31 Aug '14, 11am

EPA staff policy assessment recommends reduction in ozone standard from 75 ppb to 60-70 ppb

EPA staff policy assessment recommends reduction in ozone standard from 75 ppb to 60-70 ppb

A level of 70 ppb is below the O3 exposure concentration that has been reported to elicit a broad range of respiratory effects. A level of 70 ppb is also just below the lowest exposure concentration at which the combined occurrence of respiratory symptoms and lung function decrements have been reported (72 ppb). A level of 70 ppb is also above the lowest exposure concentration demonstrated to result in lung function decrements and pulmonary inflammation (60 ppb). Compared to the 75 ppb standard, 70 ppb would be expected to (1) reduce the occurrence of exposures of concern to O3 concentrations that result in respiratory effects in healthy adults by about 45 to 95%, almost eliminating the occurrence of multiple exposures at or above 70 ppb; (2) reduce the occurrence of moderate-to-large O3 -induced lung function decrements by about 15 to 35%; (3) more effectively maintain sh...

Full article: http://www.greencarcongress.com/2014/08/20140831-epa.html

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