We are made of poison

kw: book reviews, nonfiction, polemics, chemistry, toxins

I would call The Body Toxic: How the Hazardous Chemistry of Everyday Things Threatens Our Health and Well-being, by Nena Baker, required reading on a level with Silent Spring. We are no longer dependent on the "canaries in the coal mine" to indicate our risk; we are ourselves losing our "song".

The developed world has had a hundred-year love affair with chemical conveniences, and now we can see that they are false lovers. For a window into your own risk, go to CDC's biomonitoring project and download the Third National Report on Human Exposure to Environmental Chemicals, or its summary; both are free downloads in pdf format.

Ms Baker is wise enough to focus on just five bad actors that are currently found in the environments, and bodies, of nearly every American resident: atrazine (an herbicide), phthalates (plasticizers in cosmetics), PBDE's (fire retardants), Bisphenol A (main component of polycarbonate food containers), and perfluorinated chemicals (surfactants).

Her treatment is the same in the chapter devoted to each of these classes of chemical: a saga, that gets repetitive, of the attempt by scientists to publicize alarming, even scandalous results about the risks of a chemical material, and the heavy-handed lobbying effort by manufacturers to discredit them and persuade regulators that "Nothing is wrong; just trust us." Amazingly, regulators in the US do so with numbing regularity.

There is a ray of hope in Europe, which two years ago legislated REACH (Registration, Evaluation, Authorization and restriction of CHemical substances). Other areas of the developed world are taking their cue from REACH, including Canada. The U.S. is suddenly the lagging black sheep! I wonder if even shame can reach the shameless at this point. Because the problem is, carrying out these regulations will make the prices of many things go up.

Let's take a quick look at two toxins we all carry. The average Western person has a "body burden" of about 20 parts per trillion (ppT) of a perfluorinated chemical called PFOS. It is found in the older version of ScotchGuard. This stuff has the chemical formula C₈HF₁₇O₃S, and a molar mass of 500 (keep this number in mind). What does 20 ppT mean?

The number of somatic cells in a human body is between 100 trillion and 200 trillion. The average cell's mass is half a nanogram, or 5x10^-10g. The number of nucleons (protons and neutrons) in a gram is just over 6x10²³. Multiply these two, and the number of nucleons in an average human cell is about 3x10¹⁴, or 300 trillion. Thus one ppT of the human cell would be the mass of 300 nucleons. If a substance has a molar mass of 300, and exists in you at a level of one ppT, then on average each cell in the body contains one molecule of that substance. With me so far?

Now we can puzzle out PFOS: 20x300/500 = 12. Every cell in your body contains about twelve molecules of PFOS. That might sound like a lot, but it probably isn't doing much; there are millions of copies of many enzymes in each of your cells.

But let's look at another bad actor that the author doesn't mention: OCDD, the most common dioxin. Dioxins are the most toxic small molecules known. According to the Third National Report mentioned above, the amount of OCDD in the fat cells ("lipids") of Americans ranges from 1,000 to 1,600 ppT, or 1-1.6 parts per billion (ppB). OCDD has a molar mass of 460, so there are 655 molecules per fat cell, though many fewer in other kinds of cells.

I realize that even 650 molecules of a dioxin isn't really very much, but numbers like that are a tad uncomfortable. Though I work in the chemical field, I am all for my company and others finding alternatives for the worst chemicals in use today, alternatives that are less risky. What will drive up the cost is not the work to find the alternatives, but the work to test them. That's where we need national backing for REACH-type regulations in America.

In my indexing I use the term "polemic". A polemic is not necessarily bad; Silent Spring is a polemic also. Polemic language is intended to wake people up and stir them to action. The Body Toxic can do so, and I hope it does.