No abstract

Novel brominated flame retardants (NBFRs) have been of great concern in the past few years due to their ubiquity in the environment and potential bioconcentration characteristics. This study takes Xilingol grassland in Inner Mongolia as the research area to analyze the pollution characteristics of NBFRs (pTBX, HBB, PBT, PBBz, and PBEB) in the grassland food chain. pTBX was more likely to be biomagnified in the food chain of amphibians, reptiles, and birds, whereas PBT and HBB were more likely to be biomagnified in the food chain of mammals. This may be because these animals have different diets and metabolic patterns. According to the concentration distribution of NBFRs in sheep organs and tissues, PBT, HBB, and PBBz easy bioaccumulated in sheep. The biomagnification effect of sheep adipose tissue and internal organs on NBFRs was inconsistent, so the biomagnification of chemicals in organisms cannot be determined only by the biomagnification of adipose tissue.

Atmospheric concentrations and sources of polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and polychlorinated dibenzo-p-dioxin/furans (PCDD/ Fs) were investigated on a steppe in North China. The concentration ranges of trichlorinated to heptachlorinated biphenyls, trichlorinated to octachlorinated naphthalenes, and 17 PCDD/Fs in the ranch samples were 1498−2168, 454−803, and 8.76−18.2 fg/m 3 , respectively. Trichlorinated biphenyls, which were the main PCBs emitted from combustion processes and PCB commercial products, accounted for 67.4%−78.9% of the total PCBs. CN14/24, the indicator of coal and wood combustion, was the main contributor to the PCNs. Interestingly, CN61, which has been obviously detected in PCB commercial products in the past, was present in the ranch samples. Source apportionment conducted using the positive matrix factorization (PMF) model confirmed that wood and coal combustion was the dominant contributor to PCBs (71%) and PCNs (49%) in the ranch samples. Legacy capacitor impregnating agents and transformer oils in the steppe were a significant source of PCBs and PCNs. The PCDD/Fs were dominated by highly chlorinated homologs and mainly affected by combustion sources. Air mass back trajectories simulated showed that long-range transport was not the main source of the persistent organic pollutants (POPs) in the ranch atmosphere during the sampling period.

Novel brominated flame retardants (NBFRs) are of great concern in the past few years due to their ubiquitousness in the environment and potential bioconcentration characteristics. This study takes Xilingol grassland in Inner Mongolia as the research area to analyze the pollution characteristics of NBFRs (pTBX, HBB, PBT, PBBz and PBEB) in grassland food chain. pTBX was more likely to be biomagnified in the food chain of amphibians, reptiles and birds, while PBT and HBB were more likely to be biomagnified in the food chain of mammals. This may be because these animals have the different diet and metabolic patterns. According to the concentration distribution of NBFRs in sheep organs and tissues, PBT, HBB and PBBz were easy to be bioaccumulated in sheep. The biomagnification effect of sheep adipose tissue and internal organs on NBFRs was inconsistent, so the biomagnification of chemicals in organisms cannot be determined only by the biomagnification of adipose tissue.

Dechlorane Plus (DP) is found widely in the environment. It is important to study DP enrichment and biomagnification in terrestrial ecosystems to improve our understanding of the possible effects of DP on the environment and human health. A total of 90 samples, including plant and animal tissues, were collected from Xilingol Prairie in Inner Mongolia, China. The DP concentrations in different species were assessed, and transmission of DP through food webs containing ectotherms and endotherms was assessed. The compound was detected in the biotic samples (plant; range 0.133–0.422 ng/g dry wt), in animal muscle (range: not dected–5.70 ng/g lipid wt), and in animal hair (range: not dected–2.03 ng/g dry wt), indicating that DP is present in remote environments such as Xilingol Prairie. These findings suggest that DP can undergo long‐distance transport in the environment. Biomagnification factors (ectotherms: range 0.146–88.0, endotherms: range 0.866–17.2) and anti‐DP/total DP concentration ratios (fanti values of 0.412–0.787) for the prairie animals were calculated. Ectotherms were found to selectively enrich syn‐DP, and stereoselective enrichment increased moving up the food web. Lower‐trophic‐level endotherms strongly stereoselectively enriched syn‐DP, and higher‐trophic‐level endotherms stereoselectively enriched anti‐DP. Environ Toxicol Chem 2021;40:413–421. © 2020 SETAC