Rapid health risk assessment of discharge of tailings water containing elevated level of arsenic and other metals

摘要

The mine waste water treatment plant was vandalized in a gold mine located in Honiara of the Solomon Islands. With the wet season fast approaching there was a risk the tailings water containing elevated level of arsenic and other metals might spill into the river system downstream. A rapid risk assessment was conducted by testing potential toxicity of mine water against river water samples obtained from both upstream and downstream of the designated discharge point. Three cell-based bioanalytical in vitro assays were employed for the comparative toxicity evaluation. The test results supported a controlled discharge of the tailings water into the river in order to avoid a potential disastrous event which might occur during the big wet season. The short-term discharge plan was allowed to be implemented until a more sustainable waste water treatment plant could be restored.