Abstract Description

Airborne dust is an important vector for both chemical and microbial exposures, with growing evidence of risks to environmental and human health. To assess these risks, we investigated dust from multiple environments around a major industrial hub on South Africa’s west coast, including the Industrial Development Zone (IDZ), the port and steel-producing area of Saldanha, the informal settlement of Naphakade, inland towns (Vredenburg and Malmesbury), a suburban site (Stellenbosch), and a nature reserve. Dust samples were collected from multiple locations and analyzed for elemental composition using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Microbial abundance was quantified with qPCR targeting the 16S rRNA gene, and metagenomic sequencing is underway to assess microbial community structure, functional potential, and antimicrobial resistance genes. ICP-MS revealed substantial enrichment of Fe, Ca, Ba, Mn, Cu, Zn, and Ni in the IDZ, Saldanha, and Naphakade relative to inland and suburban sites. These metals, many classified as potentially toxic, raise concerns about respiratory exposure and long-term health effects. Microbial qPCR showed the highest 16S rRNA gene copy numbers in the IDZ and Saldanha, moderate levels in Stellenbosch and Malmesbury, and the lowest in Vredenburg, indicating strong links between industrial activity, settlement density, and microbial proliferation. The combined enrichment of toxic metals and microbial loads in dust highlights significant environmental health risks around industrial and settlement areas. Ongoing metagenomic analyses will provide deeper insights into microbial hazards, strengthening One Health approaches to mitigate exposure in vulnerable populations.