Gareth Manning, Sunday Gleaner Reporter

Dr. Mark Harris ... believes poor treatment of solid waste in these areas could be contributing to the high concentration of cadmium in the soil.

There is a high possibility that some people in communities in central Jamaica, particularly in the northern sections of Manchester and sections of St. Elizabeth, could be exposed to poisoning as a result of a high concentration of cadmium in their soil.

Cadmium isa toxic metal that affects the function of the kidneys generally over a prolonged period of exposure. It is usually absorbed in the body from dietary sources and cigarette smoking but could have been primarily absorbed in these parishes through dust inhalation.

An environmental scientist suggests the dust could have come from mining activities near or in those areas.

Cadmium, like aluminium, exists naturally in Jamaican soils in ores, possibly due to the weathering of some rocks, scientists deduce.

Its concentration in Jamaican soils varies, with its lowest concentrations in western parishes to extraordinarily high con-centrations in central parishes, particularly in those communities close to bauxite-rich deposits.

The concentration in central parishes, scientists say, is far above world values. Some of the communities identified with rich cadmium concentrations over the years include Christiana, St. Paul's and Shipham in Manchester, scientific research has shown.

Links with kidney disease

While studies over the years have not indicated any adverse effect on human health in this region of the country, continuous studies by the International Centre for Environ-mental and Nuclear Sciences (ICENS), University of the West Indies, Mona, are making a correlation between the poisonous metal and the prevalence of kidney disease in the country.

In a 2001 paper published by the centre, scientists made a correlation between the incidence of end-stage renal failure in Jamaica and high concentrations of cadmium. End-stage renal failure refers to very bad kidney dysfunction which can lead to death in weeks or months unless there is special treatment, such as dialysis.

According to the paper, in Jamaica, there were 370 cases per one million persons each year, a rate significantly higher than in other Latin American and Caribbean countries.

But in more recent studies by the centre, the evidence of the impact on health is even clearer.

In its most recent work, which is to be published later this year, urine samples taken from a number of persons living in highly cadmium- enriched areas of Manchester showed high levels of the poisonous metal .

slow poison

Speaking with The Sunday Gleaner, environmental geo-chemist and senior lecturer at Northern Caribbean University (NCU), Dr. Mark Harris, explained that cadmium in very low thresholds is toxic to humans because it is not readily passed out as waste.

"Cadmium is a very insidious poison and the half life of cadmium in the body is up to 30 years. It does not get out of the body very easily. If you are even cumulatively taking in small amounts, it does not leave and adds up," he added.

He says because the poisoning is slow it can act as a contributing factor to other diseases. Its effects are not only on the kidneys, he notes, but on other organs, including the liver and lungs.

"So many things could happen to you and it could be cadmium. A specialist can't even tell if its cadmium or not because its symptoms are so varied," he says.

The metal is also known to cause bone diseases in people because of its similarity in structure to primary bone nutrients such as calcium.

According to Dr. Harris, in cases of calcium deficiency, the human body can utilise cadmium, if it is absorbed into the body, as a nutrient, thus assisting in preventing loss in bone mass and diseases such as osteoporosis.

But while Dr. Harris and others admit that high concentrations of the metal exist naturally in our soils, he believes other activities such as poor treatment of solid waste in these areas could be contributing to the high concentration of cadmium in the soils, though no studies have been done to confirm this.

Harris says in recent years there has been a high increase in cellular technology, without any means of treating its disposal.

"A more urgent need in Jamaica is the dumping of garbage without segregating the garbage components with the number of telephones in Jamaica now and the dumping of those batteries," he says. "Those batteries contain cadmium. The threshold of cadmium is so low that you don't need a lot of batteries to contaminate a whole area."

He explains that the method of garbage disposal in the country does not allow for the decomposition of garbage because it is buried beneath the soil where there is lesser oxygen for organisms to break down the garbage composts.

The result is a leaching of the cadmium into soil.

"I think that is more dangerous than the inherent cadmium in the soil. I would say that is a very, very urgent problem in Jamaica," says Dr. Harris.

gareth.manning@gleanerjm.com