Decline in the lung cancer hazard: a prospective study of the mortality of iron ore miners in Cumbria.

Abstract

The mortality of 1947 Cumbrian iron ore miners has been studied over the period 1939-82 in relation to that among other groups of men in England and Wales: (a) all men, (b) men of similar social class, and (c) men living in similar types of(mainly rural) area. Significant excesses were found for deaths from tuberculosis and respiratory diseases compared with each of the reference populations. Lung cancer showed an excess over that in comparable (mainly rural) areas of England and Wales, as reported in a previous study using a proportionate method of analysis and which covered the period 1948-67 but no appreciable excess after 1967. Reasons for this decline are discussed.Iron ore miners in Cumbria have been found to have a significantly increased mortality from lung cancer, an effect attributed either to the radioactivity in the underground air or to a carcinogenic effect of iron oxide.' In that study it was not possible to obtain adequate details of the population exposed and consequently the mortality data were analysed using a proportionate method. It was considered that a prospective study would be of interest, since this would allow not only a comparison of the findings with those of the previous study but also an examination of mortality from causes not covered previously. Such a study has now been carried out using data held in the National Health Service Central Register (NHSCR) for England and Wales. MethodsDetails were abstracted from the NHSCR by staff of the Office ofPopulation Censuses and Surveys (OPCS) of men resident in September 1939 in Ennerdale RD and Whitehaven UD, Cumberland, and whose occupation as stated included a mention of "iron ore mine"; those described as retired were also covered. In addition to the job description as given the details abstracted included dates of birth and, when relevant, dates of death or emigration.In the case of deaths details of the underlying cause Accepted 6 April 1987 were obtained from the death certificates and coded by the OPCS according to the rules of the 8th revision of the International Classification of Diseases (ICD). In many cases the men were specifically described as "surface" or "underground" workers and the data for these categories have been analysed separately, as has also a third group comprising those in which neither term was mentioned. In a few cases when there could be no doubt about the matter a worker was allocated to one of the first two categories even though the words underground or surface did not appear-for example, "shopfirer" or "clerk in the iron mine". For each work category and for each area of residence in 1939 (Ennerdale RD and Whitehaven MB), man-years at risk by age group and calendar period were calculated for 1939-83. Expected numbers of deaths attributed to particular causes were obtained by multiplying the man-years at risk in each area, age group, and calendar period by the corresponding mortality rates for the following: (1) all men in England and Wales, (2) men in all rural districts (for comparison with...

Mechanisms of DNA Oxidation

“…However, excessive iron becomes a risk factor in many human diseases, including cancer. Iron ore miners have been observed to have an increased incidence of lung cancer (8,9). There is an increased risk of liver cancer among victims of the iron overload diseases, hereditary hemochromatosis (10,11) and porphyria cutanea tarda (12,13).…”

Mortality of iron miners in Lorraine (France): relations between lung function and respiratory symptoms and subsequent mortality.

“…The values of the SMRs were however, generally much higher for heavy than for moderate smokers, but a significant excess of overall mortality was found only for heavy smokers with stage 1-2 dyspnoea. By contrast, the risk of lung cancer was as a whole clearly higher for men having a respiratory symptom than for symptom free subjects (table 9). Due to the small numbers it was not considered suitable to compare the values of the SMRs for various symptoms.…”

“…They found a significant excess of deaths from tuberculosis, respiratory diseases, and lung cancer. 9 The role of radon daughters has been studied by many researchers.-5 27 workers employed between 1948 and 1980 at a uranium mine in Canada. Edling3 found an increased risk of lung cancer among iron miners (smokers and non-smokers) and he attributed this excess to radon daughters.…”

Occupational and Environmental Exposures to Radon: Cancer Risks

“…uranium miners in the US, Canada, Czechoslovakia, and France (24,51,62,73,77,83,86,88,89,92,93,101,105); iron and other metal miners in the US, UK, China, France, Italy, and Sweden (12,13,15,19,27,35,42,57,58,60,71,84,85,102); and fluorspar miners in Canada (31,75,76). Some results of these studies are summarized in Tables 1 and 2. It is relatively uncommon for all studies on a particular occupational exposure to be totally consistent in their findings.…”