Grunerite
asbestos (amosite) has been shown in epidemiological and experimental animal studies to cause
lung cancer,
mesothelioma and
pulmonary fibrosis commonly referred to as
asbestosis. An overview of the human and experimental animal studies describing the health hazards of grunerite
asbestos (amosite) is presented. Of the many human studies describing the health hazards of
asbestos, only three factories using mainly, if not exclusively, grunerite
asbestos (amosite) have been studied. The first is a series of reports on a cohort of 820 workers from a plant located in Paterson, NJ. Among this cohort, 18.7% died of
lung cancer and 17
mesotheliomas occurred. The Paterson factory closed in 1954 and moved to Tyler, Texas where it operated until 1972. Among the 1130 former workers in the Tyler plant 6
mesotheliomas were reported with 15.8%
lung cancer mortality. The third grunerite
asbestos (amosite) exposed cohort was an insulation board manufacturing facility in Uxbridge, United Kingdom. Here 17.1% of the workers died of
lung cancer and 5
mesotheliomas occurred. The lung content from 48 Uxbridge workers was analyzed by analytical transmission electron microscopy for
mineral fibers. The relationship between grunerite
asbestos (amosite) concentrations in the lung correlated with grades of
fibrosis and
asbestos bodies and was lower than the concentration found in the cases with malignant
tumors. The
lung cancer cases contained more grunerite
asbestos (amosite) than
mesothelioma cases, and in the cases of non-malignant disease the concentrations were still lower. In both types of
malignancies the concentration of grunerite
asbestos (amosite) was very high-over a billion fibers per gram of dried lung tissue. Occupational exposure to airborne concentrations of between 14 and 100 fibers of grunerite
asbestos (amosite) per milliliter after 20 year latency causes marked increases in
lung cancer,
mesothelioma and
pulmonary fibrosis (
asbestosis).