Gareth Manning, Sunday Gleaner Reporter

Director of ICENS, Professor Gerald Lalor.

The best known case of cadmium poisoning was the extremely painful Itai-Itai disease in Japan in the 1950s. - file

Scientists at the International Centre for the Environment and Nuclear Sciences (ICENS) at the Mona campus of the University of the West Indies are set to release a report on their study of the metal, cadmium in the Jamaican environment later this year.

The results are showing a wide range of cadmium concentrations in soils and foods, an it is ingested by humans there is no clear evidence of its toxic effects.

Cadmium highly toxic

Cadmium is a relatively rare heavy metal, that ranks 65th in abundance among elements in the earth's crust. It has no apparent beneficial effects for humans, and is generally considered to be highly toxic. It accumulates in the body over time, mainly in the kidneys and liver, scientists say; but the metal also affects the bone, the gall bladder, pancreas, prostate, testes, thyroid and other organs. There have been reports of links between the metal and various diseases including, lung cancer, osteoporosis and renal diseases, cardiovascular problems and prostate cancer.

The best known case of cadmium poisoning was the extremely painful Itai-Itai disease in Japan in the 1950s. Since that occurrence, the World Health Organisation (WHO) has steppedin to recommend the maximum weekly intake of the toxic metal, which ICENS' director, Professor Gerald Lalor says is mostly ingested through food intake in Jamaica and not through dust inhalation as occurred among cadmium workers.

He says the substance is very mobile in the soil/plant system, noting that the homeostasis mechanisms that control plant elemental uptake from soils, appear to be much weaker for cadmium than for other elements. Its concentrations in plants depends on the type of soil and the type of plant. Leafy vegetables, such as callaloo and root crops can contain the higher levels of cadmium and can be the likely pathway of the metal to man.

Jamaica has unusually high concentration of cadmium in some soils, studies by the ICENS show. It is matched worldwide only by similar soils in the Dominican Republic. The greatest concentrations are found in central regions of the country in the parishes of St. Elizabeth and Manchester and some adjoining parishes, where the soils are rich in bauxite.

The link

In a paper published by ICENS in the Jamaican Journal of Science and Technology in 1999, a scientific team, headed by Professor Lalor, speculated that there could be a link between the high incidence of the disease in Jamaica and the metal. The paper noted that in Jamaica there were 370 cases of end renal disease per million people, an incidence far greater than that of the Latin American countries of Costa Rica, Puerto Rico and the Dominican Republic.

Autopsy studies by ICENS of cadmium concentrations in the kidneys and livers of 39 cases in the island of people ages 40 years old, have shown significant levels of cadmium intake. This is confirmed by more recent analyses of urine samples.

"But, to date, there remain only hints of possible health effects an the work continues, it appears to be showing that despite international concerns, under Jamaican conditions in our people, cadmium toxicity does not show a first order effect on health," says Professor Lalor.