Time trend and geographic patterns of lung adenocarcinoma in the United States, 1973-2002

Abstract

Objective: To find the major factor explaining the substantial increase in incidence of adenocarcinoma of the lung (ADL), we observed its temporal trend, distributions in geographic areas and populations, and compared them with the distributions of air pollution and low-tar cigarette consumption in time, place, and populations. Methods: The temporal and spatial patterns of ADL were compared with the level of nitrogen oxides (NOx) emissions as well as the use of low-tar cigarettes. Results: Similar increasing trends followed by declining trends were seen in emission levels of NOx and ADL incidence rates. These trends peak about 20 years earlier for NOx levels than for ADL incidence. Incidence rates of ADL in high NOx emission areas were substantially higher than those in low NOx emission areas. Incidence rates of ADL in Black males are about 50% higher than in White males and can be explained by the differences in air quality related to residence site and size. Conclusions: The descriptive epidemiologic data help generate the hypothesis that long-term exposure to low-dose NOx may play a major role in causing steep increases in past ADL incidence rates. There is an urgent need to conduct further studies to determine whether the association is a causal relationship between long-term, low-dose exposure to NOx and ADL. Copyright © 2007 American Association for Cancer Research.