Minister of Health, Professor Christian Onyebuchi Chukwu
By Femi Williams
Within the next few days in Geneva, Switzerland, a communiqué will be issued from an important conference by United Nations Environmental Programme (UNEP) on mercury poisoning. UNEP has sounded the alarm about the potential increase in risk of exposure to mercury in African countries, including Nigeria. This will be a consequence of environmental pollution due to higher level of mercury emissions from a variety of sources.
The increased risk of poisoning in Nigeria will largely be a result of prolonged exposure to mercury during artisanal gold mining and consumption of contaminated fish and shell fish by inhabitants of coastal towns in riverine areas like the Niger Delta.
A rigorous and comprehensive study needs to be designed and conducted in collaboration with oil industry to evaluate the severity and extent of mercury pollution from oil exploration and also numerous unregulated oases of gold mining sites throughout the country.
In addition, clinical and epidemiological surveys, including chemical estimation of mercury levels in hair samples of inhabitants, should be carried out to assess the burden of mercury-related diseases in the vulnerable coastal communities.
The findings of such surveys will permit affected people to be treated and preventive measures can be instituted.
The findings of a medical research group for instance, discovered how endangered children in some mining communities have been in Zamfara State, because of staying around where gold-mining activities take place.
Over 400 children - mostly under the age of 5 - have died in the last two years as a result of lead poisoning, while 1,500 of such children have been treated with chelaton therapy and another 2,000 are in urgent need of treatment.
The environmentalists are currently preoccupied with thermophilic effects on the planet resulting in global warming that leads to flooding and erratic weather patterns but there are other hidden environmental dangers due to heavy metal poisoning of which mercury is an important element that needs to be addressed urgently in developing countries.
The International Negotiating Committee on Mercury will be seized this week with issues posed by mercury toxicity and poisoning but one is not sure of the level of active participation by technocrats and toxicologists from African countries including Nigeria.
Exposure to mercury is well known to public health practitioners in industries over several centuries and mercury has been used in medicine and dentistry for centuries.
The famous statement of "As mad as a hatter" emanated in the 1800s from the use of mercury in the industrial manufacture of felt hats treated with mercury.
The Chisso-Minimata Bay disease of Japan is a classical case study in public health involving mercury poisoning that eluded researchers for many years until Sir George MacAlpine, the eminent British neurologist, visited Japan to solve the "enigma" in the late fifties.
The recently published alarm by UNEP is timely but has failed to emphasise the neurological and subtle psychiatric complications of mercury toxicity as exemplified by the Japanese disaster for 50 years.
The inhabitants of the Minamata Bay consumed large quantities of fish loaded with organic mercury for many years and their offspring developed severe neurological defects from birth that incapacitated them for life.
However, exposure to various forms of mercury can result in either similar or different symptoms and these dose-related symptoms and signs are dependent on the three forms of mercury namely: 1) elemental and vaporised mercury; 2) organic mercury; and 3) inorganic mercury.
The questions that need to be addressed in Nigeria are as follows: 1) What is the level of mercury in our oceans, rivers and lakes particularly those bodies of water into which factory effluents are discharged? 2) What is the level of mercury in the fish consumed from these contaminated rivers and other rivers close to industries with waste waters being discharged into them? 3) What is the state of health of inhabitants and their children in these affected areas particularly their mental and neurological profiles? 4) Are the victims of mercury poisoning being adequately compensated by the offending industry unlike Chisso company in Japan where there was a 30-year struggle for meagre compensation and, 5) What national policies are in place to protect those inhabitants at risk in our coastal areas and among gold miners?.
In the United States, EPA and OSHA are acronyms for Environmental Protection Agency and Occupational Safety and Health Administration, respectively. These statutory bodies are charged with protecting American citizens from any harmful environmental agents. Does Nigeria have functional equivalents of EPA and OSHA and well qualified, competent, and federal-characterised Nigerian toxicologists and epidemiologist and will they be at the table in Geneva when UNEP and experts take critical decisions this week? The unfortunate lessons from chronic lead toxicity in some states in Nigeria are enough for us to appreciate the deleterious effects of heavy metal poisoning particularly in children.
Mercury is another heavy metal that needs to be studied in order to prevent its potential lethal consequences not only on human lives but also on animals that share the same environment with man. Mercury (Hg) is a ubiquitous element found in soil, rocks, water and trace amounts are found in the air.
There should be an increased awareness for recognition of symptoms and signs of heavy metal poisoning in man and animals among medical, dental, veterinary and occupational safety professionals in our nation.
The diseases produced or associated with acute or chronic mercury toxicity can be treated effectively with drugs following diagnosis and all efforts must be made to identify the point source of contamination so that preventive measures can be instituted to prevent epidemic proportions of mercury toxicity.
The use of bleaching creams and soaps that contain mercury compounds in Nigeria should be discouraged as they are capable of affecting both the adults and their unborn off springs.
National policies and legislative activism for prevention of heavy metal toxicities are overdue for review and implementation.
•Williams, a professor of Pathology, is Director of African Cancer Centre (ACC) in Lagos