Pregnant Pause?

Yet another health link to diesel emissions appears to have been established with the finding of soot-like carbon particles in the placentae of pregnant women (http://nohealthproblemsnews.com/health-news/scientists-find-toxic-soot-particles-inside-the-placenta/). It has long been known that toxic air pollution has detrimental effects on the health of neonates but, how it has this action, has been unclear. I am not certain, however, that advising pregnant women (and anyone else?) to avoid, where possible, areas with high air pollution (as some have done) is terribly helpful.