Odor Advisory Issued For Part Of Riverside County

RIVERSIDE COUNTY, CA ? The South Coast Air Quality Management District issued an Odor Advisory warning that the smell of rotten eggs from hydrogen sulfide will move through part of Riverside County between 6 a.m. and 7 p.m. Monday, July 29.

Hydrogen sulfide, known as H25, is a natural process occurring in the Salton Sea. Sunday morning monitors at communities near the sea showed the gas at between 40 and 60 parts per billion.

Most people can smell H25 at 30 parts per billion.

"At that level, most individuals can smell the odor and some may experience symptoms such as headaches and nausea," according to the advisory. "However, the symptoms associated with this level of exposure are temporary and do not cause any long-term health effects. Humans can detect hydrogen sulfide odors at extremely low concentrations, down to a few parts per billion."The winds should pick up Monday night, reducing H25 levels but increasing levels of PM10 particulate dust," the AQMD said.

Hydrogen sulfide is a product of organic decay and has an unmistakable rotten-egg odor.

Parts of the Coachella Valley will be potentially impacted, though historically the smell has wafted as far west as the nearby San Gorgonio Pass Area and communities in Southwest Riverside County. September 2012 was a particularly smelly month.

Low wind speeds can also affect how long the gases will sit in the area. According to the National Weather Service, low wind speeds were forecast for Monday.

In terms of area covered, the Salton Sea is California's largest lake. It was formed in 1905 and is now saline. It straddles Riverside and Imperial counties in the Colorado Desert.

For years, California state agencies have advanced projects at the Salton Sea to improve air quality and provide critical environmental habitat for birds along the Pacific Flyway.