Health

Silent killer lurks in miners' lungs

Heidi Swart

Silicosis might appear only 15 years after exposure to gold ore dust, long after they have gone home. Heidi Swart reports.

Kholekile Rouben Mdaka is one of 3500 claimants bringing a class ­action against Anglo American South Africa. (Madelene Cronjé, M&G)

They called them the radium girls – five factory workers who sued a company that produced glow-in-the-dark radioactive paint because it knowingly exposed them to radiation poisoning.

The United States Radium Corporation operated from 1917 until late 1926 in Orange, New Jersey. The company employed women to paint watch dials that were sold to the country's military services to help soldiers to keep track of time at night in the trenches of World War I.

The women used their tongues and lips to sharpen the tips of their paint brushes for the fine work needed in painting the small dials. But, starting in 1920, many of the women began to show signs of severe radiation poisoning, such as developing physical deformities and the infamous radium jaw, when jaw tissue literally starts to rot. Radium poisoning also leads to tumors, anaemia and the erosion of bone marrow.

The end result was a slow, painful death for many of the workers. The first woman died in 1923. By 1949, 44 former dial painters had died.

But, in 1927, five women filed against the corporation and the outcome was that radiation illness was recognised as an occupational disease for which workers were entitled to compensation under New Jersey state law. The case also lead to the US department of labour setting the first health and safety standards for people who work with radioactive substances. The corporation settled out of court, with each woman receiving a payment of $10 000 and a yearly stipend of $600. The company also agreed to pay for their medical expenses.

In March 2011, a similar landmark case took place in South Africa when the Constitutional Court ruled that the former mineworker Thembekile Mankayi could seek compensation from his former employer, Anglo Gold Ashanti. He contracted silicosis, a debilitating, incurable lung disease, while working for the company. But he did not live long enough to hear the outcome of the ruling.

Silicosis
Several other lawsuits are underway which could cost the South African mining industry billions in compensation for gold mine workers suffering from silicosis. Among them is a potential mass claim by 17 000 mine workers and widows of mineworkers, including Mankayi’s wife, against 30 South African mining companies. There is also a mass claim against Anglo American South Africa seeking compensation for 3 500 workers.

Silicosis has plagued gold miners in Southern Africa for more than a century but the mines have been slow to tackle the problem. The reason is perhaps to be found in the major difference between the symptoms of radiation poisoning and silicosis. The case of the radium girls was extensively covered by the media. It horrified the public and so received much attention from litigators. But silicosis is a silent, invisible disease. It creeps slowly into the lungs, breaking down their ability to function over time. The deformities can only be detected by X-ray.

According to a former director of the South African National Institute for Occupational Health, Professor Tony Davies, silicosis is caused by microscopic silica dust particles. Silica is found in the ore that contains gold. Whenever the ore is blasted, milled or drilled, toxic silica dust is released. It has no smell, no taste and is invisible. Silicosis "is irreversible and no treatment has been known to be effective".

The lungs have several mechanisms for keeping harmful particles from entering them. "Tiny hairs, known as cilia, are found in the nasal passages and parts of the respiratory tract, like the windpipe [trachea]. Cilia capture foreign particles – dirt, in plain language – and push it up the respiratory tract where it is expelled as phlegm," Davies says. But microscopic silica particles are "not all caught by the cilia, and eventually end up in tiny air sacs, called the alveoli, in the lungs where carbon dioxide is exchanged for oxygen". Once silica reaches the alveoli, defence mechanisms again spring into action.

Macrophages are white blood cells in the alveoli that "eat" foreign particles such as silica in an attempt to remove them from the lungs. "But, because the silica is toxic, the macrophages die once they have attacked the silica particles. The dead macrophage then recruits more macrophages, which then form a cluster of dead macrophages," Davies says.

This cluster attracts tiny cells that form layer upon layer around the macrophages. The end result is silicotic nodules – spots in the lungs – that can lead to respiratory diseases.

Mining sector
It can take up to 15 years for a miner to become ill. According to several studies, miners are mostly migrant workers from rural areas. Once they retire, they return home where they rely on distant, overburdened state health facilities and their illness often goes undetected.

However, the National Institute for Occupational Health provides some insight into how many miners might be ill. Since 1975, it has released an annual report on occupational lung diseases in South African mining and has performed autopsies on more than 100 000 miners' bodies. According to these studies, each year, for the past five years, silicosis was found in at least three out of 10.

The department of mineral resources says about half a million workers were employed in South African gold mines in 1983, the greatest number at any point in the history of mining. Although this number has decreased over the years, it could mean that thousands of the miners are still affected. The department of labour puts the number of former miners in Southern Africa who live with pneumoconiosis, which includes lung diseases such as asbestosis and silicosis, at nearly 500 000.

According to Davies, silicosis also increases the risk of developing tuberculosis, including drug-resistant TB (XDR), which is often untreatable. "When macrophages are occupied by silica dust day in and day out, they can't handle the TB bugs in your lungs. This puts a miner with silicosis at permanent risk of tuberculosis," he says. This has led to a "river of disease" – workers go back home and expose their family and friends to TB.

Health department figures show that the mining sector is responsible for 9 out of every ten cases of reported occupational lung diseases, and the gold mining industry has the fastest-growing TB epidemic in the world. Long work hours in dusty environments and high HIV-infection rates are some of the main reasons for this. HIV weakens the immune system which drastically increases the risk of developing TB.

Today, workers are still at risk of silicosis, despite considerable efforts by the mines to improve the working environment and reduce the incidence of lung diseases. Silica dust can be suppressed, for example, by spraying water on to dust during drilling and blasting, and proper, but expensive, ventilation in mines can also provide fresh air.

Professor Gary Stevens from the department of earth sciences at the University of Stellenbosch says gold mines have vastly improved dust control mechanisms but the mines could become unsustainable if the dust limit is to be lowered significantly. "It's just not possible. The profit margin for gold mines is pretty small … The problem can be likened to changing oil in a motorcar. You cannot do it without getting your hands dirty."


The full meaning of silicosis hits home

Kholekile Rouben Mdaka is 56 years old and retired. He was a gold miner at a mine in which Anglo American South Africa held shares during the 26 years that he worked there, from 1977 to 2001. He is one of 3500 miners engaged in a mass claim against Anglo who say they contracted silicosis while working on the mines. Now, he is living in his home in rural Eastern Cape.

Mdaka coughs between sentences and wheezes occasionally. He has a gruff voice. He was once the leader of a team that did the most physical work in the mines. He oversaw drilling, blasting and the installation of timber supports, work that exposed them to dust.

He started feeling sick in 1998. He coughed constantly and the skin started peeling off his fingers. But doctors employed by the mine said they could find nothing wrong. He was only told that he had a lung disorder in 2001 during an exit examination. He still was not sure what was wrong with him.

"I didn't understand what this was. I was told there is no cure. I only learnt this in 2001. That was when the mine closed. I only stopped [working] then because the mine closed." Anglo American SA denies any liability.

Heidi Swart is the Eugene Saldanha fellow in social justice reporting.


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