Open waste burning causes fast and sharp changes in particulate concentrations in peripheral neighborhoods

The open burning of municipal solid waste (MSW) -frequently observed in developing countries- emits harmful pollutants, including fine particulate matter (PM_2.5) and black carbon (BC), and deteriorates the air quality in urban areas. This work reports on PM_2.5 and BC measurements (fixed and mobile) conducted in a residential neighborhood on the outskirts of a Brazilian city (Londrina), complemented by a public opinion survey to understand the open burning in the context of waste management. Mean (± standard deviation) BC concentration (1.48 ± 1.40 μg m^-3) at the fixed sites of the neighborhood was lower than downtown, while PM_2.5 (9.68 ± 8.40 μg m^-3) concentration was higher. The mobile monitoring showed higher mean PM_2.5 concentrations but lower BC/PM_2.5 ratios than downtown, with sharp and fast spikes (up to 317.87 and 565.21 μg m^-3 for BC and PM_2.5, respectively). The large spatial heterogeneity of particulate concentrations was associated with the occurrence of MSW burning events. Our observations were verified by the survey respondents who identified poor waste management practices: garbage in streets, waste burning, and illegal dump sites. Even though the area has a municipal waste collection service, the majority of the respondents (87%) had seen waste burning close to their homes on a weekly basis, and think that people burn waste out of habit (54%) and because they are not patient to wait for the collection services (67%). To combat this illegal practice, we suggest raising the public awareness through campaigns at local level, adopting education initiatives and economic incentives for correct waste segregation, and enforcing regular inspection of burning events by the authorities. Our research method proved to be a time- and cost-effective approach for mapping particulate concentrations and for identifying undesirable waste practices, and could be effectively applied to other global cities.