With discussion about a possible silica mine in Tasmania it might be worth noting that the International Agency for Research on Cancer (IARC) has concluded that crystalline silica in the form of quartz or cristobalite from occupational sources should be classified as carcinogenic to humans (Group 1), upgraded from its previous classification as probably carcinogenic to humans (Group 2A).
This conclusion was drawn on the basis of a relatively large number of human population studies that together provide sufficient evidence in humans for the carcinogenicity of inhaled crystalline silica. In many (although not all) of these studies, lung cancer risks were elevated and could not be explained by other factors.
The US National Toxicology Program (NTP) identifies crystalline silica (respirable size) as a substance which may reasonably be anticipated to be a carcinogen.
Given the fact that fine particle pollution travel distance is 100 Km for PM10 and 1000Km plus for PM2.5 for days to weeks, it is not a bright idea to be considering such a mining and smelter project in Tasmania upwind of populated areas.
Clive M. Stott [email protected]
