EXPOSURE AND CANCER MORTALITY IN THE UK SILICA SAND INDUSTRY

Findings reported this month by Brown and Rushton^1,2 may rekindle debate about the carcinogenicity of crystalline silica. They studied mortality among 2703 workers employed in silica sand quarries in the UK where over 3000 exposure measurements had been taken, and found no consistent association between the level of respirable silica and lung cancer. However, in an accompanying commentary,³ Steenland finds these negative results unsurprising, primarily because exposures in the UK cohort were quite low. He writes that in light of the prior evidence that silica is carcinogenic, …