Preliminary review of mine air pollution in Zambia

Abstract

Zambia is endowed with mineral wealth that includes copper, cobalt, gold, nickel, lead, silver, uranium, zinc, and numerous precious and semi-precious stones. Mining activities are predominantly found on the Copperbelt and North-Western Provinces, although these minerals are dotted all over the country. Copper mining in Zambia dates back to the 1900s and this period witnessed massive investment in mine development with concomitant increase in support facilities including building of new towns, roads and other commercial infrastructure. The mining sector has therefore evoked considerable national attention for its potential to contribute towards economic growth, job creation and poverty alleviation. However, mining and mineral processing by its very nature comes with environmental costs and the effects can continue long after the mining has stopped. The aim of this article was to review the relevant publications on the impacts of air pollution arising from mining operations with respect to human health, plants, animals and infrastructure and synthesize the views of researchers and suggest any additional research required to inform policy and remedial actions. This review has revealed that there is a paucity of studies on mining-related air pollution in Zambia. The main identified air pollutants were SO2 and particulate matter (PM), both fine and ultrafine (PM10, PM5.0, PM2.5 and PM0.1). The main sources of these pollutants were flue gases from smelter operations and dusts within the mines and those blown from both operational and abandoned waste rock, overburden and tailings dump sites. The identified occupational diseases for miners in Zambia were silicosis and tuberculosis, which have been compounded by the prevalence of HIV/AIDS. In the hotspot townships of air-borne exposures from smelter emissions in Mufulira, ambient air SO2 levels exceeded the ‘safe’ limits of international and National standards. Moreover, the top soils have turned acidic and have become laden with heavy metals (Pb, Zn, Cu, Co and Fe). These metals were also found in the dust deposited on leaves of crops. There were also visual signs of impaired vegetation cover and corroded housing infrastructure in the affected areas. In the vicinity of the abandoned Pb–Zn mine in Kabwe, the soils have been contaminated by heavy metals and pathological lead poisoning of children and wild mammals have occurred. The review article has further examined study gaps and suggested areas that need further research in order to address the challenges arising from the legacy of copper mining in Zambia. These include comprehensive PM characterization from mining environments, extent of occupation exposure to air pollutants, efficiency and efficacy of airborne control technologies, health risks and epidemiological studies in mining towns, and the influence of exposure to PM on pulmonary tuberculosis and HIV/aids among miners.