A study published Aug. 28, 2017, in the Proceedings of the National Academy of Sciences adds a new dimension to the controversial decision to inject large amounts of chemical dispersants immediately above the crippled oil well at the seafloor during the Deepwater Horizon disaster in 2010. The dispersants may have significantly reduced the amount of harmful gases in the air at the sea surface—diminishing health risks for emergency responders and allowing them to keep working to stop the uncontrolled spill and clean up the spilled oil sooner.