San Diego County's Air Pollution Control District launched a website showing hydrogen sulfide levels detected in Nestor and San Ysidro. There are currently two air quality monitoring systems ...

Hydrogen sulfide SMAC values will define safe limits for spaceflight crews on future missions and could drive new requirements for monitoring and mitigation of this chemical during spaceflight.

The EPA tested the hydrogen sulfide concentrations in the air at 20 sites in Crossett. The highest and lowest two-week averages at each site during the first 16 weeks are expressed in parts of ...