California becomes the 3rd state to ban smoking in cars with children

California motorists will risk fines of up to $100 next year if they are caught smoking in cars with minors, making their state the third to protect children in vehicles from secondhand smoke.

Gov. Arnold Schwarzenegger on Wednesday signed a bill that will make it an infraction to smoke in a vehicle if someone under age 18 is present. But the traffic stop would have to be made for another offense, such as speeding or an illegal turn, before the driver could be cited for smoking.

The ban, which takes effect Jan. 1, joins a string of smoking prohibitions adopted in California, including a ban on smoking in enclosed workplaces and within 25 feet of a playground.

A Harvard School of Public Health report issued last year said secondhand smoke in cars can be up to 10 times more of a health risk than secondhand smoke in a home.

"Protecting the health of our children is among government's highest responsibilities," said the bill's author, state Sen. Jenny Oropeza, a Democrat. "It is clear that increasing public awareness about the dangers of secondhand smoke is the right thing to do."

At least 20 states and a number of municipalities have considered limiting smoking in cars where minors are present. Arkansas now bans smoking in cars with children age 6 and younger, while Louisiana has limited it when children 13 and younger are in the vehicle. Maine lawmakers will take up the issue in January.