Particulate matter pollution at traffic hotspots of Accra: levels, exposure experiences of street traders, and associated respiratory and cardiovascular symptoms

Abstract

BACKGROUND AND AIM: There is limited studies on health effects of street trading in spite of common knowledge that individuals engaged in the trade are exposed to high levels of traffic-related air pollution per their mode of operation, and also the fact that the venture is a dominant occupation in cities of Sub-Saharan Africa and other developing regions. We characterized particulate matter (PM) pollution levels at traffic hotspots of Accra, Ghana during the dry and wet seasons, and assessed exposure experiences of street traders. METHODS: A cross-sectional study was conducted among 236 street traders operating along six selected traffic routes of Accra and a comparison group of 186 office workers. PurpleAir PA-II monitors was used to measure PM levels at the selected traffic routes. We estimated annual PM exposure of street traders using assigned seasonal PM2.5 and PM10 levels, and information collected in a structured questionnaire on activity patterns of the street traders. RESULTS:PM levels at Accra traffic hotspots were high in both seasons. 1ug/m3 increase in PM2.5 exposure increased respiratory, cardiovascular and overall symptoms by a score of 0.0001 (95% CI: 0.00004, 0.0002), 0.00008 (95% CI: 0.00002, 0.0001) and 0.0002 (95% CI: 0.00008, 0.0003), respectively. Compared to office workers, high PM2.5 exposure among street traders was statistically associated with increased odds of coughing, catarrh, sneezing, rapid heart beating, sharp chest pains, irregular heartbeat, fainting spells, headaches and dizziness. Low and medium PM2.5 exposure was also statistically associated with increased odds of dermatitis and rapid heart beating, and sharp chest pains, respectively. CONCLUSIONS:We found consistent evidence that PM2.5 exposure among street traders increases occurrence of self-reported respiratory and cardiovascular symptoms. We also provide indicative measurements of PM levels at traffic hotspots of a rapidly growing SSA city with heavy vehicular traffic and yet, limited air quality monitoring capacity. KEYWORDS: Street trader, Traffic-related air pollution, Particulate matter, Respiratory symptoms, Cardiovascular symptoms