A concern is the vog, which surprisingly so far has
not been shown to be the threat that one might assume. There is info online, including these links:
This
Hawaii Dept of Health website has tons of info.
Here is a
"State of Asthma Hawaii 2010" report.
This article talks about
vog and includes asthma info. It states, "On the other hand, Dr. Elizabeth Tam, from the University of Hawaii John A. Burns School of Medicine, studied 2,000 Big Island children and asthma for three years and found the Big Island’s windward side, t
he part of the island with the least amount of vog, has more kids with asthma. That research showed tobacco smoke to be more strongly correlated with asthma than vog". Her studies seem to indicate that there is correlation between the wet areas [windward] having more mold, and thus more asthma.
This
2008 article speaks about vog and asthma.
Side note: of course, smoking and second-hand smoke exposure is the biggie, and Hawaii Island has many protective laws to help decrease that exposure.