Elsevier

Chemosphere

Volume 231, September 2019, Pages 378-384
Chemosphere

Correlations between dechlorane plus concentrations in paired hair and indoor dust samples and differences between dechlorane plus isomer concentrations in hair from males and females

https://doi.org/10.1016/j.chemosphere.2019.05.155Get rights and content

Highlights

  • DP concentration in male dormitory dust was significantly higher than that in female dormitory.

  • DP concentration in female hair was significantly higher than that in male hair.

  • Anti-DP can bind HSA better than syn-DP.

  • DP in hair is mainly from endogenous exposure.

  • The significant difference in DP concentration between male and female hair was mainly caused by anti-DP.

Abstract

Dechlorane plus (DP) is found widely in environmental media. Determining DP concentrations in dust and hair and identifying relationships between the concentrations in dust and hair could improve our understanding of the effects of DP in humans. DP concentrations in 48 hair samples from male and female students and in 30 indoor dust samples from dormitories and classrooms used by the students were determined. The objective was to determine the difference of DP concentration between indoor dust and hair, and to explore the effect of DP in dust on DP in hair of male and female students. The mean DP concentration was significantly higher in male dormitory dust than female dormitory dust, and the estimated DP dose through exposure to dust was also significantly higher for males than females. However, the mean DP concentration was significantly higher for hair from females than from males. The median DP fanti was significantly lower for hair than dust, indicating DP may be stereoselectively metabolized by humans. The median DP fanti was significantly higher for hair from females than from males, indicating DP may be metabolized differently by males and females. Human serum albumin preferred combination with anti-DP, rather than syn-DP. DP in indoor dust was not a major direct source of the DP in the hair, meaning DP in hair mainly came from within the body. There may be significant differences in DP, particularly anti-DP, metabolism in males and females.

Introduction

Dechlorane plus (DP) is an aliphatic organochlorine compound which is used as an additive flame retardant (Wang et al., 2016). DP is added to cables, electronic components, nylon, television and computer cases, wires, and other polymers. Pure DP is white powder with two DP isomers, syn-DP and anti-DP. DP is classed as a high-production-volume chemical by the U.S. Environmental Protection Agency (Xian et al., 2011). DP is one of the most widespread environmental pollutants (Yang et al., 2011).

Indoor dust is an important environmental medium through which humans are exposed to certain pollutants. Human hair is a convenient tissue for analysis because it can be sampled non-invasively and may indicate human exposure to certain pollutants, including some organic pollutants. Hair has been analyzed in several previous studies and the results used to assess human exposure to organic pollutants such as organochlorine pesticides, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans, polybrominated diphenyl ethers, and polycyclic aromatic hydrocarbons (Toriba et al., 2003; Nakao et al., 2005). Comparing DP concentrations in indoor dust and human hair and identifying relationships between the concentrations could allow the pathways through which humans are exposed to DP to be identified. DP was first detected in the environment in 2006, and much research on DP concentrations and behavior in the environment has been performed since then.

Zheng et al. studied the relationship between DP concentrations in hair and dust and did not find clear evidence for stereoselective enrichment of DP in hair (Zheng et al., 2010), but Wang et al. found that syn-DP is more strongly stereoselectively enriched than anti-DP in humans (Wang et al., 2016). Chen et al. analyzed hair from e-waste disassembly workers in southern China and found higher DP concentrations in hair from female workers (mean 200 ng g−1 dry weight (dw)) than in hair from male workers (mean 19 ng g−1 dw), so stated that differences between males and females should be considered when studying DP in human hair (Chen et al., 2015). It is important to determine whether indoor dust is the main source of DP to humans. It is also important to determine whether DP concentrations are different in males and females and, if so, to identify the reason(s).

The accumulation of organic pollutants in organisms depends on their transport and metabolism. Human Serum Albumin (HSA), which accounts for about 60% in blood, help to carry, transform and transport a variety of endogenous or exogenous substances (Hao et al., 2013). The strong binding ability of exogenous substances with HSA makes it more likely to be transported to fat cells for storage or to liver cells for metabolism. Therefore, whether organic pollutants can accumulate in the organism and be reflected by hair samples, the binding level of organic pollutants with HSA is an important influencing factor. BIA core (Biomolecular Interaction Analysis) system based on Surface Plasmon Resonance (SPR) technology is a very useful method for monitoring and combining dynamics. It is widely used to study the characteristics of various molecular interactions and has the advantages of free labeling, real-time and rapid (Shankaran et al., 2007).

In this study, we determined the DP concentrations in 48 samples of hair from male and female students and in 30 dust samples from the dormitories and classrooms used by the students. The DP extracted from the hair and dust were also analyzed in HSA interaction tests. Differences between the DP concentrations in hair from males and females were assessed. The results improve our understanding of the mechanisms involved in the toxicology of DP.

Section snippets

Sampling

Hair samples from students of the Minzu University of China, Beijing, and dust samples from the dormitories and classrooms used by the students were collected. About 1.0 g of every hair sample was collected from the posterior occipital region 1.0 cm away from the hair root of each of 48 students (24 males and 24 females), and a 1.0 g dust sample was collected from each of the 11 male dormitories and 13 female dormitories used by the students. Each dormitory dust sample was paired with the hair

DP concentrations in dust

DP was detected in all the classroom and dormitory dust samples (i.e., the syn-DP and anti-DP detection rates were both 100%), and the mean concentrations were shown in Fig. 1. The DP levels in the indoor dust ranged from 0.220 to 155 ng g−1 dw with a mean of 12.0 ng g−1 dw (the concentration ranges (mean) of classroom, female dormitory and male dormitory were 2.17–17.1 (5.62), 0.220–4.06 (1.57), 1.91–255 (27.4) ng·g−1 dw, respectively). The mean DP concentration in the male dormitory dust was

Conclusions

The DP concentrations in hair from male and female students at an university in Beijing and in dust from the classrooms and dormitories used by the students were determined. The DP concentrations in the dust samples increased in the order female dormitories, classrooms, male dormitories. The DP concentrations in the indoor dust samples were relatively low compared with concentrations found in dust at an e-waste disassembly site in a previous study, but the risks posed by DP to the students was

Acknowledgments

This work was supported by the Collaborative Innovation Center for Ethnic Minority Development, Minzu University of China, Fundamental Research Funds for the Central Universities [grant numbers 0910KYQN50 and 2015MDTD23C], and the Institution of Higher Education Innovation Talent Recruitment Program (111 Program) [grant number B08044].

References (34)

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