Hill: The Environmental Protection Agency (EPA) sent potential changes to the standard for ground-level ozone to the White House Office of Management and Budget onn Wednesday. The EPA has not said whether it will try to lower the Bush administrations maximum limit of 75 parts per billion; it could simply reaffirm that standard. The EPAs staff and its scientific advisers have asked the agency to reduce to 60-70 parts per billion the allowable concentration of ozone, the main component of smog. The White...