Only 10 minutes exposure of small doses of second-hand tobacco smoke or smoke from cooking oil and wood could adversely affect the cardiovascular function in both men and women, according to a University of Kentucky study.
The study confirmed previous findings that tobacco smoke could possibly harm cardiovascular function.
The study also demonstrated that cardiovascular responses during brief exposures were similar to those found during longer or higher-level exposures.
The scientists found evidence that an increase in air pollution is linked with an increase in heart attacks and deaths.
Pollutants, including tobacco and cooking oil smoke, contain fine particles that evoke responses from heart and blood vessels indicating effects on their function.
In the study, 40 healthy non-smokers (21 women, 19 men) with average age of 35 years were briefly exposed to low levels of common pollutants, and their cardiovascular and cardiorespiratory responses were measured.
The researchers exposed the participants to second-hand cigarette smoke, wood smoke or cooking oil smoke in separate trials as they sat in a 10-by-10-foot environmental chamber. The researchers cleared the air in the chamber after each trial.
They measured respiratory and cardiovascular function-including heart rate variability, breathing and blood pressure- which in turn gave a picture of how the heart, circulatory and respiratory systems were reacting to the pollutants.
It was found that, particularly among men, exposure to smoke changed breathing patterns, raised blood pressure oscillations in peripheral arteries and shifted control of heart rate toward sympathetic domination.
The researchers further found that men responded to environmental tobacco smoke with a greater increase in indexes of sympathetic outflow to blood vessels, compared to women
The sympathetic nervous system produces the "fight or flight" response, which drives the heart and blood pressure and may cause damage if activated too long.
Women responded with a greater parasympathetic response, dubbed "rest and digest," which acts as a brake on the heart and blood pressure.
"I was surprised we got statistically significant results with this low level of exposure. If we can detect these effects with smaller exposures, then the public health hazard from cigarettes and other particulate exposures may have been underestimated," said Evans.
Evans will present the findings during the 122nd annual meeting of The American Physiological Society, which is part of the Experimental Biology 2009 conference.