Polybrominated diphenyl ether contamination in soil, vegetation, and cow milk from a high-mountain pasture in the Italian Alps

Persistent Organic Pollutants and Fatty Acid Profile in a Typical Cheese from Extensive Farms: First Assessment of Human Exposure by Dietary Intake

Dairy products represent an important source of beneficial substances for humans. At the same time, they can expose the consumers to environmental contaminants ingested by animals through their diet, influencing their health negatively. This experiment aims to evaluate the risk and benefits related to the consumption of typical stretched cheeses, considering their fatty acid (FA) profile and persistent organic pollutants (POPs) content. Six representative farms, two of them organic, raising Cinisara cattle were selected, considering the typical extensive management systems, based on feeding of natural pasture integrated with concentrate and hay depending on the availability of forage on pastures. A total of 18 cheeses produced in winter, spring and summer with bulk milk of each farm were sampled and analyzed. The chemical composition of cheeses was influenced by farm management, and the FA profile mainly by the season. In particular, cheeses made in spring showed a healthier FA profile with the content of polyunsaturated fatty acids (PUFA), of omega3-PUFA and omega6/omega3 ratio pair to 7.29%, 1.44% and 1.32, respectively, while in winter 5.44%, 0.98% and 2.55, respectively, and in summer 4.77% 0.49% and 3.04, respectively. Due to high levels of feeding integration, cheese made in winter presented unhealthier characteristics compared to the cheeses made in spring and summer, showing high levels of saturated FA (66.2%, 64.2% and 65.5%, respectively), and large contents of polycyclic aromatic hydrocarbons (PAH) (57.07 ng/g fat, 36.25 ng/g fat and 10.22 ng/g fat, respectively) and polychlorinated biphenyls (PCBs) (36.19 ng/g fat, 4.68 ng/g fat and 3.73 ng/g fat, respectively), mainly in those from non-organic farms. Levels of PCBs considered to be hazardous to human health were found in nine samples.

Polybrominated diphenyl ether quinone exposure leads to ROS-driven lysosomal damage, mitochondrial dysfunction and NLRP3 inflammasome activation

Polybrominated diphenyl ethers (PBDEs) are aromatic compounds that containing bromine atoms, which possess high efficiency, good thermal stability. However, PBDEs had various known toxic effects and were characterized as persistent environmental pollutants. Exposure to a quinone-type metabolite of PBDEs (PBDEQ) is linked with excess production of intracellular reactive oxygen species (ROS) in our previous studies. Here, we observed that PBDEQ exposure led to ROS and mitochondrial dysfunction, which promoted canonical and non-canonical Nod-like receptor protein 3 (NLRP3) inflammasome activation. Further experiments demonstrated that PBDEQ exposure activated Toll-like receptors (TLRs), subsequently regulating nuclear factor kappa B (NF-κB) signaling. Moreover, lysosomal damage and K⁺ efflux were involved in PBDEQ-driven NLRP3 inflammasome activation. Our in vivo study also illustrated that PBDEQ administration induced liver inflammation in male C57BL/6J mice. Cumulatively, our current finding provided novel insights into PBDEQ-induced pro-inflammatory responses.

Plant accumulation and transformation of brominated and organophosphate flame retardants: A review

Plants can take up and transform brominated flame retardants (BFRs) and organophosphate flame retardants (OPFRs) from soil, water and the atmosphere, which is of considerable significance to the geochemical cycle of BFRs and OPFRs and their human exposure. However, the current understanding of the plant uptake, translocation, accumulation, and metabolism of BFRs and OPFRs in the environment remains very limited. In this review, recent studies on the accumulation and transformation of BFRs and OPFRs in plants are summarized, the main factors affecting plant accumulation from the aspects of root uptake, foliar uptake, and plant translocation are presented, and the metabolites and metabolic pathways of BFRs and OPFRs in plants are analyzed. It was found that BFRs and OPFRs can be taken up by plants through partitioning to root lipids, as well as through gaseous and particle-bound deposition to the leaves. Their microscopic distribution in roots and leaves is important for understanding their accumulation behaviors. BFRs and OPFRs can be translocated in the xylem and phloem, but the specific transport pathways and mechanisms need to be further studied. BFRs and OPFRs can undergo phase I and phase II metabolism in plants. The identification, quantification and environmental fate of their metabolites will affect the assessment of their ecological and human exposure risks. Based on the issues mentioned above, some key directions worth studying in the future are proposed.

Polybrominated diphenyl ethers in the environment: a wake-up call for concerted action in India

Polybrominated diphenyl ethers (PBDEs) are a class of persistent organic pollutants (POPs) used as flame retardants in the products utilized in day-to-day life. Their bioaccumulation, low volatility, and high persistence in the environment have led to their global spread even to remote and distant regions. The present study identifies gaps in the investigation of the neurotoxic potential of PBDEs, their effects on brain development, toxicokinetic, and their potential as a carcinogen. In India, to date, only human breast milk was assessed for levels of PBDEs, and it is suggested that other human tissues can also be explored. No data on the reproductive toxicity of PBDEs are reported from Indian cohorts. Long-range transport and deposition of PBDEs in colder regions necessitates monitoring of Himalayan regions in India. An inventory of PBDEs is required to be made for addressing the worrisome situation of the unregulated import of E-waste from the developed countries in India. The study also emphasizes providing guidelines for the articulation of policies regarding sound surveillance and management of PBDE production, consumption, and release in the Indian context. It is recommended that a separate cell for monitoring and follow-up of PBDEs should be established in India. Also, the development of better alternatives and environment-friendly remediation technologies for PBDEs is the need of the hour.

Polybrominated diphenyl ethers (PBDEs) in raw milk from different animal species and in infant formula. Occurrence and risk assessment

Polybrominated diphenyl ethers (PBDEs) are widespread, persistent in the environment, and classified as global pollutants. Their presence has been confirmed in various types of food which adversely affect human health when consumed in sufficient amounts. Although milk has advantageous nutritional qualities and there are health benefits associated with its consumption, it could also contain toxic PBDEs. The aim of the study was the determination of the concentrations of ten congeners (BDE -28, -47, -49, -99, -100, -138, -153, -154, -183, and 209) in cow's, sheep's, and goat's milk obtained from Polish farms and their determination in infant formula. A total of 103 samples of raw milk and infant formula were tested using an accredited high-resolution gas chromatography-high-resolution mass spectrometry method. PBDEs were detected in all analyzed samples, the highest concentration being found in sheep's milk (11.9 ng g^-1 fat), and cow's milk containing the least contamination. BDE-209 makes the predominant contribution to the sum of the ten congeners, constituting at least 38%. The profiles of PBDEs were dependent on the milk type and the differences between its varieties are discussed. The highest median concentration of the sum of ten PBDEs (0.473 ng g^-1 fat) was determined in infant formula, which was identified as an important source of infants' exposure (5.48 ng kg^-1 b.w. day^-1 calculated based on P95 concentration). Milk is a source of PBDE in the diet; however, considered in isolation its consumption does not pose a risk to either adults' or children's health.

The occurrence of polybrominated diphenyl ether (PBDE) contamination in soil, water/sediment, and air

As a kind of brominated flame retardants (BFRs), polybrominated diphenyl ethers (PBDEs) are extensively used in different types of electronic equipment, furniture, plastics, and textiles. PBDEs are ubiquitous environmental contaminants that may impact human health and ecosystems. Here we highlight recent findings on the occurrence, contamination status, and transport of PBDEs in soil, water/sediment, and air. Four aspects are discussed in detail: (1) sources of PBDEs to the environment; (2) occurrence and transport of PBDEs in soil; (3) PBDEs in aquatic ecosystems (water/sediment) and their water-sediment partitioning; and (4) the occurrence of PBDEs in the atmosphere and their gas-particle partitioning. Future prospects for the investigation on PBDEs occurrence are also discussed based on current scientific and practical needs.

Critical review of soil contamination by polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NBFRs); concentrations, sources and congener profiles

Polybrominated diphenyl ethers (PBDEs) have been used in a broad array of polymeric materials such as plastics, foams, resins and adhesives to inhibit the spread of fires since the 1970s. The widespread environmental contamination and well documented toxic effects of PBDEs have led to bans and voluntary withdrawals in many jurisdictions. Replacement novel brominated flame retardants (NBFRs) have, however, exhibited many of the same toxic characteristics as PBDEs and appear to share similar environmental fate. This paper presents a critical review of the scientific literature regarding PBDE and NBFR contamination of surface soils internationally, with the secondary objective of identifying probable pollution sources. An evaluation of NBFR distribution in soil was also conducted to assess the suitability of the newer compounds as replacements for PBDEs, with respect to their land contamination potential. Principle production of PBDEs and NBFRs and their consequent use in secondary polymer manufacture appear to be processes with strong potential to contaminate surrounding soils. Evidence suggests that PBDEs and NBFRs are also released from flame retarded products during disposal via landfill, dumping, incineration and recycling. While the land application of sewage sludge represents another major pathway of soil contamination it is not considered in this review as it is extensively covered elsewhere. Both PBDEs and NBFRs were commonly detected at background locations including Antarctica and northern polar regions. PBDE congener profiles in soil were broadly representative of the major constituents in Penta-, Octa- and Deca-BDE commercial mixtures and related to predicted market place demand. BDE-209 dominated soil profiles, followed by BDE-99 and BDE-47. Although further research is required to gain baseline data on NBFRs in soil, the current state of scientific literature suggests that NBFRs pose a similar risk to land contamination as PBDEs.

Bioindication of PBDEs and PCBs by native and transplanted moss Pleurozium schreberi

PBDEs and PCBs are toxic, persistent organic pollutants (POPs), and the use of PCBs is forbidden, but they are still present in many environments and biota. 90-day assays were conducted with the moss Pleurozium schreberi transplanted from an uncontaminated control site to ten sites (rural and urban) selected in one of the most polluted regions of Upper Silesia in Poland. Native P. schreberi mosses were collected from the same ten polluted sites. Concentrations of PBDEs (28, 47, 66, 85, 99, 100, 153, 154, 183 and 209) and PCBs (28, 52, 101, 118, 138, 153, 180) were determined in all native and transplanted P. schreberi from all sites. Native P. schreberi contained the highest ΣPBDE and ΣPCB levels (63.6ngg^-1 and 4.47pgg^-1, respectively) when collected in the vicinity of a steel smelter. After 90 days of the experiment native and transplanted P. schreberi contained the highest concentrations of the same BDE 209 congener (88-91% of total PBDEs in the native mosses and 85-90% of the total PBDE burden in the transplants). The native and transplanted mosses from the industrial sites after 90 days of exposure contained significantly higher concentrations of all the examined PBDE and PCB congeners (except for 153 and 180) than mosses from rural sites. PBDE and PCB values were higher in native than in transplanted mosses after 90 days of exposure in both rural and industrial sites.

Polychlorinated biphenyls and polybrominated diphenylethers in soils from planted forests and adjacent natural forests on a tropical island

Transformation from natural forests to planted forests in tropical regions is an expanding global phenomenon causing major modifications of land cover and soil properties, e.g. soil organic carbon (SOC). This study investigated accumulations of POPs in soils under eucalyptus and rubber forests as compared with adjacent natural forests on Hainan Island, China. Results showed that due to the greater forest filter effect and the higher SOC, the natural forest have accumulated larger amounts of POPs in the top 20 cm soil. Based on correlation and air-soil equilibrium analysis, we highlighted the importance of SOC in the distribution of POPs. It is assumed that the elevated mobility of POPs in the planted forests was caused by greater loss of SOC and extensive leaching in the soil profile. This suggests that a better understanding of global POPs fate should take into consideration the role of planted forests.

Polychlorinated biphenyl and polybrominated diphenyl ether profiles in serum from cattle, sheep, and goats across California

It has been previously been shown by our lab and others that persistent organic pollutants, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), are contaminants in milk produced for human consumption. To further this research we determined the concentration of 21 PCB and 14 PBDE congeners in livestock serum, mainly bovine, across California. Congeners were extracted from serum using solid phase extraction (SPE), cleaned up by silica cartridge and quantified using gas chromatography-triple quadruple mass spectrometry. We detected significant differences among species and the production class of cattle (beef or dairy). The sum of all 21 PCB congeners (ΣPCBs) in caprine and ovine sera had a mean value of 9.26 and 9.13 ng/mL, respectively, compared to 3.98 ng/mL in bovine sera. The mean value for the sum of all 14 PBDE congeners (ΣPBDEs) in caprine and ovine sera was 2.82 and 2.39 ng/mL, respectively, compared to 0.91 ng/mL in bovine sera. Mean ΣPCBs in dairy cattle was 5.92 ng/mL compared to 2.70 ng/mL in beef cattle. Mean ΣPBDEs in dairy cattle was 1.33 ng/mL compared to 0.70 ng/mL in beef cattle. There were no regional differences in the ΣPCBs or ΣPBDEs in cattle distributed across California. These results highlight the fact that livestock are still being exposed to these pollutants yet little is known about where this exposure may be coming from.

Quantification of Polychlorinated Biphenyls and Polybrominated Diphenyl Ethers in Commercial Cows' Milk from California by Gas Chromatography-Triple Quadruple Mass Spectrometry

We determined 12 polybrominated diphenyl ethers (PBDEs) and 19 polychlorinated biphenyls (PCBs) congeners in eight different brands of commercial whole milk (WM) and fat free milk (FFM) produced and distributed in California. Congeners were extracted using a modified quick, easy, cheap, effective, rugged and safe (QuEChERS) method, purified by gel permeation chromatography, and quantified using gas chromatography-triple quadruple mass spectrometry. PBDEs and PCBs were detected in all FFM and WM samples. The most prevalent PBDE congeners in WM were BDE-47 (geometric mean: 18.0 pg/mL, 0.51 ng/g lipid), BDE-99 (geometric mean: 9.9 pg/mL, 0.28 ng/g lipid), and BDE-49 (geometric mean: 6.0 pg/mL, 0.17 ng/g lipid). The dominant PCB congeners in WM were PCB-101(geometric mean: 23.6 pg/mL, 0.67 ng/g lipid), PCB-118 (geometric mean: 25.2 pg/mL, 0.72 ng/g lipid), and PCB-138 (geometric mean: 25.3 pg/mL, 0.72 ng/g lipid). The sum of all 19 PCB congeners in FFM and WM were several orders of magnitude below the U.S. FDA tolerance. The sum of PBDEs in milk samples suggest close proximity to industrial emissions, and confirm previous findings of elevated PBDE levels in California compared to other regions in the United States.

BDE-47 exposure changed the immune function of haemocytes in Mytilus edulis: An explanation based on ROS-mediated pathway

Brominated Tetra-BDE (BDE-47), is suggested to be widely distributed in marine environments and highly accumulated in marine organisms. Blue mussel Mytilus edulis is a sentinel organism that is commonly used for monitoring chemical contaminants in coastal ecosystems, and its haemocytes play an essential role in immune function. Therefore, we estimated the effects of BDE-47 exposure on the M. edulis haemocytes' immune function under controlled laboratory conditions. The study found the following results: (1) BDE-47 exposure increased the mortality of the haemocytes and decreased the total haemocyte counts. The ultrastructure and microstructure in the haemocytes were significantly changed, and the micronucleus frequency was increased steadily in a concentration-dependent manner, inferring that cellular and molecular damages occur during the exposure. (2) The immune function of the haemocytes was estimated from lysosomal and phagocytic changes. The lysosomal membrane stability was significantly disrupted compared to the control according to neutral red retention time changes, and the phagocytic ability was reduced significantly. Two lysosomal enzymes, acid phosphatases and alkaline phosphatases, presented similar increasing trends during the treatment. (3) BDE-47 exposure significantly induced the overproduction of reactive oxygen species and malondialdehyde in a clear time- and concentration-dependent manner, suggesting the occurrence of oxidative stress. We thus presumed that BDE-47 exposure affected the immune function of the mussel's haemocytes, and an ROS-mediated pathway might be one of the possible explanations for the observation.

Spatial distribution of old and emerging flame retardants in Chinese forest soils: sources, trends and processes

The levels and distribution of polybrominated diphenylethers (PBDEs), novel brominated flame retardants (NBFRs) and Dechlorane Plus (DP) in soils and their dependence on environmental and anthropological factors were investigated in 159 soil samples from 30 background forested mountain sites across China. Decabromodiphenylethane (DBDPE) was the most abundant flame retardant (25-18,000 pg g(-1) and 5-13,000 pg g(-1) in O-horizon and A-horizon, respectively), followed by BDE 209 (nd-5900 pg g(-1) and nd-2400 pg g(-1) in O-horizon and A-horizon, respectively). FRs distributions were primarily controlled by source distribution. The distributions of most phasing-out PBDEs, DP isomers and TBPH were in fact correlated to a population density-based index used as proxy of areas with elevated usage and waste of FR containing products. High concentrations of some NBFRs were however observed in industrialized regions and FR manufacturing plants. Strongly positive correlations were observed between PBDEs and their replacement products suggesting similar emission pattern and environmental behavior. Exposure of mineral subsoils depended on precipitations driving leaching of FRs into the soil core. This was especially evident for some emerging BFRs (TBE, TBPH, and TBB etc.) possibly indicating potential for diffuse groundwater contamination.

Mountain cold-trapping increases transfer of persistent organic pollutants from atmosphere to cows' milk

Concentrations of long-lived organic contaminants in snow, soil, lake water, and vegetation have been observed to increase with altitude along mountain slopes. Such enrichment, called "mountain cold-trapping", is attributed to a transition from the atmospheric gas phase to particles, rain droplets, snowflakes, and Earth's surface at the lower temperatures prevailing at higher elevations. Milk sampled repeatedly from cows that had grazed at three different altitudes in Switzerland during one summer was analyzed for a range of persistent organic pollutants. Mountain cold-trapping significantly increased air-to-milk transfer factors of most analytes. As a result, the milk of cows grazing at higher altitudes was more contaminated with substances that have regionally uniform air concentrations (hexachlorobenzene, α-hexachlorocyclohexane, endosulfan sulfate). For substances that have sources, and therefore higher air concentrations, at lower altitudes (polychlorinated biphenyls, γ-hexachlorocyclohexane), alpine milk has lower concentrations, but not as low as would be expected without mountain cold-trapping. Differences in the elevational gradients in soil concentrations and air-to-milk transfer factors highlight that cold-trapping of POPs in pastures is mostly due to increased gas-phase deposition as a result of lower temperatures causing higher uptake capacity of plant foliage, whereas cold-trapping in soils more strongly depends on wet and dry particle deposition. Climatic influences on air-to-milk transfer of POPs needs to be accounted for when using contamination of milk lipids to infer contamination of the atmosphere.

Background levels of polybrominated diphenyl ethers (PBDEs) in soils from Mount Meru area, Arusha district (Tanzania)

This study investigates the contamination by 13 polybrominated diphenyl ether (PBDE) congeners in an altitudinal soil transect on Mt. Meru area, Northern Tanzania. A ∑13PBDEs mean concentration of 386±200 pg/g d.w. (4900±3500 pg ∑13PBDEs/g soil organic matter - SOM) was measured, pointing out that, in a prevalently agricultural area from the southern hemisphere, PBDE contamination can be even higher than in similar semi-remote environment of industrialized country of the northern one. The Mt. Meru PBDE pattern of contamination was characterized by the prevalence of intermediate brominated congeners (tetra- and penta-BDEs). Among the detected compounds, BDE-47 was the main congener, followed by BDE-99, BDE-190 and BDE-100. The distribution of PBDEs confirmed that organic carbon had a substantial impact on their accumulation in Tanzanian soils. The altitudinal profile of PBDEs (log TOC-normalized concentrations) fitted a second order polynomial model with altitude, with an initial concentration decrease, interpreted as a dilution effect from local/regional sources, and a following consistent increase with altitude according to the cold condensation theory. Evidences of distillation effect among PBDE congeners were also observed.

The influence of climate change on the global distribution and fate processes of anthropogenic persistent organic pollutants

The effect of climate change on the global distribution and fate of persistent organic pollutants (POPs) is of growing interest to both scientists and policy makers alike. The impact of warmer temperatures and the resulting changes to earth system processes on chemical fate are, however, unclear, although there are a growing number of studies that are beginning to examine these impacts and changes in a quantitative way. In this review, we examine broad areas where changes are occurring or are likely to occur with regard to the environmental cycling and fate of chemical contaminants. For this purpose we are examining scientific information from long-term monitoring data with particular emphasis on the Arctic, to show apparent changes in chemical patterns and behaviour. In addition, we examine evidence of changing chemical processes for a number of environmental compartments and indirect effects of climate change on contaminant emissions and behaviour. We also recommend areas of research to address knowledge gaps. In general, our findings indicate that the indirect consequences of climate change (i.e. shifts in agriculture, resource exploitation opportunities, etc.) will have a more marked impact on contaminants distribution and fate than direct climate change.