In-home air purifiers that emit more than a tiny amount of ozone will be banned under a new California regulation. While manufacturers of ozone air purifiers claim that their products can relieve asthma and other respiratory symptoms, thousands of studies have shown that ozone exposure can actually worsen such conditions. “There are reports of ozone being generated in someone’s living room … at levels equivalent to having a Stage 1 smog alert right in your own house,” says former Assemblywoman Fran Pavley, who sponsored anti-purifier legislation. Some 2 percent of California’s population owns one of the popular purifers, and some say they have seen dramatic health benefits. “God gave humans these air purifiers, and you should not take away that gift,” said one satisfied customer at the air board’s public hearing yesterday. Other types of purifiers are available.