Airborne mercury levels in some small-scale mining communities across Ghana have risen to alarming levels, more than 150 times higher than global safety limits, according to a national study by Pure Earth and the Environmental Protection Agency.
The Mercury and Other Heavy Metals Impact Assessment, conducted between August 2024 and September 2025, covered the Ashanti, Western, Eastern, Savannah, Central and Western North Regions, and described the situation as an escalating environmental and public health emergency.
At Wassa Kayianko in the Western Region, mercury vapour averaged 1.84 microgrammes per cubic metre, surpassing the global safety limit of 1 microgramme per cubic metre by 84 percent. The highest reading recorded was 150.2 microgrammes per cubic metre, indicating extreme exposure risks for residents.
Dr. Esmond Wisdom Quansah, Country Director of Pure Earth, warned that gaseous mercury poses immediate danger because it is directly inhaled into the body, stating, “Mercury in its gaseous state is more deadly, the effects can be instantaneous.”
Water samples from Lake Amponsah in Western North, Asiakwa in Eastern Region and Nyamebekyere in Western Region contained mercury levels up to 0.01 milligrammes per litre, ten times Ghana’s national limit. Soil samples from Konongo Zongo in Ashanti Region contained an average of 56.4 parts per million of mercury, exceeding the global soil guideline of 10 parts per million.
The highest soil contamination reached 1,342 parts per million at Konongo Zongo, representing more than 130 times the internationally recognized safe limit. Other sites including Prestea, Dakrupe and Konongo Odumase also showed contamination well above permissible levels.
Food crops such as spinach and tomatoes recorded mercury levels between 0.01 milligrammes per kilogramme and 4 milligrammes per kilogramme, within World Health Organization and Food and Agriculture Organization limits. However, Dr. Quansah cautioned that without testing for methylmercury, the most toxic form, the real dietary risk may be underestimated.
The study also found lead and arsenic contamination threatening both soil and water quality. Water from Asiakwa contained 0.47 milligrammes per litre of lead, far exceeding Ghana’s drinking water limit of 0.01 milligrammes per litre. Fish from Konongo Zongo and Akwaboso in Central Region contained lead concentrations up to 2.8 milligrammes per kilogramme, surpassing the World Health Organization and Food and Agriculture Organization guideline of 0.3 milligrammes per kilogramme.
Soil arsenic levels reached 10,060 parts per million in some locations, more than 40 times the international guideline of 25 parts per million. Water samples from Konongo Odumase, Nyamebekyere and Ankobrah showed arsenic concentrations up to 3.3 milligrammes per litre, far above the World Health Organization limit of 0.01 milligrammes per litre.
Dr. Quansah warned that exposure to mercury, lead and arsenic can cause intelligence quotient loss in children, neurological damage, reproductive complications, kidney and liver failure and even death. He cited findings by Pure Earth and United Nations Children’s Fund linking chronic lead exposure to miscarriages and stillbirths.
The project is funded by the United Kingdom government through The Evident Fund and aims to uncover actionable insights and sustainable solutions to safeguard ecosystems and communities affected by mercury pollution.
Dr. Quansah stressed that the report’s aim is not to create fear but rather urge authorities to act swiftly. While acknowledging ongoing government efforts, he called for faster policy reforms and stronger enforcement. He also encouraged the adoption of mercury-free mining technologies already implemented successfully in Peru, Colombia, Indonesia and the Philippines.
