture detector (GC–ECD). Statistical analyses used were repeated-measures analysis of variance (ANOVA), a multivariate regression model, and Pearson's correlations.We observed a statistically nonsignificant trend toward increases in the serum levels of most POPs in response to both hypocaloric diets with no differences between groups. In the groups combined, the change in serum concentrations of total POPs was correlated to changes in HbA1c (r = +0.34; p < 0.01), fasting plasma glucose (r = +0.41; p < 0.01) levels, and β-cell function measured as insulin secretion at a reference glucose level (r = −0.37; p < 0.01), independent of the changes in body weight and volume of visceral fat. ConclusionShort-term hypocaloric vegetarian and conventional diets did not reduce the POP levels, possibly due to mobilization of fat stores. Our findings support the relationship between POPs and diabetes, especially β-cell function. Trial registrationClinicalTrials.gov number, NCT00883038, completed.

Determination of atmospheric polybrominated diphenyl ethers and polybrominated biphenyl 153 using isotope dilution-high resolution gas chromatography/high resolution mass spectrometry

Considering the features and demands of the environmental monitoring, an isotope dilution-high resolution gas chromatography/high resolution mass spectrometry method was developed for the determination of polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyls 153 (BB153) in the ambient air. PBDEs and BB153 were extracted using an accelerated solvent extraction apparatus with a mixture of hexane-dichloromethane (v/v, 1:1) and hexane, respectively. The concentrated extracts were loaded on the composite silica gel column for cleanup. The mean recoveries of native compounds at 10% and 90% of the highest levels of calibration curves were 100% and 104% with 5% and 6% of the mean relative standard deviations (n = 7), respectively. The recoveries of 13C labeled surrogates for di- to deca-brominated diphenyl ethers and BB153 were in the range of 36.5%-133%. However, the recoveries of 13C-monobrominated diphenyl ethers were relatively low, maybe due to the different physicochemical properties compared with the other homologues. No breakthrough of pollutants was estimated under real sampling volume of 300 m3. The limits of detection were lower than 2 x 10(-4) ng/Nm3. The recoveries of 13C labeled surrogates were between 56% and 126%, except monoBDEs. The results demonstrated that the method is suitable for the analysis of di- to decabrominated diphenyl ethers and BB153 in the ambient air with precise quantification.

Levels for toxaphene in three categories of animal originated food in Pearl River Delta area

To explore the present contamination status and profile of toxaphene in fish, chicken and meat samples in Pearl River Delta area. Totally 60 independent samples including fish, chicken, meat were collected from Huizhou,Guangzhou,Dongguan,Jiangmen of Pearl River Delta area in Guangdong by purposive sampling from Oct 2010 to Jun 2011. Toxaphene monomer Parlar26, Parlar50 and Parlar62 levels in three various categories of foods were quantitatively and qualitatively analyzed referencing international authoritative standard methods by utilizing isotope dilution high-resolution gas chromatography/high-resolution double-focusing magnetic mass spectrometry (HRGC-HRMS). The levels of pollution and characteristics were compared. The concentration of toxaphene median(M) in fish, chicken and meat were 12.87, 5.8 and 1.89 ng/kg (gross weight) , respectively and the difference was significant(H = 14.29, P = 0.001). The toxaphene level in seafish (M = 32.07 ng/kg) was significantly higher than that in freshwater fish (M = 10.63 ng/kg, Z = -2.52, P = 0.012). The profile analysis showed that Parlar50 and Parlar26 were the predominant characteristic monomers in fish, which contributed about 44% (9.91/22.60, ng/kg) and 39% (8.89/22.60, ng/kg) to total concentration, and Parlar62 and Parlar26 were the two predominant congeners in poultry products, the two congeners accounted for 42% (5.03/11.90, ng/kg) and 38% (4.58/11.90, ng/kg). Furthermore Parlar26 and Parlar62 made up about 57% (3.45/6.08, ng/kg) and 26% (1.58/6.08, ng/kg) of total concentration in livestock meat respectively. Toxaphene levels in all tested food samples are far lower than the limited standard stipulated by the European Food Safety Authority (EFSA) in 2002, which was 0.1 mg/kg. The congener characteristic difference in the three categories food indicated that the different enrichment ability in Toxaphene in different animal species.

Determination of mono- to tri-chlorinated dibenzo-p-dioxins and dibenzofurans in stack gas using isotope dilution high resolution gas chromatography-high resolution mass spectrometry

A method for the determination of mono- to tri-chlorinated dibenzo-p-dioxins and dibenzofurans (mono- to tri-CDD/Fs) in stack gas using isotope dilution high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS) was developed. The sam- ples were extracted by Soxhlet extraction, and then the extracts were concentrated and purified using a multilayer silica gel column and a basic alumina column. The analytes were separated by HRGC on a DB-5MS column (30 m x 0.25 mm x 0.25 μm) and determined by HRMS. The identi- fication of mono- to tri-CDD/Fs was based on the retention times of 13C-labelled standard and the abundance ratios of the two exacted mass-to-charge ratios. The quantitative analysis was performed using the ratios of the integrated areas of the 13C-labelled standards. This method had the recoveries ranging from 66.6% to 112.5% and the relative standard deviations (RSD) ranging from 19.9% to 40.5% (n = 5). The limits of detection (LODs) of this method for the mono- to tri-CDD/Fs were ranging from 0.027 to 0.485 μg/L. Three stack gas samples from waste incinerators were measured using this method, with the recoveries ranging from 85.7% to 137.0% and the concentrations ranging from 11.4 to 9,183 pg/Nm3. The results indicated that the method can be applied to the precise determination of mono- to tri-CDD/Fs at trace level in stack gas.

Uncertainty evaluation of the determination of toxic equivalent quantity of polychlorinated dibenzo-p-dioxins and dibenzofurans in soil by isotope dilution high resolution gas chromatography and high resolution mass spectrometry

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in soil samples were analyzed by isotope dilution method with high resolution gas chromatography and high resolution mass spectrometry (ID-HRGC/HRMS), and the toxic equivalent quantity (TEQ) were calculated. The impacts of major source of measurement uncertainty are discussed, and the combined relative standard uncertainties were calculated for each 2, 3, 7, 8 substituted con- gener. Furthermore, the concentration, combined uncertainty and expanded uncertainty for TEQ of PCDD/Fs in a soil sample in I-TEF, WHO-1998-TEF and WHO-2005-TEF schemes are provided as an example. I-TEF, WHO-1998-TEF and WHO-2005-TEF are the evaluation schemes of toxic equivalent factor (TEF), and are all currently used to describe 2,3,7,8 sub- stituted relative potencies.

Temporal trends of PCBs, PCDD/Fs and PBDEs in soils from an E-waste dismantling area in East China

The temporal trends of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polybrominated diphenyl ethers (PBDEs) were investigated in soils from an E-waste dismantling area in East China between 2005 and 2011. Isotope dilution high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) was employed for the sample analysis. PCB levels declined as expected, while PCDD/Fs generally remained at a constant level during the sampling period, and PBDE concentrations tended to be slightly lower after 2007 although the decline was not statistically significant. The congener profiles indicated that lowly-halogenated congeners of these persistent organic pollutants (POPs) accounted for the decreasing levels and relative proportions of the POPs, suggesting that they have been gradually eliminated from the field soil over the years. However, the concentration levels of some heavy congeners (e.g., CB-209, OCDD and OCDF) showed different trends from those of the lighter ones. The general tendencies of the three types of POPs in soils were consistent with those reported in other studies in this area. The results implied that the enhanced regulations and centralized dismantling action introduced in 2005 might exert a limited influence on these three types of POPs in soils during the sampling period.

Simultaneous Determination of Polychlorinated Dibenzo- p -Dioxins/Furans, Polybrominated Dibenzo- p -Dioxins/Furans, Polychlorinated Biphenyls and Polybrominated Diphenyl Ethers by Isotope Dilution-High Resolution Gas Chromatography-High Resolution Mass Spectrometry in Ambient Air

A method for simultaneous determination of polychlorinated dibenzo-p-dioxins/furan( PCDD/Fs),polybrominated dibenzo-p-dioxins/furans( PBDD/Fs),polychlorinated biphenyls( PCBs) and polybrominated diphenyl ethers( PBDEs) was established by using elution curve and fraction cut technology to eliminate the PCB and PBDE blank of interference and optimize the pre-treatment.The technology was developed using AutoSoxtec,acid silica gel column,multi-layered silica gel column and active carbon column.The sample recovery of sampling standards was in the range of 63%-100% and the recovery of internal standards was in the range of 52%-132%.The detection limits was between 6×10!4-1×10!2pg/m3,dicabromodiphenyl ether( BDE-209) was 0.3 pg/m3,which reached the US Environmental Protection Agency( EPA) standards.Air sample toxic equivalent quantity( TEQ)( PCDD/Fs,dl-PCBs) was between 0.216-0.949 pg/L WHOTEQ,TEQ( PBDD/Fs) was 0.0181-0.0462 pg/L WHO-TEQ,and PBDEs content was 105-132 pg/m3.

Characterization of polychlorinated naphthalenes in stack gas emissions from waste incinerators

Nine typical waste incinerating plants were investigated for polychlorinated naphthalene (PCN) contents in their stack gas. The incinerators investigated include those used to incinerate municipal solid, aviation, medical, and hazardous wastes including those encountered in cement kilns. PCNs were qualified and quantified by isotope dilution high resolution gas chromatography-high resolution mass spectrometry techniques. An unexpectedly high concentration of PCNs (13,000 ng Nm(-3)) was found in the stack gas emitted from one waste incinerator. The PCN concentrations ranged from 97.6 to 874 ng Nm(-3) in the other waste incinerators. The PCN profiles were dominated by lower chlorinated homologues, with mono- to tetra-CNs being the main homologues present. Furthermore, the relationships between PCNs and other unintentional persistent organic pollutants involving polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls, hexachlorobenzene, and pentachlorobenzene were examined to ascertain the closeness or otherwise of their formation mechanisms. A good correlation was observed between ΣPCN (tetra- to octa-CN) and ΣPCDF (tetra- to octa-CDF) concentrations suggesting that a close relationship may exist between their formation mechanisms. The results would provide an improved understanding of PCN emissions from waste incinerators.

Association between blood levels of PCDDs/PCDFs/dioxin-like PCBs and history of allergic and other diseases in the Japanese population

Previous studies reported that exposure to dioxins was associated with an increased risk of various diseases in general populations. The aim of this study was to examine the association between levels of dioxins in blood and allergic and other diseases. We conducted a cross-sectional study on 1,063 men and 1,201 women (aged 15-76 years), who were living throughout Japan and not occupationally exposed to dioxins, during 2002-2010. In fasting blood samples, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like PCBs (DL-PCBs) were analyzed by isotope dilution high-resolution gas chromatography/mass spectrometry. We obtained information on life style and self-reported history of diseases using a questionnaire. Blood pressure, blood levels of hemoglobin A1c, and serum lipids were also measured. Multiple logistic regression models were used to analyze the association between dioxin levels in blood and various diseases. Toxic equivalents of PCDDs/PCDFs and total dioxins showed significant inverse dose-response relationships with atopic dermatitis, after adjustments for potential confounders. The highest quartile for total dioxins had an adjusted odds ratio of 0.26 (95 % confidence interval 0.08-0.70) compared to the reference group (first quartile). The odds ratios for hypertension, diabetes mellitus, hyperlipidemia, gout in men, and gynecologic diseases in women significantly increased with increasing toxic equivalents of PCDDs/PCDFs, DL-PCBs, and total dioxins in blood. The present findings suggest that background exposure to dioxins was associated with reduced risk of atopic dermatitis. The results also support the idea that low-level exposure to dioxins is associated with an increased risk of diabetes, hypertension, and hyperlipidemia.

Identification and characterization of the atmospheric emission of polychlorinated naphthalenes from electric arc furnaces

Electric arc furnaces (EAF) are well recognized as significant sources of dioxins. EAFs have also been speculated to be sources of polychlorinated naphthalenes (PCNs) due to the close correlation between dioxin and PCN formation. However, assessment on PCN emissions from EAFs has not been carried out. The primary aim of this preliminary study is to identify and characterize the atmospheric emission of PCNs from EAFs. In this preliminary study, stack gas samples from two typical EAFs with different scales (EAF-1, 160 t batch(-1); and EAF-2, 60 t batch(-1)) were collected by automatic isokinetic sampling technique, and PCN congeners in samples were analyzed by isotope dilution high-resolution gas chromatography combined with high-resolution mass spectrometry method. Emission concentrations of PCNs were 458 and 1,099 ng m(-3) for EAF-1 and EAF-2, respectively. The emission factors of PCNs to air were 21.6 and 30.1 ng toxic equivalent t(-1) for EAF-1 and EAF-2, respectively, which suggested that EAF is an important source of PCN release. With regard to the characteristics of PCNs from EAFs, lower chlorinated homologues were dominant. The PCN congeners comprised of CN27/30, CN52/60, CN66/67, and CN73 were the most abundant congeners for tetra-, penta-, hexa-, and hepta-chlorinated homologues, respectively. EAFs were identified to be an important PCN source, and the obtained data are useful for developing a PCN inventory. The congener profiles of PCNs presented here might provide helpful information for identifying the specific sources of PCNs emitted from EAFs.

Determination of trace organochlorine pesticides in soil using isotope dilution-high resolution gas chromatography-high resolution mass spectrometry

A method for the determination of trace organochlorine pesticides (OCPs) in soil using isotope dilution and high resolution gas chromatography-high resolution mass spectrometry (ID-HRGC-HRMS) was developed. The sample was extracted by accelerated solvent extractor (ASE) and cleaned-up by a Florisil solid phase extraction (SPE) cartridge. The analytes were separated by HRGC on a DB-5MS column (30 mx 0.25 mm x 0.25 microm) and determined by HRMS. The identifications of OCPs were based on the retention time of 13C-labelled standard and the abundance ratio of the two exact mass-to-charge ratios. The quantitative analysis was performed using the ratios of the integrated areas of the 13C-labelled standards. This method has the recoveries ranging from 77.3% to 114.5% and the relative standard deviations (RSD) less than 10.81% (n=5). The limits of detection (LODs) of this method for all OCPs were lower than 0.04 pg/g. The results indicated that the method is rapid, selective and sensitive for precise determination requirements of organochlorine pesticides at trace level in soil.

Levels and distributions of polychlorinated biphenyls in sewage sludge of urban wastewater treatment plants

Concentrations of polychlorinated biphenyls (PCBs) have been measured in sewage sludge samples from 8 urban wastewater treatment plants in Beijing, China. The PCB congeners were analyzed by isotope dilution high resolution gas chromatography/high resolution mass spectrometry method. The concentration of PCBs ranged from 65.6 to 157 ng/g dry weight (dw), with a mean value of 101 ng/g dw. The dioxin-like PCB WHO-TEQs (World Health Organization-Toxic Equivalents) of the sludge were lower than 1 pg/g dw. Consequently, all the concentrations of PCBs in sludge samples were below the upper limit for land application according to the Chinese legislation law for agriculture use. The PCB homologue profiles in sludge samples were dominated by tri-CBs and tetra-CBs. Similar distributions have been found in one of the Chinese PCB commercial products. The patterns of dioxin-like and indicator congeners observed in this study were quite similar in all samples. The predominant congener for dioxin-like and indicator PCBs were PCB-118 and PCB-28, respectively, while PCB-126 had the highest TEQ value.