The microbial and chemical risk analysis of drinking water in a small island, Spermonde Archipelago

Coastal areas face greater risk in terms of health and the environment. They are the most vulnerable to impacts resulting from climate change. Coastal areas with higher population density also have more environmental problems, such as natural disasters. Environmental health risks from chemicals and microbes continue threatening people living on small islands. Therefore, this study aims to: 1) conduct a chemical risk analysis of heavy metals Pb, Cr(VI), and Ni; 2) analyse the microbial risk posed by drinking water consumed daily by people on small islands. A method used to analyse the chemical risk of heavy metals was the environment health risk assessment (EHRA), whereas to analyse the microbial risk in small islands, the quantitative microbial risk assessment (QMRA) was used. The results showed that the concentration of heavy metals in drinking water was <0.0012 mg∙dm–3 for Pb, <0.01 mg∙dm–3 for Cr(VI), and <0.0019 mg∙dm–3 for Ni. The three heavy metals showed worrying results. Assessment and obtained risk quotient were less than one (RQ < 1) in all samples. Meanwhile, the microbial analysis found Escherichia coli, Acinetobacter calcoaceticus, Enterobacter sp ., and Citrobacter sp ., with risk characterised from low to high. Risk management is needed to control environmental health risks posed by heavy metals and the microbiological characteristics of drinking water on the small islands of the Spermonde Archipelago.