From the Editors of E/The Environmental Magazine
Dear EarthTalk: I’ve heard that the solvents commonly used in commercial dry cleaning are unhealthy and unsafe for the environment. Is this true?
—Earl Eckstrom, Portland, OR
Studies show that perchloroethylene—the solvent used by the vast majority of dry cleaning establishments—is both hazardous to human health and injurious to the environment. For one, "perc," as the solvent is commonly known in the industry, can have negative effects on the central nervous system. According to the National Institute of Environmental Health Sciences, short-term exposure to perc can lead to headaches, nausea, dizziness and memory problems.
The environmental organization Greenpeace found that perc breaks down into toxic byproducts like phosgene, vinyl chloride, carbon tetrachloride and trichloroacetic acid (TCA). Dr. Gina Solomon, a senior scientist at the Natural Resources Defense Council, says, "Phosgene is an extremely hazardous gas which evaporates and in closed spaces is potentially lethal. Vinyl chloride is a proven carcinogen and carbon tetrachloride is a known liver toxin." And TCA has been linked to the extensive damage done to trees in the Black Forest in Germany, where it was used as an herbicide in the 1950s and 1960s.
A Danish study by Kolstad, Brandt and Rasmussen revealed that pregnant dry cleaning workers are twice as likely to have a miscarriage as pregnant women in other professions. And the University of California at Berkeley found that male dry cleaning workers have more sperm abnormalities and a significantly lower sperm count than men not employed by the industry.
Less toxic alternatives to perc are beginning to take hold. Comet Cleaners, which has 350 locations in 17 states and Mexico, replaced perc a decade ago with the more benign petroleum solvent, Exxon D-2000. Other cleaners have switched over to Chevron-Phillips" EcoSolv, a similar hydrocarbon-based alternative. Meanwhile, more than 200 cleaners—including Chicago"s Greener Cleaner—employ "wet cleaning," a non-toxic, non-polluting alternative that uses biodegradable soap and water.
Perhaps the most promising non-toxic perc alternative is produced by GreenEarth Cleaning, which has patented its silicone-based dry cleaning solvent called Cyclic Silioxane. This product poses no threat to the environment or human health and simply degrades to sand, water and carbon dioxide. General Electric and Procter & Gamble have formed a joint venture with GreenEarth to help dry cleaners worldwide switch over to this more benign alternative. At greenearthcleaning.com, consumers can search an international database to find dry cleaners in their area that are using the new solvent.
While the U.S. Environmental Protection Agency (EPA) regulates the use of perc under the Toxic Substances Control Act, the Clean Water Act and the Safe Drinking Water Act, states have been reticent to adopt phase-outs. The dry cleaning industry has mounted a strong lobby in favor of keeping perc legal, but consumer opposition is building, especially as more non-toxic alternatives are becoming available.
CONTACTS: Natural Resources Defense Council, (212) 727-2700, www.nrdc.org; Comet Cleaners, (817) 461-3555, www.cometcleaners.com; Green Earth Cleaning, (816) 926-0895, www.greenearthcleaning.com; EPA Perc Fact Sheet, www.epa.gov/opptintr/chemfact/f_perchl.txt .
Dear EarthTalk: What are the environmental and health risks of genetically engineered foods, and do they outweigh the benefits such as reducing pesticide use and increasing crop yields?
—Liz from California
Genetic engineering is a technology that manipulates the genes of organisms and transfers them between species. While genetically engineered (GE) foods such as corn and wheat appear identical to their natural counterparts, they differ in that they contain genes from bacteria, viruses, insects, nuts or animals.
Proponents of genetic engineering claim that the technology actually improves upon Mother Nature, as altered plants can be made resistant to weeds, insects or even cooler temperatures. As such, the technology has been touted as the future of agriculture and looked to as a solution for world hunger.
But many scientists believe that the reality of genetic engineering is quite different. According to UC Berkeley biologist Miguel Altieri, the replacement of a wide variety of crops with a few genetically modified monocultures (large groups of a single species of plant) threatens to undermine the very genetic diversity which helps crops avoid insect infestation and the spread of disease in the first place.
"Although biotechnology has the capacity to create a greater variety of commercial plants," says Altieri, "the trend
is to create broad international markets for a single product, thus creating the conditions for genetic uniformity
" He adds that the potential transfer of genes from GE crops to wild or semi-domesticated relatives may help create "super weeds" resistant to any and all control efforts.
Additionally, some believe that GE foods can be hazardous to human health when ingested. Ronnie Cummins of the Organic Consumers Association says that GE foods have been linked to many health problems, including blood disorders and food allergies. For instance, a few years ago Pioneer Hi-Bred International, in order to boost the protein content of its products, developed a soybean using a gene from a Brazil nut. Independent tests on the GE soybean revealed that people allergic to Brazil nuts could have severe allergic reactions to the modified soybeans.
While many American lawmakers and farmers have embraced genetic engineering, governments in other parts of the world are not convinced that the known benefits of the technology outweigh the potential risks. According to Yale University researcher Kathleen McAfee, American advocacy for genetic engineering has strained foreign relations as European and African nations reject any such "modified" products for trade and food aid.
With more than 40 varieties of GE crops approved for marketing and use in the U.S., as much as 70 percent of the foods on American grocery shelves today already contain genetically modified components. Since the federal government does not require GE foods to be labeled as such, the best way for consumers to avoid them is by buying only products that have been certified organic.
CONTACTS: Organic Consumers Association, (218) 226-4164, www.organicconsumers.org; The Ecological Impacts of Agricultural Biotechnology, www.actionbioscience.org/biotech/altieri.html; Yale Global Online, www.yaleglobal.yale.edu/environment.