Personal PM2.5 Exposure Monitoring of Informal Cooking Vendors at Indoor and Outdoor Markets in Johannesburg, South Africa

Abstract

Air pollutants of concern include particulate matter (PM) in fine size fractions. Thus far, a few studies have been conducted to study the adverse health effects of environmental and occupational air pollutants among informal vendors in big cities in South Africa. Informal vendors in these cities may experience higher exposure to road dust, cooking fumes, and air pollution. This exposure assessment was part of a health risk assessment study of vendors. The objective of this exposure assessment was to determine the differences between outdoor and indoor informal vendors’ personal PM2.5 exposures during trading hours. A walkthrough survey was conducted to map the homogeneous exposure groups (HEGs) at vendor markets for sampling purposes, and one market was selected from each of the three identified HEGs. Twenty-five informal cooked food vendors from both indoor (inside buildings) and outdoor (street or roadside vendors) markets in the inner city of Johannesburg, South Africa, participated in the study. HEG-1 were vendors from indoor stalls who used electricity and gas for cooking (10 vendors), HEG-2 was composed of informal outdoor vendors at a fenced site market who used open fire for cooking (10 vendors), and HEG-3 (5 vendors) were roadside vendors who used gas for cooking. Cooking vendors from outdoor markets recorded higher TWA concentrations than indoor market vendors. The vendors’ PM2.5 concentrations ranged from <0.01 mg/m3/m3 to 16 mg/m3. The mean concentrations of PM2.5 were found to be 0.122 mg/m3, 1.75 mg/m3, and 0.184 mg/m3 for HEG-1, HEG-2, and HEG-3, respectively. HEG-2 recorded the highest PM2.5 TWA concentrations, followed by HEG-3 and HEG-3. The highest concentration of 16 mg/m3 from HEG-2 was three times higher than the South African occupational exposure limit. The findings point to the need for further research into the health risks associated with outdoor cooking vendors, particularly those who utilize open fires.

Strengthening Urban Informal Trading and Improving the Health of Vendors: An Integrated Management Model

“…The current South African literature on the occupational settings of informal vending and conceptual models (and the findings of the recent study) was used for the development of this model ( Figure 1 ), thus including the requirements of a healthy workplace model by the WHO. The majority of the findings in the recent study were published [ 12 , 13 , 14 , 15 , 16 ] excluding the content of the model and recommendations.…”

“…For the air pollution exposure assessment, five air pollutants were examined: particulate matter (PM 2.5 ), Nitrogen Dioxide (NO 2 ), Sulphur Dioxide (SO 2 ), Carbon Monoxide (CO), and Carbon Dioxide (CO 2 ) [ 15 , 16 ]. The Radiello passive sampler was used to detect NO 2 and SO 2 , an EXTECH air quality monitor for CO and CO 2 , and the GilAir pump to collect samples for ambient PM 2.5 concentrations.…”

“…The Radiello passive sampler was used to detect NO 2 and SO 2 , an EXTECH air quality monitor for CO and CO 2 , and the GilAir pump to collect samples for ambient PM 2.5 concentrations. A total of 41 air samples were taken from the indoor and outdoor market: eight PM 2.5 area samples, twenty-five personal PM 2.5 samples, and two samples of NO 2 , SO 2 , CO, and CO 2 [ 15 , 16 ]. The air sampling program was conducted on the same day in the winter season to establish each pollutant exposure during the respiratory health risk season according to the literature due to the weather conditions.…”