Tropospheric ozone reduces human exposure to harmful ultraviolet-B (UV-B) radiation.

A 10-ppb decrease in seasonal average concentrations of ozone (about 20%) is estimated to lead to increases in cancers and cataracts valued at $0.29 billion to $1.1 billion annually.

EPA in its ongoing review of the National Ambient Air Quality Standard for ozone should set a standard to minimize all identifiable health effects, including UV-B radiation-related effects.

If these estimates are confirmed, this approach may reduce avoidable cancers, cataracts, and deaths by leading to a different standard than that recently proposed in a program already costing more than $20 billion annually.