Personal Exposure to Fine Particles (PM2.5) in Northwest Africa: Case of the Urban City of Bamako in Mali

Abstract

Personal exposure to particulate matter (PM) from anthropogenic activities is a major concern in African countries, including Mali. However, knowledge of particulates is scant. This study was undertaken to characterize personal exposure to PM2.5 microns or less in diameter (PM2.5) in the city of Bamako in Mali. The exposure to PM2.5, through daily activities was observed from September 2020 to February 2021. Participants wore palm-sized optical PM2.5 sensors on their chest during their daily activities. The exposure levels in four different groups of residents were investigated in relation to their daily activities. The variation in PM2.5 concentration was measured during different activities in different microenvironments, and the main sources of exposure were identified. The highest average 10 min concentrations were observed at home and in bedrooms, while the participants were using specific products typically used in Africa, Asia, and South America that included insecticides (IST; 999 µg/m3) and incense (ICS; 145 µg/m3), followed by traffic (216 µg/m3) and cooking (150 µg/m3). The lowest average 10 min concentrations were also observed in the same microenvironment lacking IST or ICS (≤14 µg/m3). With no use of specific products, office workers and students were the least exposed, and drivers and cooks were the most exposed. The concentrations are up to 7.5 and 3 times higher than the World Health Organization’s yearly and daily recommended exposure levels, respectively, indicating the need to promptly elaborate and apply effective mitigation strategies to improve air quality and protect public health. This study highlights the importance of indoor air pollution sources related to culture and confirms previous studies on urban outdoor air pollution sources, especially in developing countries. The findings could be applied to cities other than Bamako, as similar practices and lifestyles are common in different cultures.

Investigation of the Geometric Characteristics of Inhalable Particles Emitted from the Process of Grinding Dental Restorations

“…Among the basic parameters that directly affect the level of influence on humans and technical systems are the shape, size, and dimensions of particles, alongside the chemical composition of particulate matter. The behaviour, deposition, and fate of each particle after entering the human respiratory system depend on their natures and the specified parameters [4][5][6]. Based on this, we can conclude that the importance of measuring particle size and shape distribution lies in the fact that the properties of dispersed materials depend on the uniformity of their distribution.…”

Climate, Urbanization and Environmental Pollution in West Africa

“…In addition to vehicular emission and other sources already mentioned, Sahelian dust is a major contributor to air pollution in the high-latitude Sahel countries such as Mali, Mauritania, Burkina Faso and, to a lesser extent, Senegal (see Table 1) ( [45][46][47][48][49][50][51][52][53]). Studies also shown that aerosols and other suspended particulates tend to vary seasonally across the West African region, albeit with more concentrations in the harmattan/dry periods than the wet season [48][49][50][51][52] (not reflected in Table 1). However, the pollution level also has a highly significant spatial distribution across the sub-region.…”

“…However, the pollution level also has a highly significant spatial distribution across the sub-region. Studies also shown that aerosols and other suspended particulates tend to vary seasonally across the West African region, albeit with more concentrations in the harmattan/dry periods than the wet season [48][49][50][51][52] (not reflected in Table 1). However, the pollution level also has a highly significant spatial distribution across the sub-region.…”

Temporal variability and regional influences of PM2.5 in the West African cities of Abidjan (Côte d'Ivoire) and Accra (Ghana)

“…Some of these studies have highlighted the oxidative and inammatory effect of PM 2.5 aerosol on human bronchial epithelial cells. [6][7][8][9][10][11][12] The cardiovascular health effects have also been evaluated in Accra. 13 The PM 2.5 data required for these studies were obtained from photometric measurements 14,15 and from modelling or eld campaign observations.…”