Impact of Legislation on Brominated Flame Retardant Concentrations in UK Indoor and Outdoor Environments: Evidence for Declining Indoor Emissions of Some Legacy BFRs.

Concentrations of polybrominated diphenyl ethers, hexabromocyclododecane (HBCDD), and novel brominated flame retardants (NBFRs) were measured in indoor dust, indoor air, and outdoor air in Birmingham, UK. Concentrations of ΣBFRs ranged from 490 to 89,000 ng/g, 46-14,000 pg/m3, and 22-11,000 pg/m3, respectively, in UK indoor dust, indoor air, and outdoor air. BDE-209 and decabromodiphenyl ethane (DBDPE) were the main contributors. The maximum concentration of DBDPE (10,000 pg/m3) in outdoor air is the highest reported anywhere to date. In contrast with previous studies of outdoor air in Birmingham, we observed significant correlations between concentrations of tri- to hepta-BDEs and HBCDD and temperature. This may suggest that primary emissions from ongoing use of these BFRs have diminished and that secondary emissions (e.g., evaporation from soil) are now a potentially major source of these BFRs in outdoor air. Conversely, the lack of significant correlations between temperature and concentrations of BDE-209 and DBDPE may indicate that ongoing primary emissions from indoor sources remain important for these BFRs. Further research to clarify the relative importance of primary and secondary sources of BFRs to outdoor air is required. Comparison with earlier studies in Birmingham reveals significant (p < 0.05) declines in concentrations of legacy BFRs, but significant increases for NBFRs over the past decade. While there appear minimal health burdens from BFR exposure for UK adults, dust ingestion of BDE-209 may pose a significant risk for UK toddlers.

Organophosphate triesters and their diester degradation products in the atmosphere-A critical review.

Organophosphate triesters (tri-OPEs) have found substantial use as plasticizers and flame retardants in commercial and industrial products. Despite upcoming potential restrictions on use of OPEs, widespread environmental contamination is likely for the foreseeable future. Organophosphate diesters (di-OPEs) are known biotic or abiotic degradation products of tri-OPEs. In addition, direct use of di-OPEs as commercial products also contributes to their presence in the atmosphere. We review the available data on contamination with tri-OPEs and di-OPEs in both indoor and outdoor air. Concentrations of tri-OPEs in indoor air exceed those in outdoor air. The widespread discovery of tri-OPE traces in polar regions and oceans is noteworthy and is evidence that they undergo long-range transport. There are only two studies on di-OPEs in outdoor air and no studies on di-OPEs in indoor air until now. Current research on di-OPEs in indoor and outdoor air is urgently needed, especially in countries with potentially high exposure to di-OPEs such as the UK and the US. Di-OPE concentrations are higher at e-waste dismantling areas than at surrounding area. We also summarise the methods employed for sampling and analysis of OPEs in the atmosphere and assess the relative contribution to atmospheric concentrations of di-OPEs made by environmental degradation of triesters, compared to the presence of diesters as by-products in commercial triester products. Finally, we identify shortcomings of current research and provide suggestions for future research.

Polychlorinated naphthalene concentrations in human serum caused by unintentional production and emissions, and potential effects of polychlorinated naphthalenes on thyroid hormones.

The concentrations of 75 polychlorinated naphthalene (PCN) congeners in 95 human serum samples from the Fengjiang electronic waste dismantling area and Huangyan District in Taizhou City (Zhejiang Province, China) were determined. Thyroid hormone (FT3, FT4, TSH, and TRH) concentrations in the samples were also determined. The total PCN concentrations in the samples from Fengjiang and Huangyan were 1.29 × 104-4.28 × 105 and 8.29 × 102-6.45 × 105 pg/g lipid, respectively. The less-chlorinated (Cl1-3) PCN concentrations were relatively high in all of the samples, and the concentrations in the samples from the two areas were not significantly different. The sums of the combustion-related PCN congener concentrations were significantly higher in the samples from Fengjiang than in the samples from Huangyan, and the sums of the more-chlorinated (Cl4-8) PCNs were slightly higher in the samples from Fengjiang than in the samples from Huangyan. The relationship between the PCN concentration and age indicated that electronic waste controls have decreased human exposure to PCNs but that attention should still be paid to exposure to less-chlorinated PCNs. The main PCN congeners that contributed to the toxic equivalent concentrations were markedly different for the samples from Fengjiang and Huangyan. CN-66/67 was dominant for the Fengjiang samples and CN-10 was dominant for the Huangyan samples. Attention should be paid to the risks posed by less-chlorinated PCNs to human health. CN-1, CN-2, and CN-20 concentrations are related to human thyroid hormone levels, and the relationships between less-chlorinated PCN concentrations and thyroid hormone concentrations should be further studied.

Previously identified and unidentified polybrominated biphenyl congeners in serum from people living in an electronic waste dismantling area in China.

The effects of polybrominated biphenyls (PBBs) on human health have previously attracted much attention, but recent studies of PBBs have been focused on BB-153 and a few other congeners. PBB concentrations in serum samples from residents of an area containing an electronic waste dismantling site were determined in this study. The total PBB concentrations (i.e., the sums of the concentrations of the 35 PBB congeners) were 229-1360 ng/g lipid. The BB-153 concentrations were markedly higher in the samples from people living in the electronic waste dismantling area than in samples from people living in a nearby control area. BB-153 was found in all of the samples from the study exposure area but the concentrations were relatively low (0.07-4.70 ng/g lipid). High BB-1 concentrations were found for the first time in serum from people living in both the electronic waste dismantling and control areas. The BB-1 concentrations were 211-1280 ng/g lipid. The retention times of the 35 PBB standards and PCBs (polychlorinated biphenyls) with similar structures were used to predict the retention times of unidentified PBB congeners to allow the PBB distributions in the serum samples to be identified. A total of 26 previously unidentified PBB congeners were identified in the human serum samples. BB-5, BB-35, BB-79, and BB-109 were found in >50% of the samples. The PBB patterns in the serum samples were different from the patterns previously found in serum after a PBB contamination incident in 1973, so the health risks currently posed by PBBs are worth studying.

Polychlorinated naphthalenes in human serum samples from an industrial city in Eastern China: Levels, sources, and sex differences.

Polychlorinated naphthalenes (PCNs) in the environment in China have been studied extensively. However, there have been no reports on PCNs in human serum samples from China. In this context, we collected 480 serum samples from an industrial city in Eastern China. The concentration range for the sum of the mono-to octa-CNs was 14300-50700 pg/g lipid. The most predominant congener was CN-5/7, which accounted for 21.6%-51.1% of the total PCN concentration. Further analysis indicated that residues of PCN industrial technical products in the local environment appear to be the main source of CN-5/7 in the serum samples. On the other hand, the sum of the tetra-to octa-CNs concentration was obviously higher in males (1390 ±â€¯929 pg/g lipid) than in females (267 ±â€¯25 pg/g lipid). Moreover, the concentrations of combustion-related PCNs in the male 20-24, 25-29 and 30-34 years groups were obviously higher than those in the female samples. Therefore, industrial thermal processes are important sources of PCNs in male serum in addition to PCN products. The toxic equivalent (TEQ) concentrations of PCNs in the pooled serum samples ranged from 0.12 to 0.40 pg/g lipid. CN-10 and CN-66/67 were the dominant TEQ congeners in male serum, and CN-10, CN-1, and CN-2 were the main TEQ congeners in female serum.

Levels, sources, and potential human health risks of PCNs, PCDD/Fs, and PCBs in an industrial area of Shandong Province, China.

Polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs) are of public concern worldwide because of their persistence and toxicity. To address the human health risks of these pollutants and identify possible sources, soil samples were collected from an industrial area and surrounding residential area in Shandong Province, China. The PCN, PCDD/F, and PCB levels in these samples were determined. Extremely high concentrations of PCNs were detected in two soil samples, and their congener distributions were similar to those of a PCN industrial technical product. The levels of combustion-related PCNs and PCDD/Fs were high in samples collected near a secondary copper smelter. The distribution of total PCB concentrations was similar to that of PCNs. Both historical residues from industrial technical products and emissions from the secondary copper smelter were likely sources of PCNs and PCBs, whereas emissions from the smelter were the main source of PCDD/Fs. A soil sample from near the smelter had a high ΣTEQ concentration (PCDD/Fs + PCBs + PCNs = 18.33 pg TEQ/g) and carcinogenic risk (0.85 × 10-6) to workers. For all the other samples, the levels of PCDD/Fs, PCBs and PCNs exhibited low carcinogenic and noncarcinogenic risks to workers and residents.

A Method for Remotely Sensing Vital Signs of Human Subjects Outdoors.

After chemical or nuclear leakage or explosions, finding survivors is a huge challenge. Although human bodies can be found by smart vehicles and drones equipped with cameras, it is difficult to verify if the person is alive or dead this way. This paper describes a continuous wave radar sensor for remotely sensing the vital signs of human subjects. Firstly, a compact and portable 24 GHz Doppler radar system is designed to conduct non-contact detection of respiration signal. Secondly, in order to improve the quality of the respiration signals, the self-correlation and adaptive line enhancer (ALE) methods are proposed to minimize the interferences of any moving objects around the human subject. Finally, the detection capabilities of the radar system and the signal processing method are verified through experiments which show that human respiration signals can be extracted when the subject is 7 m away outdoors. The method provided in this paper will be a promising way to search for human subjects outdoors.