From: bjgaed@bb1t.monsanto.com
Newsgroups: sci.engr.chem,sci.chem,sci.med,sci.engr.civil
Subject: Re: NRDC Criticizes Domenici Plan to Gut Drinking Water Protections
Date: 4 Sep 92 07:30:02 CST
Organization: Monsanto Company, St. Louis, MO

In article <c1lnfdl@lynx.unm.edu>, bhjelle@carina.unm.edu () writes:
> In article <des.26@helix.nih.gov> des@helix.nih.gov (David E. Scheim) writes:

[Stuff about L-Tryptophan deleted]b
> 
>>On the other hand, even though breast cancer rates are rising alarmingly, 
>>though we know many of these "trace" pesticides are carcinogenic, and 
>>though we have no idea of how much of these "trace" contaminants accumulate 
>>into our drinking water, which we injest with far less knowledge or choice, 
>>it certainly makes sense to remove any protections against these 
>>contaminants.
>>
> Yes. Since we all agree that precious little data supports the
> role of bad drinking water in carcinogenesis, we should just
> break the bank of innumerable rural communities to regulate
> the matter to death. Good logic.
> 
> Brian
-- 

That last bit is not very constructive.

People with concerns about contamination of water, however irrational 
those concerns, need to have those concerns recognized and dealt with.

First, those "carcinogenic" contaminants have for the most part never
been shown to cause cancer in humans.  Furthermore they probably never 
will be because there will never be a significant number of humans 
exposed to any of these materials in sufficient concentration 
to even gather evidcence of human 
carcinogenesis.  And that is the point I think we need to make in 
dealing with these issues.  

There are two pieces of real evidence:  
animal models and human exposure data.

For most, if not all, of the "carcinogens" found in drinking water the 
animal models give us some value of risk of cancer, given a certain 
exposure and *assuming* that we can transfer the numbers from the 
animal model to human exposure.  When you do this you find that for 
the most part the risk of human cancer is vanishingly small.

The numbers from the animal models are then to some extent confirmed 
by human exposure data.  This comes either from the days when 
industrial workers who handled the pesticide or farm workers who 
applied it were exposed to orders of magnitude more than would be 
allowable today, or from industrial accidents or inadvertent 
exposures.  (Dioxin exposures are the most well studied.)  When these 
exposures are factored in with the risks from animal models they 
predict what would be the expected increase in cancer in the exposed 
populations.  For pesticides, these studies either show that the 
actual rate of cancer in the exposed populations is no higher than 
that predicted by chance, or they show such a slight increase that it 
is not clear if this is statistically significant.  From data like 
this we cannot accurately predict just how many cancers will be caused 
by the exposure, nor can we gaurantee that there is *no* risk that 
someone will develop a cancer due to the exposure to the compound in 
question.  We *can* however, put an upper limit on the risk and say 
that:

"The risk of increased cancer due to this exposure in the affected 
population will be *less than* (some number).

Now, it may be argued that if someone in the exposed population *does* 
get cancer, they don't care if it's statistically significant or not; 
it's certainly significant to them.  But two points must be made here:

First, should Albuquerque spend $250 million to eliminate, say, less 
than two excess cancer deaths per year?  (Just to pick a number.)  Or, 
would that $250M be better spent elsewhere, say, nutrition, or 
prenatal care, or immunizations, or drunk driver programs, or public 
transportation to reduce air pollution, or child abuse prevention, or 
medical research or . . .   I'm sure you can fill in a *lot* of ideas 
that would save more than two lives per year for $250M.

Second, it can be argued that you wouldn't have to spend any money to 
remove these contaminants from drinking water if they weren't there in 
the first place, so why not just ban the pesticides or whatever other 
contaminants you may find and eventually they just won't be there.  I 
would agree with this if, for example , you were talking about 
contamination by a product or byproduct that had absolutely no benefit 
to society, (fill in your own pet peeve:  cigarette smoke, silly 
putty, . . .), but the pesticides you are talking about do have a 
benefit to society  in increased food production, and other 
contaminants from our industrial society also have very real economic 
benefits.  (*Please* do not start in on me about farming without 
chemical inputs.  That topic has been beaten to death.) 

We simply cannot afford to continue to seriously impair our economy by 
spending vast sums of money to reduce very, very small risks.  We 
*have* to prioritize our problems and spend those funds on the 
problems which will give the greatest return on our investment in 
improved health of the population.  Spending that $250M on eliminating 
those two excess cancer deaths per year, even assuming that all of our 
models and assumptions were right, *DOES NOT MEAN THAT THE CHEMICAL 
INDUSTRY THINKS A HUMAN LIFE IS WORTH $125M DOLLARS.*  Please do not 
try to hang that one on me.  My point here is that there are *a lot* 
of better ways to spend $250M that will save orders of magnitude more 
lives per year than two.

I hope that the person concerned about pesticide exposure is helped by 
this.  The numbers I am using are in the ballpark of those which I 
have seen calculated for actual cases.  For the most part the numbers 
are available, and I urge people with concerns to seek out the actual 
data and place the risks in perspective before making up their minds.

______________
[            ]
[  S O A P   ]
[            ]    There, I'm down/off now.
--------------

Electric Monk                    (Bruce Gaede)

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