RfD-oral for Dihydrogen Monoxide (fwd)

[Pawel Gluszynski <uugluszy@cyf-kr.edu.pl>]

Date: Fri, 25 Oct 1996 01:41:49 +0100
Reply-To: allen@ce.udel.edu
From: allen@ce.udel.edu (Herb Allen)
To: Multiple recipients of list <enveng-l@cedar.univie.ac.at>
Subject: RfD-oral for Dihydrogen Monoxide

A toxicologist friend has seen the recent (and not so recent postings)
regarding the dangers of  dihydrogen monoxide and concludes that an RfD is
needed for oral exposure.  I thought the readership should be informed.
His message to me follows:

Recent postings have focussed upon the toxicity of dihydrogen monoxide and,
although correct, have tended to note the more sensationalist aspects of
inhalation toxicity.  I have been researching the matter and, much to my
horror, have discovered that oral exposure to dihydrogen monoxide is far more
prevalent than I had initially believed.  Moreover, I have every reason to
believe that public health officials HAVE KNOWN THAT THIS EXPOSURE IS
OCCURRING ON A WORLD-WIDE SCALE!!  Something needs to be done!!  I offer the
following oral risk assessment  based upon standard U.S. EPA  procedures.

I have searched the literature, and although few have dared to publish, there
are documented cases of dihydorgen monoxide lethality in humans following
acute exposure to amounts estimated at 15 L.  Whether this actually
represents the true LD50-acute can be debated, but it provides us with the
starting point for establishment of an oral reference dose which can be
brought to the attention of public health officials.  Calculations are as
follow:

LD50-acute: 15 L/day.  This is a hard number based upon human observational
studies.

LD50-chronic:  Application of a 10-fold safety factor estimates a chronic
LD50 of 1.5 L per day.  No one is talking - but I suspect that data actually
supports this. A quick check of mortaility rates in developing countries
reveals that average life spans are far lower than those in the U.S.
 Apparently in many of these tropical countries dihydorgen monoxide ingestion
averages 5 L/day or even more!  This cannot be coincidence!

Lowest Adverse Effect Level:  Application of a 10-fold safety factor suggests
that the LAEL (oral,chronic) will be around 0.15 L/d.

No Adverse Effect Level:  Application of a 10-fold safety factor is standard,
setting this value at 0.015 L/d.

Correction for Hypersensitive Individuals:  Given that observational data is
lacking for the last two calculations, application of an additional 10-fold
safety factor to protect potential hypersensitive indivuduals in the general
population is needed.  This reduces the NAEL to 0.0015 L/d.

Recommended RfD-oral: 0.0015 L/d.

Current human exposures in many countries are AT LEAST 1000-FOLD HIGHER THAN
THE RfD!!!  Rigorous enforcement of this RfD would likely have untold public
health effects.  Remember, dihydrogen monoxide is often contaminated with
toxic substances such as LEAD, ZINC and CHLORINE.  The proposed RfD would
limit exposure to these substances yielding yet additional health benefits.
 HARMFUL BACTERIA often use hihydrogen monoxide as a vehicle to enter the
body - producing an estimated 3 million deaths of children per year in Africa
alone.  Enforcement of this RfD would all but eliminate mortality via this
vector.

The time to act is now!  The dihydogen monoxide industry is not going to
willingly accept the restrictions likely to flow from this risk assessment.
 But all of us, working together, may have a chance.

Herb Allen
Department of Civil and Environmental Engineering
University of Delaware
Newark, DE 19716
Tel (302) 831-8449   FAX (302) 831-3640