A new report on air quality across the United States offered a cloudy prognosis on the long-term health of about 156 million residents who live in areas that received an "F" in smog and soot pollution ...

Data: American Lung Association; Note: Days where air pollution was worse received a greater weighting in the calculation; Chart: Alex Fitzpatrick/Axios Houston continues to be one of the most ...

Bay Area residents face elevated risks of asthma, heart disease and premature death as air pollution here remains among the ...