By Abiose Adelaja Adams

Nigerian experts working in the area of environmental protection have raised fresh concerns about the effect of mercury pollution on the environment and human health in the country.

Speaking to www.icirnigeria.org last week, Oladele Osibanjo, executive director of Basel Convention and Leslie Adogame of Sustainable Research and Action for Environmental Development observed that poor awareness, lack of education about Mercury, and weak regulation all encourage importation of mercury products thus driving pollution.

Mercury is a heavy metal that exists in liquid form at room temperature. It is highly toxic and can cause brain and nervous system damage.

“Mercury has been banned in most countries, but still creeps into Africa (including Nigeria) as can be seen in the use of mercury thermometers, amalgam used in dentistry (for filling hole in the tooth),” explained Osibanjo, whose organisation works on the elimination of hazardous wastes.

Mercury is also a major ingredient in skin lightening creams. In 2011, the World Health Organization, WHO, reported that 77 percent of Nigerian women use skin lightening cream, while in Mali, Senegal, South Africa and Togo, the percentage of women who use skin lightening creams or soaps are 25, 27, 35 and 59 respectively.

WHO says that mercury in soaps, creams and other cosmetic products, when discharged into waste water enters the environment where it becomes methylated and enters the food-chain as the highly toxic methylmercury in fish.

Pregnant women who consume fish containing methylmercury transfer the mercury to their fetuses, which can later result in neuro-developmental deficits in the children.

Leslie Adogame, of Sustainable Research and Action for Environmental Development, whose organisation has been researching the the trend of toxic waste disposals from hospitals noted that although mercury thermometers are still used in a number of hospitals and medical facilities, “we found that most hospitals on their own are shifting to alternatives which are readily available even in Nigeria. Such alternatives are digital thermometers,” (Like the gun -like thermometers used during the Ebola outbreak in Nigeria).

Nevertheless, Adogame is worry about the use of mercury in dental practice in Nigeria.

“Dental mercury accounts for 10 per cent of annual global mercury consumption and 260-340 metric tons of mercury pollution around the world each year,” he said.

Dental amalgam or silver fillings (because of their silver-like appearance) is a dental filling material used to fill cavities caused by tooth decay. It is a mixture of metals, consisting of liquid mercury and a powdered alloy composed of silver, tin, and copper.

The demand for dental amalgam (and, thus, mercury) is huge because worldwide, 60-90 per cent of school children and nearly 100 percent of adults have dental cavities, which they always want to fill.

Explaining the dangers, Adogame said, “dental mercury enters the environment via many release pathways, polluting air via cremation, dental clinic releases, and sewage sludge incineration; water via human waste and dental clinic releases to septic systems and municipal wastewater; and soil via landfills, burials, and fertilizer.”

It is scientifically known that once dental mercury is in the environment, bacteria in the soil and sediments may convert it to methylmercury, a highly toxic form that builds up in fish, shellfish and animals that eat fish, thereby making fish and shellfish the main sources of methylmercury exposure to humans.

Furthermore, he noted that uncontrolled mercury vapours are a major occupational risk in the dental workplace, especially to young women of childbearing age.

Nigeria is a signatory to the Minamata Convention to control and reduce use of mercury, but the country’s environmental protection agency, National Environmental Standard Regulation Enforcement Agency, NESREA, has not done much work on that, contends Osibanjo.

Both environmentalists who are currently attending the week-long (Nov 3rd-7th) Mercury Negotiations in Bangkok, Thailand, advocate for a mercury-free Nigeria and call upon African countries to impress upon the exporting nations and funding organisations to halt the toxic trade of dental mercury into Africa.

Speaking on his expectations for the conference, Adogame said one main trust of the Mercury Convention which will soon become binding on all nations as parties to the treaty is to officially introduce a replacement for amalgam in the world for a mecury-free dentistry practice.