Children riding in cars with adults who smoke are at serious risk of respiratory problems, according to New Zealand researchers who called for legislation banning smoking in cars.

The Associated Press reported Oct. 26 that researchers from the Wellington School of Medicine compared riding in a car with a smoker to sitting in a smoke-filled bar. Smoke exposure was significant even when the car windows were rolled down, but air quality was twice as bad as in a smoky bar when the windows were rolled up, the study said.

Whereas particular levels on a smoggy city day might be 35-40 micrograms per cubic yards, the particulate level in a car with windows rolled down was 199 micrograms per cubic yards. With the windows rolled up, the particulate level was 2,926 micrograms per cubic yard.

Antismoking advocates said they hoped that if parents learn that even rolling down the car windows won't protect their kids, they might stop smoking in their cars.