The Geography of the Alzheimer’s Disease Mortality in Spain: Should We Focus on Industrial Pollutants Prevention?

Alzheimer's disease (AD) has a high worldwide prevalence but little is known about its aetiology and risk factors. Recent research suggests environmental factors might increase AD risk. We aim to describe the association between AD mortality and the presence of highly polluting industry in small areas in Spain between 1999 and 2010. We calculated AD age-adjusted Standardized Mortality Ratio (SMR), stratified by sex, grouped by industrial pollution density, compared for each small area of Spain. In the small areas with the highest mortality, the SMR among women was at least 25% greater than the national average (18% in men). The distribution of AD mortality was generally similar to that of high industrial pollution (higher mortality in the north, the Mediterranean coast and in some southern areas). The risk of AD mortality among women was 140% higher (123% among men) in areas with the highest industrial density in comparison to areas without polluting industries. This study has identified a geographical pattern of small areas with higher AD mortality risk and an ecological positive association with the density of highly polluting industry. Further research is needed on the potential impact of this type of industry pollution on AD aetiology and mortality.