Polybrominated diphenyl ethers (PBDEs) in foodstuffs: human exposure through the diet

In situ high-valued transformation of nonmetals in waste printed circuit boards into supercapacitor electrodes with excellent performance

Nonmetals in waste printed circuit boards after metal separation containing brominated resin and fiberglass are considered hazardous and low-recoveryvalue e-waste. However, if these nonmetals are not treated or are improperly treated, they can cause serious environmental pollution. Therefore, there is an urgent and significant need to develop an efficient recycling process for these nonmetals. Based on the concept of high-valued recycling of waste, this study in situ utilized such nonmetals to prepare a porous supercapacitor electrode through a facile carbonization, activation, and carbon thermal reduction process. The results indicated that the activation was a key role in constructing a porous structure. The optimal parameters for activation were a temperature of 800 °C, mass ratio of KOH to pyrolytic residues of 2, and an activation time of 1 h. The electrode materials exhibited a surface area of 589 m2 g-1 and hierarchical porous structures. In addition, the supercapacitors exhibited a capacitance of 77.14 mF cm-2 (62.5 mF cm-2) at 0.5 mA cm-2 (100 mV s-1). Moreover, the supercapacitors had excellent temperature resistance and adaptability. The capacitance retention was 89.36% and 90% at -50 °C and 100 °C after 10 000 cycles, respectively. This study provides a high-valued recycling strategy to utilize the nonmetals in e-waste as energy materials.

BDE-47 flame retardant exposure induces microglial pyroptosis and cognitive deficits by activating the mtROS-NLRP3 axis via Sirt3 downregulation and is salvaged by honokiol

The brominated flame retardant 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) is widely distributed in the environment and poses a certain risk to human health. Studies have reported that oxidative stress is a key mechanism underlying BDE-47-induced neurotoxicity. Mitochondrial reactive oxygen species (mtROS) is a crucial mediator of NLRP3 inflammasome activation, which is involved in cognitive dysfunction induced by environmental toxins. However, the function of the mtROS-NLRP3 inflammasome pathway in BDE-47-elicited cognitive deficits and the underlying mechanisms remain elusive. Our data illustrated that eight weeks of BDE-47 (20 mg/kg) gavage led to cognitive deficits and hippocampal neuronal injury in mice. BDE-47 exposure downregulated Sirt3 expression and decreased the activity and expression level of SOD2, thereby inhibiting mtROS scavenging and activating NLRP3 inflammasome-mediated pyroptosis in the mouse hippocampus and BV-2 cells. In vitro, BDE-47-evoked microglial pyroptosis relied on NLRP3 inflammasome activation. Moreover, a mtROS scavenger (TEMPO) attenuated NLRP3 inflammasome activation and subsequent microglial pyroptosis under BDE-47 stress. Furthermore, Sirt3 overexpression restored the activity and expression of SOD2 and enhanced mtROS scavenging, thereby suppressing NLRP3 inflammasome activation and ameliorating microglial pyroptosis. Notably, honokiol (HKL), a pharmacological agonist of Sirt3, mitigated BDE-47-evoked hippocampal neuronal injury and cognitive impairment by inhibiting mtROS-NLRP3 axis-mediated pyroptosis via Sirt3 upregulation.

Polybrominated diphenyl ethers in water, suspended particulate matter, and sediment of reservoirs and their tributaries in Shenzhen, a mega city in South China

Urban reservoirs serve many purposes including recreation and drinking water, and larger bodies of water can alter the surrounding air temperatures, making urban areas cooler in summer and warmer in winter. However, reservoirs may also be sinks for contaminants. One such group of contaminants, the polybrominated diphenyl ethers (PBDEs), are persistent organic pollutants known to accumulate in sediments and suspended particulate matter (SPM). Few studies have been conducted on PBDEs in water, SPM, and sediment from reservoirs of Shenzhen which is a mega city in South China. To this end, 12 PBDEs were measured in water, SPM, and sediment samples during the dry season (DS) and wet season (WS), to explain the spatiotemporal distribution, congener profiles, sources, and risks of pollutants in four reservoirs (A-D) and their tributaries in the study region. The concentration of ∑₁₂PBDEs during the DS was found to be significantly higher than that during the WS. Source apportionment suggested that commercial penta-, octa-, and deca-BDEs are the major components of PBDEs, resulting mainly from atmospheric deposition, wastewater discharge, and external water-diversion projects. Further, attention should be paid to electronic equipment manufacturing factories in the study area. Risk assessment indicated risk of PBDEs (especially BDE-209) in sediment and SPM to be of concern. This study provides important data support for the control of PBDEs in natural drinking water sources.

Legacy and emerging pollutants in Latin America: A critical review of occurrence and levels in environmental and food samples

The increase and indiscriminate use of personal care products, food products, fertilizers, pesticides, and health products, among others, have resulted/are resulting in extensive environmental contamination. Most of these products contain traces of widespread chemicals, usually known as emerging pollutants (EPs) or pollutants of emerging concern (PEC). The Latin American (LA) region comprises 20 countries with different social and cultural aspects, with 81 % of the population living in urban areas. The LA region has some countries on the top list of users/consumers of EPs, from pesticides and fertilizers to personal care products. However, there is a gap in information related to the distribution of EPs in the environment of this region, with very few existing review texts exploring this issue. Therefore, this present paper advances this approach. An exhaustive literature review, with the selection of 176 documents, provided unique up-to-date information on the presence/distribution of 17 classes of legacy or emerging pollutants in different food and environmental matrices (soil, sediment, water, and air). The study shows that the wide distribution and recorded levels of these pollutants in the continental environment are potential risks to human health, mainly through food and drinking water ingestion. Polycyclic aromatic hydrocarbons are pollutants of deep public concern since they show carcinogenic properties. Several classes of pollutants, like endocrine disruptors, have caused harmful effects on humans and the environment. Besides that, pharmaceutical products and pesticides are compounds of high consumption worldwide, being environmental contamination a real and ongoing possibility. Finally, gaps and future research needs are deeply pointed out.

Risk Assessment of Macronutrients and Minerals by Processed, Street, and Restaurant Traditional Pakistani Foods: a Case Study

The current work is aimed to assess the impact of macronutrient and mineral contents in food products of packaged food, restaurant food, and street food in Hyderabad. The estimated daily intake of macronutrients and minerals, followed by the toxic risk assessment of microminerals by consuming studied food dishes, was also conducted. The collected products were freeze-dried and standard procedures for measuring macronutrients were followed. At the same time, the acid digestion method was used to prepare the solution for detecting minerals by atomic absorption spectrometry. The resulting data indicated that all the food dishes supplied 134-454 kcals/100 g. The chicken/meat and pulse food dishes of all three categories were enriched with protein except bhindi masala. All the food dishes have a massive variation in fat contents and differ based on the used quantity of hydrogenated oil during their preparations. A significant difference in the macro- and microminerals in studied food products was observed. However, all food dishes are a good supplementary source of fundamental nutrients, supplying the recommended daily allowances for adults. The estimated hazardous index (I_h) of microminerals in some street and restaurant food products (based on a survey) showed possible toxicity risk, especially for the workers of automechanic workshops (I_h > 1.00). Thus, it is concluded that the contaminated (cheap) raw materials and unhygienic conditions for preparing street and restaurant foods and hawking places (atmospheric pollution) are the significant sources of micromineral contamination.

Human exposure to polybrominated diphenyl ethers (PBDEs) through the diet: An update of the scientific literature

Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame-retardants (BFRs). As for other persistent organic pollutants, dietary intake (followed by dust inhalation) is the main route of human exposure to PBDEs. In 2012, we reviewed the scientific literature on the concentrations of PBDEs in foodstuffs and their dietary exposure. The current review is aimed at updating the results of recent studies (2012-2022) focused on determining the levels of PBDEs in food samples, as well as the dietary intake of these compounds. We have revised studies conducted over the world. The current information on the concentrations of PBDEs in food and their dietary intake is now much more notable than that available in our previous review, being China the country contributing with the highest number of studies. Because of the important differences in materials and methods used in the available studies, the comparison of results is certainly complicated. However, there seems to be a general trend towards a decrease in the levels of PBDEs in foods, and consequently, in the dietary intake of these contaminants. The lack of tolerable daily intakes of PBDEs is an issue that needs to be solved for assessing human health risks of these BFRs.

Polybrominated diphenyl ethers in the environmental systems: a review

PBDEs are human-influenced chemicals utilized massively as flame retardants. They are environmentally persistent, not easily degraded, bioaccumulate in the biological tissue of organisms, and bio-magnify across the food web. They can travel over a long distance, with air and water being their possible transport media. They can be transferred to non-target organisms by inhalation, oral ingestion, breastfeeding, or dermal contact. These pollutants adsorb easily to solid matrices due to their lipophilicity and hydrophobicity; thus, sediments from rivers, lakes, estuaries, and ocean are becoming their major reservoirs aquatic environments. They have low acute toxicity, but the effects of interfering with the thyroid hormone metabolism in the endocrine system are long term. Many congeners of PBDEs are considered to pose a danger to humans and the aquatic environment. They have shown the possibility of causing many undesirable effects, together with neurologic, immunological, and reproductive disruptions and possible carcinogenicity in humans. PBDEs have been detected in small amounts in biological samples, including hair, human semen, blood, urine, and breastmilk, and environmental samples such as sediment, soil, sewage sludge, air, biota, fish, mussels, surface water, and wastewater. The congeners prevailing in environmental samples, with soil being the essential matrix, are BDE 47, 99, and 100. BDE 28, 47, 99, 100, 153, 154, and 183 are more frequently detected in human tissues, whereas in sediment and soil, BDE 100 and 183 predominate. Generally, BDE 153 and 154 appear very often across different matrices. However, BDE 209 seems not frequently determined, owing to its tendency to quickly breakdown into smaller congeners. This paper carried out an overview of PBDEs in the environmental, human, and biota niches with their characteristics, physicochemical properties, and fate in the environment, human exposure, and health effects.

The association between prenatal concentrations of polybrominated diphenyl ether and child cognitive and psychomotor function

Previous studies suggest a negative association between prenatal polybrominated diphenyl ethers (PBDEs) exposure and child cognitive and psychomotor development. However, the timing of the relationship between PBDE exposure and neurodevelopment is still unclear. We examined the association between PBDE concentration at two different prenatal times (early and late pregnancy) and cognitive function in children 6-8 years of age.

Methods

Eight hundred pregnant women were recruited between 2007 and 2009 from Sherbrooke, Canada. Four PBDE congeners (BDE-47, -99, -100, and -153) were measured in maternal plasma samples collected during early pregnancy (12 weeks of gestation) and at delivery. At 6-8 years of age, 355 children completed a series of subtests spanning multiple neuropsychologic domains: verbal and memory skills were measured using the Wechsler Intelligence Scale for Children, Fourth Edition; visuospatial processing using both Wechsler Intelligence Scale for Children, Fourth Edition and Neuropsychological Assessment second edition; and attention was assessed through the Test of Everyday Attention for Children. Additionally, parents completed subtests from the Developmental Coordination Disorder Questionnaire to measure child motor control. We used linear regression and quantile g-computation models to estimate associations of PBDE congener concentrations and psychologic test scores.

Results

In our models, no significant associations were detected between PBDE mixture and any of the child psychologic scores. BDE-99 concentration at delivery was nominally associated with higher scores on short-term and working memory while a decrease in spatial perception and reasoning was nominally associated with higher BDE-100 concentration at delivery.

Conclusion

Overall, our results did not show a significant association between PBDEs and child cognitive and motor development.

Levels of polybrominated diphenyl ethers in Brazilian food of animal origin and estimation of human dietary exposure

Polybrominated diphenyl ethers (PBDEs) are persistent organic pollutants, commonly used as flame retardants in a wide variety of products. In the last years, the concentration of PBDEs is increasing in the environment, turning human exposure more common. Since the diet is the primary source of human exposure, several surveys evaluate the levels of PBDEs in foods to estimate the dietary intake and the hazard index (HI). However, this data is limited in Brazil. Thus, this study aims to determine the level of seven PBDE congeners (BDE-28, 47, 99, 100, 153, 154, 183) in Brazilian food of animal origin. The total concentration of PBDE (∑PBDE) determined in the food samples were 2.29 (0.92-4.85) ng/g wet weight (ww), 1.98 (1.23-3.12) ng/g ww, 1.91 (1.23-3.12) ng/g ww, and 4.42 (1.26-8.42) ng/g ww in eggs, fish, seafood, and milk, respectively. BDE-47 was the most abundant compound. Based on consumer habits and the found levels of PBDEs in Brazilian food, we estimated the daily intake of ∑PBDEs as 3.25 (0.02-2.19) ng/kg bw per day. Surprisingly, the PBDE levels in milk samples were higher than those found in reported studies in other countries, and the consumption of milk products give a higher relative contribution to PBDEs exposure. The HI was <1. A complete risk assessment of the human exposure to PBDEs most likely could be evaluated considering all commercial PBDEs congeners and other exposure sources of these contaminants.

Human Health Risk Assessment by Dietary Intake and Spatial Distribution Pattern of Polybrominated Diphenyl Ethers and Dechloran Plus from Selected Cities of Pakistan

A class of intractable bio accumulative halogenated compounds polybrominated diphenyl ethers (PBDEs) was studied. Specifically, PBDEs and dechloran plus (DP) contamination in wheat and the assaulted environment—agricultural soil and dust—from metropolitan cities of Pakistan was the focus. The exposure of brominated flame retardants (BFRs) to humans, their probable toxicological impact on health, source apportionment, and the spatial tendency of BFRs were studied. Chromatographic analysis was performed, and concentrations (ng g⁻¹) of ΣPBDE and ΣDP in soil, dust, and cereal crops were estimated in a range from 0.63 to 31.70 n.d. to 6.32 and n.d. to 3.47, respectively, and 0.11 to 7.05, n.d. to 4.56 and 0.05 to 4.95, respectively. Data analysis of source apportionment reflected that the existence of solid and e-waste sites, long-range transport, urban and industrial fraction can be the potential source of PBDE and DP pollution. Moreover, potential hazardous risks to human health across the study area via the dietary intake of cereal foods were deemed trifling, and were gauged on the basis of existing toxicological data.

Absorption, distribution, metabolism, and excretion of three [14C]PBDE congeners in laying hens and transfer to eggs

Polybrominated diphenyl ethers (PBDEs) levels in environmental matrices have generally declined following their phaseout as flame retardants. The objective of this study was to determine the absorption, distribution, metabolism, and excretion of three persistent PBDEs in laying hens and their transfer into eggs. Laying hens (n = 4 per congener) received a single oral dose of BDE-99, -153, or -209 and eggs and excreta were collected daily for 7 days, then tissues were collected and analysed. Cumulative BDE-209 excretion was 93% of dose, and bioavailability was approximately 17%. Lesser amounts of BDE-99 (41%) and -153 (26%) were excreted with bioavailabilities of 87% and 79%, respectively. Phenolic metabolites were observed in excreta extracts from BDE-99 dosed birds. Cumulative transfers based on bioavailability of BDE-99, -153, and -209 to eggs were 17%, 34%, and 15%, respectively. Egg residues were primarily present in yolk (12.3%, 23.5%, and 2.1% of the total dose for BDE-99, -153, and -209, respectively). Adipose, skin, ova, intestine, and thigh muscle contained the highest levels of radioactive tissue residues. These studies demonstrate movement of PBDE residues into edible tissues and eggs of laying hens.

Estimating polybrominated diphenyl ether (PBDE) exposure through seafood consumption in Switzerland using international food trade data

Seafood is a major source of human exposure to polybrominated diphenyl ethers (PBDEs). The intake of these globally distributed and bioaccumulative contaminants depends on both consumption patterns (which seafoods are consumed) and on their origins. Here, we investigate exposure to PBDEs through seafood consumption as a function of species, origins and consumption levels. We estimate the contribution of seafood consumption to PBDE exposures in the Swiss population using two approaches. The first approach estimates exposures by estimating the composition of the Swiss seafood diet using trade data and national statistics on total seafood consumption. This naïve approach could be used for any country for which no individually reported consumption data are available for a population. The second approach uses dietary survey data provided by the Swiss Federal Statistical Office as part of the menuCH study for exposure estimates. To support region- and species-specific estimates of exposures for both approaches, we built a database of PBDE concentrations in seafood by analysis of published PBDE levels in fish from food markets or freshwater resources from various countries. We find estimated PBDE exposures ranging from 0.15 to 0.65 ng/kg bw/day for the trade data-based diet. These were close to the median exposures of 0.68 ng/kg bw/day for the Swiss population based on the menuCH survey, indicating that the composition and consumption rate derived from trade data are appropriate for calculating exposures in the average adult population. However, it could not account for PBDE exposures of more vulnerable (high seafood consuming) populations captured only by the survey data. All estimates were lower than the PBDE Chronic Oral Reference Doses (RfD's) suggested by the EPA, but could increase substantially to a value of 7 ng/kg bw/day if fish are sourced from the most contaminated origins, as in the case of Vietnamese shrimp/prawn, Norwegian salmon, and Swiss whitefish. Exposures as high as 8.50 ng/kg bw/day are estimated for the survey-based diet, which better captures the variability in consumption by individuals, including extreme high and low values. In general, the most frequently consumed species reported by Swiss consumers are consistent with those predicted using trade data.

Legacy and Emerging Brominated Flame Retardants in Bizerte Lagoon Murex (Hexaplex Trunculus): Levels and Human Health Risk Assessment

Occurrence of traditional (PBDEs) and novel (HBB, PBEB, DBDPE) brominated flame retardants, as well as the natural compounds of MeO-PBDEs, were studied in a shellfish species (Hexaplex trunculus) sampled from Bizerte Lagoon. PBDE and MeO-PBDE mean concentrations in murex soft tissues were 187 and 264 ng g^-1 lw respectively. The alternative flame retardants were not identified. The sum of PBDE and MeO-PBDE levels recorded in murex from the investigated aquatic ecosystem were comparable or a relatively lower than those reported for other organisms from other regions across the world. The amount of PBDE and MeO-PBDE concentrations from the Bizerte Lagoon recorded in murex were comparable or a relatively lower than those recorded from other areas across the world for other species. There is not a danger to the population health with regard to PBDE intakes associated with the consumption of murex in Bizerte city. We believe that this is the first study of the analysis of these pollutants in marine gastropod mollusks from Tunisian aquatic areas.

Occurrence and congener profiles of polybrominated diphenyl ethers in green mussels (Perna viridis) collected from northern South China Sea and the associated potential health risk

Polybrominated diphenyl ether (PBDE) contamination has become a major concern over the effects on human health. In the present study, we collected widely consumed green mussels (Perna viridis) samples from the northern South China Sea (NSCS) to investigate the occurrence, spatial distribution, congener profiles as well as potential risk of 18 PBDEs. All the target PBDEs were detected in green mussel samples, indicating their ubiquitous distribution. The concentrations of the total 18 PBDE_S (ΣPBDEs) in all samples varied from 6.96 to 55.6 ng/g lipid weight (lw), with BDE-47 and BDE-209 being the predominant PBDE congeners. Overall, the ΣPBDEs pollution in green mussels from NSCS was at a moderate to high level in comparison with the PBDEs pollution worldwide. The dietary exposure of the local population in South China to PBDEs via consuming green mussels was estimated to be 0.30-0.80 ng/kg body weight (bw)/day. Evaluation of the exposure risk for BDE-47, 99, 153 and 209 indicated that health risks due to green mussel consumption are substantially lower than the U.S. EPA minimum concern level.

Evaluation of the Burdening on the Czech Population by Brominated Flame Retardants

The completed environmental study was concerned with assessing the exposure of the Czech population to polybrominated diphenyl ethers (PBDEs). Simultaneously, the levels of polychlorinated pollutants such as polychlorinated biphenyls (PCBs) and chlorinated diphenyl ethanes (DDTs) were also monitored. The pollutant levels were newly measured in solid fat tissue removed during plastic surgery. A total of 107 samples of fat were taken from 19–76-year-old volunteers. A total of 16 PBDE congeners were determined, of which only six occur in more than 38% of fat tissue samples. The total PBDE level attains an average value of 3.31 ng/g, which is 25% less than was measured in 2009. On the other hand, there was an increase in the levels of two PCB congeners, which was caused by an increase of the total PCB concentration from level of 625.5 ng/g, published in 2009, to the current level of 776 ng/g. The level of DDTs decreased and currently has a value of 467.4 ng/g, which is about 24% lower than in 2009. The contamination of obese middle-aged women in Czechia by more modern types of pollutants, such as PBDEs, is incomparably lower than that by PCBs and DDTs and is also decreasing in time.

Polybrominated diphenyl ethers (PBDEs) in chicken eggs and cow milk around municipal dumpsites in Abuja, Nigeria

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in electronic equipment, as polymers in vehicles or construction, and in textiles. These additive flame retardants are emerging pollutants in Africa, released by the non-environmentally sound disposal of consumer products, often imported as secondhand, that have increasingly reached their end-of-life in the last decade. In Nigeria, which is a major receiver of e-waste and secondhand cars, there is a dearth of information regarding the levels of PBDEs in the environment, biota, and food. Thus, this study was designed to investigate the PBDE contamination of food samples of animal origin (chicken eggs and cow milk) around municipal waste dumpsites and background areas in Nigeria, to elucidate the role of dumpsites as potential sources of PBDE pollution and exposure in the country. Biological samples were collected over two years from two municipal waste dumpsites in Abuja. Fifty-six samples each of free-range chicken eggs and cow milk were collected. Control samples were collected approximately 5 km away from the dumpsites. After extraction and clean-up, the levels of POP-PBDEs listed in 2009 (major congeners of tetraBDE to heptaBDE), plus BDE-28 (Σ₇PBDEs) were determined using GC-ECD. Data were analysed using descriptive statistics, t-test at α_0.05. Levels of Σ₇PBDEs (ng/g lipid weight (lw)) in chicken eggs at the two study sites ranged from 262.3 to 313.4 (ng/g lw), more than one order of magnitude higher than those at the control site in a village near the dumpsites (14.9 ± 3.73 ng/g lw), and two and more orders of magnitude higher compared to PBDE levels in these products in industrial countries and Nigerian supermarkets. Median PBDE levels in cow milk from the two dumpsites were 49.1 and 81.5 ng/g lw, respectively, considerably higher than levels in other studies. Proper disposal methods of waste polymers containing PBDEs such as co-incineration in BAT cement kilns and plastic recycling with separation is urgently needed in Nigeria and other parts of Africa, to prevent open burning as well as crude recycle to reduce PBDE levels in the environment and human food.

Dietary intake of arsenic, cadmium, mercury and lead by the population of Catalonia, Spain: Analysis of the temporal trend

In 2017, a monitoring study was conducted in Catalonia (Spain) to analyse, in widely consumed foodstuffs, the concentrations of arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb), as well as those of inorganic As (InAs) and methylmercury (MeHg). Health risks were estimated for various population groups, classified according to age. A continued reduction of dietary exposure to these elements was observed when comparing the results from the current and previous studies performed during the last 17 years. This reduction would be associated to a decrease of As, Cd, Hg and Pb concentrations in food, as well as by changes in dietary habits. None of the adult groups exceeded the safety threshold established by the EFSA, but toddlers, infants and children exceeded the PTWI for Cd and MeHg. The greatest intake of Cd and MeHg corresponded to infants, being due to the consumption of cuttlefish and hake. The consumption of these species should be reduced to two or three weekly portions, being combined with the intake of other non-predator species. Anyhow, the current results indicate that is necessary to conduct further periodical surveys, paying special attention to the trend in the intake of Cd and MeHg.

Biochar combined with compost to reduce the mobility, bioavailability and plant uptake of 2,2',4,4'-tetrabrominated diphenyl ether in soil

Biochar application to soil is recognised for its capacity to immobilise pollutants (through sorption) while composted inputs can accelerate the biodegradation of organic pollutants. However, little is known about the influence of combined incorporation on plant uptake of organic pollutants. Therefore, we investigated the effects of maize straw-derived biochar (MSB), compost derived from maize straw and pig manure (SMC), and their combination (MSB-SMC) as soil amendments on bioavailability of 2,2',4,4'-tetrabrominated diphenyl ether (BDE-47) and carrot (Daucus carota L.) uptake in a horticultural soil. We found that biochar alone performed well in reducing BDE-47 bioavailability, but was less effective at degrading the pollutant. Conversely, addition of compost stimulated BDE-47 biodegradation. MSB-SMC enhanced BDE-47 biodegradation in soil, reduced contamination of carrot roots, and caused significant reductions in soil extractable BDE-47. The combination of contrasting approaches to remediation thus resulted in the most favorable outcome for a contaminated soil: immobilisation of contaminant from vegetable crops (via biochar) with simultaneous bioremediation of the growing medium. These findings point towards an effective strategy for reducing plant uptake of PDBEs through the combined use of biochar and compost as soil amendment - reducing mobility and facilitating degradation of the accessible contaminant fractions.

Exposure to PBDEs associated with farm animal meat consumption

One of the ways to reduce the number of fires and the amount of damage caused by them is to use flame retardants (FRs). Polybrominated diphenyl ethers (PBDEs), like other FRs, have been used in a wide array of easily flammable products. As they are not chemically bonded with materials, PBDEs can be released from polymers into the environment. PBDEs can act as endocrine disruptors and affect neurological and thyroid activity. Although human intake of PBDEs is mainly through food, data about meat as a PBDE source and human exposure through diet are limited. The objective of the present study was to develop a comprehensive database of congener-specific PBDE concentrations in farm animal muscle and to characterize potential consumer exposure. For exposure assessment, two consumption scenarios were used for adults and children. The dietary exposure to PBDE congeners is based on the assumed portion size of 100 g of different meat species. Calculations for the participants were performed using food consumption data of the Statistical Yearbook (2015/2016). The intake of PBDEs was estimated as the median (P50) and the average for all kinds of tested meat. For health risk assessment, the margin of exposure (MOE) approach was used. MOE values were in range from 5 to 149 352 132. The obtained results indicate that concentrations of ten tested congeners (BDE-28,47,49,99,100,138,153,154,183,209) in different kinds of farm animal meat (cow, chicken, farm deer, horse, ostrich, pig, rabbit, sheep, turkey) are low and meat consumption does not pose a risk for human health.

Reducing plant uptake of a brominated contaminant (2,2',4,4'‑tetrabrominated diphenyl ether) by incorporation of maize straw into horticultural soil

Application of crop residues is a conventional practice that contributes to crop production through nutrient returns and other benefits to soil health: driving soil physicochemical and biological functions. However, little is known about the impacts of straw residue incorporation on the bioavailability of organic pollutants and associated changes in microbial community structure in contaminated soils. In this study, maize straw was added to a soil contaminated with a model polybrominated diphenyl ether (BDE-47). A pot experiment was conducted and planted with carrot (Daucus carota L.). We found that straw addition greatly reduced the bioavailability of BDE-47, changed the bacterial community structure and affected a range of soil physiochemical properties. Moreover, the amount of BDE-47 that had accumulated in carrot roots and aboveground tissues was significantly reduced. This study may therefore describe an effective agronomic strategy to reduce the bioavailability of polybrominated diphenyl ethers (PBDEs) in a soil used to grow high value vegetable crops. This strategy draws on traditional wisdom and shows promise as a practical method to support horticultural production systems, remediate soils, and help to ensure food safety.

Characterizing PBDEs in fish, poultry, and pig feeds manufactured in China

A total of 53 feeds from 23 brands for four types of animals, i.e., fish, chicken, duck, and pig, as well as six types of raw materials, were bought from Guangxi, Hubei, Anhui, and Guangdong provinces in China and analyzed for polybrominated diphenyl ethers (PBDEs). The raw materials including super fish meal, ordinary fish meal, poultry ore, soybean, stone powder, and rapeseed were selected because they were added to all the animal feeds manufactured. The occurrence of PBDEs was ubiquitous in the feeds and raw materials, with BDE-209 as the most abundant congener. The average concentration of ∑₈PBDE was 1.1 and 0.44 ng g^-1 dry weight in feeds (range 0.25-5.7) and raw materials (range 0.27-0.84), respectively. No statistically significant differences in ∑₈PBDE concentrations were observed among the four groups of animal feeds. Feeds from Yangzhiyuan Brand (n = 11) contained statistically (p < 0.01) lower ∑₈PBDE concentrations than all other brands except for Baoshun Brand. Chicken was selected as a representative animal to assess health risk for human exposure to PBDEs via the consumption of chicken raised by the feeds under investigation. Hazard quotients based on per-capita consumption of chicken were all below 1, indicating low potential risk to humans consuming chicken raised with the feeds. Graphical abstract.

Hydrophobic Organic Pollutants in Soils and Dusts at Electronic Waste Recycling Sites: Occurrence and Possible Impacts of Polybrominated Diphenyl Ethers

Concerns about the adverse consequences of informal electronic waste (e-waste) recycling is increasing, because e-waste contains some hazardous substances such as polybrominated diphenyl ethers (PBDEs) which is used as flame retardants in electronics. There is dearth of information on the concentrations of PBDEs and the pattern of distribution at the various e-waste recycling sites in Nigeria. This study therefore measured the concentrations of 13 PBDE congeners, in top soils (0–10 cm) and in various dust samples from different e-waste recycling sites (burning, dismantling, repair). PBDE concentrations at e-waste sites were compared with the concentrations in samples from corresponding control sites in three study locations in Nigeria (Lagos, Ibadan, and Aba). There were significant differences in the level of PBDEs congeners between each of the e-waste recycling sites and the corresponding control sites. The levels of PBDEs at the e-waste recycling sites exceeded the levels at the controls sites by a factor of 100 s to 1000 s. In general, PBDE concentrations at the e-waste sites decreased with the intensity of the e-waste recycling activities: burning sites > dismantling sites > repair sites > control sites. Our results suggest that the informal e-waste recycling has negative impacts on the enviroment and human health.

Translocation of polybrominated diphenyl ethers from field-contaminated soils to an edible plant

Polybrominated diphenyl ethers (PBDEs), recognised emerging contaminants, widely exist and persist in the environment. Samples were taken from a heavily contaminated farm in Taiwan located near a factory known to regularly use PBDEs. Sweet potato vines (Ipomoea batatas L., a commonly consumed vegetable in Asia) growing in the surrounding farmlands were found to contain a high concentration of PBDEs of 19.36 ng/g. The possibility of PBDEs translocation into sweet potato vines from soil samples was evaluated. To prevent the PBDEs from air through that factory, the pot experiments were performed in a greenhouse, which showed that the PBDEs concentration of 24 congeners (tri- through deca-BDE) in the sweet potato vine after 14-days cultivation was 29.90 ng/g, 40-times higher than that in the contaminated soil. After another 14-days, the PBDE concentration decreased to 12.30 ng/g as high-brominated PBDEs were transformed to medium- and/or low-brominated PBDEs in the sweet potato vine. The bioconcentration factor (BCF) values exceeded 20.0 for most of the deca-, nona-, and octa-BDEs but BCFs were below 18.9 for the rest of the medium- and low-brominated PBDEs. Our results demonstrate that high-brominated PBDEs can translocate into leafy vegetables from soils, and sweet potato vines tend to accumulate high-brominated PBDEs into their edible parts.

Anthropogenic (PBDE) and naturally-produced (MeO-PBDE) brominated compound levels in Bizerte Lagoon clams (Ruditapes decussatus): Levels and human health risk assessment

Information on the occurrence of organobrominated compounds in bivalves from Tunisia is scarce. To the best of our knowledge, this is the first report of these compounds in clams from Tunisia. The aim of this study is to measure natural and synthetic organobrominated compound concentrations and evaluate congener distribution and pollution sources in a clam species (Ruditapes decussatus) from three sites of the Bizerte Lagoon. Total synthetic organobrominated pollutant levels in clam ranged from 34.8 to 188ngg^-1lw. For natural organobrominated compounds, concentrations varied from 18.2 to 49.5ngg^-1lw. Total PBDE and MeO-PBDE concentrations in clams from the Bizerte Lagoon were similar or slightly lower than those reported for other species from other locations around the world. The health risks associated with the consumption of this species were assessed and posed no threat to public health concerning PBDE intakes.

Absorption, tissue distribution, metabolism, and elimination of decabrominated diphenyl ether (BDE-209) in rats after multi-dose oral exposure

Human and ecological risks of BDE-209 have drawn much attention, particularly with growing e-waste recycling activities in developing countries. To further address the issue of BDE-209 biotransformation, a laboratory-controlled study was conducted. Female Sprague-Dawley rats were dosed orally by gavage at a daily dose of 1 mg kg^-1 body weight for 7 d and a depuration period of 22 d, to characterize absorption, distribution, metabolism, and elimination dynamics of BDE-209 during multi-dose exposures simulating short-term oral exposure of e-waste workers. The concentrations of BDE-209 in all tissues increased exponentially during the 7-d exposure period, indicating that multi-dose exposure could lead to increased accumulation of BDE-209 in rats. The liver accumulated the greatest amount of BDE-209 on a wet-weight basis, while adipose tissue had the highest concentration by the end of the 22-d depuration period. Half-lives of BDE-209, 207, and 197 during depuration were 1.1 ± 0.1, 2.7 ± 0.3, and 10.5 ± 3.1 d in serum and 0.9 ± 0.1, 2.2 ± 0.2, and 11.8 ± 2.3 d in liver, i.e., the half-life increased with decreasing level of bromination from deca- to octa-BDEs and was similar in both serum and liver. By contrast, the half-life of the debromination metabolite BDE-207 (21.7 ± 7.7 d) was longer in small intestine than in serum and liver, suggesting slower depletion of BDE-209 metabolites in small intestine. The metabolism of BDE-209 was not responsible for the occurrence of low brominated BDE congeners and OH and MeO-PBDEs in human tissues.

Autism, Mitochondria and Polybrominated Diphenyl Ether Exposure

BACKGROUND

Autism spectrum disorders (ASD) are a growing concern with more than 1 in every 68 children affected in the United States by age 8. Limited scientific advances have been made regarding the etiology of autism, with general agreement that both genetic and environmental factors contribute to this disorder.

OBJECTIVE

To explore the link between exposure to PBDE, mitochondrial dysfunction and autism risk.

RESULTS

Perinatal exposures to PBDEs may contribute to the etiology or morbidity of ASD including mitochondrial dysfunction based on (i) their increased environmental abundance and human exposures, (ii) their activity towards implicated in neuronal development and synaptic plasticity including mitochondria, and (iii) their bioaccumulation in mitochondria.

CONCLUSION

In this review, we propose that PBDE, and possibly other environmental exposures, during child development can induce or compound mitochondrial dysfunction, which in conjunction with a dysregulated antioxidant response, increase a child's susceptibility of autism.

Partition uptake of a brominated diphenyl ether by the edible plant root of white radish (Raphanus sativus L.)

Polybrominated diphenyl ethers (PBDEs) are of a class of emerging contaminants. In this study, the accumulation of 4-bromodiphenyl ether (BDE-3) by different parts of a live white radish was investigated. Different cultural media (hydroponics, silica sand, and soil) were used to sustain the radish plant during its uptake and in-plant translocation of BDE-3. The results showed that BDE-3 can be translocated from the roots to the aboveground organs and the accumulated levels of BDE-3 in different parts of the white radish followed the order for the three types of cultivation: fibrous roots > peels > main roots > leaves. The results were analyzed by the aid of the partition-limited model for the plant uptake. The relevant partition coefficients (K_OC and K_d) and uptake parameters of BDE-3 with plant components (K_pt and K_lip) were obtained for analyzing the BDE-3 distribution. The partition-limited model offers a significant insight into the uptakes of BDE-3 by the various components of live white radishes. The types of cultivation affected the total sorption level, translocation factors (TFs), extent to equilibrium (α_pt), and root concentration factors (RCFs).

Human Excretion of Polybrominated Diphenyl Ether Flame Retardants: Blood, Urine, and Sweat Study

Commonly used as flame retardants, polybrominated diphenyl ethers (PBDEs) are routinely detected in the environment, animals, and humans. Although these persistent organic pollutants are increasingly recognized as having serious health implications, particularly for children, this is the first study, to our knowledge, to investigate an intervention for human elimination of bioaccumulated PBDEs. Objectives. To determine the efficacy of blood, urine, and perspiration as PBDE biomonitoring mediums; assess excretion of five common PBDE congeners (28, 47, 99, 100, and 153) in urine and perspiration; and explore the potential of induced sweating for decreasing bioaccumulated PBDEs. Results. PBDE congeners were not found in urine samples; findings focus on blood and perspiration. 80% of participants tested positive in one or more body fluids for PBDE 28, 100% for PBDE 47, 95% for PBDE 99, and 90% for PBDE 100 and PBDE 153. Induced perspiration facilitated excretion of the five congeners, with different rates of excretion for different congeners. Conclusion. Blood testing provides only a partial understanding of human PBDE bioaccumulation; testing of both blood and perspiration provides a better understanding. This study provides important baseline evidence for regular induced perspiration as a potential means for therapeutic PBDE elimination. Fetotoxic and reproductive effects of PBDE exposure highlight the importance of further detoxification research.

Nutrients and Chemical Pollutants in Fish and Shellfish. Balancing Health Benefits and Risks of Regular Fish Consumption

Dietary patterns and lifestyle factors are clearly associated with at least five of the ten leading causes of death, including coronary heart disease, certain types of cancer, stroke, non-insulin insulin-dependent diabetes mellitus, and atherosclerosis. Concerning specifically fish and seafood consumption, its beneficial health effects in humans are clearly supported by an important number of studies performed in the last 30 years. These studies have repeatedly linked fish consumption, especially those species whose contents in omega-3 fatty acids are high, with healthier hearts in the aging population. The nutritional benefits of fish and seafood are also due to the content of high-quality protein, vitamins, as well as other essential nutrients. However, a number of studies, particularly investigations performed in recent years, have shown that the unavoidable presence of environmental contaminants in fish and shellfish can also mean a certain risk for the health of some consumers. While prestigious international associations as the American Heart Association have recommended eating fish at least two times (two servings a week), based on our own experimental results, as well as in results from other laboratories, we cannot be in total agreement with that recommendation. Although a regular consumption of most fish and shellfish species should not mean adverse health effects for the consumers, the specific fish and shellfish species consumed, the frequency of consumption, as well as the meal size, are essential issues for adequately balancing the health benefits and risks of regular fish consumption.

Polybrominated diphenyl ethers (PBDES) and hexa-brominated biphenyls (Hexa-BBs) in fresh foods ingested in Taiwan

Polybrominated diphenyl ethers (PBDEs) and hexa-brominated biphenyls (Hexa-BBs) are bioaccumulative and aggregate in the food chain. Therefore, background monitoring and risk assessment for dietary intake are necessary. In present study, a systematic sampling method was first used to collect the high fat content foodstuff such as poultry, livestock, eggs, fish, other seafood, dairy products, and the infant foods and then foodstuff with high consumption in seven categories of 600 food samples. After integrating four years of background surveys of PBDE levels (2010-2013) and one year of that of Hexa-BBs (2013), the highest estimated daily intake (EDI) of PBDEs for Taiwanese food consumption was found in 0- to 3-year-olds (mean = 9.38 ng kg-1 bw d-1, the 95% upper limit of Monte Carlo Simulation (MCS P95) was 21.52 ng kg-1 bw d-1), and the lowest in 16- to 18-year-old girls (mean = 3.35 ng kg-1 bw d-1, MCS P95 was 6.53 ng kg-1 bw d-1). Moreover, the highest of EDI of Hexa-BBs was found in 0-3 years old (mean = 0.007 ng kg-1 bw d-1, MCS P95 = 0.019 ng kg-1 bw d-1), and lowest in 17-18 years old female (mean = 0.002 ng/kg/day, MCS P95 = 0.005 ng kg-1 bw d-1). This study suggests that the large MOEs (>2.5) for the four important congeners BDE-47, -99, -153, and -209, indicate that the dietary exposures are not probably a significant health concern for Taiwanese.

Serum levels of brominated flame retardants (BFRs: PBDE, HBCD) and influence of dietary factors in a population-based study on Swedish adults

The aim of this study was to investigate associations between serum concentrations of brominated flame retardants and personal characteristics, including diet, in adults participating in a population-based study in Sweden 2010-11. Moreover, observed concentrations were used in a health risk assessment, using published health-based reference values. Serum samples of 170 adult individuals of both sexes were analyzed for 10 PBDE congeners and HBCD by GC-MS. When including concentrations between LOD and LOQ, highest median serum concentration was observed for BDE-153 (1.2 ng/g serum lipid), followed by BDE-209 (0.95 ng/g lipid), BDE-47 (0.49 ng/g lipid) and BDE-100 (0.21 ng/g lipid). Median concentration of HBCD was 0.10 ng/g lipid. A few markedly elevated concentrations of BDE-209, HBCD (77-78 ng/g lipid) and BDE-47 (44 ng/g lipid) were observed. The only statistical significant findings were higher BDE-153 concentrations in men than in women, and positive associations between serum BDE-153 concentrations and consumption of fish (total), beef, mutton and poultry. PBDE concentrations were in accordance with concentrations reported in other European countries but generally lower than those found in North America. Median PBDE serum concentrations observed in adults from Sweden suggest sufficient health protection, when compared with published health-based reference values, although some outliers with high serum concentrations had lower safety margins.

Applicability of Gas Chromatography (GC) Coupled to Triple-Quadrupole (QqQ) Tandem Mass Spectrometry (MS/MS) for Polybrominated Diphenyl Ether (PBDE) and Emerging Brominated Flame Retardant (BFR) Determinations in Functional Foods Enriched in Omega-3

This paper reports on the optimization, characterization, and applicability of gas chromatography coupled to triple-quadrupole tandem mass spectrometry (GC-QqQ(MS/MS)) for the determination of 14 polybrominated diphenylethers (PBDEs) and 2 emerging brominated flame retardants, 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenylethane (DBDPE), in functional food samples. The method showed satisfactory precision and linearity with instrumental limits of detection (iLODs) ranging from 0.12 to 7.1 pg, for tri- to octa-BDEs and BTBPE, and equal to 51 and 20 pg for BDE-209 and DBDPE, respectively. The highest ΣBFR concentrations were found in fish oil supplements (924 pg/g fresh weight, fw), followed by biscuits (90 pg/g fw), vegetable oil supplements (46 pg/g fw), chicken eggs (45 pg/g fw), cow's milk (7.7 pg/g fw), and soy products (1.6 pg/g fw). BDE-47, BDE-99, and DBDPE were the most abundant compounds. Foodstuffs enriched with omega-3 presented concentrations similar to or even lower than those of conventional foods commercialized in Spain since 2000.

Fish consumption pattern among adults of different ethnics in Peninsular Malaysia

Background

Understanding different patterns of fish consumption is an important component for risk assessment of contaminants in fish. A few studies on food consumption had been conducted in Malaysia, but none of them focused specifically on fish consumption. The objectives of this study were to document the meal pattern among three major ethnics in Malaysia with respect to fish/seafood consumption, identify most frequently consumed fish and cooking method, and examine the influence of demographic factors on pattern of fish consumption among study subjects.

Methods

A cross-sectional survey was conducted between February 2008 and May 2009 to investigate patterns of fish consumption among Malaysian adults in Peninsular Malaysia. Adults aged 18 years and above were randomly selected and fish consumption data were collected using a 3-day prospective food diary.

Results

A total of 2,675 subjects, comprising male (44.2%) and female (55.7%) participants from major ethnics (Malays, 76.9%; Chinese, 14.7%; Indians, 8.3%) with a mean age of 43.4±16.2 years, were involved in this study. The results revealed 10 most frequently consumed marine fish in descending order: Indian mackerel, anchovy, yellowtail and yellow-stripe scads, tuna, sardines, torpedo scad, Indian and short-fin scads, pomfret, red snapper, and king mackerel. Prawn and squid were also among the most preferred seafood by study subjects. The most frequently consumed freshwater fish were freshwater catfish and snakehead. The most preferred cooking style by Malaysians was deep-fried fish, followed by fish cooked in thick and/or thin chili gravy, fish curry, and fish cooked with coconut milk mixed with other spices and flavorings. Overall, Malaysians consumed 168 g/day fish, with Malay ethnics’ (175±143 g/day) consumption of fish significantly (p<0.001) higher compared with the other two ethnic groups (Chinese=152±133 g/day, Indians=136±141 g/day).

Conclusion

Fish consumption was significantly associated with ethnicity, age, marital status, residential area, and years of education of adults in Peninsular Malaysia, and the data collected are beneficial for the purpose of health risk assessment on the intake of contaminants through fish/seafood consumption.

Monthly variation in faeces:blood concentration ratio of persistent organic pollutants over the first year of life: a case study of one infant

Previous studies have found that the concentrations of a range of persistent organic pollutants (POPs) in faeces is linearly proportional to the POP concentrations in blood of human adults irrespective of age and gender. In order to investigate the correlation between POP concentrations in faeces and blood in infants, the monthly variation of POP concentrations in faeces over the first year of life of one infant was investigated in this study and compared to modelled blood concentrations. Faecal samples were collected from one male infant daily. The samples were pooled by month and analysed for three selected POPs (2,2('),4,4('),5,5(')-Hexachlorobiphenyl (PCB153), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and 2,2('),4,4'-tetrabromodiphenyl ether (BDE47)). The POP concentrations in faecal samples increased for the first four months by a factor of 2.9, 4.9 and 1.4 for PCB153, BDE47, and p,p'-DDE, respectively. The faecal concentrations of all POPs decreased rapidly following the introduction of formula and solid food to the diet and subsequent weaning of the infant. Further, a one-compartment model was developed to estimate the daily POP concentrations in the blood of the infant. The POP concentrations in blood were predicted to vary much less over the first year than those observed in faeces. The faeces:blood concentration ratio of selected POPs (Kfb) differed significantly (P<0.0001) between the period before and after weaning, and observed changes in Kfb are far greater than the uncertainty in the estimated Kfb. A more stable Kfb after weaning indicates the possibility of applying the stable Kfb values for non-invasive assessment of internal exposure in infants after weaning. The intra-individual variation in Kfb in infants is worthy of further investigation.

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.

Review on the occurrence and profiles of polybrominated diphenyl ethers in the Philippines

The environmental occurrence of polybrominated diphenyl ethers (PBDEs) has been a subject of concern for the past decade because they are persistent, bioaccumulative, and toxic. These compounds have been listed as persistent organic pollutants (POPs) by the Stockholm Convention and are expected to disperse in the global environment even after their use and production. While the occurrence of PBDEs has been well characterized in environmental and biological samples from North America, Europe, and some Asian countries (i.e. China, Japan, and Korea), there is a scarcity of available data in developing Asian countries, such as the Philippines. Examination of PBDE contamination in the Philippine environment is particularly important because regulations have only recently been implemented on the production and use of PBDEs in this country. Additionally, the Philippines receives e-waste from Western countries, which is becoming a major source of organic contaminants in the tropical Asian regions. Ultimately, the Philippines may be a hot spot for contributing to on-going global PBDE pollution due to long-range atmospheric transport. This paper presents a review of the available literature on PBDEs in both environmental and biological samples collected from the Philippines. It is also intended to provide an overview on the levels and congener profiles of PBDEs in samples from the Philippines and to compare these data with other Asian countries. New data are presented on PBDE occurrence and congener profiles in fish commonly consumed by Filipinos and in particulate matter samples collected in Metro Manila, the capital of the Philippines. Both studies contribute to the available knowledge of PBDEs in the Philippines. We aim to stress the importance of future studies in countries receiving e-wastes, such as the Philippines, and suggest what future directions might be taken to enhance the available data on the presence of PBDEs in the Philippine environment.

Dynamics of brominated flame retardants removal in contaminated wastewater sewage sludge under anaerobic conditions

Disposal of solid waste to landfills from waste water sewage treatment plants (WWTPs) serves as a potential source of contamination by polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). Native microbial communities have been found to degrade a variety of xenobiotics, such as PBDEs and HBCDs. This study investigates the potential of autochthonous microflora to remove 11 PBDE congeners and HBCDs in waste water sludge under anaerobic conditions. Laboratory microcosms were constructed with sewage sludge from the WWTPs of Hradec Kralove and Brno. BDE 209 was detected as the prevailing congener in concentrations 685 and 1403 ng/g dw and the total amounts of 10 lower PBDEs (BDE 28, 47, 49, 66, 85, 99, 100, 153, 154, 183) were 605 and 205 ng/g dw in sludge from Hradec Kralove and Brno, respectively. The levels of HBCD were detected in both sludge lower than 24 ng/g dw. The experiment was carried out for 15 months. After three months of incubation, HBCD was completely degraded to below detection limits. In sewage from both WWTPs, the higher brominated DEs were removed faster than the lower brominated congeners. One exception was tri-BDE, which was degraded completely within 15 months of cultivation. A significant increase in congener tetra-BDE 49 concentrations was observed over the course of the experiment in all tested sewage. The relative distribution of individual congeners among all PBDEs changed after 15 months of the incubation in favour of lower brominated congeners. This indicates that debromination is the major mechanism of anaerobic biodegradation. Despite of the increase of BDE 49, the overall removal of all 11 PBDEs achieved the levels of 47.4 and 68.7% in samples from WWTPs Hradec Kralove and Brno, respectively.

Endocrine disruptor activity of multiple environmental food chain contaminants

Industrial chemicals, antimicrobials, drugs and personal care products have been reported as global pollutants which enter the food chain. Some of them have also been classified as endocrine disruptors based on results of various studies employing a number of in vitro/vivo tests. The present study employed a mammalian reporter gene assay to assess the effects of known and emerging contaminants on estrogen nuclear receptor transactivation. Out of fifty-nine compounds assessed, estrogen receptor agonistic activity was observed for parabens( n = 3), UV filters (n = 6), phthalates (n = 4) and a metabolite, pyrethroids (n = 9) and their metabolites (n = 3). Two compounds were estrogen receptor antagonists while some of the agonists enhanced 17b-estradiol mediated response.This study reports five new compounds (pyrethroids and their metabolites) possessing estrogen agonist activity and highlights for the first time that pyrethroid metabolites are of particular concern showing much greater estrogenic activity than their parent compounds.

Potential risk assessment of polybrominated diphenyl ethers (PBDEs) by consuming animal-derived foods collected from interior areas of China

Polybrominated diphenyl ethers (PBDEs) are one class of brominated flame retardants (BFRs). Although studies have reported the occurrence of PBDEs in freshwater fish species from several locations, to our best knowledge, there was no comprehensive data on PBDEs in foods of animal origin, such as pork, egg, and milk samples from interior areas of China, where pork and eggs are the major constituents of diet. The levels of PBDEs (BDE-28, 47, 99, 100, 153, 154, and 183) were determined in samples of animal-derived foods widely consumed by the population of Hubei in east-central China and the middle reaches of the Yangtze River. Two hundred six samples of animal-derived foods were randomly acquired in 17 sites of Hubei in 2010. The highest medium concentration of ∑7PBDEs was found in chicken eggs (0.191 ng/g wet weight (ww)), followed by duck eggs (0.176 ng/g ww), pork (0.050 ng/g ww), carps (0.047 ng/g ww), and cow milk (0.013 ng/g ww). The estimated dietary intake of Σ7PBDEs for a standard adult of 60 kg body weight based on medium and 95th percentile concentrations with consumption of animal-derived foods in Hubei province were 157.5 and 1960.3 pg/kg body weight/day, respectively. Chicken eggs (65.9 %) and pork (23.4 %) were the largest contributors to dietary intake of ∑7PBDEs through animal-derived foods. The same PBDE sources were exposed in Hubei province via principal component analysis (PCA), and the particular congener profile in samples of animal-derived foods revealed the possible exposure history of octa-BDEs and penta-BDEs in the local region. The large margins of exposure (MOE) calculated following the European Food Safety Authority (EFSA) approach for three important congeners, BDE-47, BDE-99, and BDE-153, indicated that the estimated dietary exposures were unlikely to be a significant health concern to in Hubei.

Human exposure to PBDE and critical evaluation of health hazards

Polybrominated diphenyl ethers (PBDEs) are used in large quantities as flame-retardant additives in a number of commercial products. Biomonitoring data show that, in recent years, PBDE concentrations have increased rapidly in the bodies of wildlife and humans. Usually, PBDE levels in North America have been reported to be higher than those in Europe and Asia. Moreover, body burden of PBDEs is three- to ninefold higher in infants and toddlers than in adults, showing these last two age groups the highest levels of these compounds, due to exposure via maternal milk and through dust. Tetra-, Penta-, and Hexa-BDEs are the isomers most commonly found in humans. Based on studies on experimental animals, the toxicological endpoints of exposure to PBDEs are likely to be thyroid homeostasis disruption, neurodevelopmental deficits, reproductive changes, and even cancer. Experimental studies in animals and epidemiological observations in humans suggest that PBDEs may be developmental neurotoxicants. Pre- and/or postnatal exposure to PBDEs may cause long-lasting behavioral abnormalities, particularly on motor activity and cognition. This paper is focused on reviewing the current status of PBDEs in the environment, as well as the critical adverse health effects based on the recent studies on the toxic effects of PBDEs.