Exposure lasted a total of 150 hours, spread over 10 weeks, in three sessions per week lasting five hours each.
"Of course this leads to the question, 'How can we protect urban dwellers from this type of toxicity?' And that's a huge unknown," Finch said.
The authors hope to conduct follow-up studies on issues such as:
If further studies confirm that freeway particulates pose a human health hazard, solutions will be hard to find.
Even an all-electric car culture would not solve the problem on its own, Finch said.
"It would certainly sharply decrease the local concentration of nanoparticles, but then at present electrical generation still depends upon other combustion processes coal that in a larger environment contribute nanoparticles anyway.
"It's a long-term global project to reduce the amount of nanoparticles around the world. Whether we clean up our cars, we still have to clean up our power generation."
|Contact: Suzanne Wu|
University of Southern California