Thesis (MSc) - Cyprus International University. Institute of Graduate Studies and Research Environmental Sciences Department

Includes bibliography (sheets 64-68)

This research endeavor aims to assess the impact of Sierra Mineral Holdings (SL) Ltd (Vimetco)'s bauxite mining activities within the Moyamba districts of Sierra Leone's southern province at the different locations of the mining area, from January 20, 2020, to December 27, 2022. PM2.5 levels were monitored once a month by company personnel across 12 distinct sites to evaluate emissions from various operational areas. Analysis of the dataset indicates heightened PM2.5 concentrations across all sites, notably peaking at Nitti Port Harbour area, which is Stockpile in 2020 with concentration levels reaching 131.5 μg/m3, and in 2021 with PM2.5 concentration level of 62.3 μg/m3. These elevations are attributed to bauxite ore exportation and temporary storage. Peak concentration levels in 2022 is at Volvo Garage and CAT Garage, reaching 91.4 μg/m3 respectively. Comparisons with World Health Organization (WHO) standards reveal an increased risk of adverse health effects, particularly among mine workers. Monthly data show fluctuations influenced by seasonal and economic factors, with peak levels observed in February 2021 and 2022, reaching 108.9 μg/m3 and 93.5 μg/m3, respectively. Conversely, in June 2020, a concentration of 90.2 μg/m3 was recorded due to heightened commercial bauxite production activities. Despite fluctuations, a persistent trend of elevated PM2.5 concentrations is evident. The Air Quality Index (AQI) was calculated using the concentration levels. In 2020, Nitti Stockpile recorded an AQI of 182, falling within the WHO's "Unhealthy" category. Similarly, in 2021, the AQI for Nitti Stockpile was 107.5, indicating unfavorable air quality. In 2022, AQI results for Volvo Garage and CAT Garage were 146.4 and 138.6, respectively, signifying an unhealthy working environment. The monthly AQI analysis reveals that, in June 2020, an AQI of 151.9 was recorded, also indicating unfavorable conditions. In February 2021 and 2022, AQI values of 167.2 and 154.1, respectively, were recorded, aligning with an "Unhealthy" designation.