Environmental concentration and atmospheric deposition of halogenated flame retardants in soil from Nepal: Source apportionment and soil-air partitioning

Ishwar Chandra Yadav; Ningombam Linthoingambi Devi; Jun Li; Gan Zhang

doi:10.1016/j.envpol.2017.10.104

Environmental concentration and atmospheric deposition of halogenated flame retardants in soil from Nepal: Source apportionment and soil-air partitioning

Environ Pollut. 2018 Feb:233:642-654. doi: 10.1016/j.envpol.2017.10.104. Epub 2017 Nov 5.

Authors

Ishwar Chandra Yadav¹, Ningombam Linthoingambi Devi², Jun Li³, Gan Zhang³

Affiliations

¹ State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; Department of International Environmental and Agricultural Science (IEAS), Tokyo University of Agriculture and Technology (TUAT) 3-5-8, Saiwai-Cho, Fuchu-Shi, Tokyo 1838509, Japan. Electronic address: icyadav.bhu@gmail.com.
² Centre for Environmental Sciences, Central University of South Bihar, BIT Campus, Patna 800014, Bihar, India.
³ State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China.

PMID: 29107904
DOI: 10.1016/j.envpol.2017.10.104

Abstract

While various investigations have been driven on polybrominated diphenyl ethers (PBDEs) and other flame retardants (FRs) in different framework around the world, information about contamination and fate of PBDEs and other FRs in developing countries especially in the Indian subcontinent is uncommon. Nepal being located in the Indian subcontinent, very little is known about contamination level of semi-volatile organic pollutants discharged into the environment. This motivated us to investigate the environmental fate of halogenated flame retardant (HFRs) in Nepalese condition. In this study, we investigated the concentration, fate, and sources of 9 PBDEs, 2 dechlorane plus isomers (DPs), and 6 novel brominated flame retardants (NBFRs). Moreover, air-soil exchange and soil-air partitioning were also evaluated to characterize the pattern of air-soil exchange and environmental fate. In general, the concentrations of NBFRs in soil were more prevalent than PBDEs and DPs, and accounted 95% of ∑HFRs. By and large, the concentrations of NBFRs and DPs were measured high in Kathmandu, while PBDEs level exceeded in Pokhara. Principal component analysis (PCA) study suggested contributions from commercial penta-, octa-, and deca-BDEs products and de-bromination of highly brominated PBDEs as the significant source of PBDEs. Likewise, low f_anti ratio suggested DPs in soil might have originated from long-range atmospheric transport from remote areas, while high levels of decabromodiphenyl ethane (DBDPE) in soil were linked with the use of wide varieties of consumer products. The estimated fugacity fraction (ff) for individual HFR was quite lower (<0.05) than equilibrium value, suggesting that deposition and net transport from air to the soil is overwhelming. Soil-air partitioning study revealed neither octanol-air partition coefficient (K_OA) nor black carbon partition coefficient (K_BC-A) is an appropriate surrogate for soil organic matter (SOM), subsequently, absorption by SOM has no or little role in the partitioning of HFRs.

Keywords: Building materials; Consumer products; Fugacity fraction; Persistent organic pollutants; Soil organic matter; Technical-BDE.

MeSH terms

Air Pollutants / analysis*
Bromobenzenes / analysis
Environmental Monitoring*
Flame Retardants / analysis*
Halogenated Diphenyl Ethers / analysis
Halogenation
Hydrocarbons, Chlorinated / analysis
Nepal
Polycyclic Compounds / analysis
Soil / chemistry*
Soil Pollutants / analysis*
Soot / analysis

Substances

Air Pollutants
Bromobenzenes
Flame Retardants
Halogenated Diphenyl Ethers
Hydrocarbons, Chlorinated
Polycyclic Compounds
Soil
Soil Pollutants
Soot
decabromodiphenyl ethane
dechlorane plus