Nitrogen Oxides Emissions and Lung Adenocarcinoma Incidence: A Spatial Analysis of the United States

In the United States lung adenocarcinoma (ADL) incidence over the past century has risen continually surpassing lung squamous cell (SQL) carcinoma as the most common type. The underlying factors influencing this trend have yet to be satisfactorily explained. Prior research has demonstrated the rising trend of NOx emissions, largely a consequence of fossil fuel consumption that resembles the ADL incidence trend, preceding it by about 20 years. The EDGAR project, a joint venture of the Netherlands Ministry of the Environment and the Dutch National Research Programme on Global Air Pollution and Climate Change in collaboration with the Global Emissions Inventory Activity, has produced a 1x1º latitude-longitude grid of global emissions of pollutants that this study used to locate counties in the United States that experienced high NOx emissions ( >100,000 Gg) in 1970. For high and lower NOx emissions areas, the incidences of ADL and SQL were calculated for the period 1990-1995 using SEER*stat, provided by the Surveillance Epidemiology and End Results program. Age-adjusted incidence rates for high and lower NOx areas were 24.4 (24,24.7) and 18.9 (18.6,19.3) for ADL, respectively, and 16.5 (16.2,16.8) and 14.4 (14.2,14.7) for SQL, respectively. Consequently, the relative risks for high vs. lower areas of NOx emissions were 1.3 for ADL and 1.15 for SQL. Such findings add strength to the noted temporal relation of NOx emissions and ADL incidence.