Not a breath of fresh air: study finds sewage bacteria in ocean spray

Pathogens such as E coli, norovirus and salmonella can be blown miles into coastal communities after a rainstorm

After a rainstorm passes, the air coming off the ocean just feels different – cleaner and fresher. But a first of its kind study shows how bacteria from sewage in the ocean can get whipped up in salt spray and blow into coastal communities miles away, a phenomenon exacerbated by storm runoff.

The study, released on Thursday by researchers at the Scripps Institution of Oceanography, looked at an area south of San Diego near the US-Mexico border, where a Mexican wastewater treatment plant often becomes overwhelmed and spews sewage into the Tijuana River. That river then flows north into Imperial Beach on the northern side of the border. The beach there was closed 249 days last year due to high levels of pathogens like E coli, norovirus and salmonella – but until now, little was known about what happened when crashing waves sent salt spray into the air.