The relationship among PM2.5, traffic emissions, and socioeconomic status: Evidence from Gabon using low-cost, portable air quality monitors

A problem in many cities in sub-Saharan Africa (SSA) is the absence of air quality monitoring due to the high costs and technical expertise often required. We circumvent these issues by using low-cost, low-maintenance, portable air quality monitors, specifically the Dylos 1700, to observe potential pollution sources and urban PM2.5 levels in Gabon, a country in the region of Central Africa where no air quality data existed prior. Our study occurred during the dry season between June 29 and July 24, 2015 in Libreville and Port Gentil, the two largest cities in Gabon. We collaborate with local students and government employees to gather data on PM2.5 and pollution sources in a high- and low-income neighborhood and explore differences in exposure by socioeconomic status. Due to possible biases from using the Dylos 1700, we are careful to interpret the quantitative size of these effects or differences and instead focus on their qualitative implications. We find worse air quality levels in the low-income neighborhood and substantial neighborhood variation in PM2.5 associated with traffic in low-income areas, which is in agreement with previous work in SSA. Finally, we provide anecdotal evidence that our monitoring approach and resulting data initiated interest and conversations around PM2.5, its sources and impacts at the local and national level. This suggests that low-cost pollution monitors could be a reasonable intermediary solution and educational tool to collecting air quality information in low- and middle-income countries in SSA where no data exist.