The Environmental Protection Agency (EPA) has revised the air quality standards for sulfur dioxide (SOâ‚‚) to better protect the environment. The previous standard had a three-hour measurement period, but now it is an annual average over three years, limited to 10 parts per billion (ppb). The EPA decided to keep the existing standards for nitrogen oxides and particulate matter the same. This update comes after reviewing scientific evidence and public feedback to ensure the standards protect public wellness without being too strict.
Simple Explanation
The EPA wants the air to be cleaner, so they changed the rules for how much smelly sulfur stuff can be in the air, saying it should be very tiny over a long time. They looked at science stuff to decide, but didn't change the rules for some other things like smoke and car fumes.