Slashdot Mirror

I read those articles. The first one doesn't say anything about their relative toxicities; I expect that Dr. Cohen expected Mr. Nader to cease ingestion of caffeine at a point that would still be safe for both of them.

The second says that, under certain conditions, caffeine can be more toxic. It doesn't discuss the conditions.

The third was best. It stated that the chemical toxicity of caffeine was greater than that of plutonium, but I didn't see anything to back it up.

The fourth didn't address the issue. Dr. Cohen clarified what he said previously, and discussed ingestion vs inhalation, but regarding relative toxicities only said: "eating plutonium is about equal in danger to eating the same quantity of caffeine", but I couldn't find where he explains that claim. (Admittedly, since it's a 17-chapter book, I didn't finish the whole thing.)

The final link again makes the claim that caffeine is more toxic than plutonium, but doesn't discuss it further.

Now, I took it upon myself to do a bit of research, using TOXNET (which doesn't handle deep linking well). I couldn't find any toxicity reports regarding ingestion of plutonium. But there are a number of intravenious studies of both caffeine and plutonium.

It looks like the LDLo (smallest dose recorded to kill) of intravenious caffeine on a dog is 4 mg/kg, while the LD50 (50% kill) of intravenious plutonium citrate is merely 300 ug/kg. Note that since this is comparing an LDLo to an LD50, it doesn't tell us the relative toxicities, but it does seem to suggest that plutonium is more toxic. (Sources: plutonium citrate, caffeine).

To compare LD50 to LD50, we can first look at [JPETAB Journal of Pharmacology and Experimental Therapeutics. (Williams & Wilkins Co., 428 E. Preston St., Baltimore, MD 21202) V.1- 1909/10- Volume(issue)/page/year: 82,89,1944]. This paper establishes the LD50 of caffeine administered intraveniously to a rat at 105 mg/kg. Now, [Venugopal, B. and T.D. Luckey. Metal Toxicity in Mammals, 2. New York: Plenum Press, 1978. 169 (peer reviewed)] establishes the LD50 for plutonium administered intraveniously to a rat at 0.0014 uCi/g. Now, since 5 ug of plutonium has a radioactivity of 0.3 uCi (reference), this figure is equivalent to 8.4e-5 mg/kg.

Perhaps the absorption rate of plutonium is 1e6 times less than that of caffeine. There are suggestions that plutonium is not absorbed easily. But 1e6 still seems like a lot, lacking any other evidence.

But pointing the other way, remember that plutonium builds up on the bones, leading to a chronic toxicity which is higher than its acute toxicity.

So, I'm going to remain skeptical for the time being. I'm not saying it's right or wrong, just that I'm not sure that I agree with that statement.

I read those articles. The first one doesn't say anything about their relative toxicities; I expect that Dr. Cohen expected Mr. Nader to cease ingestion of caffeine at a point that would still be safe for both of them.

The second says that, under certain conditions, caffeine can be more toxic. It doesn't discuss the conditions.

The third was best. It stated that the chemical toxicity of caffeine was greater than that of plutonium, but I didn't see anything to back it up.

The fourth didn't address the issue. Dr. Cohen clarified what he said previously, and discussed ingestion vs inhalation, but regarding relative toxicities only said: "eating plutonium is about equal in danger to eating the same quantity of caffeine", but I couldn't find where he explains that claim. (Admittedly, since it's a 17-chapter book, I didn't finish the whole thing.)

The final link again makes the claim that caffeine is more toxic than plutonium, but doesn't discuss it further.

Now, I took it upon myself to do a bit of research, using TOXNET (which doesn't handle deep linking well). I couldn't find any toxicity reports regarding ingestion of plutonium. But there are a number of intravenious studies of both caffeine and plutonium.

It looks like the LDLo (smallest dose recorded to kill) of intravenious caffeine on a dog is 4 mg/kg, while the LD50 (50% kill) of intravenious plutonium citrate is merely 300 ug/kg. Note that since this is comparing an LDLo to an LD50, it doesn't tell us the relative toxicities, but it does seem to suggest that plutonium is more toxic. (Sources: plutonium citrate, caffeine).

To compare LD50 to LD50, we can first look at [JPETAB Journal of Pharmacology and Experimental Therapeutics. (Williams & Wilkins Co., 428 E. Preston St., Baltimore, MD 21202) V.1- 1909/10- Volume(issue)/page/year: 82,89,1944]. This paper establishes the LD50 of caffeine administered intraveniously to a rat at 105 mg/kg. Now, [Venugopal, B. and T.D. Luckey. Metal Toxicity in Mammals, 2. New York: Plenum Press, 1978. 169 (peer reviewed)] establishes the LD50 for plutonium administered intraveniously to a rat at 0.0014 uCi/g. Now, since 5 ug of plutonium has a radioactivity of 0.3 uCi (reference), this figure is equivalent to 8.4e-5 mg/kg.

Perhaps the absorption rate of plutonium is 1e6 times less than that of caffeine. There are suggestions that plutonium is not absorbed easily. But 1e6 still seems like a lot, lacking any other evidence.

But pointing the other way, remember that plutonium builds up on the bones, leading to a chronic toxicity which is higher than its acute toxicity.

So, I'm going to remain skeptical for the time being. I'm not saying it's right or wrong, just that I'm not sure that I agree with that statement.

Heh. Here is the safety card for ethanol. Guess we won't be seeing that stuff on airplanes either, will we?

The "safety card" for lithium.

It's doesn't seem to me that methanol in a sealed cell is any more dangerous than the lithium you have in your current laptop battery, or for that matter than the ethanol in the spirits sold as "Duty Free" on international flights.

Completely unlike the alternative right? I doubt it would be too hard to package methanol into safe, disposable, self-sealing packages.
At least methanol doesn't ignite when it comes in contact with air.

Here is the methanol safety card. I don't see these on airplanes anytime soon. Anyway, remember those old photocopies from the 70's/early 80's that made pages with blue text? They always smelled a bit and came out a little wet. Yup, methonal was the fluid used in them....

-Sean

Hrmm...I've taken several chem labs, and wouldn't it be a good idea to let the caffinated water evaporate for a while? This will increase the caffene concentration by removing excess dillution media (i.e. water).

Oh, and FYI:
Caffeine MSDS
Caffeine Toxicity Info

I knew the bio major in me would be useful someday ;-)
--------------------------