The Iowa Department of Natural Resources extended its air quality advisory today for parts of Iowa after monitors showed continued pollution in the air. D-N-R air quality specialist Brian Button says the advisory covers virtually all of central and eastern Iowa. He says it’s especially important that people with heart or lung disease postpone strenuous outdoor activities. Button says the polluted air has hung over the midwest without any clean air to push it out of the way, or mix with it.He says air temperatures at eight or 10-thousand feet have been similar to the ground level temperatures, and he says that’s keep the emmissions from mixing vertically and move out. He says a new air mass is gradually moving into the state by tonight. Button says western counties from a line extending west from Atlantic, Denison and Estherville are already receiving a new air flow today.