Underground » Health and Safety
Coal worker's pneumoconiosis (CWP) is an irreversible lung disease associated with inhalation of coal dust. Epidemiological patterns suggest that the chemical properties of coal dust can influence disease risk. However, to date, no studies have been able to identify which chemical component(s) of the coal dusts might be driving this geographical variation in disease risk.
In an earlier project (C29035), a strong association between the potassium content of coal dust and lung cell response was found. Preliminary analysis suggested that this was linked to potassium alumino-silicates in the coal; most likely illite. However, further studies were required to confirm the likelihood of this association.
The overarching aim of this project was to further probe the potential relationship between potassium alumino-silicates in coal and the risk of pneumoconiosis. In project C29035 researchers conducted a thorough systematic review of the literature to determine whether there is evidence for a plausible link between inhalation of potassium aluminosilicate dusts and a heightened risk of developing pneumoconiosis. Using a systematic search process, some evidence was found linking exposure to potassium containing dusts (illite, feldspar etc) and increased risk of poor respiratory health, however the evidence was inconsistent suggesting that further study was required. In order to address this gap in knowledge, a laboratory based study was conducted using our well established techniques employed in projects C27007 annd C29035, to determine whether there is causal link between potassium / potassium enriched dusts and the adverse lung cell response.
Laboratory data showed that
- adding potassium oxide to coal caused mild increases in coal-induced cell toxicity;
- some forms of illite were highly toxic, and;
- high potassium concentration in natural coal dusts was negatively associated with epithelial cell proliferation.
Collectively, these data suggest that there is strong evidence for a causal relationship between potassium alumino-silicates and coal dust induced cell toxicity. However, this relationship is complex and highly dependent on the form of potassium rich minerals that are present in the dust.