Toxic metals from galamsey found in vegetables across mining districts – Study

A new study reveals that toxic metals from illegal mining, or galamsey, are contaminating vegetables across mining districts in Ghana, posing a significant health risk to consumers. Researchers Eric Osei Bonsu and his team found cadmium to be the most concerning, with transfer factors above 1.0, indicating that the concentration of cadmium in vegetables could match or surpass that in the soil.

Lead, arsenic, and mercury also exceeded safe limits set by the WHO and FAO, particularly in the Ashanti and Western Regions. At the most contaminated sites, arsenic levels reached up to 200 times the limit, and mercury up to 400 times. The study highlights that in areas where mining sites and vegetable consumption overlap, the cumulative hazard index exceeds 1.0, implying an elevated risk of non-cancer health issues for residents who regularly eat vegetables from these areas.

While chromium transfer into plants remained low, even in soils with high levels, the researchers noted that most studies did not differentiate between the less toxic trivalent and more dangerous hexavalent chromium. To address these issues, the researchers propose targeted monitoring of vegetables, soil, and irrigation water in mining-affected districts, post-harvest washing to reduce surface contamination, and the establishment of agricultural buffer zones around mining sites based on local contamination data.

The review also points out three research gaps: the need to measure chromium and arsenic in their various chemical forms, better modeling of the combined effects of multiple metals, and long-term human biomonitoring to link food contamination with human health impacts.