Significant decreasing trend in human dietary exposure to PCDD/PCDFs and PCBs in Catalonia, Spain

Dietary intake of polychlorinated dibenzo-p-dioxins and furans, adiposity and obesity status

INTRODUCTION

The principal source of exposure to Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-p-furans (PCDD/Fs) in humans comes from food intake. PCDD/Fs, are a family of potential endocrine disruptors and have been associated with different chronic diseases such as diabetes and hypertension. However, studies assessing the relationship between dietary exposure to PCDD/Fs and adiposity or obesity status in a middle-aged population are limited.

OBJECTIVE

To assess cross-sectionally and longitudinally the associations between estimated dietary intake (DI) of PCDD/Fs and body mass index (BMI), waist circumference, and the prevalence/incidence of obesity and abdominal obesity in a middle-aged population.

METHODS

In 5899 participants aged 55-75 years (48% women) living with overweight/obesity from the PREDIMED-plus cohort, PCDD/Fs DI was estimated using a 143-item validated food-frequency questionnaire, and the levels of food PCDD/F expressed as Toxic Equivalents (TEQ). Consequently, cross-sectional and prospective associations between baseline PCDD/Fs DI (in pgTEQ/week) and adiposity or obesity status were assessed at baseline and after 1-year follow-up using multivariable cox, logistic or linear regression models.

RESULTS

Compared to participants in the first PCDD/F DI tertile, those in the highest tertile presented a higher BMI (β-coefficient [confidence interval]) (0.43kg/m2 [0.22; 0.64]; P-trend <0.001), a higher waist circumference (1.11 cm [0.55; 1.66]; P-trend <0.001), and a higher prevalence of obesity and abdominal obesity (1.05 [1.01; 1.09] and 1.02 [1.00; 1.03]; P-trend = 0.09 and 0.027, respectively). In the prospective analysis, participants in the top PCDD/F DI baseline tertile showed an increase in waist circumference compared with those in the first tertile after 1-year of follow-up (β-coefficient 0.37 cm [0.06; 0.70]; P-trend = 0.015).

CONCLUSION

Higher DI of PCDD/Fs was positively associated with adiposity parameters and obesity status at baseline and with changes in waist circumference after 1-year of follow-up in subjects living with overweight/obesity. Further large prospective studies using a different population with longer follow-up periods are warranted in the future to strengthen our results.

The environmental pollution caused by cemeteries and cremations: A review

In recent years the funeral industry has drawn attention from the scientific community concerning the potential pollution of the environment and the urban environment. In this review, the pollution caused by the cemeteries and crematoria around the world was addressed. The traditional burial leads to the production of ions, in the form of organic and heavy metals, bacteria, fungi, and viruses, that spread along with the soil and underwater. The crematoria produce small particles, trace gases (SO_x, NO_x, CO), and toxic organic volatiles. The effluent generated by both methods can lead to several environmental problems and further threaten human health. The current solution for the cemeteries in the development of a system in which effluent generated by the traditional burials are collected and treated before realizing in the environment. In addition to that, the green burial should be an alternative, since the corpse does not go through the embalming process, thus eliminating the presence of any undesired chemicals, that are further leached onto the environment. The crematoria should be employed as it is, however, the gas treatment station should be employed, to ensure the minimization of the impact on the environment. Last, future researches regarding the treatment of the cemeteries leached still need to be explored as well as the optimization and further development of the crematoria gas treatment process.

Update of Indicator PCB Levels in Food in Southern Italy: Assessment of the Dietary Exposure for Adult and Elderly Population

The levels of non-dioxin-like PCB indicators (iPCBs 28, 52, 101, 138, 153, and 180) were determined in food samples (seafood, meat and processed meat, milk and dairy products, hen eggs, olive oil, and other fats) to evaluate the exposure of adult and elderly population. iPCB levels in samples were in the following order: fishery products > meat and processed meat > milk and dairy products > olive oil and other fats. None of the samples had concentrations above the maximum permissible limits for human consumption established by the European Union legislation, except for salami samples. The dietary intake for the total population was 12.33 ng·kg−1 bw·d−1, while depending on the sex/age groups, exposure was estimated between 9.60 and 12.11 ng·kg−1 bw·d−1, with seafood being the major contributor. The exposure scenario indicates that further efforts must still be carried out to protect the consumer from these harmful chemicals.

Survey of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and non-ortho-polychlorinated biphenyls in U.S. meat, poultry, and siluriform fish from 2018-2019: toxic equivalency levels, temporal trends, and implications

The U.S. Department of Agriculture (USDA) conducted a survey of domestic animal products including beef fat, pork fat, chicken fat, turkey fat, dairy cow fat, and siluriform fish muscle (i.e. catfish) to determine the current residue levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and non-ortho-polychlorinated biphenyls (no-PCBs). The following types of fat samples were analysed: beef from heifers and steers (referred to as "beef"), pork, chicken, turkey, dairy cow (referred to as "dairy cow"), and siluriform fish muscle, which includes catfish. The survey is conducted every 5 years. Fat samples for each slaughter class and siluriform fillets were collected from U.S. federally inspected slaughter facilities, processed, and analysed for 17 PCDD/Fs and 3 no-PCBs. Toxic equivalency concentrations were calculated using 2005 toxic equivalency factors and summed (sum-TEQ) for all slaughter classes. The sum-TEQs ranged from non-detect (nd) to 16.5 pg TEQ/g lipid. The median sum-TEQs, when nd = ½ LOD, for beef, pork, chicken, turkey, dairy cow, and siluriform fish were 0.48, 0.08, 0.07, 0.21, 0.38, and 0.62 pg TEQ/g lipid (wet weight for siluriform fish), respectively. A comparison of the current and previous surveys typically depicts a significant declining trend depending on the slaughter class (such as chicken and turkey), however, beef and pork fat median values slightly increased and decreased, respectively, but neither were significant compared to the previous survey. The congener patterns for some high concentration beef and pork fat samples suggested that pentachlorophenol treated wood continues to be a likely on-farm dioxin exposure source.

Dietary Exposure to Polychlorinated Biphenyls and Dioxins and Its Relationship to Telomere Length in Subjects Older Than 55 Years from the SUN Project

Exposure to persistent organic pollutants (POPs) may influence telomere length (TL), which is considered as a marker of biological age associated with the risk of chronic disease. We hypothesized that dietary exposure to polychlorinated biphenyls (PCBs) and dioxins could affect TL. Our aim was to evaluate the association of dietary exposure to PCBs and dioxins with TL. In this cross-sectional study of 886 subjects older than 55 y (mean age: 67.7; standard deviation (SD): 6.1; 27% women) from the “Seguimiento Universidad de Navarra” (SUN) project. TL was determined by real-time quantitative polymerase chain reaction and dietary PCBs and dioxins exposure was collected using a validated 136-item Food Frequency Questionnaire. Multivariable linear regression models were used to control for potential confounding factors. Shorter TL was associated with dietary total PCBs (SD of T/S ratio/(ng/day) = −0.30 × 10⁻⁷; 95% CI, −0.55 × 10⁻⁷ to −0.06 × 10⁻⁷), dioxin-like PCBs (DL-PCBs) (SD of T/S ratio/(pg WHO TEQ (Toxic Equivalents)/day) = −6.17 × 10⁻⁷; 95% CI, −11.30 × 10⁻⁷ to −1.03 × 10⁻⁷), and total TEQ exposure (SD of T/S ratio/(pg WHO TEQ/day) = −5.02 × 10⁻⁷; 95% CI, −9.44 × 10⁻⁷ to −0.61 × 10⁻⁷), but not with dioxins (SD of T/S ratio/(pg WHO TEQ/day) = −13.90 × 10⁻⁷; 95% CI, −37.70 × 10⁻⁷ to 9.79 × 10⁻⁷). In this sample of middle-aged and older Spanish adults, dietary exposure to total PCBs and DL-PCBs alone and together with dioxins was associated with shorter TL. Further longitudinal studies, preferably with POPs measured in biological samples, are needed to confirm this finding.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in food and human dietary intake: An update of the scientific literature

It is well established that for non-occupationally exposed populations, dietary intake is, by far, the main way of human exposure to polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-p-furans (PCDD/Fs), a family of environmental POPs with a well-known potential toxicity -including carcinogenicity-in humans. We here summarize the results of recent studies (2010-2021) (databases: Scopus and PubMed), focused on determining the levels of PCDD/Fs in food samples of different origins, as well as the dietary intake of these pollutants. We have revised studies conducted in various Asian, American and European countries. However, information is rather limited, with no recent data for most countries over the world. Due to the enormous differences in the methodologies of the studies, to conduct a detailed comparison of the results for the different regions and countries has not been possible. Notwithstanding, where data over time are available, important reductions have been observed. These reductions have been linked to the decreases in the environmental emissions of PCDD/Fs noted in recent years. Interestingly, reductions in the levels of PCDD/Fs in biological tissues are also occurring in parallel. In general, the tolerable daily/weekly/monthly dietary intakes of PCDD/Fs are not being currently exceeded where data are available.

Autopsy, thanatopraxy, cemeteries and crematoria as hotspots of toxic organic contaminants in the funeral industry continuum

The occurrence and health risks of toxic organic contaminants (TOCs) in the funeral industry are relatively under-studied compared to other industries. An increasing body of literature reports TOCs including emerging contaminants in the funeral industry, but comprehensive reviews of the evidence are still lacking. Hence, evidence was analysed to address the proposition that, the funeral industry constitutes several hotspot reservoirs of a wide spectrum of TOCs posing ecological and human health risks. TOCs detected include embalming products, persistent organic pollutants, synthetic pesticides, pharmaceuticals, personal care products and illicit drugs. Human cadavers, solid wastes, wastewaters and air-borne particulates from autopsy, thanatopraxy care facilities (mortuaries, funeral homes), cemeteries and crematoria are hotspots of TOCs. Ingestion of contaminated water, and aquatic and marine foods constitutes non-occupational human exposure, while occupational exposure occurs via inhalation and dermal intake. Risk factors promoting exposure to TOCs include unhygienic burial practices, poor solid waste and wastewater disposal, and weak and poorly enforced regulations. The generic health risks of TOCs are quite diverse, and include; (1) genotoxicity, endocrine disruption, teratogenicity and neurodevelopmental disorders, (2) development of antimicrobial resistance, (3) info-disruption via biomimicry, and (4) disruption of ecosystem functions and trophic interactions. Barring formaldehyde and inferential evidence, the epidemiological studies linking TOCs in the funeral industry to specific health outcomes are scarce. The reasons for the lack of evidence, and limitations of current health risk assessment protocols are discussed. A comprehensive framework for hazard identification, risk assessment and mitigation (HIRAM) in the funeral industry is proposed. The HIRAM includes regulatory, surveillance and control systems such as prevention and removal of TOCs. Future directions on the ecotoxicology of mixtures, behaviour, and health risks of TOCs are highlighted. The opportunities presented by emerging tools, including isotopic labelling, genomics, big data analytics (e.g., machine learning), and in silico techniques in toxicokinetic modelling are highlighted.

Decreasing temporal trends of polychlorinated dibenzo-p-dioxins and dibenzofurans in adipose tissue from residents near a hazardous waste incinerator

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are very toxic chemicals which are emitted in waste incineration and whose exposure has important adverse effects for the human health. In 2019, adipose tissue samples were collected from 15 individuals with a median age of 61 years, who had been living near a hazardous waste incinerator in Constantí (Spain). The content of PCDD/Fs in each sample was analyzed. The results were compared with data from previous studies, conducted before (1998) and after (2002, 2007 and 2013) the facility started to operate, and based on populations of similar age. In 2019, the mean concentration of PCDD/Fs in adipose tissue was 6.63 pg WHO-TEQ/g fat, ranging from 0.95 to 12.95 pg WHO-TEQ/g fat. A significant reduction was observed with respect to the baseline study (1998), when a mean PCDD/Fs concentration of 40.1 pg WHO-TEQ/g fat was found. Moreover, the current level was much lower than those observed in the 3 previous studies (9.89, 14.6 and 11.5 pg WHO-TEQ/g fat in 2002, 2007 and 2013, respectively). The body burdens of PCDD/Fs were strongly correlated with age. The significant reduction of PCDD/Fs levels in adipose tissue fully agreed with the decreasing trend of the dietary intake of PCDD/Fs by the population of the zone (from 210.1 pg I-TEQ/day in 2018 to 8.54 pg WHO-TEQ/day in 2018). Furthermore, a similar decrease has been also observed in other biological, such as breast milk and plasma. The current data in adipose tissue, as well as those in other biological monitors, indicate that the population living near the HWI is not particularly exposed to high levels of PCDD/Fs. However, biomonitoring studies cannot differentiate the impact of the HWI emissions from food consumption patterns. This question can be only solved by conducting complementary investigations and contrasting the results of monitoring and epidemiological studies.

Exposure to dietary polychlorinated biphenyls and dioxins, and its relationship with subclinical coronary atherosclerosis: The Aragon Workers' Health Study

BACKGROUND

Experimental evidence has revealed that exposure to polychlorinated biphenyls (PCBs) and dioxins directly impairs endothelial function and induces atherosclerosis progression. In the general population, despite a small number of recent studies finding a link between PCBs, and stroke and myocardial infraction, the association with early coronary atherosclerosis has not been examined yet.

OBJECTIVE

To examine whether dietary exposure to PCBs and dioxins is associated with subclinical coronary atherosclerosis in a middle-aged men.

DESIGN

Cross-sectional analysis comprising 1844 men in their 50 s and free of cardiovascular disease, who participated in the Aragon Workers' Health Study (AWHS). Individual dietary exposures to PCBs and dioxins were estimated by the contaminant's concentration in food coupled with the corresponding consumption and then participants were classified into quartiles of consumption. Coronary artery calcium score (CACS) was assessed by computerized tomography. We conducted ordered logistic regressions to estimate the odds ratio (OR) and 95% confidence intervals (CIs) for progression to the categories of more coronary artery calcium, adjusting for potential confounders.

RESULTS

Among the participants, coronary calcium was not shown in 60.1% (n = 1108), 29.8% had a CACS > 0 and <100 (n = 550), and the remaining 10.1% (n = 186) had a CACS ≥ 100. Compared with those in the first quartile of PCBs exposure, those in the fourth one had an increased odds for having coronary calcium (OR 2.02, 95% CI [1.18, 3.47], p trend 0.019) and for having progressed to categories of more intense calcification (OR 2.03, 95% CI [1.21, 3.40], p trend 0.012). However, no association was found between dietary dioxins exposure and prevalent coronary artery calcium.

CONCLUSIONS

In this general male population, dietary exposure to PCBs, but not to dioxins, was associated with a higher prevalence of coronary calcium and to more intense subclinical coronary atherosclerosis. PCBs exposure seems to increase the risk of coronary disease in men from the very early stages.

Hypertension in Relation to Dioxins and Polychlorinated Biphenyls from the Anniston Community Health Survey Follow-Up

BACKGROUND

In 2014, we conducted a longitudinal study [Anniston Community Health Survey (ACHS II)] 8 y after the baseline (ACHS I).

OBJECTIVES

We investigated the relationship between persistent chlorinated compounds and hypertension in residents living around the former polychlorinated biphenyl (PCB) production plant in Anniston, Alabama. We also examined the potential role of inflammatory cytokines in those with hypertension.

METHODS

A total of 338 participants had their blood pressure measured and medications recorded, gave a blood sample, and completed a questionnaire. Prevalent hypertension was defined as taking antihypertensive medication or having systolic blood pressure >140 mmHg and/or diastolic pressure >90 mmHg; incident hypertension used similar criteria in those who developed hypertension since the baseline in 2005-2007. PCB congeners were categorized into structure-activity groups, and toxic equivalencies (TEQs) were calculated for dioxin-like compounds. Descriptive statistics, logistic and linear regressions, as well as Cox proportional hazard models, were used to analyze the associations between exposures and hypertension.

RESULTS

Prevalent hypertension (78%) in ACHS II showed statistically significant adjusted odds ratios (ORs) for PCBs 74, 99, 138, 153, 167, 177, 183, and 187, ranging from 2.18 [95% confidence interval (CI): 1.10, 4.33] to 2.76 (95% CI: 1.14, 6.73), as well as for two estrogenic-like PCB groups, and the thyroid-like group [ORs ranging from 2.25 (95% CI: 1.07, 4.75) to 2.54 (95% CI: 1.13, 5.74)]. Furthermore, analysis of quartiles demonstrated a monotonic relationship for dioxin-like non-ortho (non-o)-PCB TEQs [fourth vs. first quartile: 3.66 (95% CI: 1.40, 9.56)]. Longitudinal analyses of incident hypertension supported those positive associations. The results were strongest for the di-o-PCBs [hazard ratio (HR)=1.93 (95% CI: 0.93, 4.00)] and estrogenic II PCB group [HR=1.90 (95% CI: 0.96, 3.78)] but were weaker for the dioxin TEQs.

DISCUSSION

Findings supportive of positive associations were reported for dioxin-like mono-o- and non-o-PCBs as well as for nondioxin-like estrogenic and thyroid-like congeners with prevalent and incident hypertension, suggesting that multiple pathways may be involved in hypertension development. https://doi.org/10.1289/EHP5272.

Dioxin and PCB residues in meats from Italy: Consumer dietary exposure

In order to investigate PCB and PCDD/F concentrations and potential human health risk a study has been conducted in meat samples (beef, pork, chicken and turkey) purchased from Italian supermarkets. PCBs were dominant (41.8-77.7 ng g^-1 l.w.) with respect to PCDD/Fs (20.1-91.1 pg g^-1 l.w.). The levels were variable and largely dependent upon the type of meat. Accumulation pattern showed a distribution typically reported for meat. PCBs tended to decrease from lowest to highest congeners, while for PCDD/Fs the concentration profile was dominated by highly chlorinated dioxins and furans. Concentrations of PCDD/Fs plus dl-PCBs and indicator PCBs exceeding the EU maximum permissible levels were found in 23.3% and 53.3% of the samples, respectively. Exposure estimates to PCDD/Fs plus dl-PCBs (0.08-4.16 pg WHO-TEQs kg^-1 b.w. w.^-1) were within the new limit proposed by the EFSA's expert panel, except for pork sausage, showing a twofold higher value. Concerning the exposure derived from indicator PCBs, the maximum level set by different European countries (10 ng kg^-1 b.w. d.^-1) was surpassed solely via consumption of pork sausage (17.22 ng kg^-1 b.w. d.^-1), thought also the estimated intake from hamburger consumption (6.88 ng kg^-1 b.w. d.^-1) merits attention being close to guideline limit.

Occurrence of environmental pollutants in foodstuffs: A review of organic vs. conventional food

In recent years, there is an increasing trend to consume organic foods instead of the conventional foodstuffs. This tendency is mainly due to the concern raised by the potential adverse health effects derived from the intake of pesticides, fertilizers, hormones and antibiotics, which are widely used in regular food production. Although organic label forbids the use of these products, environmental contamination is likely to occur in both, conventional and organic foodstuffs. The main purpose of this review was to compare the levels of a number of environmental pollutants such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), mycotoxins, trace elements, polycyclic aromatic hydrocarbons (PAHs), etc., in organic and conventional food items. The results show that, in general, the presence of nearby anthropogenic sources of pollution is the key issue influencing the occurrence of environmental pollutants in foodstuffs, regardless their organic or conventional origin. Based on this, we suggest that environmental contaminants should be monitored in both conventional and organic foods. Finally, the safety feature, which has been globally attributed to organic foods, might be questionable depending on the potential environmental contamination of these foods.

Marine environment pollution: The contribution of mass spectrometry to the study of seawater

The study of marine pollution has been traditionally addressed to persistent chemicals, generally known as priority pollutants; a current trend in environmental analysis is a shift toward "emerging pollutants," defined as newly identified or previously unrecognized contaminants. The present review is focused on the peculiar contribution of mass spectrometry (MS) to the study of pollutants in the seawater compartment. The work is organized in five paragraphs where the most relevant groups of pollutants, both "classical" and "emerging," are presented and discussed, highlighting the relative data obtained by the means of different MS techniques. The hyphenation of MS and separative techniques, together with the development of different ion sources, makes MS and tandem MS the analytical tool of choice for the determination of trace organic contaminants in seawater. © 2016 Wiley Periodicals, Inc. Mass Spec Rev 37:492-512, 2018.

Atmospheric concentrations and gas-particle partitioning of PCDD/Fs and dioxin-like PCBs around Hochiminh city

Atmospheric PCDD/Fs and dl-PCBs samples were collected in Hochiminh city, Vietnam to address the effect of meteorological parameters, especially rainfall, on the occurrence and gas/particle partitioning of these persistent organic pollutants. The results indicate that PCDD/Fs and dl-PCBs concentrations in industrial site are higher than those measured in commercial and rural sites during both rainy and dry seasons. In terms of mass concentration, ambient PCDD/F levels measured in dry season are significantly higher than those measured in rainy season while dl-PCB levels do not vary significantly between rainy and dry seasons. The difference could be attributed to different gas/particle partitioning characteristics between PCDD/Fs and dl-PCBs. PCDD/Fs are found to be mainly distributed in particle phase while dl- PCBs are predominantly distributed in gas phase in both rainy and dry seasons. Additionally, Junge-Pankow and Harner-Bidleman models are applied to better understand the gas/particle partitioning of these pollutants in atmosphere. As a results, both PCDD/Fs and dl-PCBs are under non-equilibrium gas/particle partitioning condition, and PCDD/Fs tend to reach equilibrium easier in rainy season while there are no clear trend for dl-PCBs. Harner-Bidleman model performs better in evaluating the gas/particle partitioning of PCDD/Fs while Junge-Pankow model results in better prediction for dl-PCBs.

Development and Application of a Probabilistic Risk-Benefit Assessment Model for Infant Feeding Integrating Microbiological, Nutritional, and Chemical Components

A probabilistic and interdisciplinary risk-benefit assessment (RBA) model integrating microbiological, nutritional, and chemical components was developed for infant milk, with the objective of predicting the health impact of different scenarios of consumption. Infant feeding is a particular concern of interest in RBA as breast milk and powder infant formula have both been associated with risks and benefits related to chemicals, bacteria, and nutrients, hence the model considers these three facets. Cronobacter sakazakii, dioxin-like polychlorinated biphenyls (dl-PCB), and docosahexaenoic acid (DHA) were three risk/benefit factors selected as key issues in microbiology, chemistry, and nutrition, respectively. The present model was probabilistic with variability and uncertainty separated using a second-order Monte Carlo simulation process. In this study, advantages and limitations of undertaking probabilistic and interdisciplinary RBA are discussed. In particular, the probabilistic technique was found to be powerful in dealing with missing data and to translate assumptions into quantitative inputs while taking uncertainty into account. In addition, separation of variability and uncertainty strengthened the interpretation of the model outputs by enabling better consideration and distinction of natural heterogeneity from lack of knowledge. Interdisciplinary RBA is necessary to give more structured conclusions and avoid contradictory messages to policymakers and also to consumers, leading to more decisive food recommendations. This assessment provides a conceptual development of the RBA methodology and is a robust basis on which to build upon.

Concentrations of environmental organic contaminants in meat and meat products and human dietary exposure: A review

Meat and meat products is one of the most relevant food groups in an important number of human diets. Recently, the IARC, based on results of a number of epidemiological studies, classified the consumptions of red meat and processed meat as "probably carcinogenic to humans" and as "carcinogenic to humans", respectively. It was suggested that the substances responsible of the potential carcinogenicity would be mainly generated during meat processing, such as curing and smoking, or when meat is heated at high temperatures. However, the exposure to environmental pollutants through meat consumption was not discussed. The purpose of the present paper was to review recent studies reporting the concentrations of PCDD/Fs, DL-PCBs and PAHs in meat and meat products, as well as the human exposure to these pollutants through the diet. It is concluded that the health risks derived from exposure to carcinogenic environmental contaminants must be considered in the context of each specific diet, which besides meat and meat products, includes other foodstuffs containing also chemical pollutants, some of them with carcinogenic potential. Anyhow, meat and meat products are not the main food group responsible of the dietary exposure to carcinogenic (or probably carcinogenic) environmental organic pollutants.

Exposure assessment of PCDD/Fs for the population living in the vicinity of municipal waste incinerator: Additional exposure via local vegetable consumption

While the exposure assessment of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/Fs) for people living in the vicinity of municipal solid waste incinerators (MSWI) has been investigated, indirect exposure to MSWI-emitted PCDD/Fs via consumption of local foods has not been well assessed. In this study, the PCDD/F concentration in the local vegetables grown near a MSWI located in Shenzhen, South China, was determined to be 0.92 ± 0.59 pg/g wet weight (ww), significantly higher than that (0.25 ± 0.35 pg/g ww) in commercial vegetables (p < 0.05). The PCDD/F concentrations in Banyan leaf (Ficus microcarpa) samples collected from 5 sampling sites at 1 km intervals from the MSWI were found to be significantly decreased with increasing distance, suggesting that the local plants would be impacted by emissions from the MSWI. The exposure assessment of PCDD/Fs for the population living in the vicinity of MSWI was carried out by simultaneously analyzing PCDD/Fs in other food groups that were commonly consumed by the residents. If only the local vegetables were consumed and other foods were acquired commercially, the total dietary intake for a general adult was 0.94 ± 0.41 pg TEQ/kg bw/day, of which consumption of local vegetables accounted for 52.3%. If all foods consumed including vegetables were from a commercial source, the total dietary intake was 0.56 ± 0.30 pg TEQ/kg bw/day, of which consumption of commercial vegetables accounted for 20.1%. The present study for the first time reported the additional human exposure to PCDD/Fs via consumption of local vegetables impacted by emissions from MSWI.

Occurrence and Estimated Dietary Intake of PCBs and PCDD/Fs in Functional Foods Enriched with Omega-3 from Spain

The polychlorinated biphenyl (PCB), polychlorinated dibenzo-p-dioxin, and dibenzofuran (PCDD/F) contents of six functional foods enriched with omega-3 were characterized. All the samples analyzed showed concentration levels below the maximal levels established by Regulation EC 1259/201120. PCB concentrations were higher than those of PCDD/Fs; oil supplements were the most contaminated samples [1.8 pg of WHO-TEQ/g of lipid weight (lw)] followed by chicken eggs (1.3 pg of WHO-TEQ/g of lw), cow's milk (0.23 pg of WHO-TEQ/g of lw), biscuits (0.15 pg of WHO-TEQ/g of lw), soy milks (0.11 pg of WHO-TEQ/g of lw), and soy lecithin (0.049 pg of WHO-TEQ/g of lw). The most abundant non-dl-PCBs were PCBs 52 and 101 in cow's milk, soy products, and biscuits, while in chicken eggs and oil supplements, they were PCBs 153 and 138. PCBs 118 and 105 were the most frequent dl-PCBs in all samples. Only oil supplements presented quantifiable concentrations for almost all PCDD/Fs, OCDD and OCDF being the most abundant. The estimated daily intake was 2.7 pg of WHO-TEQ/day for chicken eggs, 0.91 pg of WHO-TEQ/day for cow's milk, 0.45 pg of WHO-TEQ/day for soy milks, and 0.44 pg of WHO-TEQ/day for biscuits. For oil supplements, it was more variable, but always higher.

Comparative analysis of selected semi-persistent and emerging pollutants in wild-caught fish and aquaculture associated fish using Bogue (Boops boops) as sentinel species

The marine environment acts as a sink for diverse anthropogenic pollutants, although the environmental contamination may be non-uniformly distributed. In recent decades, the aquaculture sector has experienced a steady growth postulating as a good alternative for seafood production. However, a social debate exits about the differential level of pollutants in wild and farmed species. This study was designed to evaluate the level of pollutants in a sentinel species: Bogue (Boops boops) associated and non-associated to fish-farm cages. A total of 82 chemical substances were determined by gas chromatography-mass spectrometry, including persistent (polychlorobiphenyls (PCBs) and organochlorine pesticides (OCPs)), semi-persistent (bromodiphenyl ethers (BDEs) and polycyclic aromatic hydrocarbons (PAHs)), and emerging pollutants (such as organophosphate flame retardants (OPFRs) and UV-filters). In general, aquaculture-associated bogues showed lower levels of semi-persistent and emerging pollutants than wild-caught fish, especially when sums were considered. Thus, sum of BDEs was significantly lower in the aquaculture group (p=0.01). A similar trend was also observed for benzo(a)anthracene, the UV-filter 2-ethylhexyl-p-methoxycinnamate and some OPFRs. In the case of persistent pollutants, the sum of dioxin-like PCBs and sum of DDTs were lower in the group of wild-caught bogues (p=0.034 and p=0.003, respectively) than in aquaculture-associated bogues, as previously described for some aquaculture species. Fish feed appear as an important factor in the uptake of such substances suggesting a diet intervention to reduce their levels in the aquaculture products. Another interesting result is that for almost all chemical substances analyzed, bogues captured near sewage outfalls showed the highest levels of pollutants, pointing out the need of stringent measures for wastewater treatment units discharging in coastal areas. On the light of these results, further research in specific farmed and wild fish species in relation to their dietary value and pollutant's levels seems to be mandatory.

Comparative study of the intake of toxic persistent and semi persistent pollutants through the consumption of fish and seafood from two modes of production (wild-caught and farmed)

Adverse effects of chemical contaminants associated with seafood counteract the undoubted benefits for the health of its valuable nutrients. So much so that many dietary guidelines recommend no more than one serving a week of fish and seafood. Although is estimated that aquaculture provides more than 50% of the fish and seafood consumed globally, few research studies have focused in the assessment of the intake of pollutants through aquaculture products. In this study we determined the levels of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and toxic elements (Pb, Cd, Ni, Al, As, and Hg) in a large sample of farmed and wild-caught seafood, and we estimated the intake of these contaminants in two hypothetical models of consumers: those consuming only farmed fish, and those consuming only wild fish. Measured levels of most organic and many inorganic pollutants were higher in aquaculture products, and consequently intake levels if only such products were consumed would be also significantly higher. Thus, the intake of ∑PAHs in adults consuming aquaculture seafood would be 3.30ng/kg-bw/day, and consuming seafood from extractive fishing 2.41ng/kg-bw/day (p<0.05); ∑OCPs, 3.36 vs. 1.85ng/kg-bw/day, respectively (p<0.05); ∑PCBs, 2.35 vs. 2.11ng/kgbw/day, respectively; and the intake of Pb, Ni, As, and Al would be also significantly higher consuming farmed seafood. For children the estimations were very similar, but the difference of intake of PCBs reached statistical significance. The implementation of several decontamination practices in aquaculture would allow not only match the levels of pollution from wild-caught seafood, but also could provide products with much lower levels of pollutants than those, which in turn would allow to increase consumption over the "one serving per week", and so benefit the consumer of the enormous positive health effects of the valuable nutrients of seafood.

Temporal trend of polychlorinated dibenzo-p-dioxin/polychlorinated dibenzofuran and dioxin like-polychlorinated biphenyl concentrations in food from Taiwan markets during 2004-2012

The levels of polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) or polychlorinated biphenyl (PCB) in foodstuffs have decreased over the past decade in many countries. However, the trend for the levels of these compounds in foodstuffs in Taiwan remains unknown. In this study, we compared the distribution of PCDD/F and PCB in nine foodstuff categories acquired from Taiwan markets from 2004 to 2012. The levels expressed as World Health Organization toxic equivalents (WHO-TEQs) in the different foodstuffs tested were as follows: fish, average 0.463 pg WHO₉₈-TEQ/g sample > seafood, 0.163 pg WHO₉₈-TEQ/g > eggs, 0.150 pg WHO₉₈-TEQ/g > oils, 0.126 pg WHO₉₈-TEQ/g > meats, 0.095 pg WHO₉₈-TEQ/g > dairy products, 0.054 pg WHO₉₈-TEQ/g > cereals, 0.017 pg WHO₉₈-TEQ/g > vegetables, 0.013 pg WHO₉₈-TEQ/g > fruits, 0.009 pg WHO₉₈-TEQ/g. Levels were particularly high in crab (average: 0.6 pg WHO₉₈-TEQ/g sample (1.243 pg WHO₉₈-TEQ/g sample) and large marine fish (0.6). In Taiwan, a decreasing trend of PCDD/Fs or dioxin-like PCBs (dl-PCBs) was observed in meat, dairy, eggs, and vegetables, whereas an elevated trend was observed in cereals or the levels were nearly equal in fruits and oils at alternative time shift. Dl-PCBs contributed to 60–65% toxicity equivalence levels in fish and seafood, but only to 13–40% in meat and cereal samples. The decreasing trend was consistent with the results in other countries; however, the trends in cereals, fruits, and oils were in contrast to previous results reported in other countries. Cereals and fruits are important crops in southern Taiwan, and the local pollution generated by industries or incinerators may seriously affect the distribution of PCDD/Fs and dl-PCBs. To ensure food safety, a risk assessment for residents living in different areas should be adopted for all food categories simultaneously in the future.

Carcinogenicity of consumption of red and processed meat: What about environmental contaminants?

In October 26, 2015, the International Agency for Research on Cancer (IARC) issued a press release informing of the recent evaluation of the carcinogenicity of red and processed meat consumption. The consumption of red meat and processed meat was classified as "probably carcinogenic to humans", and as "carcinogenic to humans", respectively. The substances responsible of this potential carcinogenicity would be generated during meat processing, such as curing and smoking, or when meat is heated at high temperatures (N-nitroso-compounds, polycyclic aromatic hydrocarbons and heterocyclic aromatic amines). However, in its assessments, the IARC did not make any reference to the role that may pose some carcinogenic environmental pollutants, which are already present in raw or unprocessed meat. The potential role of a number of environmental chemical contaminants (toxic trace elements, polycyclic aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls, polybrominated diphenyl ethers, polychlorinated diphenyl ethers, polychlorinated naphthalenes and perfluoroalkyl substances) on the carcinogenicity of consumption of meat and meat products is discussed in this paper. A case-study, Catalonia (Spain), is specifically assessed, while the influence of cooking on the concentrations of environmental pollutants is also reviewed. It is concluded that although certain cooking processes could modify the levels of chemical contaminants in food, the influence of cooking on the pollutant concentrations depends not only on the particular cooking process, but even more on their original contents in each specific food item. As most of these environmental pollutants are organic, cooking procedures that release or remove fat from the meat should tend to reduce the total concentrations of these contaminants in the cooked meat.

Levels of Some Heavy Metals in Raw Cow's Milk from Selected Milk Production Sites in Iran: Is There any Health Concern?

Background: The aim of this study was to evaluate the content of mercury (Hg), arsenic (As), nickel (Ni) and tin (Sn) in raw cow’s milk of traditional and industrial sites from 8 different sites in Arak City, Markazi Province, Iran.

Methods: In this cross sectional study, a total of 32 samples were collected from sub-cities of Arak, Iran via subjective sampling method. Both industrial and traditional dairy farms were selected for sampling. Twenty-five gram of each sample was turned to ash in ovens for metal analyses including Hg, As, Ni and Sn by anatomic absorption spectrometer.

Results: The residue amounts of Hg and As were lower than permissible limit suggested by Codex Alimentarius, but for Ni and Sn it was higher only in one of the collection sites. The average concentra­tion of Hg was significantly higher (P<0.05) in traditional farms as compared to industrial farms. Be­sides, amounts of Sn was significantly high in the traditional farms (P<0.05). Further, a high contents Ni was detected in industrial farms (P<0.05).

Conclusion: High Sn and Ni contents of some milk samples from this region might be potentially hazardous to consumers. Further, none of the other metals tested crossed permissible levels.

Long-time monitoring of polychlorinated dibenzo-p-dioxins and dibenzofurans over a decade in the ambient air of Porto, Portugal

As part of a monitoring program initiated in 1998 and conducted by IDAD - Institute for Environment and Development and supported by regional municipal solid waste (MSW) management authorities, an extensive database of dioxins' and furans' (PCDD/PCDF) concentrations in ambient air was collected in Porto, in two sites classified as suburban. The present paper summarizes the analytical results of PCDD/PCDF in ambient air obtained from 2001 to 2014 through this intensive monitoring work. The toxic equivalent (WHO-TEQ 1998) concentrations of the PCDD/PCDF in the air ranged from 8.2 to 904.4 fg TEQ m(-3), with an average and median values of 104.5 fg TEQ m(-3) and 49.8 fg TEQ m(-3), respectively. The PCDD/PCDF concentration trend in Porto's ambient air shows a clear drop of the annual average values occurred during the study period. The presence of seasonal variations is very clear in the present study. Winter levels (average: 154.3 fg TEQ m(-3)) are significantly higher than summer levels (average: 42.9 fg TEQ m(-3)). The PCDD/PCDF profiles' details show that several differences occurred over time. The homologue profiles presented changes and the PCDD congeners have decreased in terms of mass. The analysis of concentrations in combination with specific homologue and congener patterns of PCDD/PCDF allowed identification of potential emission sources.

Health risks for the population living in the vicinity of an Integrated Waste Management Facility: screening environmental pollutants

We performed a screening investigation to assess the human health risks of the Integrated Waste Management Facility (IWMF: mechanical-biological treatment (MBT) plant plus municipal solid waste incinerator (MSWI); Ecoparc-3) of Barcelona (Spain). Air concentrations of pollutants potentially released by the MBT plant (VOCs and bioaerosols) and the MSWI (trace elements, PCDD/Fs and PCBs) were determined. Trace elements, PCDD/Fs and PCBs were also analyzed in soil samples. The concentrations of trace elements and bioaerosols were similar to those previously reported in other areas of similar characteristics, while formaldehyde was the predominant VOC. Interestingly, PCDD/F concentrations in soil and air were the highest ever reported near a MSWI in Catalonia, being maximum concentrations 10.8 ng WHO-TEQ/kg and 41.3 fg WHO-TEQ/m(3), respectively. In addition, there has not been any reduction in soils, even after the closure of a power plant located adjacently. Human health risks of PCDD/F exposure in the closest urban nucleus located downwind the MSWI are up to 10-times higher than those nearby other MSWIs in Catalonia. Although results must be considered as very preliminary, they are a serious warning for local authorities. We strongly recommend to conduct additional studies to confirm these findings and, if necessary, to implement measures to urgently mitigate the impact of the MSWI on the surrounding environment. We must also state the tremendous importance of an individual evaluation of MSWIs, rather than generalizing their environmental and health risks.

Occurrence, variability and human exposure to Polychlorinated Dibenzo-p-dioxins (PCDDs), Polychlorinated Dibenzofurans (PCDFs) and Dioxin-Like Polychlorinated Biphenyls (DL-PCBs) in dairy products from Chile during the 2011-2013 survey

Levels, congener profiles of PCDD/Fs, DL-PCBs and human exposure for these xenobiotics never have been reported in Chile. For that purpose 102 raw cow milk samples were collected from seven different regions of Chile during 2011 until 2013. The highest mean level for PCDD/Fs, corresponds to 0.32 pg WHO-TEQ2005 g(-1) fat (2012) and for DL-PCBs 0.17 pg WHO-TEQ2005 g(-1) fat (2011), using the upper bound approach. Penta and tetra chlorinated congeners dominated PCDD/Fs profiles in a WHO-TEQ2005 basis during the survey. In the case of DL-PCBs, PCB 126 dominated the profiles with 89%. Statistical analysis showed significant difference among years only in DL-PCBs residues. Also dietary intake was estimated, and the highest level for total sum of PCDD/Fs and DL-PCBs for adult was 0.16 pg WHO-TEQ kg(-1) b.w d(-1) (2011) and for children correspond to 0.65 pg WHO-TEQ kg(-1) b.wd(-1) (2011). Concentrations and dietary intake for the studied compounds in milk and butter samples were below international and national regulations.

Human exposure to PCDD/Fs and PCBs through consumption of fish and seafood in Catalonia (Spain): Temporal trend

The concentrations of PCDD/Fs and 18 PCBs (DL- and NDL-) were analyzed in 16 fish and seafood species widely consumed in Catalonia (Spain). The exposure of these pollutants was subsequently estimated according to various groups of population. The concentrations of PCDD/Fs and PCBs showed an important decrease in relation to the baseline study (2000) and our last survey (2008). Sardine and red mullet were the species showing the highest pollutant concentrations, while canned tuna and cuttlefish presented the lowest levels. Sardine was the main contributor to the exposure of PCDD/Fs and PCBs. In contrast, swordfish was the species with the lowest contribution to the exposure of PCDD/Fs, DL-PCBs, and PCDD/Fs+DL-PCBs, while clam was the minor contributor for NDL-PCBs and total PCBs. For all groups of population, the current intakes of PCDD/Fs and PCBs were lower than the TDI (1-4 pg WHO-TEQ/kg body weight/day), being children the group with the highest exposure. However, this exposure should not mean a health risk for this group of population. The current intake of PCDD/Fs and PCBs through fish and seafood consumption was similar or even lower than most values reported in recent studies all over the world.

The estimation of consumer health risk associated with organochlorine xenobiotics in hard smoked cheese in Poland

The aim of this study was to estimate the health risks associated with consumption of smoked cheeses, which are popular in Poland. The analysis covered polychlorinated biphenyl (PCB) indicator congeners (ndl-PCBs: PCB 28, PCB 52, PCB 101, PCB 138, PCB 153, PCB 180), dioxin-like PCBs (dl-PCBs): non-ortho (PCB 77, PCB 81, PCB 126, PCB 169) and mono-ortho (PCB 105, PCB 114, PCB 118, PCB 156, PCB 157), as well as organochlorine pesticides (OCPs: αHCH, βHCH, γHCH, heptachlor, aldrin, heptachlor epoxid isomer B, dieldrin, pp'DDE op'DDD, pp'DDT, pp'DDD, op'DDT, endrin). The pesticide residues detected in the examined cheese were below the maximum residues levels. The estimated daily intake [lifetime average daily dose (LADD)] referring to the sum of the compounds varied within 4.21 · 10(-7)-3.92 · 10(-6) mg · kg(-1) · day(-1) and was significantly lower than the tolerable daily intake/acceptable daily intake (TDI/ADI) for individual compounds. The health hazard quotient, being the exact measure of the magnitude of exposure potential or a quantifiable potential for developing non-carcinogenic health effects after an averaged exposure period, was also very low, ranging from 2.87 · 10(-6) to 5.32 · 10(-5). The obtained results confirmed that the intake of rennet cheese does not pose any consumer health risk in Poland.

Association between dietary intakes of PCBs and the risk of obesity: the SUN project

BACKGROUND

Polychlorinated biphenyls (PCB) are persistent organic pollutants (POP) that are consumed because of their bioaccumulation through the food chain. Recent studies have suggested the implication of POPs in the development of metabolic diseases such as type 2 diabetes and obesity. However, this relationship is not entirely consistent, and has not been investigated in longitudinal studies. The purpose of this study was to prospectively examine the association between dietary intake of PCBs and the incidence of obesity in the Seguimiento Universidad de Navarra (SUN) Project.

METHODS

Our study included 12 313 participants without obesity at baseline, who were followed-up for a median of 8.1 years. Dietary intakes of PCBs, expressed as WHO toxic equivalents, were assessed at baseline through a 136-item semiquantitative food-frequency questionnaire. The published concentration levels of PCBs measured in samples of food consumed in Spain were used to estimate intakes. Multivariable Cox regression models were fitted to estimate HRs and 95% CI for incident obesity.

RESULTS

During follow-up, we observed 621 incident cases of obesity. After adjustment for total energy intake and additional adjustment for potential confounders, participants in the fifth quintile of PCBs intake were at higher risk of becoming obese (adjusted HR: 1.58; (95% CI 1.21 to 2.06)) compared to those in the first quintile. The linear trend test was statistically significant (p<0.001).

CONCLUSIONS

Dietary intake of PCBs as estimated using a food frequency questionnaire was associated with a higher incidence of obesity. Nevertheless, further longitudinal studies are needed to confirm our results.

Seasonal surveillance of airborne PCDD/Fs, PCBs and PCNs using passive samplers to assess human health risks

This study aimed at determining the air concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) near a municipal solid waste incinerator (MSWI) in Tarragona (Catalonia, Spain) by means of passive air sampling. Seasonal trends in airborne levels were also assessed by comparing the results of 6-month surveys conducted between spring of 2010 and autumn of 2011. These data were used to estimate exposure for the population living nearby and to evaluate the non-carcinogenic and carcinogenic risks associated to inhalation of those persistent organic pollutants (POPs). No seasonal differences were noted in POP concentrations among the sampling campaigns. The highest levels of PCDD/Fs were found in the 3rd campaign, while significantly lower levels of PCNs were found in the 4th survey. The concentrations of PCDD/F and PCB congeners, as well as those of PCN homologues, did not change significantly with time, which indicates that the MSWI does not have an important influence on the surrounding environment. The levels of POPs near the facility are at the lower part of the range, when compared with data from the scientific literature. Consequently, the current levels of POPs in ambient air around the MSWI are associated to a low human exposure to PCDD/Fs, PCBs and PCNs, which means a lack of additional health risks for the local population. In addition, passive samplers have been confirmed to be a good tool for local environmental monitoring, as well as a good method to study seasonal trends in POP concentrations in air.

Temporal comparison of PBDEs, OH-PBDEs, PCBs, and OH-PCBs in the serum of second trimester pregnant women recruited from San Francisco General Hospital, California

Prenatal exposures to polybrominated diphenyl ethers (PBDEs) can harm neurodevelopment in humans and animals. In 2003-2004, PentaBDE and OctaBDE were banned in California and phased-out of US production; resulting impacts on human exposures are unknown. We previously reported that median serum concentrations of PBDEs and their metabolites (OH-PBDEs) among second trimester pregnant women recruited from San Francisco General Hospital (2008-2009; n = 25) were the highest among pregnant women worldwide. We recruited another cohort from the same clinic in 2011-2012 (n = 36) and now compare serum concentrations of PBDEs, OH-PBDEs, polychlorinated biphenyl ethers (PCBs) (structurally similar compounds banned in 1979), and OH-PCBs between two demographically similar cohorts. Between 2008-2009 and 2011-2012, adjusted least-squares geometric mean (LSGM) concentrations of ∑PBDEs decreased 65% (95% CI: 18, 130) from 90.0 ng/g lipid (95% CI: 64.7, 125.2) to 54.6 ng/g lipid (95% CI: 39.2, 76.2) (p = 0.004); ∑OH-PBDEs decreased 6-fold (p < 0.0001); and BDE-47, -99, and -100 declined more than BDE-153. There was a modest, nonsignificant (p = 0.13) decline in LSGM concentrations of ∑PCBs and minimal differences in ∑OH-PCBs between 2008-2009 and 2011-2012. PBDE exposures are likely declining due to regulatory action, but the relative stability in PCB exposures suggests PBDE exposures may eventually plateau and persist for decades.

Maternal dietary intake of dioxins and polychlorinated biphenyls and birth size in the Norwegian Mother and Child Cohort Study (MoBa)

Maternal diet not only provides essential nutrients to the developing fetus but is also a source of prenatal exposure to environmental contaminants. We investigated the association between dietary intake of dioxins and PCBs during pregnancy and birth size. The study included 50,651 women from the Norwegian Mother and Child Cohort Study (MoBa). Dietary information was collected by FFQs and intake estimates were calculated by combining food consumption and food concentration of dioxins, dioxin-like PCBs and non-dioxin-like PCBs. We used multivariable regression models to estimate the association between dietary intake of dioxins and PCBs and fetal growth. The contribution of fish and seafood intake during pregnancy was 41% for dietary dioxins and dioxin-like PCBs and 49% for dietary non-dioxin-like PCBs. Further stratified analysis by quartiles of seafood intake during pregnancy was conducted. We found an inverse dose-response association between dietary intake of dioxins and PCBs and fetal growth after adjustment for confounders. Newborns of mothers in the upper quartile of dioxin and dioxin-like PCBs intake had 62g lower birth weight (95% CI: -73, -50), 0.26cm shorter birth length (95% CI: -0.31, -0.20) and 0.10cm shorter head circumference (95% CI: -0.14, -0.06) than newborns of mothers in the lowest quartile of intake. Similar negative associations for intake of dioxins and dioxin-like PCBs were found after excluding women with intakes above the tolerable weekly intake (TWI=14pg TEQ/kg bw/week). The negative association of dietary dioxins and PCBs with fetal growth was weaker as seafood intake was increasing. No association was found between dietary dioxin and PCB intake and the risk for small-for-gestational age neonate. In conclusion, dietary intakes of dioxins and PCBs during pregnancy were negatively associated with fetal growth, even at intakes below the TWI.

Dietary exposure to polychlorinated dibenzo-p-dioxins and dibenzofurans via fish consumption and dioxin-like activity in fish determined by H4IIE-luc bioassay

Dietary exposure to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) via fish consumption in two major electronic (e) waste sites: Guiyu (GY), Guangdong Province and Taizhou (TZ), Zhejiang Province, and dioxin-like activity in fish determined by H4IIE-luc bioassay. In the present study, all fish were below EU's maximum allowable concentration in muscle of fish (4 pg WHO-TEQ/g wet wt), except crucian (4.28 pg WHO-TEQ/g wet wt) and silver carps (7.49 pg WHO-TEQ/g wet wt) collected from GY rivers. Moreover, the residual concentration in bighead carp collected from GY (2.15 pg WHO-TEQ/g wet wt) was close to the EU's action level (3 pg WHO-TEQ/g wet wt) which gives "early warning" to the competent authorities and operators to take measures to eliminate contamination. In addition, results indicated that the maximum human intake of PCDD/Fs via freshwater fish consumption in GY was 4.31 pg WHO-TEQ/kg bw/day, which exceeds the higher end of the tolerable daily intake recommended by the WHO, EC-SCF and JECFA (1-4, 2 and 2.3 pg WHO-TEQ/kg bw/day respectively). Furthermore, H4IIE-luc cell bioassay provides a very sensitive and cost-efficient screening tool for assessing the overall dioxin-like toxicity in the study, and is therefore valuable for high-throughput environmental monitoring studies.

Comparison of intake and systemic relative effect potencies of dioxin-like compounds in female mice after a single oral dose

BACKGROUND

Risk assessment for mixtures of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) is performed using the toxic equivalency factor (TEF) approach. These TEF values are derived mainly from relative effect potencies (REPs) linking an administered dose to an in vivo toxic or biological effect, resulting in "intake" TEFs. At present, there is insufficient data available to conclude that intake TEFs are also applicable for systemic concentrations (e.g., blood and tissues).

OBJECTIVE

We compared intake and systemic REPs of 1,2,3,7,8-pentachlorodibenzodioxin (PeCDD), 2,3,4,7,8-pentachlorodibenzofuran (4-PeCDF), 3,3',4,4',5-pentachlorobiphenyl (PCB-126), 2,3',4,4',5-pentachlorobiphenyl (PCB-118), and 2,3,3',4,4',5-hexachlorobiphenyl (PCB-156) in female C57BL/6 mice 3 days after a single oral dose.

METHODS

We calculated intake REPs and systemic REPs based on administered dose and liver, adipose, or plasma concentrations relative to TCDD. Hepatic cytochrome P450 1A1-associated ethoxyresorufin-O-deethylase (EROD) activity and gene expression of Cyp1a1, 1a2 and 1b1 in the liver and peripheral blood lymphocytes (PBLs) were used as biological end points.

RESULTS

We observed up to one order of magnitude difference between intake REPs and systemic REPs. Two different patterns were discerned. Compared with intake REPs, systemic REPs based on plasma or adipose levels were higher for PeCDD, 4-PeCDF, and PCB-126 but lower for the mono-ortho PCBs 118 and 156.

CONCLUSIONS

Based on these mouse data, the comparison between intake REPs and systemic REPs reveals significant congener-specific differences that warrants the development of systemic TEFs to calculate toxic equivalents (TEQs) in blood and body tissues.

PCDD/Fs in plasma of individuals living near a hazardous waste incinerator. A comparison of measured levels and estimated concentrations by PBPK modeling

The construction of the first and, until now, only hazardous waste incinerator (HWI) in Spain finished in 1998. To assess its potential impact on the population living in the vicinity, a surveillance program was established. It includes the periodical biomonitoring of PCDD/Fs body burden. On the basis of this program, in 2012 we determined the levels of PCDD/Fs in plasma of nonoccupationally exposed individuals living near the HWI. The results were compared with those of the baseline study, and with those of two previous surveys (2002 and 2007). A multicompartment, physiologically based pharmacokinetic (PBPK) model was also applied to estimate the levels of PCDD/Fs in plasma. The model was validated by comparing the results with our experimental data (baseline, 2002, 2007, and 2012). The current mean concentration was 6.18 pg I-TEQ/g lipid, with a range between 2.03 and 18.8 pg I-TEQ/g lipid. In 1998 (baseline), the mean concentration of PCDD/Fs in plasma was 27.0 pg I-TEQ/g lipid (reduction of 77%, p < 0.001). Significant reductions were also noted in our previous 2002 and 2007 surveys, with mean concentrations of 15.7 and 9.36 pg I-TEQ/g lipid, respectively. However, the comparison between simulated (using the PBPK model) and experimental results was very successful, as PCDD/F values in plasma were very similar (7.95 vs 6.18 pg I-TEQ/g lipid). The levels of PCDD/Fs in plasma of nonoccupationally exposed individuals living near the HWI here assessed are comparatively lower than most recently reported values.

Body burden monitoring of dioxins and other organic substances in workers at a hazardous waste incinerator

The construction in Constantí (Tarragona County, Catalonia) of the first, and up till now the only hazardous waste incinerator (HWI) in Spain, finished in 1999. In this study, we measured the concentrations of a number of organic substances determined in blood and urine of the HWI workers. Samples of 18 men and 9 women, classified according to their respective workplaces, were collected in 2011, after approximately 12 years of regular operations in the facility. The current results were compared with those of the baseline survey, as well as with the most recent surveys performed in 2008, 2009 and 2010. Plasma analyses were carried out for hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs 28, 52, 101, 138, 153, and 180) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), while the levels of 2,4- and 2,5-dichlorophenol (DCP), 2,4,5- and 2,4,6-trichlorophenol (TCP), pentachlorophenol (PCP) and 1-hydroxypyrene (1-HP) were measured in urine samples. In plasma, the mean concentrations were the following: 10.8μg/kg lipid for HCB; 0.8μg/kg lipid for PCB28; 0.3μg/kg lipid for PCB52; 0.5μg/kg lipid for PCB101; 42.2μg/kg lipid for PCB138; 18.5μg/kg lipid for PCB153, and 51.2μg/kg lipid for PCB180. For PCDD/Fs, the mean concentration was 4.6ng I-TEQ/kg lipid (4.7ng WHO-TEQ/kg lipid). These levels, as well as those found in urine samples, are in agreement with the data of previous surveys performed in the same area. The current results in HWI workers do not show any evident sign of occupational exposure to PCDD/Fs and other organic substances. However, these results must be considered only as an indication of potential exposure, as the study presents notable limitations, such as the reduced number of participants and the lack of data relative to the air concentrations of chemicals. Consequently, general conclusions cannot be derived and the results should not be used as a basis for the implementation of industrial hygiene measures in other HWIs.

Dietary intake of PCDD/Fs and dioxin-like PCBs from the Chinese total diet study in 2007

Concentrations of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (dl-PCBs) were measured in 96 food composite samples from eight varieties of food groups from the Chinese total diet study (TDS) in 2007. The concentrations of samples, expressed as WHO toxic equivalents (TEQ), ranged from 0.001 pg TEQ g(-1) to 0.85 pg TEQ g(-1) (fresh weight). Dietary intake of PCDD/Fs and dl-PCBs of 12 age/gender subgroups of the Chinese population subsequently estimated ranges from 15.4 pg TEQ kg(-1) bw month(-1) to 38.7 pg TEQ kg(-1) bw month(-1) for average population and from 68.5 pg TEQ kg(-1) bw month(-1) to 226.1 pg TEQ kg(-1) bw month(-1) for high consumers (the 97.5th percentile). Dietary exposure of children (mean: 32.5 pg TEQ kg(-1) bw month(-1)) is significantly higher than that of the adults (mean: 21.5 pg TEQ kg(-1) bw month(-1)) (p<0.01) presumably due to more food consumed by children relative to their body weight compared to adults. There is no difference of dietary exposure, expressed as pg TEQ kg(-1) bw, found between different genders. Across various regions in China, there are large differences of dietary exposure of adult population and pattern of contribution of food groups to total exposure due to different contamination level and food habits. Dietary exposures of average population of various subgroups were all below the PTMI recommended by JECFA, but those of higher consumers were found exceeding or comparable to the PTMI.