The lawsuit is challenging a plan to allow spikes of sulfur dioxide at two power plants. Even at low levels, SO2 can affect asthmatics in as little as two minutes.
The agency went against recommendations from its own scientists that a stronger standard could save lives. Pa. is one of four states that don't meet the current standard.
A researcher found ticks with the bacteria that causes Lyme disease in Pittsburgh's parks. He says there's a risk of getting the disease at any urban or suburban park in the region.