EPA’s science advisers say the agency should tighten the federal air quality standard for ozone from the current limit of 75 ppb to no more than 70 ppb. The Clean Air Scientific Advisory Committee agreed at a recent meeting that EPA should consider setting a new standard between 60 and 70 ppb. “We believe that the current standard for ozone is not protective of human health,” the panel said in a draft letter to the agency. EPA will consider the recommendation when it reviews the existing ozone standard, which was set in 2008. Under a court-ordered deadline, the agency has until Dec. 1 to decide whether it should retain or revise the 75-ppb limit. The American Lung Association and other public health groups have urged EPA to set the standard at no higher than 60 ppb to protect children and the elderly from respiratory diseases linked to ozone pollution. But industry groups and some congressional Republicans contend that the agency should leave the ozone standard at 75 ppb, arguing that air quality is improving and a stricter limit would lead to costly new emissions-control requirements.