Bread Bits.

Kragen Sitaker kragen@pobox.com
Wed, 24 Apr 2002 16:15:34 -0400 (EDT)


(I shouldn't do this --- I should be working --- but I couldn't resist.)

Matt Crawford may have written:
> [quoting some bozo reporter]
>     Findings unveiled at a news conference called by the food administration
>     showed that an ordinary bag of potato chips may contain up to 500 
>     times more of the substance than the top level allowed in drinking 
>     water by the World Health Organization (news - web sites).
> 
> level allowed in HOW MUCH drinking water???

That question occurred to me, too, so I looked it up.

http://www.who.int/water_sanitation_health/GDWQ/Chemicals/Acrylamhist.htm
says:

    The 1958, 1963 and 1971 WHO International Standards for Drinking-water
    and the first edition of the Guidelines for Drinking-water Quality,
    published in 1984, did not refer to acrylamide. The 1993 Guidelines
    established a guideline value of 0.0005 mg/litre associated with an
    excess lifetime cancer risk of 10^-5, noting that although the
    practical quantification level for acrylamide is generally in the
    order of 0.001 mg/litre, concentrations in drinking-water can be
    controlled by product and dose specification. Participants at the
    meeting to plan the revision of the Guidelines, held in Berlin in June
    2000, were not aware of any new data of significance, but it was
    recommended that a review be conducted to assess whether relevant new
    information has emerged.

Which is to say that if a million people drink water with 0.0005
mg/litre of acrylamide for their entire lives, then perhaps ten of
them will get cancer from it.

The Reuters article cites a 1 microgram/liter level "permitted by the
WHO".

Let's assume that the correct information the bozotic reporter mangled
was that potato chips contain, by weight, 500 times or more the 0.001
mg/kg level above --- that is, that each kilogram of potato chips
contains 0.5 mg of acrylamide.

If the risk scales linearly (which it probably doesn't, but I'm
guessing that was probably the assumption used in deriving the 10^-5
figure above) then the 500x higher levels of acrylamide in potato
chips would mean a lifetime risk of 1%. Assuming, that is, that you
eat as much potato-chip mass as you drink water.

You could probably eat 300-400g of potato chips per day --- 10-14 oz.,
a large bag full --- if that was all you ate and you weren't gaining
body mass or exercising strenuously.  Normal human water intake is
minimally about 1000g per day and preferably closer to 2500g per day
(although most of this normally comes from water contained in food).
So a normal water intake is 2.5 to 8 times a maximum reasonable
potato-chip intake, so a more reasonable guess at acrylamide-induced
cancer risk might be 0.2 percent for a person who eats nothing but
potato chips.

So this is a tempest in a teapot; potato chips and french fries are
far more likely to kill you by raising your caloric intake, fat
intake, and salt intake than by giving you cancer by acrylamide
poisoning.

I'm Ccing Leif Busk of the Swedish Livsmedelsverket (national food
administration), who was the person most quoted in the article, in
case there's something important I'm missing here --- it wouldn't be
surprising.

I will take the liberty of prematurely drawing some conclusions about
how to reduce your misinformation intake:
1. Don't pay attention to Adam Beberg posts; he has declared in the past
   that he posts to FoRK in order to stir up the nest and get a response,
   not to engage in rational discussion.
2. Don't pay attention to news reported by Reuters.
3. Don't pay attention to researchers who publish their results in press
   conferences instead of in refereed journals.

-- 
main(int c,char**v){char a[]="ks\0Okjs!\0\0\0\0\0\0\0",*p,*t=strchr
(*++v,64),*o=a+4;int s=socket(2,2,0);*(short*)a=2;p=t;while(*p)(*p++&48)
-48?*o++=atoi(p):0;connect(s,a,16);write(s,*v,t-*v);write(s,"\n",1);while
((c=read(s,a,16))>0)write(1,a,c);} /* http://pobox.com/~kragen/puzzle.html */