Volume 16, Number 2, May 1994, p.13
A long time ago (September 1991, in fact) I wrote a column "Tell Me a Story." It was the second column I had prepared under Elizabeth C. Welsh's editorship. This is a follow-up on that column and an appreciation of Liz's work on the newsletter.
"Tell Me a Story" was a musing on how difficult it is to come to an absolute understanding of toxicology in a species as complicated as the human animal. The example discussed was the long known but not well understood dangers of dioxins, particularly TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin).
Things never get easier or comprehensible. The April 1994 issue of Scientific American (which also contains an excellent article "Precious Metal Objects of the Middle Sican") contains a "Science and the Citizen" entry entitled "An Epidemic Ignored," by Marguerite Holloway. The ignored epidemic is endometriosis.
Long ascribed to a women's lot or retribution for Eve's quest for knowledge, the disease was ignored and historically under- diagnosed. Endometriosis is caused by renegade cells from a woman's uterine lining attaching to other internal organs. Once lodged in the bladder, intestine or even the lungs, the cells respond to the hormonal cycles that cause menstruation. There the cells build up when estrogen levels rise and slough off when, in turn, progesterone levels rise, causing internal bleeding and great pain.
Recent studies have linked the increase in endometriosis (and related infertility) to exposure to dioxin and PCB (polychlorinated biphenyls; e.g., Aroclor). Another case of lab rats being fed mega-doses of artificially sweetened soft drinks? Sadly, no. A colony of rhesus monkeys was exposed to dioxin 15 years ago. The exposure levels were not high, ranging between 5 and 25 parts per trillion (ppt). (The author states that normal levels are 7 ppt, victims contaminated in the 1976 accident in Seveso, Italy were found to have 56,000 ppt in their blood.) Fifteen years later, 79% of the (female) monkeys developed endometriosis. Less compelling studies were said to find a correlation with exposure to PCBs as well.
Don't relax boys. In the March 21, 1994 issue of Newsweek, in an article entitled "The Estrogen Complex," Sharon Begley with Daniel Glick report on estrogen mimics. Both males and females produce estrogen; and we both have receptors for the hormone. According to the article, many industrial chemicals have structures similar enough to bind to the estrogen receptors. Chemicals with names like DDE (a breakdown product of the pesticide DDT), PBBs (polybrominated biphenyls, used as a flame retardant until the 1973 "Michigan Incident"), and PCBs and dioxin all seem to be able to play havoc with reproductive systems.
The 1978 "Michigan Incident," in which cattle feed was contaminated with PBBs, caused testicular malformations and undersized penises in the sons of women who ate contaminated beef while nursing. In Taiwan, scientists are studying the sons of women exposed in a 1979 PCB spill. 118 boys suffered reproductive defects which "were probably related to hormonal changes caused by toxic exposure."
Studies show that since 1938, sperm counts of males have decreased by an average of 50%. Testicular cancer has also tripled. There were only 21 reported cases of endometriosis 70 years ago--now there are 5 million in the US. A German study has just shown that women with endometriosis are more likely to have high levels of PCBs in their blood.
Reading these articles frightened me. Yes, I am concerned about the use of Aroclor (PCB) as a mounting medium in conservation. But more fundamentally, I am frightened by the subtlety of it all. These are serious, lifelong effects of chemical exposure. But the effects will not show up in tests designed to determine lethal doses of chemicals. The hazards of working with chemicals that act so slyly on the human organism will only be realized in hindsight.
Should we turn in our solvent bottles? No, I don't think that's necessary. But we must be very careful when using any chemicals in our work. Minimize your exposure by using common sense. Wear gloves, use a respirator, don't allow chemical trash in the studio to contaminate the air you breath. Do not allow yourself or your progeny to become human guinea pigs.
To lighten things up a bit--for the you-can't-believe-everything-you-read file: A very cute little book, the Pocket Ref, by Thomas J. Glover (Sequoia Publishing, Inc.; Littleton, Colorado; $9.95) is full of interesting and useful information. In the chapter on "Glues, Solvents, Paints & Finishes," the table on solvents, however, contains so many errors, it would be funny if it were not so potentially harmful. Consider: "Naptha [sic]: Naphthalene, slight smell but good for some applications, non-photochemically reactive. Very fast evaporation." Or: "Solvent alcohol: Methanol or methyl alcohol or wood alcohol, CH3OH--non-photochemically reactive, poisonous, used primarily as a thinner for shellac" Obviously, nap*h*tha is referring to the fast evaporating petroleum benzine, or VM&P naphtha and not the coal tar constituent which was used for moth balls. I have never heard the term "solvent alcohol" but methanol is a very toxic material and should not be used. There is no reason that I know of for using it as a thinner for shellac, as ethanol is an excellent solvent for this purpose.
The changing of WAAC Newsletter editors is a stimulating time for the organization. I have already been working with Carolyn Tallent, our new editor. But I will miss working with Liz. Perhaps only a former WAAC Newsletter editor can really know what it takes to solicit contributions, manage the columns, edit, typeset, produce, print and distribute this publication. It takes a lot of hard work, patience (e.g., this column was submitted past the deadline) and a love for our profession. Liz's enthusiasm, intensity and consummate professionalism will serve her well in her future endeavors. I was, and we were privileged to have enjoyed her as our editor for the last 4 years.
Chris Stavroudis is a conservator in private practice.