STATE
OF HAWAII
DEPARTMENT
OF HEALTH
P.0.
B0X 3378
HONOLULU,
HAWAII 96801
December
27, 2001
In
reply, please refer to:
HEER
OFFICE
01-402LA
Domus:
475
Mr. Sydney
Ross Singer, Director
Institute
for the Study of Culturogenic Disease
P.O. Box
1880
Pahoa,
Hawaii 96778
Dear Mr.
Singer:
This is in
reply to your letter, which detailed your further
concerns about the use of caffeine to control coqui
frogs.
Upon
further review, the Department of Health is more
convinced that the use of caffeine to control coqui
frogs will not pose a health risk to the people of
Hawaii, because people are not likely to absorb
caffeine from the caffeine spray or its residue.
As you
know, caffeine can cause various adverse health
effects once it enters the body. There are only three
routes for caffeine or any other substance to enter a
human body: by swallowing it, by inhaling it, or by
absorbing it or having it injected through the skin.
Our last letter of November 13, 2001, mentioned the
EPA’s restrictive spray zones which are intended to
protect pregnant women, toddlers, infants, and other
sensitive groups from swallowing or inhaling any of
the caffeine spray.
The
concentrated liquid solution of caffeine could
irritate the surface layers of the skin or eyes by
direct contact but would not be absorbed into the
body. We disagree with your statement that caffeine
"is easily absorbed through the skin." In
order to pass through the skin, a substance would have
to be nonpolar, uncharged, and able to dissolve in
fats or lipids, since a cell membrane is made of
lipids. However, caffeine is polar, charged, and
cannot dissolve in fats or lipids. Therefore, whether
caffeine is dissolved in water for the spray solution,
or whether the solution dries and leaves caffeine
crystals that may be touched with bare feet, caffeine
that originates from this frog-control project cannot
enter the body and affect internal organs or cause
mutagenicity or teratogenicity.
Thank you
again for your concern and interest in this matter.
Sincerely,
Gary Gill
Deputy
Director
Environmental
Health Administration
c: Robert
Boesch, Pesticides Branch, Dept. of Agriculture
