The distribution of lung cancer and bronchitis in England and Wales

[Greece and the European Economic Community: relations between mortality rates by cause and indices of development]

Greece is member of the European Economic Community since 1981. This paper analyses the existing relationships between mortality rates and several indices of socio-economic development; these indices deal with the rythm of industrial development, the level of urbanization, the quality and quantity of individual consumption. These indices show marked differences within EEC. Among the factors studied, those related to nutrition show strong association with cancer and coronary mortality; the level of urbanization is associated with mortality from cardiovascular and acute respiratory causes. The employment and the BIP are directly associated with mortality from accident, intoxication and respiratory diseases.

Dust exposure, pneumoconiosis, and mortality of coalminers

General mortality in approximately 25 000 British coalminers over 22 year periods ending in 1980 was 13% lower on average than in English and Welsh men in the same regions of Britain. There were significant within region variations between collieries, and standardised mortality ratios increased during the later years of the follow up, approaching or slightly exceeding 100 in most of the 20 coalmines studied. Age specific comparisons of 22 year survival rates were made in subgroups. Relative risks of death from all non-violent causes for men with the earliest stage of progressive massive fibrosis (PMF category A), compared with risks in miners with no pneumoconiosis (category O), ranged from 1.2 in those aged 55-64 initially to 3.5 for those aged 25-34. Mortality in miners with higher categories of PMF (B or C) was even more severe. Survival rates in men with category 1 simple pneumoconiosis were about 2% to 3% lower than in miners with radiographs classified as category O, but there was no consistent evidence of an increase in mortality with increasing category of simple pneumoconiosis. Mortality from all non-violent causes increased systematically with increases in estimates of exposure to dust before the start of the follow up. That gradient was attributable primarily to deaths certified as due to pneumoconiosis and those recorded as due to bronchitis and emphysema (p less than 0.001). There was some evidence of a dust related increase in deaths from cancers of the digestive system (p approximately equal to 0.05), but none of an association between exposure to coalmine dust and lung cancer. Lung cancer mortality, assessed over 17 year periods, was about 5.5 times higher in smokers than in life long non-smokers. Smokers with no pneumoconiosis had slightly higher lung cancer death rates than smokers with pneumoconiosis. We conclude that miners exposed to excessive amounts of respirable coalmine dust are at increased risk of premature death, either from progressive massive fibrosis or from chronic bronchitis or emphysema.

Room for a role for radon in lung cancer causation?

Reduced ventilation due to energy saving has focussed interest on a potential lung cancer risk from increased indoor concentrations of alpha-emitting radon and radon daughters, escaping from building materials and from the ground. Some preliminary studies now also indicate a hazard to be present as related to radon daughter exposure in homes. However, the indoor radon daughter levels have probably been continuously increasing for half a century, especially in colder climates, due to the introduction of central heating instead of stoves and open fire places, reducing thermal ventilation. Furthermore, in our time, many people have got additional exposure through extended indoor work time instead of earlier outdoor activities in farming etc. The steeply increasing lung cancer rates over the past decades as well as the various oddities affecting the relationship between smoking and lung cancer, e.g. the urban-rural difference in lung cancer risk, also after standardization for smoking, the influence of immigration on lung cancer morbidity as well as the varying rates over the world and other observations, would obtain simple explanations by taking radon daughter exposure into account in addition to smoking. Then, also some curious and hitherto unexplained "inverse" relationships between lung cancer and inhalation of cigarette smoke or bronchitis in air-polluted areas, respectively, would become understandable.

The relation of mortality in England and Wales 1969-1973 to measurements of air pollution

The relation between mortality of people aged 45 to 74 and atmospheric smoke and sulphur dioxide in the county and London boroughs of England and Wales was investigated using data for the years 1969 to 1973. Weighted multiple regression analyses, which took into account a number of socioeconomic and climatic variables, showed no consistent relation of smoke or sulphur dioxide with mortality from all causes or with mortality from specified causes postulated a priori to be related to pollution. In particular there was no significant association between smoke and mortality rates for respiratory illness. Comparison with results from similar analyses of data for the two previous decades suggested that a decline in the strength of associations had occurred in parallel with declining levels of the pollutants.

Carcinoma of the lung in Lancashire coalminers

The prevalence at death of carcinoma of the lung in miners and ex-miners has been compared in those with and without pneumoconiosis at necropsy. The prevalence of 11.4% in the group as a whole is no greater than that in the male population in North-west England. Carcinoma of the lung was present in 62 (13.1%) of those without pneumoconiosis and in 52 (9.8%) of those with pneumoconiosis. The mean age at death of those with pneumoconiosis was 71.3 years so that they cannot be said to have died before the age at which they would have developed carcinoma. Those with progressive massive fibrosis whose mean age at death was 72 years had the lowest prevalence of carcinoma of the lung at all ages--8.4%. For reasons stated in the text this is inevitably a biased sample. The number of those without pneumoconiosis is probably lower than the true figure because the deaths of miners and ex-miners in whom there is no suspicion of lung disease may not have been reported to the coroner or to the pneumoconiosis medical panel. There appears to be no positive link between carcinoma of the lung and pneumoconiosis. There is a surprisingly high number of smokers and ex-smokers among these miners, and this appears to have more relevance to the prevalence of carcinoma of the lung than does pneumoconiosis.

Late effects of air pollution with special reference to lung cancer

The Department of Environmental Hygiene of the National Swedish Environment Protection Board and of the Karolinska Institute have prepared an extensive review on health effects of air pollution, to be used by the Swedish Parliamentary Committee on Energy and the Environment. This report forms the basis for one part of the review, that on late effects. Much of the work on the review, is the result of a team effort involving researchers from numerous organizations.

Mortality from respiratory disease at follow-up of patients with asthma

Over a 20-year period 765 men and 1127 women with asthma were followed up; 272 men and 282 women died compared with expected deaths of 165 men and 185 women. As anticipated there was an appreciable number of deaths attributed to asthma but an even higher absolute excess of deaths attributed to bronchitis when compared with the expected numbers. The relative excess from asthma and bronchitis was highest in the younger subjects. Mortality from all other causes was lower than expected.

Relation between lung cancer, chronic bronchitis, and airways obstruction

Since cigarette smoking is an important cause of lung cancer and chronic bronchitis both conditions should occur together more often in cigarette smokers than would result from chance. If they do commonly occur together then severe airways obstruction, which is often associated with chronic bronchitis, should also be often associated with lung cancer. To discover whether this were so three groups of patients were studied at the London Chest Hospital. Two hundred men and 43 women who presented with lung cancer provided information on the prevalence of defined chronic bronchitis and airways obstruction in those suffering from lung cancer. The third group consisted of 233 men presenting with defined chronic bronchitis who were kept under observation to discover how many would die from lung cancer. The results suggested that simple bronchitis and lung cancer often occur together but that obstructive bronchitis and lung cancer do not often occur together. The lack of association between lung cancer and severe airways obstruction requires an explanation.

Lung cancer in miners

The clinical, histological, and biological features of 157 lung cancers in coal miners and ex-miners are presented. In most respects—age, bronchoscopic appearances, histological type, and symptoms —the two groups are similar. A high incidence of dyspnoea in the miners was attributed to the concurrence of chronic bronchopulmonary disease. A striking feature was the lower frequency with which lung cancer in miners was found to be operable. It was suggested that the lower frequency of lung cancer in miners is related to an enhancement of the state of immunological preparedness in the lung related to the immune component in the pathogenesis of pneumoconiosis. The differences in lung cancer between miners and non-miners may be partially explained in this way.