Ischemic heart disease mortality among miners and other potentially silica-exposed workers

Background Some previous studies have. observed an increased mortality regarding ischemic heart disease (IHD) among miners and industrial sand workers. The purpose was to study the occurrence of IHD mortality among silica-exposed workers. Methods Male miners, well borers, dressing plant workers, and other mine and stone workers were identified in the Swedish National Census of 1970. The total cohort (n = 11, 896) was followed from 1970 until December 31, 1995 and linked to the Cause of Death Register The referent group comprised all gainfully employed men identified in the same census. The Standardized Mortality Ratio was calculated as the ratio between observed and expected numbers of deaths. Result An increased risk due to IHD mortality was observed among miners, well borers, dressing plant workers, and other mine and stone workers. Conclusion These results indicate a possible relation between silica-dust exposure and IHD. The increased risk of IHD mortality is unlikely explained by smoking habits. Shift work might explain some of the increased risk. A low-grade inflammation in the lungs as a result of dust exposure is discussed as a possible cause. However, the key message is that better dose estimates and better confounding control is needed to study the possible relation between silica-dust exposure and IHD.