title: Epidemiology of stomach cancer in Chile--the role of nitrogen fertilizers.
abstract: Chile ranks second in the world regarding age-adjusted mortality rates from stomach cancer. Analysis of death rates along its 25 provinces for a 15-year period (1957-1971) shows a peculiar geographic pattern of high and low-risk areas. Three agricultural provinces (Maule, Linares and Nuble, located south of Santiago), population 460,000, show a median rate of 50 x 1 per 100,000. In contrast, both extremes of the country, distant some 3,000 miles from one another, carry less than one-half the risk. The three northerly provinces (Tarapacá, Antofagasta and Atacama), population 652,500, show a median rate of 21 6, whereas Aysén and Magallanes in the extreme south, population 161,600, share a figure of 22.8 per 100,000. Data showing the use of nitrates throughout the country were collected for the period 1945-1972. A high correlation has been found between death rates and cumulative per capita exposure to nitrogen fertilizers. Controlling for confounding socio-economic variables, estimated by housing and infant mortality rates, the correlation holds at a significant level. A negative correlation between stomach cancer and infant mortality rates, low correlation with housing rating, and a negative correlation with lung and cervical cancer deaths were also found. The latter reinforces the lack of association with socio-economic conditions. Other major sites show a completely different pattern. The epidemiological evidence presented agrees with biochemical findings on the synthesis of nitrosamines.
authors.affiliation: Division of Epidemiology, School of Public Health, University of California at Los Angeles, Los Angeles, California 90024, USA.
authors.forename: R
authors.initials: R
authors.lastname: Armijo
authors.forename: A H
authors.initials: AH
authors.lastname: Coulson
mesh_terms: D000328:Adult; D002677:Chile / Q000453:epidemiology; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis / Q000706:statistics & numerical data; D005260:Female; D005308:Fertilizers / Q000633:toxicity*; D006798:Housing / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D008297:Male; D009026:Mortality; D009566:Nitrates / Q000633:toxicity*; D012307:Risk Factors; D012959:Socioeconomic Factors; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000209:etiology / Q000401:mortality; D013997:Time Factors; D014877:Water Pollution, Chemical / Q000032:analysis / Q000706:statistics & numerical data
chemical_list: D005308:Fertilizers; D009566:Nitrates