EPA Proposes First Toughening of Air Quality Standards for Sulfur Dioxide (SO2) Since 1971

sox epa chart

Source: EPA
About Time
It's been almost 40 years since the EPA's SO2 standards were strengthened. Sounds like a tightening was overdue... Until now. The EPA is look at a proposal to establish a new national one-hour SO2 standard, between 50 and 100 parts per billion (ppb). "The existing primary standards were 140 ppb measured over 24-hours, and 30 ppb measured over an entire year. The Agency also is taking comment on alternative levels for the 1-hour standard up to 150 ppb."From the EPA:

EPA also is proposing changes to monitoring and reporting requirements for SO2. Monitors would be placed in areas with high SO2 emission levels as well as in urban areas. The proposal also would change the Air Quality Index to reflect the revised SO2 standards. This change would improve states' ability to alert the public when short-term SO2 levels may affect their health.

But this proposal is only for the primary SO2 standards (public health). The secondary standards (public welfare, including the environment in general) will be looked at in a second proposal in 2011.

The benefits of the new SO2 standards could be pretty big:

EPA estimates that the revised standards would yield health benefits valued between $16 billion and $100 billion. Those benefits would include reduced hospital admissions, emergency room visits, work days lost, cases of aggravated asthma and chronic bronchitis, among others.

Via EPA, Green Car Congress
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