Analyses of the ground and aircraft data performed by Setyan et al. (2012), Shilling et al. (2013), and Kleinman et al. (2016) showed that organic aerosol production increased when human -
caused emissions from Sacramento mixed with air rich in
isoprene, an organic compound wafting from many plants that originate in the area's foothills.
Isoprene is a precursor to ozone, which as a ground - level pollutant is believed to
cause many health - problems especially among the vulnerable, including premature death.