Mining communities in Kenya lose between Sh174 and Sh342 billion in earning potential every year due to mercury contamination, according to a new study published in The Journal of Environmental Management.
The report is the first peer-reviewed analysis to estimate economic losses due to IQ damage from mercury pollution in Kenya and 14 other countries.
Griffins Ochieng, the Programmes Coordinator, Centre for Environment Justice and Development (Cejad), says the study gives only a small sample of the extent of the damage that is happening across mining sites in the country.
“The high cost of mercury contamination should trigger actions to address pollution sources in Kenya,” he said.
Researchers from Cejad, a local NGO that aims at promoting environmental justice in the country, participated in the study by collecting hair samples from participants living near small scale gold mines in Masara, in Migori County.
At peak times, more than 20,000 miners work in the area, using mercury to amalgamate gold and then dumping the wastes into rivers that serve as main food sources for the surrounding communities.
“The Minamata Convention [on mercury] needs to be ratified and fully implemented to prevent lost earning potential in Kenya and other communities in the country,” Ochieng says.
Hair samples from 71 per cent of participants from the area had mercury levels greater than 0.58 parts per million, the reference dose standard proposed in light of data suggesting harmful effects of mercury at low levels of exposure.
Levels ranged between .08 parts per million to 13.3 ppm.
Mercury exposure damages the nervous system, kidneys, and cardiovascular system.
Developing organ systems, such as the fetal nervous system, are the most sensitive the toxic effects of mercury, although nearly all organs are vulnerable.
Human exposure to mercury occurs primarily through the consumption of contaminated fish, although rice and direct exposure to mercury vapor can also be sources.
“Mercury is a serious global threat to human health and this study shows that it also imposes additional burdens on the economy.
"That’s why it is critical to monitor sources of mercury pollution to minimize its impacts on people and the environment,” Dr Joe DiGangi, a co-author of the report, says.