Non-dioxin-like PCB and PBDE deposition onZeamaysL. leaves: modelled contamination in milk from dairy animals fed on silage

OPFRs in e-waste sites: Integrating in silico approaches, selective bioremediation, and health risk management of residents surrounding

A multilevel index system of organophosphate flame retardant bioremediation effect in an e-waste handling area was established under three bioremediation scenarios (scenario I, plant absorption; scenario II, plant-microbial combined remediation; scenario III, microbial degradation). Directional modification of OPFR substitutes with high selective bioremediation was performed. The virtual amino acid mutation approach was utilised to generate high-efficiency selective absorption/degradation mutant proteins (MPs) in a plant-microbial system under varying conditions. In scenario III, the MP's microbial degrading ability to replace molecules was increased to the greatest degree (165.82%). Appropriate foods such as corn, pig liver, and yam should be consumed, whereas the simultaneous consumption of high protein foods such as pig liver and walnut should be avoided; sweet potato and yam are believed to be prevent OPFRs and substitute molecules from entering the human body through multiple pathways for reduced genotoxicity of OPFRs in the populations of e-waste handling areas (the reduction degree can reach 85.12%). The study provides a theoretical basis for the development of ecologically acceptable OPFR substitutes and innovative high-efficiency bioremediation MPs, as well as for the reduction of the joint toxicity risk of multiple ingestion route exposure/gene damage of OPFRs in high OPFR exposure sites.

Dioxins and dioxin-like PCBs in buffalo milk from the Campania region (Italy): Decreasing trend and baseline assessment over 10 years (2008-2018)

Polychlorodibenzo-p-dioxins, polychlorodibenzo-furans (PCDD/Fs) and dioxin-like polychlorobiphenyls (DL-PCBs) enter the food chain from the environment. In this study, we report the 2008-2018 time-trends in the PCDD/F and DL-PCB contamination of milk from buffaloes fed on local forage in rural areas of the Campania region. Validated according to QA/QC criteria, the dataset (N = 808 on a total of 2068 samples, after excluding follow-up results and outliers) was computed on the upper-bound value pg WHO-TEQ₂₀₀₅ g^-1fat. We assessed time-trends and assayed baseline contamination levels, which displayed log-normal distribution. A significant decreasing trend (p < 0.01) was observed from 2008 to 2009 and 2010; the P50-P95 range fell from 2.37-8.48 pg WHO-TEQ₂₀₀₅ g^-1fat (N = 393) in 2008 to 1.73-4.61 in 2009 (N = 86) and to 0.67-1.46 in 2010 (N = 42). From 2010 to 2018 (N = 329), no significant variation was found among years and the related dataset fitted a log-normal distribution (p < 0.05). Occurrence descriptors indicated that the baseline contamination of dairy products (mean = 0.54; P50-P95 = 0.47-1.24) in the Campania Region was well below the EU regulatory limit in force (5.5 pg WHO-TEQ₂₀₀₅ g^-1fat). Given the Tolerable Weekly Intake of 2 pg WHO-TEQ kg^-1 body weight (bw) proposed by the EFSA for PCDD/Fs and DL-PCBs, this level of baseline contamination is discussed with regard to the orientation of food safety and food security risk connected with buffalo mozzarella cheese production.

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.

Polychlorobiphenyl levels in the serum of cats from residential flats in Italy: Role of the indoor environment

The domestic cat (Felis catus) was used as a sentinel of exposure to polychlorobiphenyls (PCBs) in indoor urban environments y. Sera from 120 cats were pooled to form 30 different groups selected by age (<2 years; > 2 ≤ 8 years; > 8 years), sex, municipality (Bologna and Turin) and environment (indoor vs. outdoor). Test portions of 1 mL were analyzed by means of gas chromatography coupled to high-resolution mass spectrometry (GC-HRMS) for six selected indicators non-dioxin-like PCBs (∑6 PCBs: congeners #28, #52, #101, #132, #153 and #180) and the results were computed in the upper-bound mode. The internal dose of PCBs attributable to the cats' alimentary lipid intake ranged from 32.4 to 1,446 ng/g (P50 165; mean 258). The Wilcoxon test revealed significantly lower PCB burden in "outdoor" groups than in "indoor" groups. Age correlated well with the heptachlorinated and most bio-accumulative congener, PCB #180, and slightly with hexachlorinated PCBs #138 and #153. Contamination attributable to house dust collected in 15 living-rooms ranged from 10.0 to 279 ng/g dry weight (P50 97.4; mean 94.4). Exposure estimates indicated a 0.6-16 ng/kg bw range of daily ∑6 PCB intake from a default value of 200 mg/cat of dust ingestion. The intake of PCBs due to dust ingestion fell within the same order of magnitude as that computed from a 60 g daily intake of commercial dry pet foods, while inhalation accounted for 0.21-8.2 ng/kg bw/day, on setting the nominal ∑6 PCB contamination in outdoor and indoor air at 0.37 and 15 ng/m³, respectively. Italian indoor cats could be exposed to higher levels of ∑6 PCBs than the Reference Dose (RfD) of 10 ng/kg/bw/day; this supports the World Health Organization's statement that the quality of the indoor environment is a major determinant of health.

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.

Potential impact on food safety and food security from persistent organic pollutants in top soil improvers on Mediterranean pasture

The organic carbon of biosolids from civil wastewater treatment plants binds persistent organic pollutants (POPs), such as polychlorodibenzo -dioxins and -furans (PCDD/Fs), dioxin and non-dioxin -like polychlorobiphenyls (DL and NDL-PCBs), polybrominated diphenyl ethers (PBDEs), and perfluorooctane sulfonic acid (PFOS). The use of such biosolids, derived digestates and composts as top soil improvers (TSIs) may transfer POPs into the food chain. We evaluated the potential carry-over of main bioavailable congeners from amended soil-to-milk of extensive farmed sheep. Such estimates were compared with regulatory limits (food security) and human intakes (food safety). The prediction model was based on farming practices, flocks soil intake, POPs toxicokinetics, and dairy products intake in children, of the Mediterranean area. TSI contamination ranged between 0.20-113 ng WHO-TEQ/kg dry matter for PCDD/Fs and DL-PCBs (N = 56), 3.40-616 μg/kg for ∑6 NDL-PCBs (N = 38), 0.06-17.2 and 0.12-22.3 μg/kg for BDE no. 47 and no. 99, 0.872-89.50 μg/kg for PFOS (N = 27). For a 360 g/head/day soil intake of a sheep with an average milk yield of 2.0 kg at 6.5% of fat percentage, estimated soil quality standards supporting milk safety and security were 0.75 and 4.0 ng WHO-TEQ/kg for PCDD/Fs and DL-PCBs, and 3.75 and 29.2 μg/kg for ∑6 NDL-PCBs, respectively. The possibility to use low-contaminated TSIs to maximize agriculture benefits and if the case, to progressively mitigate highly contaminated soils is discussed.