The U.S. Environmental Protection Agency (EPA) has issued a final science assessment for sulfur dioxide (SO2) which suggests that a short-term standard will be needed to protect public health. (more…)

The current National Ambient Air Quality Standards (NAAQS) for sulfur dioxide were set in 1971 based on a Criteria Document published in 1969 by the Department of Health Education and Welfare. The scientific articles considered in the original Criteria Document predate 1968. In 1971, the newly established EPA set the first primary sulfur dioxide NAAQS: an annual average standard of 0.03 ppm (80 µg/m3); and a 24-hour standard of 0.14 ppm (365 µg/m3). The current standards are based on 40 plus year old science. (more…)