Austin, Elena
Zanobetti, Antonella
Coull, Brent
Schwartz, Joel
Gold, Diane R
Koutrakis, Petros
Article History
Received: 14 November 2013
Revised: 14 March 2014
Accepted: 30 April 2014
First Online: 9 July 2014
Competing interests
: The authors declare no conflict of interest.