The rate of Americans dying from lung disease has rocketed 30 percent since 1980, new figures reveal.
Researchers at the University of Washington analyzed death records stretching back 34 years from the US Census Bureau.
They found the national rate of deaths increased from 40.8 per 100,000 to 52.9 per 100,000, despite recent successful measures to curb lung-related deaths in some areas.
Most states have seen an increase in deaths: decreases in the mortality rate have been confined to the most privileged seven percent of the country.
But the driving force behind the increase in national death rates comes from the impoverished South. Some counties along the Appalachian Trail have seen the mortality rate increase by as much as 224 percent.
Lung disease deaths: A report published by JAMA today revealed an increase in the rate of lung deaths in America. This map shows how deaths from pneumoconiosis (including those exposed to asbestos) were mainly confined to mining towns in Appalachia
The report, published today by the Journal of the American Medical Association (JAMA) focused on five main conditions: chronic obstructive pulmonary disease (COPD), asthma, interstitial lung disease, pulmonary sacoidosis, and pneumoconiosis (including those exposed to asbestos), as well as other conditions.
By far the most lethal was COPD, accounting for almost four million deaths between 1980 and 2014, compared to 403, 168 from interstitial lung disease and 157,066 from asthma.
Chillingly, most COPD deaths were confined to Appalachia, the impoverished belt in the south that snakes through Kentucky, Tennessee, Alabama, Mississippi, Georgia and West Virginia.
Most asthma deaths were also seen in Appalachia, particularly around the southern half of the Mississippi River, Georgia and South Carolina.
Meanwhile, interstitial lung disease and pulmonary sarcoidosis were more common in the Southwest as well as New England and the northern Great Plains (such as North Dakota).
Unsurprisingly, the highest proportion of deaths from pneumoconiosis (Caused by concrete and asbestos inhalation) were seen in mining towns, particularly in Appalachia.
The report also detailed other chronic respiratory diseases, which accounted for 56,994 deaths since 1980. These were most commonly seen in Mississippi and South Carolina.
The study is the first to estimate mortality rates on an annual basis during an extended period for any chronic respiratory disease, enabling comparison of temporal trends among counties and examination of changes in geographic disparities over time.
It shows a clear correlation between smoking rates or smoke-exposed occupations (such as mining) and lung diseases.
Nonetheless, the authors add that this unprecedented account of death rates shines a light on the growing disparities in healthcare between privileged regions of the West and Northeast, compared to the South.