For foetuses, infants and children, the primary health effect of mercury is impaired neurological development. Mercury exposure in the womb, which can result from a pregnant woman's consumption of fish that contain mercury, can adversely affect a baby's growing brain and nervous system. Impacts on thinking, memory, attention, language, and fine motor and visual spatial skills have been seen in children exposed to mercury in the womb.
Impairment of the peripheral vision; disturbances in sensations ("pins and needles" feelings, usually in the hands, feet, and around the mouth); lack of coordination of movements; impairment of speech, hearing, walking; and muscle weakness.
Mercury primarily causes health effects when it is breathed as a vapour where it can be absorbed through the lungs. Such exposure can occur when mercury is spilled or products that contain mercury break and expose mercury to the air, particularly in warm or poorly-ventilated indoor spaces.
Symptoms include tremors; emotional changes (e.g., mood swings, irritability, nervousness, excessive shyness); insomnia; neuromuscular changes (such as weakness, muscle atrophy, twitching); headaches; disturbances in sensations; changes in nerve responses; performance deficits on tests of cognitive function. At higher exposures there may be kidney effects, respiratory failure and death on animals
Exposure of animals to methylmercury affects the immune system, alters genetic and enzyme systems, and damages the nervous system.
What is Zimbabwe doing about mercury?
With the assistance of the United Nation environment, Zimbabwe has undertaken a research to collect scientific data and evidence of the impacts of mercury for use by policy makers. The research will produce a Country Diagnostic Report with current knowledge about the status of mercury contamination and environmental and health risks to miners and their families in artisanal gold mining hot spots.
The findings will inform the country's next national action plan , the review of policies, legislation, regulations and standards as well as review institutional responsibilities of various ministries, Departments and Government Agencies in regulating mercury chain of custody from source to end user in Zimbabwe.
It is of great importance that interested and affected parties make themselves aware of the implications of this Instrument so as ensure that preparations are made that insure voluntary compliance in a bid to protect human health and the environment from the adverse effects of mercury.
What does the law say about mercury?
Environmental Management Act Cap (20:27) as read with S.I 12 of 2007 Hazardous Substances, Pesticides and Toxic Substances Regulations state that, any person who imports, transports, stores or sells any hazardous substance must have a license for each purpose. Further to this the laws implores all stakeholders involved in the management of hazardous substances like mercury to ensure that they take all necessary precautions for the protection of the environment, prevention of pollution and land degradation.
What are the mercury alternatives?
As a country we should be working at embracing mercury alternatives such as gravity concentration coupled with the use of borax which proved to be equally efficient according to the findings of the Global Mercury Project which ran from 2007 to 2012 in Kadoma.
There are also new emerging technologies which involve the use of gold leaching agents.
There is need also for continuous research so as to identify mercury free technologies that are best suited for our Zimbabwean set up.