This week’s LA Weekly is running a story on density and higher human exposures to particulate matter from freeways:

Black Lung Lofts – Page 1 – News – Los Angeles – LA Weekly

The bottom line from the story is that city planning departments and developers, in their zeal to build more and more mutli-family housing, have placed a greater number of people in dangerous proximity freeway emissions.

Recent research that I have done with SPPD PhD student, Jianping Zhou, has found the same thing is true more generally. Environmental advocates have argued that reducing auto usage will improve urban air quality. Recently, public health researchers have similarly argued that infill development and sprawl reduction may improve respiratory outcomes for urban residents, largely because sprawl reduction should reduce the vehicle travel. But infill can also increase the number of residents exposed to poor air quality, and move people closer to stationary sources of pollution. Aside from emissions studies, planners have little information on the connection between urban form, ambient pollutant levels, and human exposures or how infill changes these.

We examine the neighborhood exposures in 80 metropolitan areas in the US. We used multi-level regression models to find the empirical relationship between a regional urban form measure and neighborhood air quality outcomes. Concentration levels for ozone are significantly lower in compact regions, but neighborhood exposures for both ozone and fine particulates are higher in compact regions and for neighborhoods occupied by impoverished whites, Latinos, African Americans, and Asian ethnic minorities. Fine particulate concentration levels do not correlate significantly with regional compactness.Of particular concern in our study are exposures among impoverished elders of color.