The South Coast Air Quality Management District issued an Odor Advisory Thursday through Tuesday, cautioning residents about low-speed winds from the southeast that are expected to bring hydrogen sulfide from the Salton Sea to parts of the Coachella Valley.
Winds from the southeast are expected between 6 a.m. and 7 p.m. each day, according to a statement from the agency.
Hydrogen sulfide (H2S) levels will peak around the North Salton Sea shore and north of the Salton Sea, including cities such as Mecca and Indio.
A gas that smells like rotten eggs, H2S is associated with natural processes occurring in the Salton Sea.
Between midnight on Wednesday and 8 a.m. Thursday, levels of the gas at a Mecca air monitoring station were measured between 14 and 70 ppb (parts per billion), the South Coast AQMD said. H2S levels at the Indio station were between 1 and 26 ppb over that same duration.
California’s standard for outdoor H2S levels is 30 ppb averaged over one hour. At that level, the odor is detectable by most people, with some experiencing temporary systems such as headaches and nausea, the agency said.
However, the symptoms associated with this level of exposure are temporary and do not cause any long-term health effects.
Residents can visit saltonseaodor.org for more information.