By Keri Luly, LEED AP
When I was a kid, I used to hang out of the car window to smell the gasoline as it was being pumped (which might explain a few things!). Mom wasn't a toxicologist so she had no idea that I was getting a whiff of a chemical mixture that included benzene, which is now known to be a human carcinogen. I seem to have survived, but since then I've learned enough about toxicology to be a bit concerned about it.
This summer, I've traveled throughout the United States and Canada teaching workshops and have realized that there is a need for some basic information about our chemical world and how we respond to it-and that's going to take two articles to accomplish.
In this article (Part I), I'll explain some of the chemicals that surround us; and in Part II (appearing in the January/February 2008 issue), I'll explore how the ancient art of "poisoning" (as it was once called) can provide advice today on how to make decisions about chemicals at home and at work.
CHEMICALS ARE EVERYWHEREWe're made of them; they're part of the food we eat and the rain that falls. Complex chemical structures are the basis of everything in our lives. Synthetic chemicals (my focus in this article) are those made from petroleum that are then used to make most of today's products. Many of them are worrisome to us, but it's important that we educate ourselves and make decisions based on facts rather than rumor.There was a time in our history when most of our products were made of "natural" chemicals and materials. Even the early plastics produced in the late 1800s were made from wood cellulose material before oil-based synthetic versions were created. The production of dyes from petroleum launched the synthetic chemical as the chemical of choice because they were often cheaper than traditional materials from nature. Vinyl, a material recently debated when in the form of PVC, was developed as a valuable substitute for natural rubber during World War II.1
Why should we care? Any chemical in our environment can cause health and environmental impacts, depending on how it's used and how we are exposed to it. For example, Coumarin compounds can be both rodenticides (and therefore, are poison) and anticoagulant drugs that prevent blood clots and save lives. A material made of complex synthetic chemicals bound together can lighten the weight of a car, making it more fuel efficient. However, some of those same chemicals can negatively impact human reproduction when they get into our food chain.
Clearly, we need to be smart and careful in order to enjoy the benefits of synthetic chemicals while protecting our health and environment. And we shouldn't assume that natural chemicals are automatically safe. For example, one of the most toxic chemicals in existence is botulin (the chemical some people inject to smooth wrinkles), which is made by a living organism.
VOCS? PPM? ORGANIC? VOLATILIZATION?Most of the chemical terms we hear in the field of design have been brought to our attention in recent years by the U.S. Green Building Council (USGBC) as part of its effort to increase our well-being in the built environment; and by the U.S. Environmental Protection Agency (EPA) during its 37-year history of protecting our natural environment. Some of the important terms for our use in design include:- Sick Building Syndrome (SBS), according to the EPA, is a term used to "describe situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified." The symptoms may include coughing, irritated eyes and throat, headaches, dizziness and nausea. The causes are usually linked to inadequate ventilation in a building that is tightly sealed (for energy conservation) and furnished with products that offgas. Ironically, one of the first recognized cases was in the 1980s when EPA employees had problems (later linked to carpet offgassing) in a newly renovated office building and won a lawsuit against the building's owner.
- PPM and PPB are abbreviations for the measurement of very small amounts of one material (usually a chemical contaminant) in another material (often water, air or soil). The abbreviations stand for "parts per million" and "parts per billion." One way to think about it is to picture one million grapes in a vat. If three grapes were replaced with stones, the vat would contain three parts per million of stones. In chemistry, an example might be the analysis of benzene molecules among drinking water molecules.
- Organic refers to a group of chemicals made of linked carbon atoms with other chemicals attached, and it is imprecisely used in the term "organic food" (where it means free of synthetic chemicals). All life forms are made of linked carbon, including those that were alive millions of years ago and became petroleum (remember your high school chemistry?). The term organic applies to products made of chemicals synthesized from petroleum. The other class of chemicals is inorganic, which includes metals and other chemicals that aren't from life forms.
- Synthetic Chemicals are the wide variety of chemical compounds created in labs- usually from petroleum products-that are common in our society today. These can include pharmaceuticals, pesticides, plastics, dyes and most cosmetics.
- Offgassing/Emitting/Volatilizing are terms used to describe gaseous forms of chemicals coming out of an item, such as VOCs (next on this list) being emitted from paints. (I cringe when a friend refers to the fresh smell of a newly painted room). That "new car smell" is from the offgassing of plasticizers in the car's dash board and upholstery. Technically, the smell of a homemade pie coming out of the oven is also offgassing,
so it's not always a problem. Offgassing is typically strongest when a product is new-gradually decreasing with time-and best avoided via good ventilation and/or airing out the product before use. - VOCs, or Volatile Organic Compounds, are a group of chemicals that offgas (volatilize) into the air—possibly contributing to sick building syndrome. As previously mentioned, the word organic here refers to something made up of linked carbon atoms. There are thousands of products that emit VOCs, such as cleaning
supplies, paints and other finishes, disinfectants, glues, copiers, dry-cleaned clothing, air "fresheners," hobby products, furniture and carpets. - Formaldehyde is one chemical in the group of VOCs since it is an organic chemical and because it offgasses into the air. It is commonly found in adhesives for fiberboard and fiberglass, paint, foam insulation, permanent-press fabrics, tobacco smoke, cleaning products, smog, fabric dyes and fireplaces. It occurs naturally in humans, animals and plants in very small amounts. USGBC's LEED®, the Occupational Health and Safety Administration, and several states set limits on the amount of formaldehyde that can be emitted into indoor air from those sources because it is a respiratory irritant and a human carcinogen.
A colleague of mine used to point out that "if you can smell it, it's in your lungs." His point was that once a smell, such as our morning toothpaste (or the gasoline I liked to smell as a kid) hit our nasal receptors; it is already on its way to our lungs. In Part II, I'll explain his reference to "pathways of exposure" and how much they determine our response to the chemicals we live in. Stay tuned!
DONATION: Keri Luly has elected to donate her monetary compensation for the articles she writes to an environmentally pro-active organization of her choosing. This issue, she has selected the Society of Environmental Toxicology and Chemistry (SETAC)—a nonprofit, worldwide professional society that promotes: the advancement and application of scientific research related to contaminants and other stressors in the environment; education in the environmental sciences; and the use of science in environmental policy and decision making. For more information, go to www.setac.org. |
