Health Risk Assessment of PM2.5 and PM2.5-Bound Trace Elements in Thohoyandou, South Africa.

Karl Kilbo Edlund,Peter Molnár,Leo Stockfelt,Janine Wichmann,Johan Boman,Felicia Killman

doi:10.3390/ijerph18031359

Abstract

We assessed the health risks of fine particulate matter (PM2.5) ambient air pollution and its trace elemental components in a rural South African community. Air pollution is the largest environmental cause of disease and disproportionately affects low- and middle-income countries. PM2.5 samples were previously collected, April 2017 to April 2018, and PM2.5 mass determined. The filters were analyzed for chemical composition. The United States Environmental Protection Agency’s (US EPA) health risk assessment method was applied. Reference doses were calculated from the World Health Organization (WHO) guidelines, South African National Ambient Air Quality Standards (NAAQS), and US EPA reference concentrations. Despite relatively moderate levels of PM2.5 the health risks were substantial, especially for infants and children. The average annual PM2.5 concentration was 11 µg/m3, which is above WHO guidelines, but below South African NAAQS. Adults were exposed to health risks from PM2.5 during May to October, whereas infants and children were exposed to risk throughout the year. Particle-bound nickel posed both non-cancer and cancer risks. We conclude that PM2.5 poses health risks in Thohoyandou, despite levels being compliant with yearly South African NAAQS. The results indicate that air quality standards need to be tightened and PM2.5 levels lowered in South Africa.

Highlights

Published: 2 February 2021Particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5 ) in ambient air is the largest environmental cause of morbidity and premature mortality, causing an estimated 2.9 million premature deaths globally in 2017 [1]
During the study period the 24-h World Health Organization (WHO) guideline of 25 μg ⁄m3 was exceeded in nine samples, but the 24-h South African national ambient air quality standards (NAAQS) of 40 μg/m3 was not exceeded at any time
The results of this study indicate that PM2.5 ambient air pollution in Thohoyandou, despite levels being seemingly reassuring in the South African context, could have substantial adverse effects on health of the population in Thohoyandou

Summary

Introduction

Published: 2 February 2021Particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5 ) in ambient air is the largest environmental cause of morbidity and premature mortality, causing an estimated 2.9 million premature deaths globally in 2017 [1]. There has emerged substantial epidemiological evidence for an association between PM2.5 exposure and all-cause, cardiopulmonary and lung cancer mortality, as well as a variety of noncommunicable diseases, such as cardiovascular, respiratory, and metabolic diseases [2,3]. Less surveillance and fewer preventative health care services, the burden of disease caused by PM2.5 disproportionately affects populations in low- and middle-income countries, and especially vulnerable groups such as pregnant women, infants, and young children [4]. Children and infants have immature physiological system, higher inhalation rate [5,6,7] and larger lung surface area in relation to body weight, which puts them at higher risk to adverse health effects due to ambient air pollution [8].

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