Natural aeolian dust particles have no substantial effect on atmospheric polycyclic aromatic hydrocarbons (PAHs): A laboratory study based on naphthalene

Lulu Zhang; Xuan Zhang; Wanli Xing; Quanyu Zhou; Lu Yang; Ryohei Nakatsubo; Yongjie Wei; Jianrong Bi; Masayuki Shima; Akira Toriba; Kazuichi Hayakawa; Ning Tang

doi:10.1016/j.envpol.2020.114454

Natural aeolian dust particles have no substantial effect on atmospheric polycyclic aromatic hydrocarbons (PAHs): A laboratory study based on naphthalene

Environ Pollut. 2020 Aug;263(Pt A):114454. doi: 10.1016/j.envpol.2020.114454. Epub 2020 Mar 31.

Authors

Lulu Zhang¹, Xuan Zhang², Wanli Xing³, Quanyu Zhou⁴, Lu Yang⁵, Ryohei Nakatsubo⁶, Yongjie Wei⁷, Jianrong Bi⁸, Masayuki Shima⁹, Akira Toriba¹⁰, Kazuichi Hayakawa¹¹, Ning Tang¹²

Affiliations

¹ Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan. Electronic address: zhang-lulu@stu.kanazawa-u.ac.jp.
² Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan. Electronic address: zhangxuan@stu.kanazawa-u.ac.jp.
³ Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan. Electronic address: xingwanli@stu.kanazawa-u.ac.jp.
⁴ Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan. Electronic address: zhouquanyu@stu.kanazawa-u.ac.jp.
⁵ Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan. Electronic address: veronicayl@stu.kanazawa-u.ac.jp.
⁶ Hyogo Prefectural Institute of Environmental Sciences, Suma-ku, Kobe 654-0037, Japan. Electronic address: nakatsubo-r@hies-hyogo.jp.
⁷ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environment Sciences, Beijing 100012, China. Electronic address: weiyj@craes.org.cn.
⁸ College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China. Electronic address: bijr@lzu.edu.cn.
⁹ Department of Public Health, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan. Electronic address: shima-m@hyo-med.ac.jp.
¹⁰ Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan. Electronic address: toriba@p.kanazawa-u.ac.jp.
¹¹ Institute of Nature and Environmental Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan. Electronic address: hayakawa@p.kanazawa-u.ac.jp.
¹² Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan; Institute of Nature and Environmental Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan. Electronic address: n_tang@staff.kanazawa-u.ac.jp.

PMID: 32247922
DOI: 10.1016/j.envpol.2020.114454

Abstract

Natural aeolian dust (AD) particles are potential carriers of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere. The heterogeneous interaction between them may lead to worsened air quality and enhanced cytotoxicity and carcinogenicity of ambient particulates in downwind areas, and this topic requires in-depth exploration. In this study, AD samples were collected from four Asian dust sources, and their physical properties and compositions were determined, showing great regional differences. The physical and chemical interactions of different AD particles with naphthalene (Nap; model PAH) were observed in aqueous systems. The results showed that AD particles from the Loess Plateau had weak adsorption to Nap, which was fitted by the Langmuir isotherm. There was no obvious adsorption to Nap found for the other three AD samples. This difference seemed to depend mainly on the specific surface area and/or the total pore volume. In addition, the Nap in the aqueous solution did not undergo chemical reactions under dark conditions and longwave ultraviolet (UV) radiation but degraded under shortwave UV radiation, and 2-formylcinnamaldehyde and 1,4-naphthoquinone were the first-generated products. The degradation of Nap in the aqueous solution was probably initiated by photoionization, and the reaction rate constant (between 1.44 × 10^-4 min^-1 and 8.55 × 10^-4 min^-1) was much lower than that of Nap with hydroxyl radicals. Instead of inducing or promoting the chemical change in Nap, the AD particles slowed photodegradation due to the extinction of radiation. Therefore, it is inferred that natural AD particles have no substantial effect on the transportation and transformation of PAHs in the atmosphere.

Keywords: Adsorption; Aqueous phase; Asian dust; Heterogeneous interaction; Photodegradation.

MeSH terms

Atmosphere
Coal / analysis
Dust / analysis
Naphthalenes
Polycyclic Aromatic Hydrocarbons / analysis*

Substances

Coal
Dust
Naphthalenes
Polycyclic Aromatic Hydrocarbons