Large variation in breast milk levels of organohalogenated compounds is dependent on mother's age, changes in body composition and exposures early in life

We identified factors that are important determinants of body burdens (breast milk levels) of polychlorinated biphenyls (PCBs), dioxins (polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs)) and polybrominated diphenyl ethers (PBDEs). PCBs, PCDD/Fs and PBDEs were analysed in breast milk from up to 325 first-time mothers in Uppsala, Sweden, who delivered between 1996 and 2006. Hierarchical clustering was used as a method for identification of groups of compounds with common sources of exposure and similar toxicokinetics. Based on correlations between levels of single compounds/congeners in breast milk, distinctly separated clusters were formed, strongly dependent on structural similarities of the organohalogen molecules. In a multiple regression model, levels of PCBs (except PCB 28), PCDD/Fs and BDE-153 were positively associated with age of the mother and weight loss after delivery and inversely associated with pre-pregnancy BMI (body mass index) and weight gain during pregnancy. Higher levels of mono-ortho PCB TEQ, non-ortho PCB TEQ and BDE-153 in milk were found among women with high physical activity. Women who were breastfed during infancy and grew up on the Baltic coast of Sweden, with high availability of contaminated fish from the Baltic sea, had higher levels of PCBs and PCDD/Fs in breast milk indicating that exposure early in life from breast milk and contaminated fish may still affect body burdens at the time of pregnancy. The importance of current consumption of fatty Baltic fish as a source of exposure was supported by the positive association with breast milk levels of mono-ortho PCB TEQ, PCDF TEQ and BDE-153. The results show that, in contrast to the lower brominated PBDE congeners, the hexa-brominated BDE-153 resembles the chlorinated compounds with regards to determinants in breast milk. This suggests that some of the PBDEs may have toxicokinetic properties and that are similar to the PCBs and PCDD/Fs. Our results show that a few simple advices to women regarding weight changes in connection with pregnancy and consumption of contaminated fatty fish during the whole lifetime may lower the levels of dioxins in breast milk by up to 60%.     

Chlorinated Hydrocarbon Contaminants in Grebes and Seaducks Wintering on the Coast of British Columbia, Canada: 1988–1993

Grebe and seaduck species were collected during late winter at industrial and reference sites along coastal British Columbia, and during spring migration in the Yukon Territory, from 1988 to 1993. Liver and/or breast muscle were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), organochlorine (OC) pesticides, and chlorophenol-related compounds. Piscivorous species, including western grebes (Aechmophorus occidentalis) and common mergansers (Mergus merganser), contained highest levels of all contaminants. DDE and PCBs were detectable in all species analyzed, but were at low levels (<50 and 100 g/kg [sum PCBs] wet weight, respectively) in all but some grebe and merganser samples. Highest DDE concentration (229 g/kg) was in liver of common mergansers collected at Port Alberni in 1989, and that of PCB (2300 g/kg) in breast muscle of western grebes collected in 1992 from the same site. The interspecific PCDD/PCDF pattern was similar to that of the OC pesticides and PCBs, with the fish-eating species containing highest concentrations. The only congener detected in all samples was 2,3,7,8-TCDF, although 2,3,7,8-TCDD was regularly present. Generally, of all samples collected in 1989, those from the bleached-kraft pulp mill (BKPM) site at Port Alberni were the most contaminated with PCDDs and PCDFs. Of the chlorophenolic compounds measured, only pentachlorophenol was routinely detected, typically at levels below 5 g/kg. Traces of 3,4,5,6-tetrachloroguaiacol, 5-chloroguaiacol and 4,5-dichloroguaiacol were also detected in a few samples, mainly from a BKPM site at Prince Rupert. By 1992, after changes to pulp mill bleaching processes and restrictions in chlorophenolic anti-sapstain use, PCDD and PCDF concentrations were substantially lower compared to 1989 in all species sampled and no longer posed a concern for human consumers. International TCDD-toxic equivalents (I-TEQs) in some western grebe samples were within the range of concentrations associated with sublethal effects in waterbird species (200–400 ng/kg).     

Screening of dioxin-like compounds in bio-composts and their materials: chemical analysis and fractionation-directed evaluation of AhR ligand activities using an in vitro bioassay

Application of the dioxin responsive-chemical activated luciferase gene expression (DR-CALUX) bioassay to three compost products (kitchen garbage compost, treated sludge compost, and poultry manure compost) and their organic waste materials was performed for the screening of dioxin-like compounds. Phased sample preparation was conducted for the bioassay to yield separate crude, acid-stable, and carbon column fractions. Chemical analyses were also conducted for polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polyaromatic hydrocarbons (PAHs). Their determined WHO-PCDD/PCDF/dl-PCB-TEQ values were compared to the DR-CALUX results expressed as CALUX-TEQ to ascertain their contributions to overall activity. Overall all three compost products were polluted to a low level by persistent PCDD/PCDF/dl-PCBs in a few pg/g WHO-TEQ concentration range. The organic crude fraction showed non-persistent CALUX-TEQ values 2-4 orders of magnitude higher than those of WHO-TEQ. For the acid-resistant fractions of all samples, persistent CALUX-TEQ values were 1-8-fold higher than WHO-PCDD/PCDF/dl-PCB-TEQ values. Both TEQs correlated well for this fraction, which confirms the availability of CALUX for estimation of the actual WHO-TEQ level of the samples using reflux method with 44% sulfuric acid/silica gel, although the compost and material samples examined in this study contained much lower levels of WHO-TEQ: less than 1 pg/g in almost all cases. Additional carbon column treatment enhanced the potency and efficacy of CALUX activity in the three compost samples, which showed 1.6-4.4 times higher values of CALUX-TEQ than those obtained for the acid-resistant fraction. Although further DR-CALUX data collection for compost samples will be necessary, DR-CALUX is useful as a rapid screening method for monitoring dioxin-like compounds in compost.     

Assessment of carcinogenic heavy metal levels in Brazilian cigarettes

Total mercury (Hg(T)) and bioavailability Hg (Hg(HCl)) concentrations in soil were determined in five districts in Wuhu urban area. Spatial pattern of soil Hg concentration was generated through kriging technology. Results showed that Hg concentration in soil ranged from 0.024 to 2.844 mg kg(?-1) with an average of 0.207 mg kg(?-1). Hg concentration in soil appeared to have a block distribution and decreased from downtown to surrounding district. And Hg concentrations appeared to have a medium scale spatial auto correlation, strongly affected by human activity. The maximal Hg average concentration (0.332 mg kg(?-1)) in soil appeared in Jinghu district, where the high intensity of human activities is. Second highest Hg average concentration (0.263 mg kg(?-1)) in soil appeared in development district, where the intensive industrial activities are. Bioavailability Hg concentration in soil ranged from 2.6 to 4.9 μg kg(?-1) with an average of 3.8 μg kg(?-1), which had a ratio of 0.28~6.44% to total Hg. The ratios of bioavailability Hg to total Hg in vegetable soil were bigger than those of park soil. Correlation analysis showed that total Hg, organic matter, total phosphorus, and bioavailability Hg concentrations in soil were significantly positively correlated. Hg concentration in vegetable ranged from 2.7 to 15.2 μg kg(?-1) with an average of 6.5 μg kg(?-1). Hg concentration in vegetable was positively correlated with Hg(HCl) concentration in soil. According to the calculation on hazard quotient (HQ) for children, inhalation of Hg vapor from soil is the main exposure pathway, in which HQ is 2.517 × 10(?-2), accounting for 80.3% of the four exposure pathways. Hazard index (HI) of the four exposure pathways is lower than the "safe" level of HI = 1; therefore, exposure of soil Hg exhibited little potential health risk to children in Wuhu urban area.     

Persistent organic pollutants in sediment from the southern Baltic: risk assessment

The concentrations of organochlorine pesticides, PCBs, and PCDD/Fs were measured in sediment samples collected from the Gulf of Gdańsk, the Gdańsk Deep, the Vistula Lagoon and the off-shore waters in the southern Baltic Sea. The determinations were conducted in the fraction <63 μm. The highest levels of pollutants were found in sediments from the Gulf of Gdańsk and the Gdańsk Deep. In these sediments, concentrations of pp'-DDT and its metabolites (pp'-DDE and pp'-DDD) ranged from 2 to 11 μg kg(-1) dw. Concentrations of HCB were between 0.1 and 1.0 μg kg(-1) dw. Concentrations of the sum of α-, β-, γ-HCH were between 0.3 and 2.58 μg kg(-1) dw. Concentrations of marker PCBs ranged from about 2 to 11 μg kg(-1) dry weight. Total TEQ PCDD/F/dl-PCB values in the studied samples varied between 1 and 18 ng kg(-1) dw. The data were evaluated in terms of ecotoxicological criteria based on the environmental impact of the pollutant effects. Our research indicated that in the sediment from the southern Baltic Sea, the PCDD/F and PCBs occurred at concentrations which could be dangerous to marine organisms.     

Contaminant Exposure of Barn Swallows Nesting on Bayou D'Inde, Calcasieu Estuary, Louisiana, USA

Current and historical point source discharges, storm water runoff, and accidental spills have contaminated the water, sediment, and biota within the Calcasieu Estuary in southwestern Louisiana. In 2003, barn swallow (Hirundo rustica) eggs and nestlings were collected beneath two bridges that cross Bayou d′Inde, the most contaminated waterway within the Calcasieu Estuary. Samples were also collected from a bridge over Bayou Teche, a reference site in south central Louisiana. Polychlorinated biphenyl (PCB) concentrations in barn swallow eggs and nestlings were significantly higher at the downstream site on Bayou d′Inde (2.8 μ g/g PCBs in eggs and 1.5 μ g/g PCBs in nestlings) than at the other two sites (< 0.2 μ g/g PCBs in eggs and nestlings at both sites). Ethoxyresorufin-O-dealkylase activity in nestling livers was significantly higher at the downstream site on Bayou d′Inde (50 pmol/min/mg) compared to the other two locations (24 pmol/min/mg, each), probably because of exposure to PCBs. Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran concentrations in eggs and polycyclic aromatic hydrocarbons in nestlings were at background concentrations at all sites. Trace element concentrations in barn swallow eggs and nestling livers were at background levels and did not differ among the three sites. A biomarker of DNA damage did not differ among sites.     

Contributions of dry and wet depositions of polychlorinated dibenzo-p-dioxins and dibenzofurans to a contaminated site resulting from a penetachlorophenol manufacturing process

The soils at a factory for manufacturing pentachlorophenol were heavily contaminated by polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). In order to verify the contributions of dry and wet deposition of PCDD/Fs from the ambient air, the concentration of PCDD/Fs in ambient air and soil were measured, the partition of particle- and gas-phases of atmospheric PCDD/Fs was calculated, and the annual fluxes of total dry and wet PCDD/F depositions were modeled. Average atmospheric PCDD/F concentration was 1.24 ng Nm^???3 (or 0.0397 ng I-TEQ Nm^???3). Moreover, over 92.8% of total PCDD/Fs were in the particle phase, and the dominant species were high chlorinated congeners. The total PCDD/F fluxes of dry and wet deposition were 119.5 ng m^???2 year^???1 (1.34 ng I-TEQ m^???2 year^???1) and 82.0 ng m^???2 year^???1 (1.07 ng I-TEQ m^???2 year^???1), respectively. By scenario simulation, the total fluxes of dry and wet PCDD/F depositions were 87.1 and 68.6 ng I-TEQ, respectively. However, the estimated PCDD/F contents in the contaminated soil were 839.9 ?? g I-TEQ. Hence, the contributions of total depositions of atmospheric PCDD/F were only 0.02%. The results indicated that the major sources of PCDD/F for the contaminated soil could be attributed to the pentachlorophenol manufacturing process.     

Concentrations of polychlorinated dibenzo-p-dioxins, dibenzofurans, non-ortho polychlorinated biphenyls, and mono-ortho polychlorinated biphenyls in Japanese flounder, with reference to the relationship between body length and concentration

The concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho polychlorinated biphenyls (non-ortho PCBs), and mono-ortho polychlorinated biphenyls (mono-ortho PCBs) in Japanese flounder (Paralichthys olivaceus, body length 10.4-36.6 cm) collected from Sendai Bay, Japan, were determined using high-resolution gas chromatography-mass spectrometry. The relationship between the concentrations of these compounds (dioxins) and the body length of the Japanese flounder was examined. The total PCDD and total PCDF concentrations did not correlate with body length (both r(2) < 0.1, both p > 0.05), whereas the total non-ortho PCB and total mono-ortho PCB (coplanar polychlorinated biphenyls, Co-PCBs) concentrations were significantly correlated (r(2)= 0.8, p < 0.05 and r(2)= 0.63, p < 0.05, respectively). The bioaccumulation properties of PCDD/Fs in Japanese flounder differed from those of Co-PCBs. Toxicity equivalency quotient (TEQ) values derived from the Co-PCBs made up 46.3%-63.7% of the total TEQ value for all the dioxins. Although the concentrations of non-ortho PCBs were lower than those of mono-ortho PCBs, the TEQ value for non-ortho PCBs was higher than that for mono-ortho PCBs. The TEQ value for non-ortho PCBs increased more with increasing body length than did the values for PCDDs, PCDFs, and mono-ortho PCBs. These results show that from the standpoint of risk management, non-ortho Co-PCBs are the most important of the dioxins in Japanese flounder.     

多环芳烃的健康风险评价以及暴露参数的敏感性分析

在暴露情景假设和评估模型的确定下,有必要对污染场地的风险计算结果有影响的模型参数开展敏感性分析,以便在开展土壤健康风险评估工作时,提高评估的准确性和科学性,节约修复成本。以上海市某污染场地为例,对模型参数敏感性开展敏感性分析。贡献率结果显示,经口摄入土壤和皮肤接触土壤为场地表层污染土壤的主要致癌风险暴露途径。敏感性分析结果显示,致癌风险与体重呈反向变化,当体重参数减小时,暴露风险将向不利的方向移动。当体重参数在大范围减小时,敏感程度较高。致癌风险与暴露周期、暴露频率、每日摄入土壤量、暴露皮肤表面积、皮肤表面土壤粘附系数呈同向变化,当这些参数增大时,暴露风险将向不利的方向移动;其中暴露周期和暴露频率的敏感程度中等。上海市敏感用地下苯并(a)蒽、苯并(b)荧蒽、茚并(1,2,3-c,d)芘、苯并(a)芘、二苯并(a,h)蒽风险控制值分别为0.726、0.726、0.726、0.072 6、0.072 6 mg/kg。     

Distribution and risk assessment of polycyclic aromatic hydrocarbons (PAHs) from Liaohe estuarine wetland soils

Thirty-one surface soil samples were collected from Liaohe estuarine wetland in October 2008 and May and August 2009. The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs), identified as priority pollutants by the US EPA, were measured by gas chromatography. PAHs were predominated by three- and four-ring compounds. The total PAH concentrations ranged from 704.7 to 1,804.5 μg/kg with a mean value of 1,001.9 μg/kg in October 2008, from 509.7 to 1,936.9 μg/kg with an average of 887.1 μg/kg in May 2009, and from 293.4 to 1,735.9 μg/kg with a mean value of 675.4 μg/kg in August 2009. The PAH concentration detected at most sites shared the same pattern, with maximum concentrations during the autumn (October) and minimum concentrations during the summer (August). The ecological risk assessment of PAHs showed that adverse effects would occasionally occur in the soils from Liaohe estuarine wetland based on the effects range low (ERL)/effects range median and the toxic equivalency factors. The results revealed that some of the individual PAHs were in excess of ERL which implied possible acute adverse biological effects. The BaP(eq) values in some sites surpassed the Dutch target value. Therewith, quite a part of soils in the wetland were subjected to potential ecological risks.     

Distribution patterns of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in sediments of the Xiangjiang River, China

We investigated the occurrence and distribution patterns of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in six sediment samples from the Xiangjiang River, Hunan Province, People’s Republic of China. Total concentrations of PCDD/Fs ranged from 876 to 497,759 (mean 160,766) ng/kg dw, the highest of which exceeded that have ever been reported for sediment samples. World Health Organization total toxicity equivalent (WHO-TEQ) concentrations in three out of six samples were significantly higher than the guidance level (21.5?ng WHO-TEQ/kg dw) suggested by Canadian Sediment Quality Guideline. A predominance of octachlorodibenzo-p-dioxin (OCDD) was observed with an average contribution of 90.8% to the total PCDD/F concentrations, while 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HpCDD) was the major contributor to the PCDD/F WHO-TEQ concentrations in most of the sites. Such high levels of OCDD and HpCDD may be attributed to the presence of PCP/PCP-Na pollution, although MB-WW, agricultural straw open burning, and boilers–hazardous wastes were also the potential sources of PCDD/Fs. This is the first report for the concentrations and congener profiles of PCDD/Fs in sediment samples from the Xiangtan, Zhuzhou, and Changsha sections of the Xiangjiang River, providing scientific evidence for establishing priorities to reduce ecological risks posed by PCDD/Fs in the rapidly developing areas of Hunan Province and elsewhere.     

Chemical and bioassay monitoring of PCB-contaminated soil remediation using solvent extraction technology

Illegal dumping of polychlorinated biphenyl (PCB) capacitors was discovered in Kobe, Japan, in 2001, leaving about 68 m(3) (92 tons) of soil contaminated with approximately 6.6 kg of PCBs. Solvent extraction technology carried out in 2002-2003 using isopropyl alcohol remedied the affected soil at the site. Forty-seven batch treatments were conducted during full-scale treatment. On average, 8.4 extraction cycles per batch were needed to achieve the clean-up goal for PCBs (i.e., the Japanese environmental quality standard for soil). Analytical results showed that the average PCB concentration (88 microg g(-1)-dry soil) in untreated soil samples of all the batches was decreased to 1.2 microg g(-1)-dry soil in treated soil samples, yielding a removal efficiency of 98.6%. Dioxin responsive-chemical activated luciferase gene expression assay (DR-CALUX) and enzyme-linked immunosorbent assay (ELISA) adopting a monoclonal antibody against 2,3',4,4',5-pentachlorobiphenyl (PCB #118) were used to rapidly screen soil samples before and after solvent extraction. The DR-CALUX and ELISA results were in good agreement with World Health Organization toxicity equivalent values and analytically determined PCB concentrations, respectively. Regular monitoring during the treatment period confirmed that the applied technology met Japanese environmental and control regulations concerning treatment and disposal of contaminated soils and treatment residues. After full-scale treatment, the amount of PCBs recovered from the solvent purification system approximated the estimated amount of PCBs spilled.     

Short-range transport of contaminants released from e-waste recycling site in South China

The transport behaviors of a suite of contaminants released from electronic waste (e-waste) recycling operations, including polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and heavy metals, were evaluated by analyzing the contaminant residues in surface soils sampled in the surrounding area of an e-waste recycling site in South China. Concentrations of PBDEs and PCBs in the soil samples ranged from 0.565 to 2908 ng g(-1) dw and from 0.267 to 1891 ng g(-1) dw, respectively, while soil residues were 0.082-2.56, 3.22-287, and 16.3-162 μg g(-1) dw for Cd, Cu, and Pb, respectively. Concentrations of PBDEs and PCBs in soil decreased with increasing distance from the source of pollution, indicating possible PBDE and PCB contamination in the surrounding areas due to the short-range transport of these compounds from the e-waste recycling site. Although no significant difference in the short-range transport potential among PBDE and PCB congeners was observed, reductions in concentrations of the highly-brominated-BDEs and highly-chlorinated-CBs were slightly quicker than those of their less-halogen-substituted counterparts. Conversely, heavy metals showed the lowest transport potential due to their low vapor pressure, and results showed metals would remain near the pollution source instead of diffusing into the surrounding areas. Finally, mass inventories in areas near the e-waste site were 0.920, 0.134, 0.860, 4.68, 757, and 673 tons for BDE209, PBDEs (excluding BDE209), PCBs, Cd, Cu, and Pb, respectively.     

Arsenic transformations in terrestrial small mammal food chains from contaminated sites in Canada

Arsenic in terrestrial contaminated sites has the potential to cause harm to residential wildlife. The aim of this study was to determine the arsenic species in wild rodents living in arsenic contaminated habitats, specifically deer mice from Yellowknife, NT and meadow voles from Seal Harbour, NS, along with co-located plants. Methanol : water (1 : 1) extractions were used to optimize the extraction of methylated arsenic(v) species. Total arsenic concentrations were substantially higher in the Yellowknife deer mice (1.7-3.2 μg kg(-1) wet weight in livers) and Seal Harbour meadow voles (0.67-0.97 μg kg(-1) wet weight in livers) living on the contaminated sites with respect to the surrounding background locations (0.12-0.34 μg kg(-1) wet weight in livers). Around 50% of arsenic could be identified in Yellowknife deer mouse tissues, but only <10% was identified in Seal Harbour vole tissues; inorganic arsenic (iii and v) and dimethylarsinic acid were all found. Monomethylarsonic acid was only detected in both the mice and voles living in the contaminated sites. In the Yellowknife food chain, methyl arsenic (v) proportions increased from plants to mouse inner organs, but the trend was not for clear as the Seal Harbour food chain. Seal Harbour voles may be sequestering arsenic in a less mobile form, rather than transforming it.     

Comparison of SFE with Soxhlet in the analyses of PCDD/PCDFs and PCBs in sediment

The efficiency of supercritical fluid extraction (SFE) for the isolation of polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) from sediments was investigated by comparing SFE with Soxhlet. Five sediments obtained from an international interlaboratory study were used as a test material. SFE was performed with an automatic system where extracted analytes were collected by solid-phase trapping using carbon mixed with Celite as an adsorbent. For the first time, SFE of the most toxic PCBs, coplanar PCBs, was studied with real sediment samples. The majority of PCBs investigated, a total of 38 congeners from tri- to decachlorinated, were quantitatively extracted from sediment by SFE with pure CO2 at pressure 400 atm and temperature 100 degrees C. Under these conditions a successful extraction was obtained also for PCDD/PCDFs except for hepta- and octachlorinated congeners. Copper powder added to the sediment efficiently prevented the transfer of sulfur from the sample during SFE. The TEQs of both PCDD/PCDFs and PCBs obtained by SFE corresponded well with those obtained by the Soxhlet-based method. The reproducibility of SFE was high for both groups.     

我国污染场地土壤石油烃环境质量标准体系的现状与趋势

石油烃污染场地已经成为国内外重点关注的工业污染场地类型之一。国内基于人体健康风险的污染场地管理模式及分层次评估方法已经展现雏形,为风险管理者提供了基于人体健康的土壤石油烃风险筛选值和管制值,也为污染场地的防治与修复工作提供了决策支持。在前人研究的基础上,梳理了国内土壤环境质量标准体系的建立与发展历程,分析了石油烃类污染物检测方法的现状与未来发展趋势,并着重对比与分析了各标准制订的石油烃及其指示化合物的风险评估筛选值。目前面临的关键问题:①完善石油烃监测指标体系及分析方法是精准获得风险评估结果的前提。现有石油烃馏分指标划分较为宽泛,有必要参考国外先进标准体系,逐渐完善石油烃馏分指标划分及其配套的定量分析方法。②新颁布的国家建设用地土壤污染风险管控标准在前期场地调查中具有一定的普遍适用性,但是考虑到地域建筑物参数、人群暴露参数等的差异性,在后期场地调查中还需要因地制宜地制定适合污染场地的具体修复目标值,并针对关键性参数作定量化解析。     

Human dietary intake and excretion of dioxin-like compounds

Human dietary intake and excretion of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs)--collectively referred to as dioxin-like compounds (DLCs)--were investigated. Two groups of seven subjects were studied during 1999 and 2000: one aged 23.9 +/- 4.5 years, the other aged 49.4 +/- 5.2 years. For each subject, two week-long experiments were held. In one, omnivorous diets were administered, whilst in the other, a vegan diet was studied. While exposures via the omnivorous diets exceeded those via the vegan diet on a sigmaWHO-TEQ basis; for some subjects sigmaPCB exposures were comparable in both diets, implying that plant-based foods can make an appreciable contribution to exposure to sigmaPCB. For all subjects, the average dietary exposure during the omnivorous trial to PCDD/Fs and PCBs combined (expressed as WHO-TEQ) was--at 1.09 pg kg(-1) bw d(-1)--lower than recent UK "food-basket" estimates. For the same diet, the average sigmaPCB exposure for all subjects was--at 5.01 microg person(-1) d(-1)--higher than recent UK "food-basket" estimates, but consistent with recent estimates for other industrialised countries. Net absorption/excretion but not faecal excretion rates of DLCs were related to dietary intakes. Furthermore, excretion rates of the most persistent DLCs--i.e. PCB #s 138, 153, and 1,2,3,6,7,8-HxCDD--were statistically significantly greater for the older subjects. Combined, these data imply that excretion rate is dependent on body burden, and that the majority of DLCs in human faeces arise from endogenous excretion.     

Site environmental assessment to an old paint factory in China

High ethyl-benzene and total petroleum hydrocarbons (TPHs) were found in the soil samples and groundwater samples during a site environmental assessment for an old paint factory in the city Changchun, Jilin province of China. The target old paint plant had been in operation for near 30 years by manufacturing resin and house paint. Driving force for this study was to identify potential environmental contamination existing in this paint factory which is located next to a new resident area under construction. The assessment result would be used as baseline environmental data input for remediation plan when the factory site will be changed into potential resident area in near future. The analytical data from the soil samples from different area of the factory which had high exposure to operation showed that solid waster storage area was contaminated with high heavy metals (Cd, Pb, and Zn) and waster paint storage areas were contaminated with ethyl-benzene, xylene and C9-C30 aromatic hydrocarbon solvent. The analytical data from the groundwater samples from different area of the factory showed that resin plant area and waster paint storage areas were contaminated with high concentration of naphthalene, ethyl-benzene and xylene which exceed the reference standard. Remediation action is recommended.     

Monitoring dioxins and furans in the vicinity of an old municipal waste incinerator after pronounced reductions of the atmospheric emissions

In order to get an overall picture of the environmental impact of an old municipal solid waste incinerator (MSWI) from S. Adrià del Besòs (Barcelona, Catalonia, Spain), a monitoring program addressed at determining the levels of a number of pollutants in the vicinity of the facility was initiated in 1998. In March 1999, an adaptation was carried out due to EU legislation on pollutant emissions from the stack. As a result, emissions of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were notably reduced, and a significant (30%) decrease was found in the levels of PCDD/F in herbage samples collected in the vicinity of the MSWI. In March 2001, herbage samples were collected at the same sampling points and the PCDD/F levels measured again. The current PCDD/F concentrations range from 0.23 to 1.43 ng I-TEQ kg(-1) (dry matter), with median and mean values of 0.58 and 0.66 ng I-TEQ kg(-1) (dry matter), respectively, while in the 2000 survey the PCDD/F concentrations ranged from 0.22 to 1.20 ng I-TEQ kg(-1) (dry matter), with median and mean values of 0.57 and 0.61 ng I-TEQ kg(-1) (dry matter), respectively. Although the current PCDD/F concentrations in herbage samples are comparable to those found in recent surveys carried out in various places of Catalonia, an exhaustive evaluation of the data, including principal component analysis, indicates that other emission sources of PCDD/Fs also have a notable environmental impact on the area under direct influence of the MSWI.     

PCDD/F contamination on surface soil in the vicinity of a hazardous waste incinerator: is it possible a different trend?

This study is the first to investigate the contamination of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) on surface soils in the vicinity of the first hazardous waste incinerator of Turkey. In the study, 24 soil samples were taken from a 1625-m-radius circle whose center is the stack of the incinerator. This process was repeated 1 year later. Since the acquired average PCDD/F concentrations of the two sampling campaigns (0.05 and 0.02 ng WHO-toxic equivalent (TEQ)/kg) were meaningfully low compared to the related literatures, a new sampling campaign was carried out to control this inconsistency, but this time in a foreign laboratory (0.56 ng WHO-TEQ/kg). In the same period, eight gas samples were taken from the stack under different operational conditions of the facility. According to the evaluations of the findings, the geographical-meteorological data of the study area and the specific operational conditions of the facility corroborate the concentrations of the first and the second soil samplings rather than the third one. The major underlying reason for the inconsistency of the soil concentrations may be the fact that the data analysis procedures used by the laboratories are different. The author suggests a hypothesis which argues that the soils in the vicinity of a hazardous waste incinerator may have significantly lower concentration levels than in related literatures.