RE: Hazardous vs. Radioactive Materials

["Frohmberg, Eric" <Eric.Frohmberg@maine.gov>]

Actually, NRC did an evaluation of this as part of the early talks with EPA on risk harmonization.  It is attachment 3 of SECY-96-110 dated  May 17, 1996 - from James M. Taylor called "Completion of response to the staff requirements memorandum, for SECY-95-249, on Risk harmonization white paper and recommendations by the Interagency Steering Committee on Radiation Standards". 

 

It is a VERY interesting read.  Among other gems, they conclude,

 

"99.99% of of the chems to which people are exposed are naturally occurring"

"as is the case with synthetic chemicals, about half the natural chemicals that have been tested have been classified as possible or probable human carcinogens because they cause cancer in lab rodents at very high doses"

"If one assumes that the positivity rate for untested synthetic chemicals is the same as that for untested naturally occurring chemicals, natural chemical carcinogens make up the majority of the chemical carcinogens to which humans are exposed".

 

My personal favorite:

 

"Gold et al. hazard rankings indicate that if you eat one apple a day, the calculated lifetime cancer risk form the caffeic acid in the apple would be equivalent to 3 x 10^-3.  One eighth of a head of lettuce perday would yield a lifetime risk of 1e-2 (also from caffeic acid); the risk of one mushroom per day would be equivalent to 1e-2 (from hydrazines).  A cup of coffee per day would imply a lifeitme risk of 1e-3 of cancer from caffeic acid (Coffee contains 1000 natural chemicals, and only 26 have been tested. Of those that have been tested. 19 have produced cancer in lab animals." (For what it is worth, the only way you are going to get the coffee cup out of MY hands is by prying it from my cold dead fingers ...)

 

They do, point out, however, that "one should probably not pay much attention to these absolute numbers because, despite the fact that fruit and vegetables are full of rodent carcinogens, it is fairly clear from epi studies that fruit and vegetable consumption actually reduces risk of cancer."  (A very depressing conclusion for a risk assessor).

 

They conclude:

 

"If the fraction of natural chemicals that are carcinogenic is the same as the fraction of synthetic chemicals that are carcinogenic, then the calculated chemical background risk is actually much larger relative to calculated man-made chemical risk than radiation background risk is relative to man-made radiation."

 

Anyway, it is a great read.  But also to answer part of your question, some of the naturally occurring chemical carcinogens include aflatoxin, arsenic (in groundwater for example), criminy - I mean dioxin can be produced in forest fires.  Tobacco is naturally occurring!

 

Unfortunately, I don't have a software version, or know where it is posted.  But I'm sure someone has posted it somewhere.

 

-Eric

 

Eric Frohmberg

Toxicologist

Key Plaza, 8th Floor

11 State House Station

Augusta, ME 04333-0011

Tel: (207) 287-8141

FAX: (207) 287-3981

TTY: (207) 287-8066

eric.frohmberg@state.me.us

 

 -----Original Message-----
From: BLHamrick@AOL.COM [mailto:BLHamrick@AOL.COM]
Sent: Sunday, March 09, 2003 4:37 PM
To: radsafe@list.vanderbilt.edu
Subject: Hazardous vs. Radioactive Materials

> This may be slightly off-topic for this list, but I was 
>
>   wondering if anyone knew of any specific hazardous materials (carcinogens) 
>
>   that are present in the natural background, as radioactive material is, and 
>
>   what the "background" risk levels might be for those hazardous 
>
>   materials.
>
> Barbara