Quantification and the sources identification of total and insoluble hexavalent chromium in ambient PM: A case study of Aktobe, Kazakhstan

Enoch K Adotey; Lyailya Burkutova; Lyazzat Tastanova; Amirbek Bekeshev; Mannix P Balanay; Sergei Sabanov; Anna M Rule; Philip K Hopke; Mehdi Amouei Torkmahalleh

doi:10.1016/j.chemosphere.2022.136057

Quantification and the sources identification of total and insoluble hexavalent chromium in ambient PM: A case study of Aktobe, Kazakhstan

Chemosphere. 2022 Nov;307(Pt 4):136057. doi: 10.1016/j.chemosphere.2022.136057. Epub 2022 Aug 19.

Authors

Enoch K Adotey¹, Lyailya Burkutova², Lyazzat Tastanova², Amirbek Bekeshev², Mannix P Balanay³, Sergei Sabanov⁴, Anna M Rule⁵, Philip K Hopke⁶, Mehdi Amouei Torkmahalleh⁷

Affiliations

¹ Department of Chemical and Materials Engineering, School of Engineering and Digital Sciences, Nazarbayev University, Nur-Sultan, 010000, Kazakhstan.
² K. Zhubanov Aktobe University, A. Moldagulova Ave., 34, 030000, Aktobe, Kazakhstan.
³ Department of Chemistry, School of Sciences and Humanities, Nazarbayev University, Nur-Sultan, 010000, Kazakhstan.
⁴ Department of Mining, School of Mining and Geosciences, Nazarbayev University, Nur-Sultan, 010000, Kazakhstan.
⁵ Department of Public Health Sciences, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
⁶ Institute for a Sustainable Environment, Clarkson University, Potsdam, NY 13699, USA; Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 20209, USA.
⁷ Department of Chemical and Materials Engineering, School of Engineering and Digital Sciences, Nazarbayev University, Nur-Sultan, 010000, Kazakhstan; Division of Environmental and Occupational Health Sciences, School of Public Health, University of Illinois at Chicago, Chicago, IL 60612, USA. Electronic address: mehdiat@uic.edu.

PMID: 35995192
DOI: 10.1016/j.chemosphere.2022.136057

Abstract

Hexavalent chromium (Cr(VI)), a known carcinogen, emanates from both anthropogenic and natural sources. A pilot study of the ambient Cr(VI) concentrations was conducted at the center of Aktobe which is a few kilometers away from major industrial chromium plants. Total Cr(VI) concentrations were measured in the fall and winter seasons with mean values (S.D) of 5.30 (2.16) ng/m³ and 2.26 (1.80) ng/m³, respectively. Insoluble Cr(VI) levels were 4.80 (1.96) and 2.19 (1.75) ng/m³ for the fall and winter, respectively. The total and insoluble Cr(VI) concentrations in the fall season were significantly higher than in winter, likely due to the higher rate of Cr(III) oxidation in the presence of ozone and ROS in fall compared to the rate of Cr(VI) reduction in the presence of VOCs at higher temperatures. On average, total Cr(VI) constituted 34.49% of the total Cr concentrations suggesting that the dominant valence state of Cr in the atmosphere is Cr(III). The previous reference values of exposure to Cr(VI) must be revisited by taking into account the insoluble Cr(VI) concentration since it is more prevalent in the atmosphere compared to soluble Cr(VI). The influence of the chromium plants as potential sources was not obvious in this study.

Keywords: Atmospheric chemistry; IC-UV; Insoluble hexavalent chromium; Kazakhstan; Microwave digestion.

MeSH terms

Carcinogens
Chromium* / analysis
Kazakhstan
Oxidation-Reduction
Ozone*
Pilot Projects
Reactive Oxygen Species

Substances

Carcinogens
Reactive Oxygen Species
Chromium
chromium hexavalent ion
Ozone