Coal Mining and arsenic poisoning in Bangladesh
Published by MAC on 2004-10-09Bangladesh, one of the world's poorest and most conflict-torn nations, isn't immediately identifiable as a state rich in hardrock minerals. However, the eastern part of the country has been a source of coal for decades. Now a London-listed company plans to expand the biggest deposit to world-class proportions.
Bangladesh's soil and water is also "rich" in one of the world's deadliest metals. Arsenic is found in groundwater, used for drinking purposes, and has already poisoned thousands, if not millions, of Bangladeshis as a result. Other research has painted a highly alarming picture in neighbouring West Bengal - which also has a large number of coal mines. It is well known that coal burning and smelting can result in arsenic poisoning, while research has been carried out in the USA on the association between coal mining and arsenic uptake in rivers and soil. However little such investigation seems to have been undertaken elsewhere.
Reasons to be the mining sector's 'darling'
By Rebecca Bream, Financial Times
October 9 2004
Asia Energy has become the surprise darling of the mining sector over the past two weeks after good news from the company increased its shares almost fourfold. The group, which owns the Phulbari coal mine and power plant project in Bangladesh, listed on AIM in April at 75p a share. At the end of September, it jumped sharply after Asia said it could start coal production in 2007 compared with an original target of 2009 and that independent consultants had valued assets at $2.3bn (£1.4bn). Investors started to believe in Asia's ambitious plans and there are several good reasons why. As well as an earlier start date, Asia now thinks the Phulbari project could produce 15m tonnes of coal a year rather than initial estimates of 9m tonnes. Also, Barclays Capital has been hired as Asia's financial adviser, lending further credibility. Analysts suggest, however, that the rally could be unsustainable and the current price does not reflect the risks. The company will need to raise large amounts of debt and equity - $530m at the last count - to bring the Phulbari project into production and this could require a deal with a larger partner.
Arsenic; Natural but Nasty
originally published in Positive Health issue 30 - July 1998
by Lisa Saffron
In 1900, beer drinkers in northern England died of arsenic poisoning when sulphuric acid contaminated with arsenic was used in the processing of the beer. Murderers prefer arsenic as it has no taste or odour. But arsenic is not just a cause of accidental deaths or a convenient means of eliminating enemies. It is an environmental pollutant of global proportions. An international conference in February highlighted the serious problem of arsenic-contaminated well water in Bangladesh. The scale of the problem is probably greater in Bangladesh than anywhere else in the world but people in other countries have also suffered from arsenic pollution.
In countries such as Bangladesh and Taiwan, arsenic is a natural contaminant of ground water. Arsenic is an element found in geological formations, particularly in granites also containing copper and tin. As long as the arsenic remains bound in the granite, it causes no problems to people. But in certain conditions, natural weathering of the granite occurs and the arsenic is released into the ground water. Hydrogeologist say that in Bangladesh, the weathering occurs deep in the ground where no oxygen is present and where the sediments contain high concentrations of arsenic-rich iron hydroxides.
Well Water in Bangladesh
Although well endowed with rainfall, Bangladesh does not have the resources to provide clean water to all its residents. Without proper sanitation, surface water becomes contaminated with faecal microorganisms, causing cholera, diarrhoea, hepatitis and other water-borne diseases. To avoid this, more than 3 million tubewells wells have been sunk, providing microbiologically safe drinking water to 97% of the population.
But the tubewells have generated a new health problem. Health workers began noticing symptoms of arsenic poisoning -- increased pigmentation (melanosis), painful wart-like skin lesions which start on the palms and soles and spread all over the body (keratosis), lesions on the mucous membranes, and disorders of the nervous and respiratory systems. They connected these symptoms of arsenic poisoning to high arsenic levels in water from tubewells. No one knows the extent of the problem. One tubewell may contain high levels of arsenic while a nearby tubewell in the same village may be free of arsenic. Large scale testing supported by Unicef is being carried out and other sources of clean water are being found for those whose tubewells are contaminated. But little can be done to treat people already suffering the effects of arsenic poisoning. If the experience of Taiwan is anything to go on, people in Bangladesh are at higher risk of cancers of the skin and internal organs.
Well Water in Taiwan
Residents of southern Taiwan have been drinking arsenic-contaminated well water since the Second World War. Blackfoot disease, a unique vascular disease, is common in this area. Residents also have a significantly higher rate of cancers of the liver, lung, skin, bladder, kidney, and prostate. In addition to cancer, there is a higher rate of diabetes and hypertension.
Arsenic Pollution
Natural weathering is to blame for polluting the wells in Bangladesh and Taiwan. But in other countries, the arsenic pollution has a human source. Mining, smelting, pesticide spraying and coal burning all pollute the environment with arsenic.
Pesticides
Long before organochlorine and organophosphate pesticides, arsenic-based pesticides were the most common type of pesticide used in agriculture. The evidence linking arsenic-based pesticides with skin and lung cancer is strong and persuasive. The increased cancer risk has not been associated with eating food containing residues but with occupational exposure, particularly among professional pesticide sprayers and among workers in pesticide manufacturing plants.
Mining and Smelting
Arsenic pollution is a consequence of arsenic, tin and copper mining and smelting. Mine spoils have been dumped on the land and near or into streams. Smelting of the ore scatters the arsenic through the air in a plume of soot, contaminating soil and streams in a wide area. Poisoning can occur when people are exposed to contaminated water, dust and soil.
A thousand year history of mining and smelting has left a legacy of arsenic pollution in Devon and Cornwall. During the last half of the nineteenth century, Cornwall was the world's largest producer of arsenic. Soil in some parts of Cornwall has the world's highest concentration of arsenic, up to 2500 ppm. Elsewhere in the UK and the rest of the world, arsenic levels are usually below 40 ppm. Although arsenic levels in Cornish streams and rivers occasionally exceed WHO drinking water guidelines, the main concern about human exposure is through ingesting or inhaling dust and soil. Fortunately, locally grown vegetables do not accumulate arsenic from the soil to a dangerous level.
Last year the Environmental Geochemistry Group of Imperial College tested the urine of people living in Cornwall and found higher concentrations of various forms of arsenic in people living in former mining areas than in the control group. But the research group did not find a significant increase in bladder cancer as a result of arsenic exposure in Cornwall. As yet, there have not been any proven associations between high arsenic levels and health problems in the south west of England. The Department of Health is funding ongoing research in this area.
Key References
Abernathy, Calderon, Shappell, Arsenic Exposure and Health Effects, Chapman & Hoare, San Diego, 1997.
Bates et al, "Arsenic ingestion and internal cancers: a review", American Journal of Epidemiology (1992 Mar 1) 135(5):-462-76.
Burgess & Hasan, Guardian Online, 5 March 1998, p11.
Carriere & Smith, Unicef, Guardian Online, 5 March 1998, p 11 Chen et al, "Cancer potential in liver, lung, bladder and kidney due to ingested inorganic arsenic in drinking water", British Journal of Cancer (1992 Nov) 66(5): 888-92.
Guo et al, "Arsenic in drinking water and incidence of urinary cancers", Epidemiology (1997 Sep) 8(5): 545-50.
Kavanagh et al, Environmental Geochemistry Group, "Urinary arsenic concentrations in a high arsenic area of southwest England, Occupational & Environmental Medicine, 1997, (54):840.
Pearce, "Arsenic in the water", Guardian Online, 19 February 1998, p2-3.
Xu & Thornton, "Arsenic in garden soils and vegetable crops in Cornwall, England,: implications for human health", Environmental Geochemistry & Health, 1985, 7(4), 131-133.