Monitoring SO2emission trends and residents’ perceived health risks from PGM smelting at Selous Metallurgical Complex in Zimbabwe

BACKGROUND Persistently high sulphur dioxide (SO2) emissions from platinum group metal (PGM) smelting pose a major threat to communities located around smelters. This paper examined SO2 emission trends, emission regulations and residents' perceived health risks from exposures to such emissions at Selous Metallurgical Complex (SMC) PGM smelting facility in Zimbabwe. METHODS SO2 data from roof monitoring sites at the smelter furnace were aggregated into annual, quarterly and monthly emission trends from 2008 to 2015. The regulatory regime's ability to protect human health from SO2 pollution in communities located around the smelter was examined. Questionnaire responses to perceived health risks from SO2exposure from 40 purposively sampled residents were assessed. The relationships between SO2 emission trends and residents' self-reported health risks from exposure to SO2emissions were explored using STATA version 11. Descriptive statistics were used to illustrate SO2 emission trends and residents' self-reported health risks from exposure to SO2. RESULTS Between 2008 and 2015, annual SO2emissions increased from 7951 to 2500 tonnes. Emissions exceeded the recommended standard limit of 50 mg/Nm3, presenting considerable adverse health risks to local residents. Concerns relating to inefficient environmental impact assessment (EIA) licensing system, poor monitoring and auditing by the environmental management agency, as well as non-deterring SO2emission exceedance penalties were identified as major drivers of emission increase. Thirty-two (80%) of the forty respondents perceived exposure to SO2 emissions as adverse and the cause of their illnesses, with coughing, nasal congestion and shortness of breath the most frequently self-reported symptoms. CONCLUSION A set of legally-binding SO2emission standards supported by stringent EIA licensing arrangements for smelting industries are suggested for development and enforcement to reduce the SO2emission problem. Community participation in SO2emissions monitoring is also proposed as a core part of sustainable environmental management in communities located around smelters.