Tuesday, May 27, 2008

Highways, blood vessels, and indoor air

A lot of research suggests that particles from outdoor air affect vascular function, especially at high doses. We wanted to see whether the concentration of airborne particles in a regular, normal home would be sufficient to cause similar effects, so we removed them, and indeed we found they had [adverse] effects.
---Dr. Steffen Loft, University of Aarhus, Denmark

The air here in central Denver hangs heavy in the winter and is downright visible in the summer. If ever I deluded myself in thinking that staying indoors protected me and mine from the crap in our air, Dr. Loft has proven otherwise.

Loft and company studied a delegation of Danes living near heavily trafficked roads(1). These old folks, ages 60 to 75, spent four consecutive days in their homes-- two breathing high-efficiency particle-air (HEPA) filtered air and two without. The filter removed 60% of the resident schmutz in their air and improved their flow-mediated dilation (FMD or FMV) by more than 8%. FMD is an indirect measure of the healthy function of blood vessels.

Is 8% a significant boost to vascular function? Again, per Dr. Loft: "...I believe people with overt, severe cardiovascular disease have a reduction in microvascular function in the region of 30% to 40%. I think this improvement is something like what you might expect from a well-working drug."
(1)Brauner EV, et al. Indoor particles affect vascular function in the aged. An air filtration-based intervention study. Am J Respir Crit Care Med 2008. 177:419-425.

1 comment:

Haralee said...

I am so suspect of what is in my air, since living in Portland, Oregon with the second highest rate of breast cancer, next to Washington State, you got to wonder!