Occurrence,spatial distribution,sources, and risks of polychlorinated biphenyls and heavy metals in surface sediments from a large eutrophic Chinese lake (Lake Chaohu)

Surface sediment from large and eutrophic Lake Chaohu was investigated to determine the occurrence, spatial distribution, sources, and risks of polychlorinated biphenyls (PCBs) and heavy metals in one of the five biggest freshwater lakes in China. Total concentration of PCBs (Σ₃₄PCBs) in Lake Chaohu was 672 pg g^?1 dry weight (dw), with a range of 7 to 3999 pg g^?1 dw, which was lower than other water bodies worldwide. The majority of heavy metals were detected at all sampling locations, except for Sr, B, and In. Concentrations of Al, Fe, Ca, Mn, Sr, Co, Zn, Cd, Pb, and Hg were similar to that reported for other lakes globally. Concentrations of K, Mg, Na, Li, Ga, and Ag were greater than the average, whereas those of Cr, Ni, and Cu were lower. Cluster analysis (CA) and positive matrix factorization (PMF) yielded accordant results for the source apportionment of PCBs. The technical PCBs and microbial degradation accounted for 34.2 % and 65.8 % of total PCBs using PMF, and PMF revealed that natural and anthropogenic sources of heavy metals accounted for 38.1 % and 61.8 %, respectively. CA indicated that some toxic heavy metals (e.g., Cd, In, Tl, and Hg) were associated with Ca–Na–Mg minerals rather than Fe–Mn minerals. The uncorrelated results between organic matter revealed by pyrolysis technology and heavy metals might be caused by the existence of competitive adsorption between organic matter and minerals. PCBs and heavy metals were coupling discharge without organochlorine pesticides (OCPs), but with polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenyl ethers (PBDEs). No sediment sample exceeded the toxic threshold for dioxin-like PCBs (dl-PCBs) set at 20 pg toxicity equivalency quantity (TEQ)?g^?1, (max dl-PCBs, 10.9 pg TEQ g^?1). However, concentrations of Ag, Cd, and Hg were at levels of environmental concern. The sediment in the drinking water source area (DWSA) was threatened by heavy metals from other areas, and some fundamental solutions were proposed to protect the DWSA.     

Formation pathways of polychlorinated dibenzofurans (PCDFs) in sediments contaminated with PCBs during the thermal desorption process

Thermal desorption has attracted considerable interest as a remediation technology for the removal of dioxins and polychlorinated biphenyls (PCBs) from contaminated soils and sediments. Although several research groups have confirmed that polychlorinated dibenzofurans (PCDFs) are formed from PCBs during the thermal desorption of sediments contaminated with PCB, the formation pathways remain poorly understood. Herein, thermal desorption has been used to develop a greater understanding of the formation pathways of PCDFs from sediments contaminated with PCBs. PCB decomposition experiments of sediments contaminated with PCBs were performed over 5 min at 450 °C with a gas composition of 10% O(2)/90% N(2), either in the absence (Run 1) or presence (Run 2-4) of one of three different (13)C(12)-labeled PCB individual standards. The results of Run 1 showed that 99.96% of PCBs and 98.40% of polychlorinated dibenzo-p-dioxins (PCDDs) in the treated sediments had decomposed, whereas the concentration levels of PCDFs had increased by a factor of 31. The addition of different (13)C(12)-labeled PCBs to the sediment sample yielded different (13)C(12)-PCDFs isomer patterns, with formation pathways including loss of ortho-Cl(2), loss of HCl involving a 2,3-chlorine shift, loss of ortho-H(2) and dechlorination.     

Organochlorine pesticides,PCBs and heavy metals in tissues of the mullet Liza aurata in lake Ganzirri and Straits of Messina (Sicily,Italy)

The aim of this research was to investigate the presence of organochlorine pesticides, PCBs and heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in fish living in lake Ganzirri and the Straits of Messina, using the mullet Liza aurata as a "biological indicator". Different tissues of Liza aurata, which include the muscle, gill and vertebral column, were taken for analyses. Quantitative determination of the organochlorine compounds was performed by GC-ECD and confirmed with GC-MS. The concentrations of "essential" and "toxic" heavy metals were determined by Atomic Absorption Spectrophotometry. For the mullets of lake Ganzirri, the study showed DDE in three samples of gills and one of muscle, at concentrations below the MRL; no appreciable residues of PCBs (Aroclor 1232 series) were found. The concentrations of Zn and Cu were much higher than those of the "toxic" metals. No traces of organochlorine pesticides and PCBs were found in the individuals from the Straits of Messina. Therefore, these results indicate that these two environments are not at toxicological risk.     

Human biomonitoring of polychlorinated biphenyls and polychlorinated dibenzodioxins and dibenzofuranes in teachers working in a PCB-contaminated school

Eighteen teachers from a highly contaminated school and 11 teachers from a control school participated in this study. Total polychlorinated biphenyl (PCB) indoor air concentration (six indicator congeners x 5) was beyond 12000 ng/m3 in some rooms of the contaminated school. PCB 28 and PCB 52 were the prevailing congeners. Whole blood was taken from each participant by the local health authority, pooled in two groups and analysed for the six PCB indicator congeners, non-ortho PCBs and polychlorinated dibenzodioxins (PCDD)/polychlorinated dibenzofurans (PCDF). Blood analysis showed elevated mean PCB 28 and PCB 52 levels for the exposed group, however the two groups were almost identical with regard to PCB 101, 138, 153 and 180. Moreover no difference can be observed for the concentration of non-ortho PCBs and PCDD/PCDF. The data support the finding, that heavy indoor air contamination with low chlorinated PCBs causes an increase of PCB 28 and PCB 52 blood levels. However, this increment was small compared to their total PCB load.     

Fate and effects of nutrients and heavy metals in experimental salt marsh ecosystems

Fate and effects of the macro nutrients nitrogen and phosphorus, and the heavy metals zinc, copper and cadmium, brought into experimental salt marsh ecosystems via sediment supply, were studied over a three-year period. The supply of sediment from the Marsdiep (at a low and high rate) and from the harbour of Delfzijl (at a high rate) led to an increase of the macro nutrients and heavy metals in the top soil. The growth of the salt marsh plants Aster tripolium, Puccinellia maritima and Spartina anglica and the uptake of the macro nutrients and heavy metals by the plants was only slightly affected by the addition of sediment. A high load of sediment led to an increase in growth or in the concentrations of the macro nutrients or heavy metals in the plants at a number of sampling dates, but only minor differences between treatments were found. From a mass balance constructed over a three-year study period it could be concluded that about 50% of the macro nutrients and heavy metals were retained in the salt marsh sediment. This was equal to the retained amount of organic matter, indicating that retention of the elements was closely related to retention of organic matter. The 50% loss of the macro nutrients and heavy metals probably occurred via ebb tides after resuspension of sediment and organic matter.     

Estimation of 1999-2004 dietary daily intake of PCDDs, PCDFs and dioxin-like PCBs by a total diet study in metropolitan Tokyo, Japan

A study of the dietary intake of dioxins, consisting of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dioxin-like PCBs) through foods retailed in the metropolitan Tokyo area from 1999 to 2004 was carried out by the total diet-market basket method on the basis of food classification (14 groups) and the data on food consumption in the Tokyo region obtained from the Japan Nutrition Survey. The daily intake of dioxins per kg of body weight for a 50 kg average adult body was 2.18 pg TEQ/kg/day in 1999, 1.87 pg TEQ/kg/day in 2000, 1.25 pg TEQ/kg/day in 2001, 1.60 pg TEQ/kg/day in 2002 and 2003 and 1.55 pg TEQ/kg/day in 2004, respectively. These amounts were less than the tolerable daily intake (TDI) of 4 pg TEQ/kg/day for dioxins established in Japan. The dioxins taken daily through fish and shellfish (group 10) accounted for more than 50% of sum WHO-TEQs. In addition, more than 90% of the daily intake of dioxins was taken through fish and shellfish (group 10), meat and eggs (group 11), milk and dairy products (group 12). Also, this study clearly showed that the ratio of dioxin-like PCBs in the daily intake of dioxins was increasing yearly because the reduction rate of dioxin-like PCBs was lower than that of PCDDs and PCDFs in foods.     

Dioxins, PCBs, metals, metalloids, pesticides and antimicrobial residues in wild and farmed Australian southern bluefin tuna (Thunnus maccoyii)

Data concerning the concentration of dioxins (PCDD/PCDFs), polychlorinated biphenyls (PCBs), metals, metalloids, pesticides and antimicrobials residues are reported for the edible portion of Australian wild and farmed southern bluefin tuna (Thunnus maccoyii). In 2004 wild caught (n=5) and farmed (n=26) southern bluefin tuna (SBT) were collected. The mean concentration of total mercury on a fresh weight (fw) basis was 0.34 mg/kg in wild SBT and 0.31 mg/kg in farmed SBT. Concentrations of dioxins (PCDD/PCDFs) and polychlorinated biphenyls (PCBs) found in wild SBT were extremely low. The mean concentration (fw) of the sum of PCDD/PCDFs and the dioxin-like PCBs was 0.27 pg TEQ/g in wild SBT and 0.61 pg TEQ/g in farmed SBT. Mean PCB total concentration (fw basis) was 0.47 ng/g in wild SBT and 6.60 ng/g in farmed SBT. No detectable residues of any pesticide or antimicrobial compounds were found. All residues detected were within regulatory limits set by the Japanese Competent Authority, the Ministry of Health, Labour and Welfare (MHLW) and the Australian Competent Authority, Food Standards Australia New Zealand (FSANZ). The need for harmonisation of international product integrity procedures for bluefin tunas in international trade is highlighted.     

Highly toxic coplanar PCBs: occurrence, source, persistency and toxic implications to wildlife and humans

Isomer-specific determinations of PCB congeners in a wide variety of animal species such as fish, marine mammals (whale, dolphin and porpoise) and terrestrial mammals (dog, cat and human) revealed the environmental occurrence of highly toxic coplanar 3,3',4,4'-tetrachlorobiphenyl (T(4)CB), 3,3',4,4',5-pentachlorobiphenyl (P(5)CB) and 3,3',4,4',5,5'-hexachlorobiphenyl (H(6)CB) within a range of few pg g(-1) to several ten ng g(-1) in fat tissues (except fish) on a wet weight basis. Detection of these toxic residues in wild specimens collected from remote areas such as the North Pacific suggests the already widespread distribution of coplanar PCBs as in the case of general PCB pollution. The clear positive correlations between concentrations of total PCBs and each of the three coplanar PCBs obtained in all mammals analysed suggest that the sources of coplanar PCB contamination to the environment are mainly commercial PCB preparations. Comparison of the composition of three toxic coplanar PCBs in commercial PCB mixtures and in the various animals indicates the relative metabolisability of these congeners as follows: 3,3',4,4'-T4CB>3,3',4,4',5-P5CB>3,3',4,4',5,5'-H6CB. Moreover, marine mammals seem to have lower potency to metabolise the coplanar PCBs in comparison with terrestrial mammals. In human adipose tissues, the concentrations of coplanar PCBs were found to be much higher than 2,3,7,8-tetrachlorodibenzo-p-dioxin (T(4)CDD), 2,3,4,7,8-pentachlorodibenzofuran (P(5)CDF) and other toxic congeners. 'T(4)CDD-equivalent' analysis based on the enzyme induction potencies and the residues of these toxic chemicals indicates that 3,3',4,4',5-P(5)CB may impose a greater toxic threat than dioxins and furans to the humans and probably to wildlife also.     

Human milk survey for dioxins in the general population in Japan

BACKGROUND: Much attention has been paid to the level of dioxins in breast milk in Japan but few large-scale studies have been conducted on the subject. METHODS: From 1997 to 2002, we collected 839 samples of breast milk from primiparas residing throughout Japan. Starting in 1999, breast milk was also collected from secundiparas. Seven isomers of polychlorinated dibenzo-p-dioxins (PCDDs), 10 of polychlorinated dibenzofurans (PCDFs), 4 of coplanar polychlorinated biphenyls (Co-PCBs) and 8 of mono-orthochlorinated polychlorinated biphenyls (mono-ortho PCBs) were analyzed by employing gas chromatography and mass spectrometry. A correlation between the level of dioxins in human milk and the age of the mothers was noted for the primiparas and the secundiparas; and the levels were compared between the first and the second deliveries. Grouped by parity and prefecture in each year, observations were also made on the trends in these levels. Dioxin levels are shown by using geometric means because their distributions were skewed to the left. RESULTS: The sum of PCDDs and PCDFs, Co-PCBs, mono-ortho PCBs, and total dioxins in the breast milk of primiparas were 13.9, 5.4, 3.4, and 22.7 pg TEQ/g fat, respectively. In the samples obtained from secundiparas, these levels were 63-68 percents of those taken from the primiparas. The correlation coefficients between the PCDDs/DFs, Co-PCBs, mono-ortho PCBs, and total dioxins and the age of the primiparas were 0.19, 0.17, 0.36, and 0.24, respectively. All these correlations were statistically significant (p < 0.001). The positive correlations between these contaminants and the age of the secundiparas were also examined. The total dioxins as well as PCDDs/DFs, Co-PCBs, and mono-ortho PCBs in the breast milk of the primiparas declined significantly between 1998 and 2002 (regression coefficients: -0.04, -0.05, -0.03, and -0.03, respectively). However, no significant decline in these levels was observed when sorted by prefectures. CONCLUSIONS: Much attention should be paid to the age and parity of nursing mothers when investigating the relationship between the level of dioxins in breast milk and the body burden of infants.     

Long-term environmental monitoring of persistent organic pollutants and metals in a chemical/petrochemical area: human health risks

Organic pollutants such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs) and polycyclic aromatic hydrocarbons (PAHs), as well as some metals are periodically monitored in soil and vegetation samples collected in Tarragona County (Spain). We here report the temporal trends of the concentrations of the above pollutants between the initial survey (2002) and that recently (2009) performed. The area under evaluation was divided into 4 sections (chemical, petrochemical, urban/residential and unpolluted). In general terms, urban soils presented the highest concentrations of PCDD/Fs, PCNs and PAHs, confirming that traffic is a very important emission source of these pollutants. In addition, substantially higher levels of PAHs and some metals were found in vegetation samples from the petrochemical complex. The assessment of health risks of these contaminants indicated that the current concentrations of micropollutants did not mean additional non-carcinogenic or cancer risks for the population living in the zone.     

Effects of hydroxyapatite addition on heavy metal volatility during tannery sludge incineration

The effectiveness of hydroxyapatite (HAP) on volatilization reducing of heavy metals during incineration of tannery sludge was investigated. The tannery sludge was treated through doped with different content of HAP, and then incinerated in the tube furnace at the temperature of 600 °C and 900 °C. The results showed that the volatilization rates decreased by 10.19 % for Pb, 10.17 % for Zn, 7.40 % for Cu and 5.33 % for Cr at 600 °C when the HAP content was raised to 20 %. At 900 °C, the volatilization rates of Pb, Cr and Cu decreased by about 40.0 %, 24.0 % and 9.0 %, respectively, while volatilization of Zn can be considered nearly unchanged at around 5 %. The heavy metals can be stabilized effectively in the incineration after the pyromorphite-like minerals were formed in the sludge doped with HAP.     

Persistent organic pollutants in 9/11 world trade center rescue workers: reduction following detoxification

Exposure to toxins following the September 11, 2001 attack on and collapse of the World Trade Center (WTC) is of particular concern given the ultra fine particulate dust cloud, high temperature combustion, and months-long fire. Firefighters, paramedics, police and sanitation crews are among the approximately 40000 personnel who labored for weeks and months on rescue and cleanup efforts. Many of the rescue workers have subsequently developed symptoms that remain unresolved with time. This study characterizes body burdens of polychlorinated biphenyls (PCBs), polychlorinated dibenzofurans (PCDFs), and polychlorinated dioxins (PCDDs) in rescue workers and citizens exposed following the WTC collapse. Our research includes a pilot evaluation of a detoxification method aimed at reducing toxic burden. Many congeners were found at elevated levels, in ranges associated with occupational exposures. Post-detoxification testing revealed reductions in these congeners and despite the small study size, some reductions were statistically significant. Health symptoms completely resolved or were satisfactorily improved on completion of treatment. These results argue for a larger treatment study of this method and an overall treatment approach to address toxic burden.     

复合酸化剂对电镀污泥中铬、铜的去除效果

以电镀加工厂产生的污水污泥作为主要研究对象,研究了柠檬酸、硝酸、过氧化氢为复合酸化剂,Fe3+为增效剂对电镀污泥中铬和铜的去除效果,考察了酸化剂的浓度、反应时间、摇床转速、污泥pH、Fe3+浓度等因素对污泥中重金属去除效率的影响。结果表明:在室温下,含0.15 mol/L柠檬酸、1.5%过氧化氢、0.25 mol/L硝酸的复合酸化剂与增效剂2.0g/L Fe3+溶液共同处理污泥,固液比为1∶10,以150 r/min的转速振荡4 h,对污泥中Cr的去除效率达到80.02%,Cu的去除效率可达到92.89%,使污泥中残留Cr、Cu含量均符合国家污泥农用标准。     

Vertical and horizontal distribution,source identification,ecological and toxic risk assessment of heavy metals in sediments of Lake Aygır,Kars, Turkey

Surface and core sediment samples were collected from Lake Ayg?r, Turkey, to determine heavy metal distribution, probable sources and potential ecological and toxic risks for the lake. Heavy metals, total sulfur, total phosphate, total organic carbon, chlorophyll degradation products, and CaCO₃ content were established. The enrichment factor, PLI, potential ecological risk index, and toxic risk index were calculated. Zn was determined to have the highest accumulation in surface sediment, followed by Cr, Pb, and Cd, respectively. Cd was the only element that exceeded the critical value of 40 and posed a moderate potential ecological risk. According to TRI, no ecotoxic risk was found. It is thought that local fossil fuel consumption is responsible for the accumulation of heavy metals since there is a lack of urbanization, industrialization, and agricultural activities around the lake.     

Organochlorine, PCB, PAH, and metal concentrations in eggs of loggerhead sea turtles (Caretta caretta) from northwest Florida, USA

Composite samples of unhatched and physically unaltered loggerhead sea turtle, Caretta caretta, eggs collected from 20 nests along northwest Florida were analyzed for organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and metals. Chemical analyses revealed that turtle eggs contained detectable amounts of metals, PAHs, and PCBs. Only one OCP, p,p'-DDD, was detected, and its presence was restricted to eggs from two nesting sites. None of the PCB concentrations exceeded the Food and Drug Administration's (FDA) action limit. Concentrations of dioxin-like PCB congeners, 105, 118, and 126, and total PCBs were also detected and are contributors to the toxic burden of loggerhead sea turtle eggs. Concentrations of PAHs, 1,2,5,6-dibenzanthracene, 1-methyl naphthalene, C1-naphthalene and naphthalene were variable at nesting sites. Comparison of mean metal burdens in eggs from different beaches suggested that no uniform geographic gradients exist. Presence of OCPs, PCBs, PAHs and metals and their additive or synergistic toxicity is a concern to loggerhead sea turtle eggs; however, additive or synergistic impacts for loggerhead sea turtles are largely undocumented.     

Export of toxic chemicals - a review of the case of uncontrolled electronic-waste recycling

This paper reviews the concentrations of persistent organic pollutants such as flame retardants (PBDEs), dioxins/furans (PCDD/Fs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metals/metalloid concentrations of different environmental media at Guiyu, a traditional rice-growing village located in southeastern Guangdong Province (PR China), which has turned into an intensive electronic-waste (e-waste) recycling site. Incomplete combustion of e-waste in open air and dumping of processed materials are the major sources of various toxic chemicals. By comparing with existing data available in other areas and also guidelines adopted in different countries, it is obvious that the environment is highly contaminated by these toxic chemicals derived from the recycling processes. For example, the monthly concentration of the sum of 22 PBDE congeners contained in PM(2.5) (16.8ngm(-3)) of air samples at Guiyu was 100 times higher than published data. In order to safeguard the environment and human health, detailed investigations are urgently needed, especially on tracking the exposure pathways of different toxic chemicals which may affect the workers and local residents especially mothers, infants and children.     

Polychlorinated biphenyls (PCBs) in sediments in Hong Kong: a congener-specific approach to the study of coplanar PCBs in aquatic ecosystems

Patterns of contamination by polychlorinated biphenyls (PCBs) were investigated in fourteen samples of coastal sediments from Hong Kong. Congener-specific analyses revealed nine sediment samples from Junk Bay to contain PCBs at concentrations ranging from 31 to 2200 ng g(-1) dry weight, concentrations generally increasing with distance north in the Bay. By contrast, five sediments from the Tolo area to the north-east of Hong Kong exhibited total PCB levels of only 6.6 to 45 ng g(-) dry weight. The patterns of relative abundance of PCB congeners in the northern Junk Bay sediments suggested the existence of ongoing source(s) of PCBs in this area; biphenyls of lower chlorination were present at high concentration in these samples. Three coplanar PCBs (3', 4, 4'-tetrachlorobiphenyl; 3,3',4,4',5-pentachlorobiphenyl; and 3,3',4,4',5,5'-hexachlorobiphenyl) were found to be present in Junk Bay sediments; these are highly toxic and are cause for concern in aquatic environments. The abundance of the three coplanar PCBs in the sediments studied was similar to that in commercial PCB mixtures, suggesting that these congeners are not enriched over other PCBs by the sediments of coastal ecosystems. It is concluded that the preferential enrichment of coplanar PCBs occurs in the biosphere, rather than in sediments.     

渤海南部表层沉积物重金属污染及潜在生态风险评价

利用电感耦合等离子体/质谱仪(ICP/MS)测定了渤海南部21个站位表层沉积物中Cr、Cu、Zn、Cd和Pb共5种重金属浓度,比较分析了重金属来源及分布特征,同时应用Hakanson潜在生态危害指数法进行潜在生态风险评价.结果表明,调查区域沉积物中Cr、Cu、Zn、Cd、Pb的平均质量浓度分别为43.67、17.27、...     

Change of PCBs and forms of heavy metals in sewage sludge during thermophilic anaerobic digestion

Determination of seven congeners of PCBs was carried out for sewage sludge before, during and after thermophilic digestion. The overall content of heavy metals (Zn, Cu, Ni, Cd, Pb, Cr) in sludge before and after digestion was determined. Moreover the concentration of heavy metals in particular chemical fractions of the sludge was analyzed. After the thermophilic digestion total concentration of seven PCBs was reduced by 47%, which suggests that thermophilic digestion affects PCB reduction positively. On the 10th d of the process, concentration of lower chlorinated PCBs increased, whereas those of higher chlorinated PCBs decreased. The thermophilic digestion process showed no accumulation of the studied heavy metals in the mobile fractions (exchangeable and carbonate) of the stabilized sewage sludge, except for nickel. The highest increase in zinc, copper, cadmium, and chromium concentration was observed in the organic-sulfide fraction, whereas the highest increase in lead was found in the residual fraction of the sludge. In case of nickel both fractions of organic-sulfide and exchangeable-carbonate fractions were enriched.     

Persistent organic pollutants and heavy metals in adipose tissues of patients with uterine leiomyomas and the association of these pollutants with seafood diet, BMI, and age

Background, aim, and scope  

Persistent organic pollutants and heavy metals can cause diseases in women, however, the relationships of these pollutants and uterine leiomyomas (UL), which are non-cancerous tumors of the uterus, are unclear. This study focused on the quantification of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), and heavy metals in subcutaneous and visceral fat obtained from patients with UL and in subcutaneous fat of a control group of women without UL to determine if there were any correlations between concentrations of persistent organic pollutants (POPs) and heavy metals and the incidence of UL.