An updated study of taconite miners and millers exposed to silica and non-asbestiform amphiboles

J Occup Med. 1992 Dec;34(12):1173-80.


This is the second update of a study of 3,444 taconite miners and millers who were first exposed to taconite, with associated exposures to silica and nonasbestiform amphiboles, in the period 1947 through 1958. Previous analyses of deaths through 1977, and again through 1983, showed no significant excess deaths from any specific causes. The present study continues the follow-up through 1988, adding 14,748 person-years of observation and 261 death certificates for analysis. The population, reduced to 3,431 because of the detection of 13 earlier duplications, has now been observed for 101,055 person-years, with 1,058 deaths and 1,039 death certificates. Death certificates were obtained for 98.2% of those known to be dead. The total number of deaths was significantly fewer than expected. Based on US rates, the standardized mortality ratio (SMR) was 83 (ie, 83% of expected). Based on Minnesota death rates, it was 91. With both US and Minnesota death rates, the SMRs for malignant neoplasms, cancer of the respiratory tract, cancer of the digestive system, heart disease, nonmalignant respiratory disease, and cirrhosis of the liver were all below 100. Slightly elevated SMRs were found for cancer of the colon, cancer of the kidney, and lymphopoietic cancer. These elevations were not statistically significant. Separate analyses were made of total deaths, lung cancer deaths, and kidney cancer deaths in men who had worked with taconite for time periods of less than 1 year, 1-5 years, 5-10 years, and over 10 years, during observation periods less than 10 years, 10-20 years, and over 20 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dust
  • Follow-Up Studies
  • Humans
  • Iron*
  • Male
  • Metals
  • Minerals*
  • Mining*
  • Minnesota / epidemiology
  • Mortality*
  • Neoplasms / mortality
  • Occupational Exposure*
  • Silicates*
  • Silicon Dioxide*
  • Time Factors


  • Dust
  • Metals
  • Minerals
  • Silicates
  • taconite
  • Silicon Dioxide
  • Iron