Exposure to secondhand smoke from cigarettes, cooking oil and wood - even a small amount for as little as 10 minutes - has harmful effects on the heart and blood vessels of men and women, a new study shows.

“I was surprised we got statistically significant results with this low level of exposure,” study investigator Joyce McClendon Evans, from the University of Kentucky, Lexington, noted in a statement. “If we can detect these effects with smaller exposures, then the public health hazard from cigarettes and other particulate exposures may have been underestimated.”

In a carefully controlled study, Evans and colleagues briefly exposed 40 healthy non-smoking men and women to low levels of secondhand cigarette smoke, wood smoke or cooking oil smoke as they sat in a 10-by-10-foot room.

Tests showed that low-level exposure to smoke from cigarettes, cooking oil and wood for as little as 10 minutes altered breathing patterns and blood pressure, and ramped up the “sympathetic nervous system” - the “fight-or-flight” system that pumps up the heart and blood pressure during times of high stress, but can be harmful if activated too often or too long.

The effects of brief secondhand smoke exposure were more pronounced in men, probably, Evans said, because the fight-or-flight response is “more active in men than women.”

The magnitude of the effects of brief, low-level exposure to secondhand smoke was similar to longer term, higher level of exposures to environmental tobacco smoke and to smoking a cigarette.

Evan’s presented her team’s research at the American Physiological Society annual meeting - part of the Experimental Biology 2009 conference underway in New Orleans.

By Megan Rauscher
NEW YORK (Reuters Health)