"The re-entries are really rising quickly. If we stop measuring what is happening in the atmosphere right now, we could be ...

Coastal air samples around San Diego showed high levels of pollutants, including drugs and sunscreen chemicals.

For community groups to allege violations of environmental rules, a state law says groups have to use federally-approved testing equipment, and it sets restrictions for analyzing and sharing the data.

Community groups are fighting an unusual Louisiana law that restricts how they use data from air-quality monitors, saying it ...

"The impact has been muzzling — groups either stopping doing monitoring ... or warning people about potentially dangerous air pollution" when it's detected using air monitors that don't meet ...