Levels of Polychlorinated Dibenzo-P-Dioxins (PCDDs) and Polychlorinated Dibenzo-P-Furans (PCDFs) in the Atmosphere (PM10) of a Coastal Area of West Bengal,India

Particle-bound polychlorinated dibenzo-p-dioxins and dibenzo-p-furans (PCDDs/Fs) were analyzed in the coastal air of West Bengal, India. Total PCDD/Fs ranged from 4–2491 fg m^–3 with a mean of 355 fg m^–3 and their I-TEQ values ranged between 1 to 62.6 fg I-TEQ m^–3, with an average of 17.1 fg I-TEQ m^–3. The dominant congeners were OCDD (46%) OCDF (14%) 1,2,3,4,6,7,8-HpCDF (11%) and 1,2,3,4,6,7,8-HpCDD (10%) and accounted for >80% to the total PCDDs/Fs. TCDD (29%) > PeCDF (28%) > HxCDF (16%) > PeCDD (13%) were the dominant TEQ contributors. Rough estimates of tolerable daily intake (TDI) show a low health risk of exposure to PCDD/Fs measured in the ambient air of a rural coastal area of West Bengal, India.     

Temporal Trends in Metal Concentrations in Soils and Herbage Collected Near a Municipal Waste Incinerator: Human Health Risks

Emissions of metals by municipal solid waste incinerators (MSWIs) are still an issue of concern for the health of residents in the vicinity of these facilities. Since 1991 a MSWI has been operating in Tarragona (Spain). In 1997, a modernization of the flue gas cleaning systems of the MSWI was completed. Since then, periodically soil and herbage samples have been collected near the facility and the concentrations of the following elements determined: As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Tl, and V. In 2002, a 4-year environmental surveillance program was initiated. The mean concentrations of these elements in various surveys performed between 1997 and 2005, as well as the temporal trends are reported. Human health risks, carcinogenic and non-carcinogenic, were also assessed. Risks for adults and children were separately evaluated. Children were chosen because they are one of the most susceptible groups of a population. According to the current results, in principle, no significant health risks for the population living in the neighborhood of the facility can be expected due to metal emissions from the stack. However, a continuous environmental surveillance program is recommended because As levels in soils of Tarragona are slightly higher than the U.S. Environmental Protection Agency's Preliminary Remediation Goals.     

Concentrations of Metals in Soils in the Neighborhood of a Hazardous Waste Incinerator: Assessment of the Temporal Trends

The concentrations of arsenic (As), beryllium (Be), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), antimony (Sb), tin (Sn), thallium (Tl), and vanadium (V) were determined in 30 soil samples collected in April 2011 near a hazardous waste incinerator (HWI; Constantí, Catalonia, Spain), which is under regular operations since 1999. The results were compared with those of recent surveys performed in the same zone, as well as with data from a background study (1996?C1998). We also assessed the human health risks derived from metal exposure in the area under potential influence of the emissions of the HWI. Manganese was the most abundant element in soils, with a mean value of 316.4???g/g, followed by Pb and Cu (mean values, 42.5 and 38.2???g/g, respectively). In contrast, Sb, Cd, and Tl presented the lowest values (0.12, 0.27, and 0.29???g/g, respectively), while Hg was below its limit of detection. In the period 1998?C2011, only As, Cr, Sn, Tl, and V levels presented significant increases in soils. The estimated carcinogenic and noncarcinogenic risks derived from exposure to these metals from soils should not mean any special concern for the population living in the surroundings of the HWI.     

Dairy ruminant exposure to persistent organic pollutants and excretion to milk

Human activities produce polluting compounds such as persistent organic pollutants (POPs), which may interact with agriculture. These molecules have raised concern about the risk of transfer through the food chain via the animal product. POPs are characterised by a strong persistence in the environment, a high volatility and a lipophilicity, which lead to their accumulation in fat tissues. These compounds are listed in international conventions to organise the information about their potential toxicity for humans and the environment. The aim of this paper is to synthesise current information on dairy ruminant exposure to POPs and the risk of their transfer to milk. Three major groups of POPs have been considered: the polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), the polychlorobiphenyls (PCBs) and the polycyclic aromatic hydrocarbons (PAHs). The results show that contamination of fodder and soil by these compounds is observed when they are exposed to emission sources (steelworks, cementworks, waste incinerators or motorways) compared with remote areas. In general, soil contamination is considered higher than plant contamination. Highest concentrations of POPs in soil may be close to 1000 ng/kg dry matter (DM) for PCDD/Fs, to 10 000 mg/kg DM for PAHs and 100 μg/kg DM for PCBs. The contamination of milk by POPs depends on environmental factors, factors related to the rearing system (fodder and potentially contaminated soil, stage of lactation, medical state of the herd) and of the characteristics of the contaminants. Transfer rates to milk have been established: for PCBs the rate of transfer varies from 5% to 90%, for PCDD/Fs from 1% to 40% and for PAHs from 0.5% to 8%. The differential transfer of the compounds towards milk is related to the hydrophobicity of the pollutants as well as to the metabolic susceptibility of the compounds.     

Oral Bioavailability of Polychlorinated Dibenzo-p-Dioxins/Dibenzofurans in Industrial Soils

In this study, the oral bioavailabilities of numerous 2,3,7,8-PCDD/F congeners were evaluated in soil samples from an industrial site. The purpose of this study is several-fold: (1) to compare the soil bioavailability results of the different PCDD/F congeners; (2) to evaluate the consistency of the bioavailability results with those obtained in an in vitro bioaccessibility study with simulated GI tract fluids; and (3) to develop quantitative bioavailability measurements that are appropriate for use in a health risk assessment for this site. Soil samples containing PCDD/F toxic equivalent (TEQ) concentrations ranging from 0.53–45.2 ng/g were administered to female Sprague Dawley rats via oral gavage. Reference formulations of PCDD/Fs were administered intravenously or by oral gavage. The overall relative bioavailability of PCDD/Fs in the soil samples on a TEQ basis ranged from 17 to 51%, with a mean of 38%. The results of the in vitro bioaccessibility study were consistent with the bioavailability results (mean extracted TEQ of 22%). Because of the clear relationship between increasing chlorination and decreasing bioavailability and bioaccessibility observed in this study, we suggest that simply extrapolating results from one congener to another may be associated with a high degree of uncertainty.     

Monitoring Environmental Levels of Trace Elements near a Hazardous Waste Incinerator

In 1998, we initiated an environmental surveillance program of the only hazardous waste incinerator (HWI) in Spain. The concentrations of a number of metals (As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sn, Tl, and V) were analyzed in soil and vegetation samples collected around the facility. Since then, periodical measurements of these same elements have been performed in both matrices. In 2009 and 2010, soil and vegetation samples were again collected, and the levels of the above elements were determined. In general terms, the temporal trends in metal concentrations were not homogeneous, showing significant changes between the baseline and the latest surveys. Metal levels in soil and herbage samples analyzed in the current survey were similar to recent data reported for other urban and industrial areas, being notably lower than the reference values set by national regulatory organisms. Moreover, more than 10?years after regular operations of the HWI, exposure to metals would not mean, either now or in past surveys, any carcinogenic or non-carcinogenic health risks for the population living in the neighborhood.     

Long-Term Environmental Surveillance and Health Risks of Metals and PCDD/Fs Around a Cement Plant in Catalonia,Spain

In this study, environmental data concerning the potential impact of a cement plant were updated, 10 years after a previous monitoring study. In 2011 and 2012, samples of soil, vegetation, and air were collected in the vicinity of a cement plant located in Santa Margarida i els Monjos (Barcelona, Catalonia, Spain). The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and those of a number of metals (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sn, Tl, V, and Zn) were determined. The results were compared with data from two previous sampling campaigns, performed in 2000 and 2001. Vanadium was the only element presenting a significant increase in the three monitors. In turn, a significant decrease of PCDD/Fs was noted in vegetation, from 0.2 to 0.1 ng WHO-TEQ/kg. The Hazard Quotient (HQ) of exposure to all pollutants was below the safety limit, while cancer risk associated with the exposure to metals and PCDD/Fs was within the range considered as assumable (10^?6–10^?4). Despite the long period of time elapsed between campaigns (10 years) and the use of alternative fuels, the impact of the cement plant seems to be low, based on the emissions of the contaminants here evaluated.     

Concentrations of metals and PCDD/Fs and human health risks in the vicinity of a hazardous waste landfill: A follow-up study

In 2007, an environmental surveillance program to evaluate the impact of a hazardous waste landfill (HWL) located in Castellolí (Catalonia, Spain) was initiated. Between 2011 and 2014, samples of soil and air were collected inside the HWL as well as in nearby villages, and the concentrations of arsenic (As), some metals (cadmium (Cd), chromium (Cr), mercury (Hg), nickel (Ni), and lead (Pb)), and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed. As expected, pollutant levels were higher inside the HWL than in the remaining points. In contrast, air concentrations were similar inside and outside the HWL. Furthermore, an increasing trend of the pollutant levels was not observed in any of the environmental monitors, either soil or air, when comparing with the results from the baseline (2007) and precedent surveys. The human exposure to those pollutants was estimated to contribute to 1–26% of the total exposure, after including the dietary intake. In any case, conclusions are partially limited by the scope of the investigation, which was conducted with a relatively low number of samples. Despite this limitation, it must be highlighted that health risks for the population living in the neighborhood of HWL were considered acceptable, according to international standards.     

Comparative life cycle assessments of incineration and non-incineration treatments for medical waste

Background, aim, and scope  Management of the medical waste produced in hospitals or health care facilities has raised concerns relating to public health, occupational safety, and the environment. Life cycle assessment (LCA) is a decision-supporting tool in waste management practice; but relatively little research has been done on the evaluation of medical waste treatment from a life cycle perspective. Our study compares the environmental performances of two dominant technologies, hazardous waste incineration (HWI) as a type of incineration technology and steam autoclave sterilization with sanitary landfill (AL) as a type of non-incineration technology, for specific medical waste of average composition. The results of this study could support the medical waste hierarchy. Materials and methods  This study implemented the ISO 14040 standard. Data on steam autoclave sterilization were obtained from an on-site operations report, while inventory models were used for HWI, sanitary landfill, and residues landfill. Background data were from the ecoinvent database. The comparative LCA was carried out for five alternatives: HWI with energy recovery efficiencies of 0%, 15%, and 30% and AL with energy recovery efficiencies of 0% and 10%. Results  The assumptions on the time frame for landfill markedly affect the impact category scores; however, the orders of preference for both time frames are almost the same. HWI with 30% energy recovery efficiency has the lowest environmental impacts for all impact categories, except freshwater ecotoxicity. Incineration and sanitary landfill processes dominate global warming, freshwater aquatic ecotoxicity, and eutrophication of incineration and non-incineration alternatives, respectively. Dioxin emissions contribute about 10% to human toxicity in HWI without energy recovery alternatives, and a perturbation analysis yielded identical results. As regards eutrophication, non-incineration treatments have an approximately sevenfold higher impact than incineration treatments. Discussion  The differences between short-term and long-term time frame assumptions mainly are decided by heavy metals dissolved in the future leachate. The high heat value of medical waste due to high contents of biomass, plastic, and rubber materials and a lower content of ash, results in a preference for incineration treatments. The large eutrophication difference between incineration and non-incineration treatments is caused by different N element transformations. Dioxin emission from HWI is not the most relevant to human toxicity; however, large uncertainties could exist. Conclusions  From a life cycle perspective, the conventional waste hierarchy, implying incineration with energy recovery is better than landfill, also applies to the case of medical waste. The sanitary landfill process is the key issue in non-incineration treatments, and HWI and the subsequent residues landfill processes are key issues in incineration treatments. Recommendations and perspectives  Integrating the medical waste hierarchy and constructing a medical waste framework require broader technologies to be investigated further, based on a life cycle approach. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Cremation,Air Pollution,and Special Use Permitting: A Case Study

Risks to health posed by emissions of hazardous air pollutants from crematories are emerging concerns. The presence of silver–mercury amalgams in bodies results in airborne emissions of mercury; and the combustion of essentially any material results in emissions of polychlorinated dibenzodioxins and furans (PCDD/Fs; “dioxins”). These and other trace emissions from crematories are not regulated at the U.S. federal or (typically) state level, but neighborhood concerns may necessitate quantitative evaluations of potential local impacts, and local officials may need to rely on such evaluations in order to determine whether and under what conditions to grant (or deny) operating permits. Here we present a case study in which these and other issues were evaluated. Using air dispersion models and health risk assessment models, we predicted exposures that would be within health-based guidelines. Concerned citizens provided information that seemed to suggest otherwise. In the end, communication, education, and compromise led to a favorable result.     

Naturally Occurring Ah-Receptor Agonists in Foods: Implications Regarding Dietary Dioxin Exposure and Health Risk

The human diet contains numerous naturally-occurring compounds that are aryl hydrocarbon receptor (AhR) agonists. This analysis compares the dietary TCDD-equivalent (TEQ) dose from specific vegetable indoles vs. the AhR-active PCDD/Fs. Daily dietary doses of indole-3-carbinole (I3C) and its condensation product indolo [3,2-b]carbazole (ICZ) were derived from the published literature. Relative estimate of potency (REP) values were developed for I3C (8.7 × 10^?7) and ICZ (0.5). The TEQ doses of I3C and ICZ together comprised >99% of the total daily TEQ dose; the daily ICZ TEQ dose (1.4 × 10⁶ pg TEQ/day) was approximately 45,000-fold greater than the current dietary PCDD/F TEQ dose (32 pg TEQ/day). When 30-year accumulated body burden and area-under-the curve doses were calculated, I3C/ICZ still comprised a significant fraction (up to 95 and 96%, respectively) of the total TEQ dose. Further, reduction or elimination of meat and dairy products yielded a minimal (less than 4%) decrease in total TEQ dose. These findings indicate that reducing the intake of animal products (the primary source of dietary PCDD/Fs) might not achieve a significant reduction in total “dietary dioxin TEQ” dose; the comparisons also suggest that trace levels of PCDD/Fs in the human diet are unlikely to pose a significant health risk.     

Monitoring Metals in Blood and Hair of the Population Living Near a Hazardous Waste Incinerator: Temporal Trend

The concentrations of As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sn, Tl, and V were determined in hair of 96 school children and in blood of 144 adults living in the vicinity of a hazardous waste incinerator (HWI) (Constantí, Tarragona County, Catalonia, NE Spain). The results were compared with those obtained in previous (1998 and 2002) surveys performed in the same area. Data were analyzed in terms of age, sex, and specific place of residence. Current mean concentrations in hair ranged between not detected (ND) (As, Be, and Tl) and 1.31 μg/g for Cr. In blood, Be, Hg, Mn, Sn, and Tl levels were under the respective detection limits. The mean blood concentrations of the remaining elements ranged from 0.34 μg/dL for Cd, to 2.40 μg/dL for Pb. Significant differences in hair and blood in relation to gender were only noted for Pb in blood. In general terms, metal concentrations in hair and blood from subjects living in Tarragona County are lower than most levels reported for other countries in recent years.     

Monitoring metals in the population living in the vicinity of a hazardous waste incinerator

Hair samples of 134 school children (12-14 yr old) living in three residential zones in the vicinity of a new hazardous waste incinerator (HWI) (Constanti, Tarragona County, Catalonia, Spain) were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) for arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), tin (Sn), thallium (Tl), and vanadium (V) concentrations. These concentrations were compared with those obtained in a baseline survey performed in the same area during the period of construction of the HWI. Current mean concentrations ranged from values under the respective limit of detection (As, Be, Cd, Tl, and V) to 0.70 and 0.86 microg/g for Hg and Pb, respectively. In comparison to the baseline survey, the levels of Cr, Mn, Ni, Pb, and Sn showed a significant reduction, whereas Hg concentrations were similar. No significant differences were observed according to the sex of the children. However, some differences were noted, especially for Pb and Cr, with respect to the specific zone of residence. In general terms, the current metal levels in hair of school children are similar or even lower than those recently reported for a number of industrial and residential areas of various regions and countries.     

Influence of Low-Level Prenatal Exposure to PCDD/Fs and PCBs on Empathizing,Systemizing and Autistic Traits: Results from the Duisburg Birth Cohort Study

Background

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) are assumed to act as endocrine disruptor chemicals. Prenatal exposure to these pollutants might influence fetal steroid hormone levels, which are thought to be related to sex-typical development and autistic traits.

Objectives

We examined associations of prenatal levels of PCDD/Fs and PCBs with autism traits and sex-typical behaviour in childhood.

Methods

We measured levels of PCDD/Fs and PCBs in maternal blood samples during pregnancy using gas chromatography/high-resolution mass spectrometry. Sex-typical behaviour was assessed at 9 years of age (n = 96) and autistic traits at 10 years of age using the Social Responsiveness Scale (SRS; n = 100). Multiple regression analyses were conducted to estimate the associations between prenatal exposure and outcome variables.

Results

Blood concentrations (WHO₂₀₀₅-TEq) of ƩPCDD/Fs ranged from 2.93–46.45 pg/g _{lipid base} (median = 12.91 pg/g _{lipid base}) and concentrations of ƩPCBs were in the range of 1.24–25.47 pg/g _{lipid base} (median = 6.85 pg/g _{lipid base}) which is within the range of German background exposure. We found significant negative associations between PCDD/F levels in maternal blood and SRS scores in the whole group (β = -6.66, p < .05), in girls (β = -10.98, p < .05) and, in one SRS subscale, in boys (β = -6.86, p < .05). For PCB levels, associations with one SRS subscale were significant for the whole study group as were associations with two subscales in girls. We did not find significant associations between PCDD/F or PCB levels and sex-typical behaviour for either sex.

Conclusions

In an earlier part of this study, prenatal exposure to PCDD/Fs and PCBs was found to be associated with lower testosterone levels, therefore, our findings are consistent with the idea that autism spectrum conditions are related to fetal androgen levels. Several possible mechanisms, through which PCDD/Fs and PCBs might influence autistic behaviour, are discussed.     

Assessing Health Risks from Sub-Standard Medical Waste Incineration: A Site Conceptual Model

Poor medical waste treatment is common practice in most developing countries where on-site sub-standard incineration is common. Potentially hazardous substances such as polychlorinated dioxins and dibenzofurans and polycyclic aromatic hydrocarbons have been detected in gaseous emissions as well as bottom ash generated by the said process. There is also evidence on the emission of potentially toxic trace metals such as lead and cadmium as well as speculations on the release of brominated dioxins and dibenzofurans. The presence of residential areas within the vicinity of these sites increases human susceptibility to various health risks. This eventually necessitates the development of efficient risk assessment tools such as a site conceptual model that can adequately facilitate data collection activities and the estimation of health risks.     

Dietary Exposure to PCDD/Fs Through Animal Products in a Highly Polluted Area in Turkey

We present an estimation of dietary exposure to PCDD/Fs by animal products in Kocaeli, a highly polluted area in Turkey, based on current food data consumption. The calculation of the PCDD/F intakes by an exposure methodology concerning consumption habits of different receptor groups in Kocaeli was included. The data relate to the PCDD/F levels in food groups of animal origin (milk, egg, meat, chicken, and fish), food consumption rates, and the fractions of locally grown foods in total consumption were statistically assessed. Monte Carlo simulation was used to estimate the ranges of PCDD/F doses through the consumption of animal products. The PCDD/F intakes through the consumption of animal products were calculated to average between 0.4–1.8 pg WHO-TEQ.kg^?1 bodyweight (bw).day^?1. The results are within the range of 1–4 pg WHO-TEQ.kg^?1 bw.day^?1, proposed as the tolerable daily intake by the World Health Organization. On the other hand, contributions of the consumption of different foods to the total PCDD/F intake and the results of sensitivity analysis showed that the PCDD/F intake in semi-urban and rural settings was determined primarily by the consumption of milk products, while consumption of meat and fish had a greater importance in urban settings.     

Phylogenetic characterization of a polychlorinated-dioxin- dechlorinating microbial community by use of microcosm studies

Microcosms capable of reductive dechlorination of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) were constructed in glass bottles by seeding them with a polluted river sediment and incubating them anaerobically with an organic medium. All of the PCDD/F congeners detected were equally reduced without the accumulation of significant amounts of less-chlorinated congeners as the intermediate or end products. Alternatively, large amounts of catechol and salicylic acid were produced in the upper aqueous phase. Thus, the dechlorination of PCDD/Fs and the oxidative degradation of the dechlorinated products seemed to take place simultaneously in the microcosm. Denaturing gel gradient electrophoresis and clone library analyses of PCR-amplified 16S rRNA genes from the microcosm showed that members of the phyla Firmicutes, Proteobacteria, and Bacteroidetes predominated. A significant number of Chloroflexi clones were also detected. Quantitative real-time PCR with specific primer sets showed that the 16S rRNA genes of a putative dechlorinator, "Dehalococcoides," and its relatives accounted for 0.1% of the total rRNA gene copies of the microcosm. Most of the clones thus obtained formed a cluster distinct from the typical "Dehalococcoides" group. Quinone profiling indicated that ubiquinones accounted for 18 to 25% of the total quinone content, suggesting the coexistence and activity of ubiquinone-containing aerobic bacteria. These results suggest that the apparent complete dechlorination of PCDD/Fs found in the microcosm was due to a combination of the dechlorinating activity of the "Dehalococcoides"-like organisms and the oxidative degradation of the dechlorinated products by aerobic bacteria with aromatic hydrocarbon dioxygenases.     

On the isolation of polychlorinated dibenzo-p-dioxins and furans from serum samples using immunoaffinity chromatography prior to high-resolution gas chromatography–mass spectrometry

Immunoaffinity chromatography (IAC) for the purification of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) from biological samples was explored as a means to simplify the cleanup procedure and thereby decrease the time and cost of dioxin analysis. A monoclonal antibody (DD3) was used to produce IAC columns and to isolate the PCDD/Fs from serum. Native and ¹³C-labeled PCDD/Fs were spiked at the ppq to ppt range into serum. Quantitation of the PCDD/Fs was performed by a standard dioxin analytical method, i.e. high-resolution gas chromatography–mass spectrometry (GC–MS), which was easily compatible with IAC. Five of the most toxic PCDD/Fs consistently showed acceptable recoveries (>25%) and were reliably quantitated. The congeners specifically recovered by this method represent almost 80% of the toxic equivalency of dioxins and furans present in the serum samples. Dioxin-like polychlorinated biphenyls (PCBs) were not recognized by this antibody column. Compared to conventional dioxin cleanup methods, IAC decreased solvent usage by 1.5 l/sample and took only 2 h to process a sample for analysis.     

Risk Assessment of Some PCDDs,PCDFs, Dioxin-Like PCBs,and PCBs in Contaminated Dairy Products: An Egyptian Pilot Case Study

Samples of butter, cream, and white cheese were collected from the city of Ismailia, Egypt, and analyzed for polychloro dibenzo-p-dioxins, pentachloro dibenzo-p-furans, and dioxin-like polychlorinated biphenyl, PCBs. Butter samples had the highest mean content of PCDD/F and dioxin-like PCBs. Butter samples were the most contaminated samples in all dairy products analyzed in this study, whereas white cheese samples were the least contaminated. The spectrum of congeners detected in butter and cream were similar, with all congeners at detectable levels, whereas the spectrum of congeners detected in white cheese differed, with some congeners, namely 1,2,3,4,7,8-Hexa CDD, 1,2,3,4,6,7,8-Hepta CDD, and 1,2,3,7,8,9-Hexa CDD below WHO TE toxicity levels. 1,2,3,7,7-PeCDD, with its high concentration, was the principal contributor to the TEQ intake in both cream and butter samples. Similarly, the high concentration of 2,3,4,7,8-PeCDF in cream, butter, and white cheese samples was the main factor contributing to their TEQ intake. Estimated intakes of PCDDs/Fs were 129.2, 115.8, and 51.25 pg WHO-TEQ/day for butter, cream, and white cheese, respectively. Taking into account the sum of PCDDs/Fs and dioxin-like PCBs, estimated intakes were, 171.7, 155.8, and 68 pg WHO-TEQ/day, for butter, cream, and white cheese, respectively. Assuming an average bodyweight of 60 kg (WHO-TEQ/kg), these levels correspond to bodyweight-normalized intake levels of .15, 2.92 and 0.95 pg WHO-TEQ/kg/day.     

Exposure and risk assessment of 1,3-butadiene in Japan

1,3-Butadiene is on the list of Substances Requiring Priority Action published by the Central Environmental Council of Japan in 1996. Emission of 1,3-butadiene has been controlled by a voluntary reduction program since 1997. Although the industrial emission of 1,3-butadiene in Japan has decreased in recent years, primarily due to a voluntary industrial emissions reduction program, the risks of exposure to it remain largely unknown. We assessed the risks and consequences of exposure to 1,3-butadiene on human health. A remarkable advantage of our risk assessment approach is the detailed assessment of exposure. Previously, we developed two different models that can be applied for the assessment of exposure: the first, the AIST-ADMER model estimates regional concentration distributions, whereas the second, the METI-LIS model estimates concentration distributions in the vicinity of factories. Both models were used for the assessment of exposure to 1,3-butadiene. Using exposure concentration and carcinogenic potency determined and reported by Environment Canada and Health Canada, we evaluated the excess lifetime cancer risk for persons exposed to 1,3-butadiene over the course of a lifetime. The results suggested that the majority of the population in Japan has an excess lifetime cancer risk of less than 10(-5), whereas a small number of people living close to industrial sources had a risk of greater than 10(-5). The results of the present assessment also showed that 1,3-butadiene in the general environment originates primarily from automobile emissions, such that a countermeasure of reducing emissions from cars is expected to be effective at reducing the total cancer risk among Japanese. On the other hand, individual risks among a population living in the vicinity of certain industrial sources were found to be significantly higher than those of the population living elsewhere, such that a reduction in emissions from a small number of specific industrial sources should be realized in order to reduce the high level of individual risk. Based on the results of our assessment, the Industrial Structure Council of the Ministry of Economy, Trade and Industry (METI) in Japan decided to announce that the voluntary reduction program had been successful, and that emissions reductions should no longer be targeted across all industries in general, but instead that such reductions should be carried out in a small number of selected factories that emit excessively large amounts of emissions.