Malawi’s commercial city, Blantyre, is one of the 10 cities that have been negatively affected by car air pollution in the world, exposing residents to preventable death and economic losses, findings of a journal which Environment International publishes show.
Other cities highlighted in the report are Dhaka (Bangladesh), Chennai (India), Guangzhou (China), Medellín (Colombia), São Paulo (Brazil), Cairo (Egypt), Sulaymaniyah (Iraq) Addis Ababa (Ethiopia) and Dar-es-Salaam (Tanzania).
The article, titled ‘Potential Health Risks Due to In-air Aerosol Exposure Across Ten Global Cities’ and published on June 15 2021, points out that exposure to airborne fine particulate matters is one of the top 10 environmental health risk factors globally.
The study—aimed to assess the relationship between air pollution levels and socio-economic indicators, fuel prices, city-specific gross domestic product (GDP), road density, the value of statistical life, health burden and economic losses resulting from exposure to fine particulate matter during car journeys in 10 cities— indicated that Blantyre City displayed higher Particulate Matter (PM) concentrations of carbon monoxide, nitrogen dioxide and sulphur dioxide and disproportionately high inhaled doses for residents.
“Carbon monoxide levels—2.5 micrograms per 3 cubic metres—was below the Malawian limit value of 10.3 micrograms per 3 cubic metres while nitrogen dioxide is at 4.0 micrograms per 3 cubic metre and sulphur dioxide stands at 8.6 micrograms per 3 cubic metres [and] were significantly higher.
“Lower GDP was found to be associated with higher economic losses due to health burdens caused by air pollution in most cities, indicating a socio-economic discrepancy. This assessment of health and socio-economic parameters associated with in-car PM2.5 exposure highlights the importance of implementing plausible solutions to make a positive impact on peoples’ lives in these cities,” the article reads.
One of the researchers, who is also Professor of Epidemic and Public Health at Kamuzu University of Health Sciences, Adamson Muula, said these are dangerous gases, adding that the effects of carbon monoxide are acute and felt within the time of exposure.
“People may feel headache, dizziness, weakness, nausea and even vomit. If one is exposed long-term, brain damage may occur. In terms of nitrogen dioxide and sulphur dioxide, these two gases may cause airway sensitivity and irritation. People exposed to these gases are more prone to develop asthma and, for those with asthma, their symptoms can be made worse. The breathing problems can be troubling, leading to hospitalisation and sometimes death,” he said.
The article further notes that car microenvironments significantly contribute to the daily pollution exposure of commuters.
The study says the largest health burden related to in-car PM2.5 exposure was estimated for Dar-es-Salam (81.6 ± 39.3 mg m 3), Blantyre (82.9 ± 44.0) and Dhaka (62.3 ± 32.0) with deaths per 100,000 of the car commuting population per year of 1.11.
Muula said finding solutions to the problem required a holistic approach.
“Reducing the number of vehicles on the roads is one such solution. But how do we do that? We can introduce a bus system, but much of this is easier said than done. Promoting green neighbourhoods also improves air quality. As long as we do not discuss these matters, the worse the problems will become,” he said.