Mercury pollution associated with illegal mining is extending beyond mining sites into water bodies and other parts of the environment, raising concerns about the safety of water sources and food consumed by communities across Ghana.
Presenting research findings at the Ambassador’s Water Experts Program Symposium in Accra, Dr Pennante Bruce-Vanderpuije of the Council for Scientific and Industrial Research (CSIR) highlighted the spread of mercury contamination across different environmental systems.
“Wherever there is galamsey, mercury flows,” she said, describing the connection between illegal mining and the spread of mercury into surrounding ecosystems.
Research conducted across mining-affected areas has identified mercury contamination in rivers, sediments, groundwater, soil, crops and fish. Dr Bruce-Vanderpuije said about 37 studies had been undertaken on heavy-metal contamination, providing evidence of the scale and complexity of the problem.
A nationwide survey of rivers affected by illegal mining across eight regions found total mercury concentrations above recommended guidelines at several sampling locations. The findings also confirmed mercury contamination in water sources across several mining-affected areas.
The contamination of groundwater presents a further concern because boreholes remain an important source of drinking water for many communities
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A study in the Lower Pra River Basin, which examined 65 boreholes, reportedly found that 88 per cent contained mercury above Ghana’s permissible standard of 0.001 milligrams per litre. Another study conducted in northern Ghana in 2015 recorded concentrations ranging from 0.04 to 0.13 milligrams per litre in borehole water.
The findings raise questions about the extent to which communities relying on these sources may be exposed to mercury over time.
Professor Daniel Nukpezah, who discussed mercury exposure and public-health surveillance, explained that the metal can accumulate in aquatic organisms and move through the food chain. He highlighted methylmercury in fish as a particular concern because of the risks associated with human consumption.
The research points to a challenge that goes beyond detecting contamination in water bodies. Environmental monitoring must also establish whether mercury is entering the human body and contributing to health risks.
Professor Nukpezah called for a national surveillance framework that connects environmental sampling with human biomonitoring. Such a system would bring together testing of water, sediment, soil and fish with the examination of human samples, including hair, blood and urine.
He also identified gaps in the way environmental and health data are collected and used. Research is often conducted through individual projects, with findings not routinely connected to public-health decisions or long-term monitoring.
The symposium highlighted the need for stronger coordination among research institutions, environmental regulators, health authorities and local communities. Standardised laboratory procedures and sustained monitoring would also help ensure that findings from different studies can be compared and used to guide policy.
The discussions also highlighted the need to communicate the risks to communities that rely on rivers, boreholes and fish for their daily needs.
The evidence presented suggests that addressing mercury pollution will require more than enforcement against illegal mining. It will also require a coordinated system capable of tracking contamination across the environment, identifying exposure among affected populations and informing timely public-health interventions.
