Levels of trace elements in PM10 collected at roadsides of Addis Ababa, Ethiopia, and exposure risk assessment

Asamene Embiale; Feleke Zewge; Bhagwan Singh Chandravanshi; Endalkachew Sahle-Demessie

doi:10.1007/s10661-019-7503-3

Levels of trace elements in PM₁₀ collected at roadsides of Addis Ababa, Ethiopia, and exposure risk assessment

Environ Monit Assess. 2019 May 24;191(6):397. doi: 10.1007/s10661-019-7503-3.

Authors

Asamene Embiale¹, Feleke Zewge¹, Bhagwan Singh Chandravanshi², Endalkachew Sahle-Demessie^{3

4}

Affiliations

¹ Department of Chemistry, College of Natural and Computational Sciences, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia.
² Department of Chemistry, College of Natural and Computational Sciences, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia. bscv2006@yahoo.com.
³ U.S. Environmental Protection Agency, Office of Research and Development National Risk Management Research Laboratory, 26 W. Martin Luther King Dr, Cincinnati, OH, 45268, USA.
⁴ Department of Chemistry, Missouri University of Science and Technology, Rolla, MO, 65409, USA.

PMID: 31127376
DOI: 10.1007/s10661-019-7503-3

Abstract

Estimation of personal exposure to air pollution is needed to identify high-risk population and to develop mitigation strategies. In this study, an assessment of the potential effects of short-term exposure to PM₁₀ and the elements bound within PM₁₀ was conducted. Samples were obtained from the ten sub-cities of Addis Ababa (three sampling points from each) during the commuting time (traffic congestion and taxi queues). A particle counter consisting of a portable sampling unit with multi-fraction dust samplers was used for sample collection. The elemental composition was analyzed by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The mean concentrations of PM₁₀ ranged from 206 to 308 μg m^-3. The highest concentrations of pollutants were found in the major open-market part of the city, Addis Ketema. The lowest concentrations were found at the old-town, Arada sub-cities. The concentration of trace elements (Fe, Cd, As, Cr, Pb, B, Ni, Co, Sn, Cu, and Zn) bound in PM₁₀ ranged from below detectable limit to 0.981 μg m^-3. Regardless of the sampling sub-city, the overall patterns of the mean concentration of elements bound in PM₁₀ were found in the following increasing order of Cr < Cd < As < Co < Ni < Cu < Fe < Pb < Sn < B < Zn < Mn. The results showed that the primary source of Zn, Cr, and Cd may be emissions from on-road vehicles, tire and brake wear. Pb originates mainly from industries and suspended soil dust at the roadside, whereas As, Mn, and B are associated with dust resuspension and biomass and biofuel combustion, respectively. The carcinogenic and non-carcinogenic risks due to chronic exposure to trace elements bound in PM₁₀ at the roadside were assessed in accordance with the U.S. Environmental Protection Agency (US EPA) guidelines. It was determined that Mn, As, and Cd contributed substantially to the inducement of non-carcinogenic health problems to children and adults as a result of exposure while in close proximity to the roadsides.

Keywords: Addis Ababa; Commuter exposure; Elemental composition; Ethiopia; Health risk assessment; Vehicle sources.

MeSH terms

Adult
Air Pollutants / analysis*
Air Pollution / analysis*
Child
Cities
Dust / analysis
Environmental Monitoring / methods*
Ethiopia
Humans
Industry
Risk Assessment / methods
Soil / chemistry
Trace Elements / analysis*

Substances

Air Pollutants
Dust
Soil
Trace Elements