The Natural Resources Defense Council released an air quality map this week, with a county-by-county look at ragweed pollen levels and ozone pollution.
The analysis found 40 percent of Americans live in areas with both unhealthy ozone days and pollen-producing ragweed. That includes 4.5 million Arizonans.
Kim Knowlton is a senior scientist with the NRDC who worked on this analysis, and she joins us.
