Particulate matter pollution in an informal settlement in Nairobi: Using citizen science to make the invisible visible

Sarah E West,Patrick Büker,Mike Ashmore,George Njoroge,Natalie Welden,Cassilde Muhoza,Philip Osano,Jack Makau,Patrick Njoroge,William Apondo

doi:10.1016/j.apgeog.2019.102133

Sarah E West, Patrick Büker + Show 8 more

Open Access

https://doi.org/10.1016/j.apgeog.2019.102133

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Abstract

We used a citizen science approach to explore personal exposure to air pollution of selected informal settlement dwellers in Nairobi, Kenya. This paper presents the methods used, with the aim of informing others who wish to conduct similar work in the future, and some results, including policy impact. We used three interlinked methods: 1) a personal mobile exposure monitoring campaign in which individual workers used Dylos monitors to measure variations in their exposure to fine particulate matter (PM2.5) within the settlement over the course of a day, 2) a questionnaire conducted before and after the monitoring campaign to assess any changes in knowledge or attitude in the wider community, and 3) two workshops, which facilitated the citizen science approach and brought together members of the community, local policy makers and researchers. The three elements of the study provided the local community, policymakers and scientists with new insights into the challenges air pollution poses for human health in such settlements, and opportunities for exploring how to monitor, mitigate and avoid these pollutants using a citizen science approach. We found significant differences in PM2.5 exposure between individual workers that could be partially explained by spatial differences in concentration that we identified within the settlement. Residents of the informal settlement identified a number of sources that might explain these differences in concentration, although many residents perceived air quality to be good both indoors and outdoors. The workshops raised awareness of the issue of air pollution and brought together affected community members and local and national policy makers to discuss air pollution issues in Nairobi's informal settlements. As a result, a new knowledge exchange network, the Kenya Air Quality Network, of policy-makers, researchers and community members was formed with the aim to facilitate the improvement of air quality across Kenya.

Highlights

Outdoor air pollution is a major environment and health issue, and a policy challenge in both developed and developing countries
In low and middle income countries, 98% of cities do not meet these guidelines, whilst in high income countries this falls to 56% (WHO, 2016b), but most monitoring of PM2.5 takes place in high income countries, rather than the low and middle income countries where the problem is worse (Lelieveld et al, 2019). This mismatch between the severity of pollution problem and the degree of monitoring is particu larly marked in Africa (UNEP, 2016, p. 215); the WHO Ambient Air Pollution database only contains data from 39 locations throughout Africa, of which 37 exceed the WHO annual mean guideline, the two exceptions being located in rural Liberia (WHO, 2016b)
This paper describes what we believe is the first study in a major African city to actively engage the community of an informal settlement in monitoring and mapping the air pollution within it, linking this directly to their perception of issues, and to the air pollution policy framework in Nairobi

Summary

Introduction

Outdoor air pollution is a major environment and health issue, and a policy challenge in both developed and developing countries. In low and middle income countries, 98% of cities do not meet these guidelines, whilst in high income countries this falls to 56% (WHO, 2016b), but most monitoring of PM2.5 takes place in high income countries, rather than the low and middle income countries where the problem is worse (Lelieveld et al, 2019). This mismatch between the severity of pollution problem and the degree of monitoring is particu larly marked in Africa This mismatch between the severity of pollution problem and the degree of monitoring is particu larly marked in Africa (UNEP, 2016, p. 215); the WHO Ambient Air Pollution database only contains data from 39 locations throughout Africa, of which 37 exceed the WHO annual mean guideline, the two exceptions being located in rural Liberia (WHO, 2016b)

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