Document e57G1w6mBDjG49Yb5MG9xk7k4

FILE NAME: Newspaper & Magazine Articles (NMA) DATE: 1956 Mar 16 DOC#: NMA111 DOCUMENT DESCRIPTION: Journal Article - News of Science Smoking, Air Pollution, and Lung Cancer News of Science Smoking, Air Pollution, and Lung Cancer P. C. Stocks and J. M. Campbell sum marize the results of the first 2 years of a 5-year study in England of environ mental histories of persons with and without pulmonary cancer in the Brit ish Medical Journal [1955, II, 923 (15 Oct. 1955)]. The death rates from cancer of the lung, bronchus, and pleura were calculated in men between 45 and 74 years of age, of different smoking habits, living in rural, mixed, and urban areas. The death rates were then related to measurements of 3 : 4-benzpyrene and other carcinogens present in the air in the areas studied. Concentrations of smoke and sulfur dioxide were deter mined according to standard methods, and anthracene, pyrene, fluoroanthrene, 3 :4-benzpyrene, and 1 : 12-benzperylene were quantitatively determined by spectrophotometric techniques. It was found that the concentration of smoke, 3 : 4-benzpyrene, other polycyclic hydrocarbons, and sulfur dioxide in the air rises with increasing urbanization. The air concentration of benzpyrene in Liverpool was 8 to 11 times that in rural areas. This ratio corresponded with the estimated mortality ratio among nonsmokers in those areas. The rural death rate from lung cancer increased propor tionately to the number of cigarettes smoked per week, and pipe smokers as a group ranked with cigarette smokers of approximately 25 per week. The city death rates exceeded the rural rates, but the urban/rural ratio fell from approxi mately 9/1 in nonsmokers to nearly 1 in heavy smokers. The authors estimate that approximately one-half of Liver pool deaths of men from lung cancer arise from cigarette smoking, and about three-fourths of the remaining half are due to a factor only slightly present in rural areas. All death rates from lung cancer were directly proportional to the estimated amount of exposure to 3 : 4-benzpyrene, either from cigarette smoke, air pollu tion, or both. Stocks and Campbell sug gest an "urban" factor in the etiology of lung cancer, and feel that benzpyrene plays a dual part, through cigarettes and air pollution. The authors note that their report is presented as an interim com munication and that its indicated conclu sions are far from final. W. C. Hueper notes that the total evi dence from epidemiological, clinical, and pathological studies indicates that lung cancer is caused by several atmos pheric pollutants, rather than a single factor, in Public Health Reports [71, 94 (Jan. 1956)]. He states that the avail able data do not allow determination of the relative importance of the various recognized respiratory carcinogens in the general population, although single car cinogens in the air have been implicated in lung cancer in restricted occupational groups exposed to well-defined, potent carcinogens. He feels that the recent alarming in crease in frequency of lung cancer may be. causally related, in part, to atmos pheric pollutants that are carcino genic, as a by-product of modern indus trial development. A number of general environmental and specific occupational air pollutants have been implicated in the causation of lung cancer, such as dusts and fumes of nickel, chromium compounds, arsenicals, asbestos, coal tar, soot, vapors or mists of isopropyl oil, cer tain cancer-producing petroleum deriva tives, radioactive ores and gases; and carcinogens present in gasoline or diesel engine exhaust, dust of asphalted roads, and carbon black (in automobile tires). Numerous epidemiological observations strongly suggest that industry-related factors have played an important causal role in the increase of lung cancers ob served in industrialized countries during the last 50 years. According to Hueper, there does not seem to exist any parallelism between the lung cancer death rate and the per capita consumption of cigarettes for different countries,"but the lung cancer death rate parallels as closely, or even more closely, the rise in production and/or consump tion rates of motor fuel, coal tar, and several other carcinogenic substances, or the production of asphalted roads, (hart that of cigarettes. He feels that the medi cal evidence supporting a major role of cigarette smoking in the , .tus.uu.u ot cancer is inadequate. Alrhough the r e p o r t s r,t f>. v -d r's are essentiailv opposed trgauf'ng the unity or multiplicity of causative agents of respiratory cancer among the general population, as well as regarding the role of cigarette smoking in this disease, cer tain common factors are apparent. The identification of more- or-less proved car cinogens in air pollutants and/or in cig arette smoke is becoming increasingly correlated with the incidence of lung cancer. The qualitative relationship ap pears convincing; the quantitative rela tionship to the estimation of concentra tions of these compounds is of impor tance if the quantification of lung cancer incidence can be accurately established from reliable pathological observations. At present, the latter does appear to cor relate with this incidence, and does sup port the qualitative relationship thereto. An interesting and important consid eration is raised by Hueper: that the in dications that tobacco tar contains car cinogenic agents have been derived from observations of the skin of a selectively inbred strain of hyper-reactive mice, and have no equivalent in man. However, the finding of Stocks and Campbell that ex posure to 3 :4-benzpyrene, whether from tobacco smoke or from air pollution, is consistently and quantitatively related to human lung cancer incidence consti tutes a strongly suggestive piece of evi dence. It would appear at present that at least one, if not several, carcinogenic com pounds are of etiological significance in this disease, and that increasing indus trialization with its by-product of air pol lution is a significant factor in the in creasing evidence of lung cancer. Al though the more quantitative aspects have yet to be firmly established, the present reports represent somewhat of an advance in the direcrion of clarifying a field of investigation that has too fre quently been the subject of extremely equivocal or sensational reports.-- E.M.L. Cosmic Spherules in Deep Sea Sediments The small magnetic spherules con tained in deep-sea deposits [Science 123, 1081, 2 Dec. 1955)] sontinue to interest scientists in various Darts of the world. E. J. Opik (Ireland; considers various kinds of evidence foi the cosmic source of these deep-sea deposits, stressing par ticularly that the frequency of spherule diameter distributor extracted from samples of deposits obtained by the Swedish deep-sea expedition shows ex cellent agreement with theoretical fre quency of mirro m neois u\a tw e 176. 926 [ iJ5t>; . th e i a i e c a m o u n t. . :v a iSC 1in . en re, m o , o - n u t iu t h u t these p 11 { t C i : . C t ' . " . . i ' I L c to 4