Respiratory hospital admissions in young children living near metal smelters,pulp mills and oil refineries in two Canadian provinces

BackgroundIndustrial plants emit air pollutants like fine particles (PM2.5), sulfur dioxide (SO2) and nitrogen dioxide (NO2) that may affect the health of individuals living nearby.ObjectiveTo assess the effects of community exposure to air emissions of PM2.5, SO2, and NO2 from pulp mills, oil refineries, metal smelters, on respiratory hospital admissions in young children in Quebec (QC) and British Columbia (BC), Canada.MethodsWe assessed QC, BC and pooled associations between the following estimates of exposure and hospital admissions for asthma and bronchiolitis in children aged 2–4 years for the years 2002–2010: i) Crude emission exposures at the residential postal codes of children, calculated by multiplying estimated daily emissions of PM2.5, SO2, or NO2 from all nearby (< 7.5 km) pulp mills, oil refineries, metal smelters emitting yearly ≥ 50 t and their total emissions, by the percent of the day each postal code was downwind; ii) Daily levels of these pollutants at central ambient monitoring stations nearby the industries and the children's residences.ResultsSeventy-one major industries were selected between QC and BC, with a total of 2868 cases included in our analyses. More cases were exposed to emissions from major industries in QC than in BC (e.g. 2505 admissions near SO2 industrial emitters in QC vs 334 in BC), although air pollutant levels were similar. Odds ratios (ORs) for crude refinery and smelter emissions were positive in QC but more variable in BC. For example with PM2.5 in QC, ORs were 1.13 per 0.15 t/day (95% CI: 1.00–1.27) and 1.03 (95% CI: 0.99–1.07) for refinery and smelter emissions, respectively. Pooled results of QC and BC for crude total SO2 emissions from all sources indicated a 1% increase (0–3%) in odds of hospital admissions per 1.50 t/day increase in exposure. Associations with measured pollutant levels were only seen in BC, with SO2 and NO2.ConclusionHospital admissions for wheezing diseases in young children were associated with community exposure to industrial air pollutant emissions. Future work is needed to better assess the risk of exposure to complex mixture of air pollutants from multiple industrial sources.     

Perceptions toward stewardship among residents living near U.S. Department of Energy Nuclear Facilities

Although stewardship has been widely defined and used in environmental management and planning, there is a dearth of studies that describe how the lay public perceives this concept. A national sample of residents in 14 states who live near DOE nuclear facilities were interviewed to delineate public understanding and awareness of the stewardship program of the U.S. Department of Energy (DOE). This study discusses the findings of the survey and discusses how institutional trust influences public participation and resident’s choices of potential stewards. Almost 40% of the respondents could not define stewardship; those who did, believed that ‘responsibility,’ ‘management,’ and ‘accountability’ are key elements of stewardship. In addition, about a third of the respondents identified Federal groups and the DOE as potential stewards. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue     

Increased incidence of allergic rhinitis,bronchitis and asthma,in children living near a petrochemical complex with SO2 pollution

This study aims to investigate incidence of allergic rhinitis, bronchitis and asthma, in children living near a petrochemical complex with SO₂ pollution obtained by air monitoring stations. A total of 587 children aged 11 to 14 were recruited and classified into high and low exposure groups based on a radius of 10 km from the complex. To study the influence of health on children since the operation of complex in 1999 and observe the difference of these diseases' short-term and long-term impact, we obtained the incidence rates of allergic rhinitis (ICD-9: 477), bronchitis (490–491) and asthma (493) from the Taiwan Health Insurance Database for three periods: 1999–2002, 1999–2006, and 1999–2010. Since 2001, the mean and 99th percentile of SO₂ concentrations in the high exposure area have been significantly higher than those in low exposure area. There were significant differences between the high and low exposure groups in the percentage of smoking, alcohol consumption, passive smoking exposure and incense burning habits. The incidence rates of three intervals were 26.9%, 35.7%, 41.7%; 8.3%, 8.8%, 10.2%; 18.5%, 25.0%, 26.9% for allergic rhinitis, bronchitis and asthma in high exposure group. Significant differences were found between groups for allergic rhinitis in all periods, bronchitis in the first two periods, and asthma in the first period using Student's t-test. After we adjusted age, gender, group, living near roads, incense burning and passive smoking exposure, the hazard ratios between exposure groups were 3.05, 2.74, and 1.93 for allergic rhinitis with significant difference in three periods, and 2.53, 1.92 and 1.72 for bronchitis with significant difference in first period and 1.60, 1.28 and 1.29 for asthma with significant difference in first period by Cox regression. The higher incidence of allergic rhinitis was related to boys and living near roads and the higher incidence of asthma was also related to younger children, boys, and passive smoking 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.     

Po determination in urines of people living in Central Italy

This paper presents the results of the monitoring programme on the urines of people living in an area of Central Italy (near the Republic of S. Marino) to evaluate the background level of the ²¹⁰Po excretion rate (mBq day⁻¹) in this region. The volunteers were subdivided in five age classes and in every age class groups of males and females, cigarette smokers and non-smokers were taken into account. The results indicated that the ²¹⁰Po excretion rate was widely distributed within each group of volunteers. The ²¹⁰Po excretion rate was <30 mBq day⁻¹ for 93.2% of people. The obtained results are discussed and some conclusion, based upon the average values, was drawn.     

Patterns of serum PCDD/Fs affected by vegetarian regime and consumption of local food for residents living near municipal waste incinerators from Taiwan

The aim of this study was to evaluate possible factors affecting serum polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) levels of people living near municipal waste incinerators (MWIs). We selected 19 MWIs in Taiwan and collected 1708 serum samples from residents 18-65 years old who had lived within 5 km of one of the selected MWIs for at least 5 years. The samples were analyzed using a standardized study protocol to assure comparability of the concentrations from 17 PCDD/F congeners. The results suggested that a vegetarian regimen was a protective factor to avoid serum PCDD/F accumulation in the subjects. In addition, the current data seemed to support the hypothesis that serum PCDD/F levels of residents living near MWIs are related to they consumed the locally grown or cultivated vegetable and animal foods, such as poultry products near the MWIs. Our results can be used to create guidelines for preventing excessive PCDD/F accumulation from eating animal and vegetable foods grown near MWIs.     

Increased risk of non-Hodgkin lymphoma and serum organochlorine concentrations among neighbors of a municipal solid waste incinerator

Organochlorine chemicals may contribute to an increased risk of non-Hodgkin lymphoma (NHL) within non-occupationally exposed populations. Among these chemicals, dioxins and furans were mainly released by municipal solid waste incinerators (MSWIs) until a recent past in France, a source of exposure that is of public concern. We investigated organochlorines and the risk of NHL among neighbors of a French MSWI with high levels of dioxin emissions (Besan?on, France), using serum concentrations to assess exposure. The study area consisted of three electoral wards, containing or surrounding the MSWI. Pesticides, dioxins, furans, and polychlorinated biphenyls (PCBs) were measured in the serum of 34 newly diagnosed NHL cases (2003-2005) and 34 controls. Risks of NHL associated with each lipid-corrected serum concentration were estimated using exact logistic regression. The pesticides β-hexachlorocyclohexane (odds ratio [OR]=1.05, 95% confidence interval [CI]=1.00-1.12, per 10 ng/g lipid) and p,p' dichloro-diphenyl-trichloroethane (DDT) (OR=1.20, 95% CI=1.01-1.45, per 10 ng/g lipid) were associated with NHL risk. Evidence indicated an increased NHL risk associated with cumulative WHO(1998)-toxic equivalency factor (TEQ) concentrations (dioxins, OR=1.12, 95% CI=1.03-1.26; furans, OR=1.16, 95% CI=1.03-1.35; dioxin-like PCBs, OR=1.04, 95% CI=1.00-1.07; and total TEQ, OR=1.04, 95% CI=1.01-1.05), as well as with non dioxin-like PCBs (OR=1.02, 95% CI=1.01-1.05, per 10 ng/g lipid). Most congener-specific associations were statistically significant. This study provides strong and consistent support for an association between serum cumulative WHO(1998)-TEQ concentrations, at levels experienced by people residing in the vicinity of a polluting MSWI, and risk of NHL.     

A systemic health risk assessment for the chromium cycle in Taiwan

Health risk assessment (HRA) has been recognized as a useful tool for identifying health risks of human activities. In particular, this method has been well applied to spatially defined units, such as a production plant, a treatment facility, and a contaminated site. However, the management strategies based on the risk information will be more efficient if the comprehensive picture of total risks from all kinds of sources is depicted. In principle, the total risks can be obtained when all risk sources are assessed individually. Apparently, this approach demands huge amount of efforts. This study develops a methodology that combines substance flow and risk estimation to facilitate examination of risk in a systemic way and provide comprehensive understanding of risk generation and distribution corresponding to flows of substances in the anthroposphere and the environment. Substance flow analysis (SFA) and HRA method is integrated to produce a systemic risk assessment method, from which substance management schemes can be derived. In this study, the chromium cycle in Taiwan is used as an example to demonstrate the method, by which the associated substance flow in the economy and the risk caused by the substance in the environmental system is determined. The concentrations of pollutants in the environmental media, the resultant risks and hazard quotients are calculated with the widely-used CalTOX multimedia model.     

Survey of residential extremely-low-frequency magnetic field exposure among children in Taiwan

This survey estimated the extremely-low-frequency magnetic field (ELF-MF) exposure in households with children under the age of 7 years in Taiwan. To select a representative sample, we used the probability proportional to size sampling technique and simple random cluster sampling technique to select study districts in each city/county of Taiwan. A total of 40 districts were selected and all households with children aged less than 7 (n=4184) were visited and solicited for in-home measurements. Four trained interviewers carried out spot-measurements in rooms of each selected household during a two-year period. A questionnaire inquiring residential characteristics and nearby power facilities was also administered to a parent or caregiver. ELF-MF measurements were performed in a total of 2214 households (53% participation rate). Controlling for participation rate, the weighted overall mean magnetic field exposure was estimated at 0.121 (standard deviation 0.185) micro-Tesla (microT) (range 0.010-3.304 microT). Mean exposures were higher than 0.3 and 0.4 microT in an estimated 7.3% (n=159) and 5.4% (n=115) of the households, respectively. There was a substantial agreement between overall mean residential exposure and exposure measured in children's bedrooms. In a multivariate logistic regression model, we noted that buildings with advanced age, buildings for both residential and commercial uses, and buildings close to power facilities were more likely a to have mean exposure above 0.4 microT. Our survey results indicate that residential ELF-MF exposure is likely to be higher for children in Taiwan than for children in Europe and North America.     

Transfer of dioxin risk between nine major municipal waste incinerators in Taiwan

The objective of this study was to assess site-specific carcinogenic risks of incinerator-emitted dioxins and risk transfers among the areas covered by nine municipal incinerators in Taiwan. We used actual emission data and the industrial source complex short-term model (ISCST3) to determine the dioxin impact areas within the 8 x 8-km simulation regions surrounding the incinerators. We then used multimedia model to estimate cancer risks in individual impact areas for two exposure scenarios, which were sufficient (SFP) and insufficient food production (IFP) for residents' consumption in each impact area. We also used information of food supply and consumption between impact areas to calculate risk transfers among these nine incinerators. We found that dioxins' carcinogenic risks ranged from 1.4 x 10(-8) (Incinerator F) to 7.1 x 10(-5) (Incinerator A) for the nine incinerators under the exposure scenario of SFP, and ranged from 8.7 x 10(-8) (Incinerator D) to 1.1 X 10(-6) (Incinerator E) under the exposure scenario of IFP. The food ingestion was the main exposure pathway, which accounted for 64-99% of total dioxin risks among nine impact areas. For the nine major food items consumed by residents in the impact areas, eggs (14-35%) and chicken (11-26%) were two main routes of dioxin exposure in the SFP scenario, while chicken (8-78%) and vegetables (0.2-81%) were two main routes of dioxin exposure in the IFP scenario. Significant risks of dioxins were transferred among incinerators, which accounted for up to 88% among the incinerators. Incinerator E was the major risk-exporting source to six Incinerators C, D, F, G, H, and I. For these six incinerators, Incinerator E accounted for their 51-88% imported risks. We concluded that risk transfers among incinerators through routes of food consumption should be considered in assessing health risks associated with incinerator-emitted dioxins in Taiwan. We should place high priority on implementing control measures to lower dioxin emissions in important food-exporting areas like Incinerator E. We should also emphasize analyzing dioxin contents in eggs, chicken, and vegetables in order to improve dioxin-related health risk assessments in the future.     

Nitrate in drinking water and risk of death from colon cancer in Taiwan

The relationship between nitrate levels in drinking water and colon cancer has been inconclusive. A matched case-control and a nitrate ecology study were used to investigate the association between colon cancer mortality and nitrate exposure from Taiwan's drinking water. All colon cancer deaths of Taiwan residents from 1999 through 2003 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair matched to the cases by sex, year-of-birth, and year-of-death. Each matched control was selected randomly from the set of possible controls for each case. Data on nitrate-nitrogen (NO3-N) level of drinking water throughout Taiwan have been collected from Taiwan Water Supply Corporation (TWSC). The municipality of residence for cases and controls was assumed to be the source of the subject's nitrate exposure via drinking water. The adjusted odds ratios for colon cancer death for those with high NO3-N levels in their drinking water, as compared to the lowest tertile, were 0.98 (0.84-1.14) and 0.98 (0.83-1.16), respectively. The results of the present study show that there was no statistically significant association between NO3-N in drinking water at levels in this study and risk of death from colon cancer.     

Biomonitoring of the general population living near a modern solid waste incinerator: A pilot study in Modena,Italy

Background and goalsAs part of the authorization process for the solid waste incinerator (SWI) in Modena, Italy, a human biomonitoring cross-sectional pilot study was conducted to investigate the degree to which people living and working in the proximity of the plant were exposed to SWI emissions.MethodsBetween May and June 2010, 65 subjects living and working within 4 km of the incinerator (exposed) and 103 subjects living and working outside this area (unexposed) were enrolled in the study. Blood, serum and urinary metals (Pb, Cd, Cu, Zn, Hg, Mn, Ni), urinary benzene, toluene, xylene (BTEX), S-phenylmercapturic acid (SPMA), and urinary polycyclic aromatic hydrocarbons (PAHs) were analysed. Information about lifestyle, anthropometric characteristics, residence, and health status was collected by a self-administered questionnaire. Exposure to particulate matter (PM) emitted from the SWI was estimated using fall-out maps from a quasi-Gaussian dispersion model. A multiple linear regression analysis investigated the relationship between biomarkers and the distance of a subject's place of residence from the SWI plant or the exposure to PM.ResultsUrinary BTEX and SPMA and blood, serum and urinary metals showed no differences between exposed and unexposed subjects. PAHs were higher in exposed than in unexposed subjects for phenanthrene, anthracene, and pyrene (median levels: 9.5 vs. 7.2 ng/L, 0.8 vs. < 0.5 ng/L and 1.6 vs. 1.3 ng/L, respectively, p < 0.05). Multiple linear regression analysis showed that blood Cd and Hg and urinary Mn, fluorene, phenanthrene, anthracene and pyrene were inversely correlated to the distance of a subject's residence from the SWI. Urinary Mn, fluorene and phenanthrene were directly correlated to PM exposure.ConclusionsThis study, although not representative of the general population, suggests that specific biomarkers may provide information about the degree of exposure the subjects working and living in the proximity of the SWI plant may have to emissions from that facility.     

Chronic risk assessment of exposure to volatile organic compounds in the atmosphere near the largest Mediterranean industrial site

This study focuses on characterising the risk of exposure to volatile organic compounds (VOCs) by means of inhalation in people living in the vicinity of the largest chemical production site in the Mediterranean area. Eighty-six VOCs were initially selected for this study based on their adverse environmental and health effects. The monitoring campaign was conducted for 276 days in three different locations around the chemical site. The analytical method used for the characterisation was based on European standard method EN-14662-2, which consists of the active sampling of air for 24 h in charcoal tubes, followed by extraction with carbon disulphide and GC-MS analysis. Forty-four VOCs with toxicological data available concerning their carcinogenic and non-carcinogenic health effects were quantified during the monitoring campaign. None of the quantified VOCs showed average concentrations exceeding their chronic reference concentrations and, therefore, no non-carcinogenic health effects are expected as a result of this exposure. However, the global average cancer risk due to VOC exposure in the area (3.3 × 10^− 4) was found to be above the values recommended by the WHO and USEPA.The influence of the analytical method was also evaluated by comparing cancer risk estimates using a thermal desorption (TD) method based on method EN-14662-1. The results of the 24-h samples for the solvent extraction method were compared with the average of 12 daily samples of 2-h for the TD method for 24 sampling days. Although the global estimated lifetime cancer risk was statistically comparable for both methods, some differences were found in individual VOC risks.To our knowledge, this is the first study that estimates the carcinogenic and non-carcinogenic risks posed by the inhalation of VOCs in people living near a chemical site of this size, and compares the estimated cancer risk obtained using two different standard analytical methods.     

Soil As contamination and its risk assessment in areas near the industrial districts of Chenzhou City, Southern China

In order to assess soil As contamination and potential risk for human, soil, paddy rice, vegetable and human hair samples from the areas near the industrial districts in Chenzhou, southern China were sampled and analyzed. The results showed that the anthropogenic industrial activities have caused in local agricultural soils to be contaminated with As in a range of 11.0-1217 mg/kg. The GIS-based map shows that soil contamination with As occurred on a large scale, which probably accounted for up to 30% of the total area investigated. Soil As concentration abruptly decreased with an increase in the distance from the polluting source. High As concentrations were found in the rice grain that ranged from 0.5 to 7.5 mg/kg, most of which exceed the maximal permissible limit of 1.0 mg/kg dry matter. Arsenic accumulated in significantly different levels between leafy vegetables and non-leafy vegetables. Non-leafy vegetables should be recommended in As-contaminated soils, as their edible parts were found in relatively low As level. Arsenic concentrations in 95% of the total human hair samples in the contaminated districts were above the critical value, 1.0 mg/kg, set by the World Health Organization. Arsenic could be enriched in human hair to very high levels without being affected by As containing water. The results revealed that the soils and plants grown on them are major contributors to elevate hair As in the industrial population. Therefore, the potential impact on human health of ingestion/inhalation of soil As around the industrial districts seems to be rather serious. Hence proper treatments for As contaminated soils are urgently needed to reduce the contamination.     

Different profiles of anthropogenic and naturally produced organohalogen compounds in serum from residents living near a coastal area and e-waste recycling workers in India

We determined the contamination status and accumulation profiles of polychlorinated biphenyls (PCBs), hydroxylated PCB congeners (OH-PCBs), polybrominated diphenyl ethers (PBDEs), hydroxylated PBDEs (OH-PBDEs), methoxylated PBDEs (MeO-PBDEs), and bromophenols (BPhs) in serum from e-waste recycling workers and residents near a coastal area in India. Residue levels of penta- to octa-chlorinated PCBs, penta- to octa-chlorinated OH-PCBs, 6MeO-BDE47, 6OH-BDE47, and 2,4,6-tri-BPh in serum from residents living near the coastal area were significantly higher than those in serum from e-waste recycling workers. Residue levels of tri- to tetra-chlorinated PCBs, tri- to tetra-chlorinated OH-PCBs, PBDEs, octa-brominated OH-PBDEs, and tetra-BPhs in serum from e-waste recycling workers were higher than those in serum from residents living near the coastal area. Principal component analysis revealed that residents living near the coastal area and e-waste recycling workers had different serum profiles of chlorinated and brominated compounds.     

Toxicokinetics/toxicodynamics of arsenic for farmed juvenile milkfish Chanos chanos and human consumption risk in BFD-endemic area of Taiwan

This paper presents a toxicokinetic/toxicodynamic analysis to appraise arsenic (As) bioaccumulation in farmed juvenile milkfish Chanos chanos at blackfoot disease (BFD)-endemic area in Taiwan, whereas probabilistic incremental lifetime cancer risk (ILCR) and hazard quotient (HQ) models are also employed to assess the range of exposures for the fishers and non-fishers who eat the contaminated fish. We conducted a 7-day exposure experiment to obtain toxicokinetic parameters, whereas a simple critical body burden toxicity model was verified with LC50(t) data obtained from a 7-day acute toxicity bioassay. Acute toxicity bioassay indicates that 96-h LC50 for juvenile milkfish exposed to As is 7.29 (95% CI: 3.10-10.47) mg l(-1). Our risk analysis for milkfish reared in BFD-endemic area indicates a low likelihood that survival is being affected by waterborne As. Human risk analysis demonstrates that 90%-tile probability exposure ILCRs for fishers in BFD-endemic area have orders of magnitude of 10(-3), indicating a high potential carcinogenic risk, whereas there is no significant cancer risk for non-fishers (ILCRs around 10(-5)). All predicted 90%-tiles of HQ are less than 1 for non-fishers, yet larger than 10 for fishers which indicate larger contributions from farmed milkfish consumptions. Sensitivity analysis indicates that to increase the accuracy of the results, efforts should focus on a better definition of probability distributions for milkfish daily consumption rate and As level in milkfish. Here we show that theoretical human health risks for consuming As-contaminated milkfish in the BFD-endemic area are alarming under a conservative condition based on a probabilistic risk assessment model.     

Substantial decline of polychlorinated biphenyls serum levels 10 years after public health interventions in a population living near a contaminated site in Northern Italy

IntroductionPolychlorinated biphenyls (PCBs) are persistent pollutants classified among endocrine disruptors and human carcinogens. In an urban area in Northern Italy (Brescia), a chemical factory producing PCBs from 1938 to 1984 caused soil and food pollution. Since the discovering of the environmental pollution in the area in 2001, various public health interventions have been implemented to avoid human contamination.MethodsTwo independent surveys were carried out in 2003 and 2013 using the same study design and methods. A random sample of the adult general population living in four areas of the town with different soil contamination level was enrolled in both surveys. Investigation included serum levels of 24 PCB congeners and of other common clinical-chemical parameters and questions about residential and occupational history as well as current and past diet and consumption of locally produced food. 537 subjects were tested in the 2003 and 488 in the 2013 survey.ResultsTotal PCB serum levels showed a strong correlation with age (Spearman r = 0.71 in 2003 and r = 0.80 in 2013), but not with gender. Consumers of food produced in the most polluted area had higher total PCB serum levels (median 15.6 and 4.7 ng/ml in 2003 and 2013, respectively) than non-consumers (4.1 and 2.3 ng/ml) and consumers of food produced in non-polluted areas (6.5 and 1.9 ng/ml), with increasing trend of PCB serum levels with cumulative local food intake. PCB serum levels from 2003 to 2013 survey declined by around half in all age groups, especially among the youngest people. The total PCB reduction was found to be due to a combination of a birth cohort effect (− 41% every 10 years) and survey period effect (− 18% in 2013 versus 2003), with medium chlorinated CB congeners showing the most relevant reduction (− 30%) between the two surveys. High chlorinated CBs were more strongly associated with birth cohort (− 46% every 10 years): in the 2013 survey they represented 58% of total PCBs in 60–79 years old while they were 37% among the under 40s with a median value 20 times higher in the oldest than in the youngest (3.1 versus 0.16 ng/ml).ConclusionsPCBs serum levels declined from the 2003 to 2013 survey though they are still high in the elderly mainly because of past intake of locally produced contaminated food. Present findings suggest that PCBs food chain contamination and human absorption have been interrupted successfully in the area since discovery of the pollution in 2001.     

Exposure to heavy metals and PCDD/Fs by the population living in the vicinity of a hazardous waste landfill in Catalonia, Spain: Health risk assessment

Most fly ashes produced in municipal waste incinerators of Catalonia (Spain) are deposited in a hazardous waste landfill (HWL) placed in Castellolí (Barcelona). This facility means a concern for the population living nearby. In response to this, we performed a probabilistic study focused on assessing human health risks derived from environmental exposure to heavy metals and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) around the HWL. Concentrations of various metals and PCDD/Fs were determined in soil and air samples collected at the HWL, and in 4 locations around it. Health risks were evaluated according to the distance from the sampling locations to the HWL (near and far-sites). In general terms, metal and PCCD/F levels were relatively low in air and soil samples. However, concentrations of PCDD/Fs, as well as those of some metals, were found to be relatively higher in the HWL and Castellolí (the nearest village) samples than in those collected far away, resulting in a slight increase of exposure to those pollutants. Anyhow, the current concentrations of metals and PCDD/Fs suggest that it is highly unlikely that there are any additional non-carcinogenic and carcinogenic risks for the population living near the HWL.     

Mutagenicity, genotoxicity and carcinogenic risk assessment of indoor dust from three major cities around the Pearl River Delta

The mutagenicity and genotoxicity of workplace dust including commercial office, secondary school, shopping mall, hospital, electronics factory and manufacturing plant in Hong Kong and settled house dust from Hong Kong, Shenzhen and Guangzhou were measured. Results indicated that indoor dust contained both frameshift and base pair substitution mutagens. Dust from manufacturing plant showed highest mutagenic potency on TA98±S9 and TA100±S9 activation, whereas, electronics factory showed highest genotoxicity with and without S9 activation. TA100 (-S9) mutagenic potency was significantly correlated with genotoxicity expressed as SOSIP (-S9) of workplace dust (r(2)=0.37, p<0.01). The total PAHs concentration of settled house dust from PRD ranged from 1.63 to 29.2μg/g. Linear regression analyses indicated that the PAHs likely accounted for about 45% of the TA98 with S9 mutagenic activity of workplace dust. TA98 (-S9) mutagenicity (r(2)=0.27, p<0.05) and SOSIP (-S9) of house dust (r(2)=0.41, p<0.01) were both significantly correlated with the number of inhabitants in the house. To achieve a more accurate cancer risk assessment, the oral bioaccessibility of B(a)A, Chry, B(b+k)F, B(a)P, D(ah)A and I(cd)P in different dust ranging from 1.3% to 17% was taken into account. Risk assessments indicated that about 26% of house dust samples resulted in unacceptable cancer risk (>1×10(-6)) for preschool children.     

Tobacco smoke increases the risk of otitis media among Greenlandic Inuit children while exposure to organochlorines remain insignificant

BackgroundPrenatal exposure to environmental levels of organochlorines (OCs) has been demonstrated to have immunotoxic effects in humans. We investigated the relationship between prenatal exposure to OCs and the occurrence of otitis media (OM) among Inuit children in Greenland.MethodsWe estimated the concentration of 14 PCB congeners and 11 pesticides in maternal and cord blood samples and in breast milk in a population-based cohort of 400 mother–child pairs. At follow-up, we examined the children's ears and used their medical records to assess the OM occurrence and severity. Multivariate regression analyses were used with adjustments for passive smoking, crowding, dietary habits, parent's educational level, breast feeding and the use of child-care.ResultsThe children were 4–10 years of age at follow-up and 223 (85%) participated. We found no association between prenatal OC exposure and the development of OM. Factors associated with the child's hazard of OM during the first 4 years of life were: mother's history of OM (HR 1.70, 95% CI 1.11–2.59, p = 0.01); mother's smoking habits: current (HR 2.47, 95% CI 1.45–4.21, p < 0.01) and previous (HR 2.00, 95% CI 1.19–3.36, p < 0.01); number of smokers in the home (HR 1.17, 95% CI 1.05–1.31, p < 0.01). After adjustment mothers' smoking habits remained significant.ConclusionWe found no relationship between high levels of prenatal exposure of OCs and occurrence of OM. Passive smoking was found as the strongest environmental risk factor for the development of OM.Interventions to reduce passive smoke in children's environment are needed.