You might want to mask up: Fireworks cause spikes in short-term air pollution

Officials predict Delaware County, Pa., and Camden County, N.J., will fail to meet the new standard without further action to reduce pollution.

A new study says Earth has pushed past seven out of eight scientifically established safety limits and into “the danger zone."

The city limits toxic air pollutants like lead and formaldehyde. A policy revision expands the list, but critics say it doesn't go far enough.