Researchers have warned that indoor air pollution-mostly caused by heating and cooking with a biomass fuel such as wood-increases blood pressure among older women.
In a remote area of Yunnan Province, China, 280 women in an ethnic minority called the Naxi wore a portable device that sampled the air they were breathing for 24 hours.
The Naxi live in compounds including a central, free-standing kitchen that often has both a stove and a fire pit, says Jill Baumgartner, who performed the study with National Science Foundation funding while a Ph.D. student at UW-Madison.
"I spent a lot of time watching women cook in these unvented kitchens, and within seconds, my eyes would burn, it would get a little difficult to breathe. The women talk about these same discomforts, but they are viewed as just another hardship of rural life," Baumgartner says.ost women are exposed to this smoke for several hours a day, and even if the cookstove is vented, a second fire is often burning for heat, says Baumgartner, who is now a global renewable energy leadership fellow at the Institute on the Environment at the University of Minnesota.
By correlating exposure over 24 hours with blood pressure, Baumgartner and colleagues associated higher levels of indoor air pollution with a significantly higher blood pressure among women aged 50 and over.
Small-particle pollution raises blood pressure over the short term by stimulating the nervous system to constrict blood vessels. In the long term, the particles can cause oxidative stress, which likewise raises blood pressure.
The study was recently published online in the peer-reviewed journal Environmental Health Perspectives.