Arsenicosis status and urinary malondialdehyde (MDA) in people exposed to arsenic contaminated-coal in China

The current arsenic exposure condition, arsenicosis prevalence, urinary arsenic and MDA (malondialdehyde) concentrations in people were studied. The study area, a village in Xing Ren County in Guizhou Province, PR China, is a coal-borne arsenicosis endemic area that was identified several decades ago. The residents in Xing Ren have been using coal containing high arsenic levels all their life. Urinary arsenic levels of villagers were 192.2+/-22 microg/g creatinine (n=113) in the coal-borne endemic area (Xing Ren county) and were significantly higher than 63.6+/-5.9 microg/g creatinine (n=30) in a neighbouring control site (a village in Xing Yi county). The urinary MDA concentrations of villagers from the endemic area were also significantly higher compared to those of the control area. There was a strong correlation between age and urinary arsenic and MDA concentrations in the endemic area of Xing Ren; urinary arsenic and MDA levels decreased with age. Fifty out of 113 (44.3%) villagers in the endemic area had arsenicosis symptoms and the prevalence in villagers older than 40 y was 100% in male (92.2% overall). Urinary MDA concentration was significantly higher in people with arsenicosis symptoms in the endemic areas. Oxidative stress (urinary MDA concentration) was strongly related to arsenic exposure but not to the age and smoking habit. Higher urinary arsenic and MDA levels in younger villagers from the endemic area suggest that they are having a higher exposure to coal-borne emitted arsenic because they spend more time indoor. There is an urgent need to develop proper intervention methods in the Guizhou endemic areas in order to reduce the risk to the local communities who are still using arsenic contaminated-coal.     

Inorganic arsenic exposure and its relation to metabolic syndrome in an industrial area of Taiwan

Past arsenic exposure was found associated with increased incidence of type 2 diabetes. However, the mechanisms remain unclear. Metabolic syndrome has been shown as a strong predictor for diabetes occurrence. We aimed at examining the association of inorganic arsenic exposure and the prevalence of metabolic syndrome. The authors recruited 660 age and gender stratified random population of residents in central Taiwan during 2002-2003. They received home interviews and health examinations at local health care units, where blood and hair specimens were collected. Hair arsenic (H-As) concentrations were determined by inductively coupled plasma-mass spectrometry. Metabolic syndrome was defined as the presence of three or more of the following risk factors: elevated levels of blood pressure, plasma glucose, and triglycerides, also the body mass index, and reduced high-density lipoprotein. Prevalence of metabolic syndrome increased from the 2nd tertile (0.034 ug/g) of H-As levels (odds ratio=2.54, 95% confidence interval: 1.20-5.39, p=0.015) after the adjustment for age, gender, occupation and life styles including cigarette smoking. We further found linear relation between H-As concentrations and increased levels of plasma glucose and lipids, and blood pressures. This first report may help identify modifiable factors associated with diabetogenesis and cardiovascular disease progression and thus be worth following for community health.     

Exposure to phthalates,bisphenol A and metals in pregnancy and the association with impaired glucose tolerance and gestational diabetes mellitus: The MIREC study

BackgroundStudies from several countries report increases in rates of gestational diabetes mellitus (GDM) over recent decades. Exposure to environmental chemicals could contribute to this trend.ObjectivesTo determine the associations between plasticisers and metals measured in early pregnancy with impaired glucose tolerance (IGT) and GDM in a Canadian pregnancy cohort.MethodsWomen enrolled in the Maternal–Infant Research on Environmental Chemicals (MIREC) Study were included if they had a singleton delivery and did not have pre-existing diabetes. Eleven phthalate metabolites and total bisphenol A (BPA) were measured in first-trimester urine samples, and four metals (lead, cadmium, mercury and arsenic) were measured in first-trimester blood samples. IGT and GDM were assessed in accordance with standard guidelines by chart review. Chemical concentrations were grouped by quartiles, and associations with outcomes were examined using logistic regression with adjustment for maternal age, race, pre-pregnancy BMI, and education. Restricted cubic spline analysis was performed to help assess linearity and nature of any dose–response relationships.ResultsOf 2001 women recruited into the MIREC cohort, 1274 met the inclusion criteria and had outcome data and biomonitoring data measured for at least one of the chemicals we examined. Elevated odds of GDM were observed in the highest quartile of arsenic exposure (OR = 3.7, 95% CI = 1.4–9.6) in the adjusted analyses. A significant dose–response relationship was observed in a cubic spline model between arsenic and odds of GDM (p < 0.01). No statistically significant associations were observed between phthalates or BPA or other metals with IGT or GDM.ConclusionsOur findings add to the growing body of evidence supporting the role of maternal arsenic exposure as a risk factor for gestational diabetes.     

村镇路网通达性与空间出行研究——以武汉市李集镇为例

道路网络是乡村地区社会经济发展的基础。综合道路网络分析和通达性分析方法，构建路网密度、公路可达性、接近中心性、直达性等指标研究了武汉市李集镇村镇范围内各行政村路网通达性空间格局，并结合农户调查将路网通达性与村民空间出行进行关联分析。结果表明：（1）境内部分行政村道路密度低、断头路较多，导致局部地区通达性较差；（2）受地理区位和公路覆盖两方面因素影响，境内行政村接近中心性呈现出明显的核心-边缘分布模式；（3）高等级道路覆盖不足，未能形成完善的路网体系，极大限制村民的对外出行效率、出行范围，显著影响居民出行满意度，并阻碍地区农业机械化推广和农业产业规模化发展。最后，结合路网通达性特征和居民出行需求，提出李集镇道路网络整治建议，研究结果对完善农村地区道路体系研究、指导新农村建设有一定意义。     

Anguilla anguilla L. Genotoxic responses after in situ exposure to freshwater wetland (Pateira de Fermentelos, Portugal)

Pateira de Fermentelos is a Cértima River enlargement, close to its river mouth (by the Agueda River), where the introduction of agricultural chemicals such as fertilisers and pesticides, domestic sewage, as well as heavy metals from electroplating industries, results in increased water pollution. The present research work concerns a 48 h in situ exposure of caged eels (Anguilla anguilla L.) at the Pateira de Fermentelos. Five exposure sites were selected, i.e., site A, site B, site C, site D and site E in order to study its water genotoxicity potential, measured in gill, blood, liver and kidney as DNA strand breaks. Eels were also exposed at a reference site by the Cértima River spring. Bottom water samples were collected for further physical-chemical analysis. Site A exposure, significantly decreased gill, blood and liver DNA integrity. Gill and liver DNA integrity was also significantly decreased at site B. At site C only blood DNA integrity was significantly decreased. The present field in situ study demonstrated that the three exposure sites close to the Pateira initial part, such as A, B and C are polluted by pro and/or genotoxic compounds. The genotoxic effects induced in A. anguilla L. suggest a different contamination of the exposure sites A, B and C, in genotoxic chemicals. Thus, according to its genotoxic potential the exposure sites A, B and C, may be ordered as follows site A>site B>site C. No genotoxic effects on A. anguilla L. were observed at site E as DNA strand breaks increase.     

Contamination of groundwater and risk assessment for arsenic exposure in Ha Nam province, Vietnam

The characteristics of arsenic-contaminated groundwater and the potential risks from the groundwater were investigated. Arsenic contamination in groundwater was found in four villages (Vinh Tru, Bo De, Hoa Hau, Nhan Dao) in Ha Nam province in northern Vietnam. Since the groundwater had been used as one of the main drinking water sources in these regions, groundwater and hair samples were collected in the villages. The concentrations of arsenic in the three villages (Vinh Tru, Bo De, Hoa Hau) significantly exceeded the Vietnamese drinking water standard for arsenic (10 microg/L) with average concentrations of 348, 211, and 325 microg/L, respectively. According to the results of the arsenic speciation testing, the predominant arsenic species in the groundwater existed as arsenite [As(III)]. Elevated concentrations of iron, manganese, and ammonium were also found in the groundwater. Although more than 90% of the arsenic was removed by sand filtration systems used in this region, arsenic concentrations of most treated groundwater were still higher than the drinking water standard. A significant positive correlation was found between the arsenic concentrations in the treated groundwater and in female human hair. The risk assessment for arsenic through drinking water pathways shows both potential chronic and carcinogenic risks to the local community. More than 40% of the people consuming treated groundwater are at chronic risk for arsenic exposure.     

Associations between polycyclic aromatic hydrocarbon (PAH) exposure and oxidative stress in people living near e-waste recycling facilities in China

Emission of polycyclic aromatic hydrocarbons (PAHs) from e-waste recycling activities in China is known. However, little is known on the association between PAH exposure and oxidative damage to DNA and lipid content in people living near e-waste dismantling sites. In this study, ten hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and two biomarkers [8-hydroxy-2′-deoxyguanosine (8-OHdG) and malondialdehyde (MDA)] of oxidative stress were investigated in urine samples collected from people living in and around e-waste dismantling facilities, and in reference population from rural and urban areas in China. The urinary levels of ∑₁₀OH-PAHs determined in e-waste recycling area (GM: 25.4 μg/g Cre) were significantly higher (p < 0.05) than those found in both rural (11.7 μg/g Cre) and urban (10.9 μg/g Cre) reference areas. The occupationally exposed e-waste workers (36.6 μg/g Cre) showed significantly higher (p < 0.01) urinary Σ₁₀OH-PAHs concentrations than non-occupationally exposed people (23.2 μg/g Cre) living in the e-waste recycling site. The differences in urinary Σ₁₀OH-PAHs levels between smokers (23.4 μg/g Cre) and non-smokers (24.7 μg/g Cre) were not significant (p > 0.05) in e-waste dismantling sites, while these differences were significant (p < 0.05) in rural and urban reference areas; this indicated that smoking is not associated with elevated levels of PAH exposure in e-waste dismantling site. Furthermore, we found that urinary concentrations of Σ₁₀OH-PAHs and individual OH-PAHs were significantly associated with elevated 8-OHdG, in samples collected from e-waste dismantling site; the levels of urinary 1-hydroxypyrene (1-PYR) (r = 0.284, p < 0.01) was significantly positively associated with MDA. Our results indicate that the exposure to PAHs at the e-waste dismantling site may have an effect on oxidative damage to DNA among selected participants, but this needs to be validated in large studies.     

Arsenic and other trace elements contamination in groundwater and a risk assessment study for the residents in the Kandal Province of Cambodia

Concentrations of arsenic and other trace elements in groundwater were examined at three villages (PT, POT and CHL) in the Kandal Province of Cambodia. Concentrations of arsenic in the groundwater ranged from 6.64 (in POT village) to 1543 microg/L (in PT village), with average and median concentrations of 552 and 353 microg/L, respectively. About 86% out of fifteen samples contained arsenic concentrations exceeding the WHO drinking water guidelines of 10 microg/L. Concentrations of arsenic (III) varied from 4 (in POT village) to 1334 microg/L (in PT village), with an average concentration of 470 microg/L. In addition, about 67%, 80% and 86% of the groundwater samples had higher concentrations for, respectively, barium, manganese and lead than the WHO drinking water guidelines. These results reveal that groundwater in Kandal Province is not only considerably contaminated with arsenic but also with barium, manganese and lead. A risk assessment study found that one sample (PT25) had a cumulative arsenic concentration (6758 mg) slightly higher than the threshold level (6750 mg) that could cause internal cancer in smelter workers with chronic exposure to arsenic from groundwater. High cumulative arsenic ingestion poses a health threat to the residents of Kandal Province.     

The consequences of chronic radiation exposure of scots pine in the remote period after the chernobyl accident

Long-term observations on Scots pine populations (2003–2012) were performed in areas of Bryansk region radioactively contaminated by the Chernobyl fallout. Throughout the observation period, the frequency of cytogenetic alterations in the root meristem of germinated seeds of pine trees from radioactively contaminated test sites significantly exceeded the control level. Seeds developing under chronic radiation exposure were characterized by high interannual variation in viability. The quality of the seeds and their resistance to additional γ-irradiation showed no definite relationship with the level of radioactive contamination in the site and the radiation dose absorbed by the generative organs of Scots pine.     

Anguilla anguilla L. antioxidants responses to in situ bleached kraft pulp mill effluent outlet exposure

This study assesses the antioxidant enzymes activities viz., catalase, glutathione peroxidase, glutathione S-transferase and nonenzymatic antioxidant molecule such as glutathione in Anguilla anguilla L. gill, kidney and liver in response to 8- and 48-h exposure to bleached kraft pulp mill effluent (BKPME). A. anguilla were caged and plunged at three different sites-50 (Site 1), 100 (Site 2) and 2000 m (Site 3) away from the closed BKPME outlet. A significant gill (8 and 48 h) and kidney (48 h) catalase activity decrease was observed at site 2 exposure whereas liver showed a significant increase in catalase activity after 8 and 48 h to site 1 exposure. Glutathione peroxidase (GPX) activity was significantly decreased in gill after 8-h exposure to site 1 and 48-h exposures to sites 1 and 2, respectively. Concerning gill, kidney and liver glutathione S-transferase (GST) activity, a significant gill GST activity decrease after 8 h at site 2 and 48 h at sites 1 and 2 was observed; in kidney, a significant decrease in its activity was observed after 48 h at sites 1 and 2, respectively, whereas in liver, the decrease was significant only at site 2 after 48-h exposure. The in situ BKPME exposure caused a significant total gill and kidney reduced glutathione (GSH) decrease after 8 h at site 2 exposure and after 48 h at site 1 and 2 exposures, respectively. However, a biphasic response was observed in liver, i.e. initial significant increase after 8 h at site 2 followed by a significant decrease after 48 h to the same site exposure. The enzymatic and nonenzymatic antioxidants pattern in gill and kidney, as observed in this study, was different than liver, demonstrating that the liver was more resistant to oxidative damage than gill and kidney. In addition, A. anguilla gill, kidney and liver antioxidants adaptation potentials may serve as a surrogate biomarker to BKPME exposure.     

Community mercury levels in the vicinity of peri-urban waste disposal sites and fossil fuel burning operations

INTRODUCTION: A study was conducted as a result of concern about mercury absorption amongst residents of a peri-urban area in Cape Town, South Africa, in close proximity to waste disposal sites and an industrial area. STUDY METHODS: The study compared urine mercury concentrations in a random sample of adult residents and children in both the formal and informal housing settlements of the "exposure" area (n = 90) and a control area (n = 90). A short questionnaire elicited demographic, lifestyle and medical details and possible occupational, household and environmental mercury exposures. RESULTS: The two samples were comparable with respect to background and potential confounding variables. The prevalence of urinary mercury levels>or=the WHO reference range in the exposure area was also higher than that in the control area (13% vs. 0%). The median urinary mercury concentrations in both study areas were below the World Health Organisation (WHO) reference level of 5.0 microg/g creatinine. The median level in the exposure area was slightly, but statistically significantly, higher than in the control area (1.1 vs. 0.25 microg/g creatinine), and the excess persisted after controlling for known possible mercury exposures. CONCLUSIONS: This is to our knowledge the first study of community inorganic mercury absorption in a developing country setting, and where airborne mercury was the exposure of concern. It was concluded that the health risk associated with the urinary mercury levels of residents in the exposure area was very low. However, low level environmental exposure in the area of concern could not be excluded.     

Serum perfluorinated chemicals,glucose homeostasis and the risk of diabetes in working-aged Taiwanese adults

BackgroundThe link among perfluoroalkyl and polyfluoroalkyl substances (PFASs), abnormal glucose homeostasis and the risk of diabetes has been intensively debated with conflicting evidence.ObjectivesWe evaluated the associations among PFASs, oral glucose tolerance testing (OGTT) curves and diabetes prevalence in 571 working-aged Taiwanese participants.MethodsExposure measures included serum perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), and perfluoroundecanoic acid (PFUA). Outcomes were OGTT curves and prevalent diabetes defined by fasting blood glucose (FBG) ≥ 126 mg/dL, 2-h glucose ≥ 200 mg/dL, or glycated hemoglobin ≥ 6.5%. Analyses were performed with multiple logistic regression and functional data analysis.ResultsA total of 39 participants (6.8%) had diabetes in this study. After full adjustment, the increase in the geometric means of FBG, 2-h glucose concentrations, and area under the OGTT curve (AUC₁₂₀) with a doubling increase in PFOS was 3% (95% CI 1–4), 8% (5–12), and 6% (4–9), respectively. Compared to the lowest-quartile of PFOS concentrations (< 2.4 ng/ml), the OGTT trajectories were significantly steeper in participants of the highest-quartile PFOS exposure (> 4.8 ng/ml) and the vertical shifting of the mean curve for each PFOS quartile showed a dose–response pattern. The adjusted odds ratio for diabetes comparing the highest to lowest quartile was 3.37 (95% CI 1.18–9.65). For PFOA, PFNA, and PFUA, the opposite pattern of OGTT trajectory and the opposite risk profile for diabetes were observed.ConclusionsChronic PFOS exposure was associated with impaired glucose homeostasis and the increased prevalence of diabetes. However, PFOA, PFNA, and PFUA showed a potential protective effect against glucose intolerance and the risk of diabetes. Future research focusing on clarifying possible differential effects of different species of PFASs on glucose homeostasis and establishing the prospective associations between PFASs and diabetes is needed.     

Effects of cadmium and zinc on larval growth and survival in the ground beetle,Pterostichus oblongopunctatus

Carabid beetles, like Pterostichus oblongopunctatus, living in metal contaminated areas may be exposed to elevated levels of metals within their diets. However, when compared to other second order consumers, they have one of the lowest observed levels of metals, indicating methods of detoxification to deal with such toxicants. In this study, we investigated if chronic, multigenerational exposure to metals leads to resistance to toxic metal concentrations, and if so, what are the costs associated with them. Adult organisms were collected from two sites, a polluted and a reference site near Olkusz, in southern Poland. These adults were immediately mated, and eggs were collected twice weekly to assess the effects in the larvae of the F(1) generation. Larvae were randomly exposed to one of four artificial mediums: control, 50 mg kg(-1) Cd, 500 mg kg(-1) Zn, and a combined treatment of 50 mg kg(-1) Cd and 500 mg kg(-1) Zn to investigate possible interactions. Individuals were sacrificed at 10, 30, and 40 days. Although metals were not accumulated in larvae (p>0.05), larvae fed the Cd or the Zn treatment grew significantly slower, and had the lowest survival rate (p<0.05) in respect to control. Out of metal treated animals, those on the combined treatment of CdZn grew the quickest and had the highest observed survival (p<0.05). Although previous studies have demonstrated changes in adult population parameters under chronic, multigeneration exposure to toxic metal concentrations, our study did not reveal any changes in the larval stage.     

Risk assessment and pathway study of arsenic in industrially contaminated sites of Hyderabad: a case study

Different areas in the industrial region of Patancheru near Hyderabad, Andhra Pradesh (A.P), India are contaminated with high concentration of arsenic, which is attributed to industrial source like veterinary chemicals, pharmaceuticals, pesticide industries, etc. Fourteen villages of this area of Patancheru were assessed for arsenic contamination by collecting samples of water (surface and ground), soil, fodder, milk, and vegetables. The total arsenic content in the whole blood, urine, hair, and nails of the residents showing arsenical skin lesions and other clinical manifestations were also studied. To understand the bioavailability of arsenic in this environment and its possible entry into human food chain, speciation studies of arsenic was carried out and the results are presented in this paper.     

Impacts of arsenic contamination in groundwater: case study of some villages in Bangladesh

The contamination of groundwater in Bangladesh by arsenic is a widespread and serious environmental problem, affecting mainly the rural population who rely extensively on groundwater for drinking and cooking. The study conducted survey work in a few affected villages of the Northwest region in Bangladesh. The household survey gathered information on the respondents (affected by arsenic) water usage and sources, knowledge of the arsenic problem, changes in the source of water for drinking and cooking, arsenic mitigation technologies and socio-economic information on the households. The survey work shows that percentage of male patient is higher than female patient among the same level of household income in each study villages. Prevalence of arsenicosis is more among poorer sections and it is directly related to the poverty situation of the community. People know more about the health problems caused by arsenicosis but lack knowledge about mitigation aspects. In one of the study areas, every year an extra 4% tubewell is getting contaminated by arsenic. Arsenic contamination in groundwater also affects the environment and the ecology negatively. The NGOs have been found contributing to a knowledge creation process in the village community as the villagers are showing marked behavioral changes in water-use practice.

Elevated childhood exposure to arsenic despite reduced drinking water concentrations — A longitudinal cohort study in rural Bangladesh

ObjectivesThe aim of this study was to evaluate the massive efforts to lower water arsenic concentrations in Bangladesh.MethodsIn our large mother–child cohort in rural Matlab, we measured the arsenic concentrations (and other elements) in drinking water and evaluated the actual exposure (urinary arsenic), from early gestation to 10 years of age (n = 1017).ResultsMedian drinking water arsenic decreased from 23 (2002–2003) to < 2 μg/L (2013), and the fraction of wells exceeding the national standard (50 μg/L) decreased from 58 to 27%. Still, some children had higher water arsenic at 10 years than earlier. Installation of deeper wells (> 50 m) explained much of the lower water arsenic concentrations, but increased the manganese concentrations. The highest manganese concentrations (~ 900 μg/L) appeared in 50–100 m wells. Low arsenic and manganese concentrations (17% of the children) occurred mainly in > 100 m wells. The decrease in urinary arsenic concentrations over time was less apparent, from 82 to 58 μg/L, indicating remaining sources of exposure, probably through food (mean 133 μg/kg in rice).ConclusionDespite decreased water arsenic concentrations in rural Bangladesh, the children still have elevated exposure, largely from food. Considering the known risks of severe health effects in children, additional mitigation strategies are needed.     

Estimation of transition rates in a multi-state proportional hazards model

An algorithm using the Interactive Scientific Processor is proposed for estimating parameters of the multi-state model for reverse and repeated transitions. The algorithm was applied to longitudinal data on diabetes mellitus collected at a diabetes hospital in Bangladesh. On the basis of blood glucose level, three distinct types of transitions from one state to another were detected. These are Transition, Reverse Transition, and Repeated Transition. Four variables are included in the models for the transitions: Sex, Body Mass Index (BMI), Age, and Area. For transition from state 2 to state 1, only sex has a significant association, indicating a higher rate of transition for male patients than that of female patients (p-value < 0.05). The variable BMI is significantly associated (p-value < 0.05) with the blood glucose level, implying that a lower BMI accelerates transition from a lower level of blood glucose to a higher level (p-value < 0.05).     

平原湖区钉螺分异规律及孳生环境特征研究——以湖北公安县为例

以血吸虫病典型流行区湖北省公安县为研究区，以行政村为基本研究单元，通过空间自相关和分组分析方法探究公安县钉螺空间分异规律，进而运用逐步回归、地理加权回归和地理探测器模型探讨公安县钉螺分布影响因素及其交互作用。结果如下：（1）公安县钉螺密度具有较强的空间集聚特性，形成2个较大的热点集聚区；综合考虑公安县钉螺密度水平和空间连接性，将公安县划分为高、中、低3个钉螺密度区。（2）人口密度、水网密度、水田比例、春季NDVI和秋季NDVI是公安县村级尺度钉螺密度主要影响因素，其影响效应具有空间异质性。（3）从整个研究区来看，两因子交互作用均产生非线性增强（NE），即两因子交互作用于钉螺密度时要比单因子具有更大的影响力。从钉螺密度类型分区来看，高、中钉螺密度区各因子之间的交互作用类型有双因子增强型（BE）和非线性增强型（NE）；而低钉螺密度区各因子交互作用均产生非线性增强作用。研究结果可为江汉平原乃至全省钉螺及血吸虫病防控工作提供决策支持。     

Sublethal toxicity of the Prestige oil spill on yellow-legged gulls

The Prestige oil spill in November 2002 is considered the biggest large-scale catastrophe of its type in Europe, thousands of seabirds dying in the subsequent months. Here, the total concentration of 16 polycyclic aromatic hydrocarbons (TPAH) was measured in the blood cell fraction of adult and chick yellow-legged gulls (Larus michahellis) from unoiled and oiled coastal areas in North Western Spain. In addition, hematocrit, plasma metabolites, electrolytes and enzymes, as well as body mass were determined in the same individuals. Our results strongly suggest the presence of health damages of sublethal nature in adult gulls breeding in oiled colonies 17 months after the Prestige oil spill. This is supported by the following evidences: (1) gulls sampled in unoiled and oiled colonies differed in blood TPAH levels, (2) gulls sampled in unoiled and oiled colonies differed in several blood parameters indicative of physiological disorders, and (3) TPAH in blood was significantly related to several of these parameters. Differences in the level of asparatate aminotransferase (AST), gamma-glutamyl transferase (GGT), total protein, glucose and inorganic phosphorus suggest damages on some vital organs (i.e. liver and kidney) in adult birds from oiled areas. Meanwhile, chicks presented weaker effects than adults, showing only between-area differences in hematocrit. Since TPAH levels in blood did not differ between both age-groups, the stronger effects on adults should be due to their longer exposure to these pollutants and/or to severe exposure in the months following the spill. The presence of PAHs in chicks indicates that these pollutants were incorporated into the food chain because nestlings would have been only exposed to contaminated organisms in the diet (e.g. fishes and crustaceans). Our findings support the view that PAHs may deeply alter the physiology of seabirds, and emphasize the necessity of quantifying the circulating levels of these compounds in order to evaluate the sublethal effects associated to large oil spills.     

Exposure to metal mixtures and human health impacts in a contaminated area in Nanning, China

Cadmium and lead have been identified as very toxic metals, which are widely present in the environment due to natural and anthropogenic emissions. Many studies have shown that the food chain is the main pathway of cadmium and lead transfer from the environment to humans. It is well documented that many factors will affect their transfer through food chains. Previous investigations on heavy metals were mostly concentrated on one contaminant in isolation. However, in real environments, exposure to mixtures of metals is ubiquitous such that cadmium pollution is invariably being associated with lead and zinc, etc. This study focuses on the contamination and health effects of the metal mixtures. For this purpose, a dietary survey was taken for 3 groups in Nanning in October 2002. Samples of soils, plants (vegetables), urine and blood of humans were measured for Cd, Fe, Cu, Zn, Ca and Pb, in addition, the urinary indicators of renal dysfunction Albumin (ALB), N-acetyl-beta-D-glucosaminidase (NAG), Beta-2-microglobulin (beta2-MG) and Retinol-binding protein (RBP) in urine were also measured. Results showed that soil contamination with metal mixtures had caused significant renal dysfunction of the local residents living in the contaminated area, and the dose-response curve was somewhat altered by the mixed contamination of Cd and Pb as well as the intake of other minerals. The importance of mixtures of metal contamination and human health are also discussed in this paper.