adminZimbabwe? Occupational health is the promotion and maintenance of the highest degree of physical, mental and social well being of workers in all occupations.
It is concerned with any substance, process or circumstance that may affect a person’s health or safety in the workplace. The term heavy metal is often used as a group name for metals and semi-metals (metalloids) that have been associated with contamination and potential toxicity or ecotoxicity. Legal regulations often specify the group.
There is a multiplicity of exposures. These include accidents and injuries, physical hazards, ergonomic, physiological and biological hazards. Toxic metals that have been cited as a hazard to occupational health are mercury, lead, arsenic, cadmium, chromium and manganese. These are used in mining, manufacturing, processing and agriculture. In Zimbabwe, the issue of mercury poisoning has been very topical as mercury is widely used in mining and gold panning.
The problem in Zimbabwe concerning toxic metals is paucity of epidemiological data and research.
A fragmented occupational health management system has also been detrimental as well as too basic medical evaluations. Lord Kelvin once said: “When you can measure what you are speaking about, and express it in numbers, you know something about it.”
In 1912, a British company, Pullman, recorded 109 cases of lead poisoning. There was major mercury poisoning that was recorded in 1953 at Minamata Bay that led to vision and auditory probs, ataxia, dysarthria and unsteadiness of a sizeable population.
There are several exposures to heavy metals. Pesticides and herbicides contain arsenic and manganese, while fungicides contain mercury. Batteries contain manganese and lead, while the leather tanning and taxidermy uses mercury. Coal and power plants use arsenic and mercury, while paints and plastics contain lead and manganese. Gold panners are exposed to mercury contamination, industrial and mining operations use mercury and lead that affect aquatic life. Some fruits, poultry and chicken feed contain arsenic. Welding processes using base metals offer exposure to toxic poisoning.
Mild steel produces iron oxide and manganese, stainless steel produces manganese and chromium, while gas welding (brazing) produces cadmium oxides, metal fumes and nitrogen oxide. Toxic metals have a many effect including loss of libido, lowered sperm count, menstrual problems, low sexual arousal, excitability and irritability. Major effects of toxic metals include damage to the central nervous, leading to memory loss, diminished intelligence, neurotoxicity, seizures and behavioural change. Other major effects are kidney failure caused by mercury and lead, cancers to the skin, lung, kidney and bladder caused by arsenic, as well as weakness and distal parasthesias caused by arsenic.
There is need for a strategic plan to be put in place, such as the formulation at national level of legal instruments and codes of practice. There is also need for research support in order to come up with informed decisions. At organisation level, there is need to invest in holistic and robust occupational health management systems. On its part, the Government of Zimbabwe is considering banning the use of mercury in recovering gold and silver as the chemical poses serious threats to human life and the environment.
Artisinal miners – otherwise known as panners – and some licenced small scale miners mostly use mercury in extracting gold and silver, a process usually carried out in rivers.
Mercury is a poisonous element that can affect the brain and nervous systems if inhaled as vapour.
Online Reporter