The study uses monitor-laced vests to give doctors a better idea what pollution - indoors and out - does to the body.
65 men & women in Detroit wore the high-tech pollution monitors for 2 weeks - 1 week in the summer, 1 in winter.
For the first time, scientists were able to measure all the pollution zones we pass through every day.
The vests show that pollution can raise blood pressure - that's something doctors didn't know before.
The vests also showed even though the volunteers weren't smokers, a third of them were exposed to secondhand smoke.
Dr. Robert Brook, a University of Michigan physician who led the study, says, "So by wearing this vest, we could see that low levels of secondhand smoke occur throughout the community, and that many of us are exposed to it, whether we know it or not."
The study was funded by the E-P-A, and could have a big impact on pollution regulation in the future.