Average life expectancy has improved for men and women across the nation since the 1960s - about 74 years for men, 79 for women. But researchers from the Harvard School of Public Health and the University of Washington combed through mortality and census data, county by county, and found that, beginning around the 1980s, life expectancy in the most economically disadvantaged counties began to level out or actually drop. It's the first study of its kind to examine mortality trends by county. You can read it here.The counties with the worst life expectancies are in Appalachia and other parts of the deep South--no surprise considering Kentucky has the second highest poverty rate in the nation.(This graphic from the study shows life expectancy by county in 1999. Red areas represent the lowest life expectancy, purple the highest.)Broken down another way, 19% of the female population of the United States, and 4% of males, experienced either a flat mortality rate or an increase in mortality. Meanwhile, in the best-off counties, life expectancy just continues to rise.So, why are more poor women dying younger? The researchers cite smoking, chronic respiratory disease, cardiovascular disease, and obesity--all treatable, and mostly preventable. Also troubling news from their report:"The rise in chronic disease mortality for relatively large segments of the American population, especially women, however, defies recent trends in other high-income countries. The epidemiological (disease-specific) patterns of female mortality rise are consistent with the geographical patterns of, and trends in, smoking, high blood pressure, and obesity." (emphasis mine)The researchers don't speculate about the cultural, social, economic, or geographic causes, but I'd say access to health care in rural and/or isolated (maybe even urban) areas could be one factor. Poverty, leading to a lack of education and access to the more expensive, healthier foods could be another. One could even imagine that environmental pollution contributes - in ways we are only beginning to understand.