Many listeners had questions for industrial hygienist Monona Rossol on yesterday's show. We didn't have time to address all of them on-air, but Monona was kind enough to answer listener questions here. 

Sabrina from Manhattan 
Monona Rossol is a national treasure. Her breadth and depth of knowledge is...staggering.
My question for Monona is about toxins in materials related to sculpture. twofold:
1) Burning wax. My mother, a sculptor, burned sheets of black wax indoors, upstairs in one of the bedrooms of our house, which she converted into a studio. She burned the wax in order to shape it into medium-sized sculptures, which were then cast in bronze at a foundry. This was in the 70s, when I was age 10-18. The air was unbreathable in the room in which she worked, and being someone prone to upper respiratory issues as a teen (bronchial infections, allergies like two others in the family, asthma later in life) I found it insupportable to even enter the room, though it permeated the entire upstairs. She wore only a small mask, a white covering over her mouth of the kind that one wears when there is dust in the air. She made well over 30 sculptures this way over the years. Later, she had a small bit of mouth cancer, which was successfully removed, and she has no respiratory issues. And it would be hard to say whether the exposure to wax was as impactful as that of...
2) Epoxy resin. My mother used epoxy resin consistently for many years on her sculptures, mainly her outdoor monumental sculptures, which she would carve parts of in Styrofoam--another favorite material. These were carved and epoxied in the garage as well as outdoors. Epoxy resin is a smell so deeply familiar to me it is like mother's milk--the kind of smell that you recognize even before you know what it is.
For someone as skeptical, as she is, that there was any toxicity whatsoever in this continuous exposure to burning wax, epoxy resin, and styrofoam carving, can you shed some light? Thanks very much.

Sabrina: Your mother sounds amazing. She proves the George Burns theory of toxicology, that is, some people can drink a fifth of gin a day, chain smoke cigars and live to 100. There clearly is nothing I could say that would change her convictions one whit. She especially wouldn't want to hear what it might have done to you living in this atmosphere as a child. My hope for you is that you have the same genes that have protected her.
-Monona

Jean H. from United States
I had to chime in on the Bath and Body Works comments...Monona raised the important issue of asthma being exacerbated by the potent scents in stores and from burning candles. I don't have asthma but suffer from frequent migraines, and many strong fragrances (even ones I like) trigger a migraine for me. I have mostly resigned myself to avoiding burning scented candles and to be very cautious when trying new scented lotions and soaps. Very interesting that Monona stated that burning candles release actual "toxins" into the air....

Jean: we have migraines in common. There was a perfume used way back in the 60s called Black Narcissus that could give me a blinding one in an instant. So I know you are not making this up.
The wax candles release a number of toxic and regulated chemicals when the burn. I refer you to an EPA Report called "Candles and Incense As Potential Sources of Indoor Air Pollution: Market Analysis And Literature Review," dated Jan. 2001. (Search for EPA-600/R-01-001). The EPA summarizes data from air tests from all the studies and compared the amounts of various chemicals emitted by burning candles: acetaldehyde, formaldehyde, acrolein, polyaromatic hydrocarbons (PAHs), benzo[a]pyrene, and naphthalene. If you read this study and have questions, I'll be happy to answer them.
-Monona

Mia (a farmer) from California
There are lots of organic trees available if you look. The reason you want an organic tree has more to do with what Organic means for soil, water and workers than it does for you having this non-edible crop in your home. All fir and pine trees are naturally pest-resistant and don't typically need a lot of chemical intervention.
Christmas trees are farmed like any herbaceous crop, they do not devastate the forests any more than kale does. Plastic trees, on the other hand, never biodegrade, are made in China from fossil fuels, and take money away from actual American farmers.

Mia: Most of what you say is true. But preventative pesticide spraying of green trees to protect them from mountain pine beetles and other bark insects is being done in many states.
-Monona

Charles from Manhattan
Does Bed Bath & Beyond have a machine that automatically blasts fragrance in to the air believing that it stimulates shopping?

Charles, Interesting question. I don't know. Could just be that the products are kept out and they outgas their fragrances. Department stores used to squirt perfumes into the air around the perfume counters. Maybe the do something like that.
-Monona

Taher from Croton on hudson
Johns may have used artist bee wax. It comes in blocks. It is melted in a can and mixed with oil colors/ pigments then painted on surface.

Taher: Paraffin also comes in blocks so it is hard to say. There is also wax made especially for encaustic paintings. It is a mix of waxes usually. From a chemist's point of view, highly refined paraffin is the clearest wax so colors would be unaltered by any color in the wax. Wax molecules are white or clear when melted. Beeswax is typically yellow from the presence of natural non-wax contaminants.
-Monona

Matthew from New York
In regards to going into stores that sell fragrances (ie. Bath and Bodyworks, Yankee Candle,etc.) I have some advice: If you have an issue with the strong fragrances in the store, don't complain to the staff or management. They have no control over it on their level and all they can do is listen to your complaint. Contact the corporate headquarters,if you want to make an impact. but be sure to stay humble. You might come off as another nuisance, after all, you're complaining to a company that sells fragrances. Just don't go into the store! People don't like "Negative Nancy's". (I've learned my lesson)

Matthew: I'm and old lady who very much enjoys her nuisance status. I have also been around long enough to know that businesses that don't listen to consumer complaints don't stay in business long. A complaint about something the sales person didn't do and can't control should not be taken personally. The sales person's job is simply to pass the complaint on to management to do with as they will. Cutting down the intensity of the odor might get more customers in the store.
-Monona

Barb from NYC
When you go into a store playing terrible music, at any time of year, I urge you to (1) complain to management, and (2) put in your earbuds and listen to your own music on your phone or iPod. I put music on my phone purely to drown out the hideous crap dished out by store PA systems, and it's so sweet to be able to shield my ears! Since nearly everyone carries a music player with them at all times, there's no excuse for stores foisting corporate music product on a captive audience!

Barb: You go, girl!
-Monona

JKV from WESTCHESTER
I agree with the caller about fragrances at Bed Bath and Beyond. Last time I was in the store, I took a sample of their free coffee. While riding up their escalator I became overwhelmed by smells and started choking to death and the coffee came spilling out of my mouth all over my coat.

JKV: More than I need to know, but very illustrative of the problem.
-Monona

Lynn Decker from NYC 
Intrigued by your guest's expertise on candles. Could she address the vogue for soy candles, which I take to be an avoidance of animal based components. Do soy candles have different safety properties than other materials?

Lynn, The data sheet that should be out soon goes into this issue in detail. Soy wax is wax. And wax is wax. There really is no health advantage what ever to burning soy wax over the other waxes.
While soy wax is derived from renewable source, I'm not at all sure there is less of a carbon footprint for them when you look at the issues extracting the oils from the beans with hexane solvents, decolorizing the oil with chlorine bleach, deodorizing it by steam distillation, and then taking this unsaturated oil and hydrogenating it with high heat and a toxic metal catalyst into and unsaturated wax.
-Monona

Tim in Queens
Two Christmases ago I was a guest at the home of a couple who had candles on their (live) tree. As the evening went on they got drunker and drunker, until they were almost unconscious. I was relieved when it came time to go home.

Tim: That's a really scary story. A lot of the candle fires reported by the National Fire Protection Association also involved alcohol.
-Monona

wayne johnson Ph.D. from Bk
Synthetic trees have their issues, but cutting down real trees devastates the forests.

Wayne: That too. Some tree farms have a regular schedule of growing and cutting down trees. Most trees don't come out of real forests anymore. But these tree farms also are not very useful habitat for wild life. It is the combination of trees of all ages, dead trees and brush that are best for wildlife.
-Monona

soigne (swan-yay) from Madison, NJ
What is the danger of exposure to residual pesticides and herbicides on a natural Christmas tree that is brought into the home?

Soigne: There were six or seven different pesticides that I saw being used for protection from various types of pine bark beetles. I would assume they could off gas in a warm room or there might be some exposure by skin contact. But I have never seen any studies or documentation of this potential hazard.
-Monona

jf from NY
HOW DARE YOU MISSREPRESENT THE CONCEPT OF UTOPIA. YOU MEAN DYSTOPIA! USE THE RIGHT WORD!THERE IS A WORD FOR THAT! USE IT! I AM A UTOPIAN. I AM EXTREMELY INSULTED BY THIS SLANDER, THE CONTENT OF YOUR BOOK, SUGGESTS YOU ARE A UTOPIAN TOO. WHY WOULD YOU SHAME THE CONCEPT OF A WORLD WHERE WE DO THE RIGHT THINGS! USE THE WORD DYSTOPIA!

JF: I'm speechless.
-Monona