Revealing the societal value of quality urban air monitoring in low resource environments

Researchers at The University of Manchester have helped to fill the gap in air quality data in West Africa using affordable and reliable calibrated sensors. The study led by Dr Ejohwomu, known as SQUARE, examined urban spatial and temporal variations, including seasonal effects over the course of two years. It has enhanced awareness and understanding of air pollution, crucial for environmental and public health management.

Gathering data to inform air pollution policies

Globally, pollution causes more than nine million deaths every year and more than 90% of these occur in low-resource and middle-resource countries. Only a small number of these countries have devoted resources to pollution control. Sub-Sahara Africa is estimated to have one ground level air quality monitor per 15.9 million inhabitants, and in West Africa, only three countries have carried out any air quality monitoring and only at intervals. Acquiring and evaluating air quality data in West Africa is essential in enacting policies to minimise the effects.  

Using robust, calibrated and relatively low-cost sensors, we acquired detailed air quality data in the region over a period of two years. Through this we identified the spatial and temporal variations in air quality, as well as the seasonal effects, sources of pollutants and nature of their dispersions.

The data revealed low air quality in the region over sustained periods of the year. The mean concentrations of five of six air pollutants studied exceeded the World Health Organization (WHO) recommended Air Quality Guidelines levels for a whole year. During the dry season, the mean monthly values for all the air pollutants are higher compared to the rainy season as there is a reduction of the wet removal of particles and a larger contribution of movement of pollutants from the north-eastern desert regions. Fine particles of less than 2.5 microns in size, such as those from combustion source, contributed significantly to the particulate matter concentrations.

Evaluating societal awareness of poor air quality

Further studies were carried out to evaluate people and stakeholder awareness of the effects of poor air quality. While people understand that poor air quality isn’t good for them, there is lack of awareness of the serious implications on human and plant health, along with the measures that are required to tackle the issue.

In collaboration with the Nigerian Society of Engineers (NSE) and the Nigerian Institute of Environment Engineers (NIEE), we held two workshops to increase awareness of air pollution in Nigeria. Participants included students from secondary schools and universities, the Nigeria Heart Foundation, and ministries such as the Lagos State Environment Protection Agency. The events have also been documented in national newspapers. 

A major obstacle to mitigating poor air quality in the region is the lack of air quality sensors as obtaining them is expensive in low resource regions. Our work has focused on training and mentoring groups of students, academics, and people in industry on designing, manufacturing, and implementing low-cost sensors across the regions.

These sessions have been running for two years and have culminated in an annual workshop where the air quality data from the sensors from the various groups is presented. This aspect of our work has helped us to mentor early career researchers, increase awareness of air pollution monitoring and enable sensors to be deployed in new areas.