Approximately 120 million people worldwide are exposed to lead in the environment - in air, soil and water. And dangerous levels of lead poisoning are found in children in some 80 countries. Most of this lead comes from the illegal or poorly regulated smelting of lead acid batteries which are used to power automobiles.
The Caribbean island of Jamaica is one of those countries where decades of informal battery smelting have left a legacy of soil pollution in some of the lowest income areas.
"Part of the IAEA´s approach in providing equipment, training and fellowships for scientists like those at the International Centre for Environmental and Nuclear Sciences (ICENS) in Jamaica, is to enable and empower these institutions in developing countries to be able to apply scientific methods to their unique development problems," says Rick Kastens, Head of one of the two Latin America Sections in the IAEA Department of Technical Cooperation.
The IAEA has eight projects ongoing in 25 countries dealing with various aspects of heavy metal pollution and the effects on humans and the environment. In Jamaica, it supports research into lead and other heavy metals by providing a total reflection x-ray fluorescence (TXRF) unit, as well as high-purity germanium photon detectors which are both involved in testing soil, plant, water and blood samples for the presence of lead and other toxins.
Lead and the Young Brain
Infants and young children can absorb as much as five to 10 times more lead than adults, because chemically, lead and calcium are similar and both enter the body in the same way and are stored in the bones. Children, because they are growing and absorbing calcium, tend to metabolise lead more efficiently than adults.
"Exposure in the first two years of life plays hell with children´s brains," says Gerald Lalor, Director General of ICENS. Their work is supported by the IAEA and funded by the Environmental Foundation of Jamaica, the Jamaican Government, the Inter-American Development Bank, the CHASE Foundation and the University of the West Indies.
Lead is a metal with no known biological benefit to humans. A direct link has been found between early exposure and extreme learning disability, hyperactivity, violence and lethargy. Too much lead in the body interferes with the normal development of the brain, the central nervous system, the kidney and the heart.
Tip of the Iceberg
Experts say Jamaica´s lead exposure problems represent the tip of an iceberg. Worldwide, lead exposure is a major health hazard. The Blacksmith Institute, an environmental health group in the USA, ranks lead recycling from batteries among the world´s top 10 pollution problems.
The problem of unsafe unregulated recycling is exacerbated by high unemployment among the underprivileged, growing industrialisation, increasing wealth in the middle classes, which results in increased car ownership, and therefore more batteries being imported.
People are exposed to lead through informal and formal - but poorly regulated - smelting activities. Informal smelting involves breaking the batteries with an axe and disposing of the sulphuric acid. Often the battery acid, which contains some lead, is carelessly dumped on the ground, waste pile or into the nearest water body. Then the lead plates are removed from the plastic battery casing. The plates are boiled in a large metal container and impurities are siphoned off with a ladle.
Worldwide, informal battery melting is done to recover and sell lead to larger processers. And despite the risks, overriding economic needs drive people to continue.
Unlike some other contaminants, lead never disappears on its own. "If it´s in the blood it has to be medically removed. And if it´s in the soil, the dirt has to either be dug up and dumped in a safe place or you have to concrete the entire polluted area," says Lalor.
Such basic and practical intervention is often prohibitively expensive for the very poor.
In Jamaica, ICENS has been spearheading remediation of contaminated sites for the last five years. But the scientists describe it as an uphill task that requires the full force of state machinery behind it as well as support from private sector entities and international non-governmental organisations. For instance, the Caribbean Recycling Company will next year begin collecting used lead acid batteries for export to Israel where both the plastic and the lead will be recycled. Co-owner Geoffrey Ziadie anticipates that 100 tonnes of batteries will be exported each month when operations begin.
Internationally, the Blacksmith Institute is working in seven countries to mitigate against lead pollution from improper recycling through education and remediation of legacy contaminated soils. The project also involves developing responsible policies for managing these batteries, and either formalizing used battery collection or providing other sources of income for the informal operators.
There are also plans for a $400 million fund dedicated to combating toxic pollution in developing countries that has resulted from industrial, mining and military operations.
Despite increases in international aid however, the havoc wreaked by heavy metal pollution on vulnerable populations will persist in developing countries unless poverty and alternate sources of employment are addressed.
Lead poisoning is determined by measuring the ratio of lead to blood in the human body. Any measurement above 10 micro grams per decilitre of blood (µg/dL) is cause for concern. Jamaican children living in communities or homes where smelting was done, often turned up with blood lead levels anywhere from 45 µg/dL to 202 µg/dL.
Treatment involves introducing a substance, often calcium disodium EDTA, into the body that essentially latches onto the lead in the blood. From there, the now soluble metal is passed out in urine and faeces. This process is called chelation. With regular treatment, the child´s condition can improve significantly, granted there is no re-exposure to the lead source.