From the Editors of E/The Environmental Magazine
Dear EarthTalk: How serious is the risk of contracting Alzheimer's disease from using antiperspirants that contain aluminum?
—Susan DeBacker, Boulder, CO
Antiperspirants often contain aluminum, zirconium or both. These substances tighten or close underarm skin pores in order to block sweat glands and the moisture they produce. While underarm products often contain both antiperspirants and deodorants, deodorants alone do not contain aluminum.
Could exposure to aluminum increase your chances of getting Alzheimer's disease? According to the Alzheimer's Disease Education and Referral Center, Alzheimer's patients do at times have abnormally high concentrations of aluminum in their brains, but research hasn't conclusively shown if the disease causes the buildup or the buildup causes the disease. Some doctors have suggested that antiperspirant might be especially problematic, as women apply it to shaved armpits, perhaps allowing aluminum to be absorbed directly into the bloodstream through hundreds of tiny cuts caused by razors. However, studies are inconclusive. "The research hasn't shown anything further between the link between Alzheimer's and aluminum," says Jennifer Watson, outreach and promotions specialist at the Center.
Procter & Gamble, which makes antiperspirants with aluminum, points out that aluminum is Earth's third most common element, and that humans are routinely exposed to it through numerous sources besides antiperspirants, including tainted water, canned foods, processed cheese, and buffered aspirin.
Those who wish to take precautionary measures can simply buy deodorants that do not contain antiperspirants. Some companies, such as Nature's Gate, offer deodorants that contain all-natural ingredients and fight odor-causing bacteria.
From the Editors of E/The Environmental Magazine
Dear EarthTalk: What is "Biodiesel" fuel?”
—Tom Morgan, Baltimore, MD
Dr. Rudolf Diesel developed the diesel, or internal combustion, engine between 1892 and 1897. Interestingly, instead of running on today's petroleum-based diesel fuel, at the time his engine used peanut oil. Dr. Diesel speculated, "The use of vegetable oils for engine fuel may seem insignificant today. But such oils may become in course of time as important as the petroleum products of the present."
What he foresaw was biodiesel—a cleaner-burning diesel replacement fuel made from the combination of natural, renewable oil sources, such as vegetable oils, recycled cooking oil, and alcohol. Biodiesel has a high "cetane" rating, which pertains to improved engine efficiency and substantially reduced emissions of unburned carbon monoxide, ozone-depleting agents such as hydrocarbons, sulfates, and particulate matter. According to the National Biodiesel Board (NBB), a national trade association representing the biodiesel industry, soy biodiesel can reduce carbon dioxide emissions by 78 percent.
This wonder fuel, often used in blends of up to 20 percent biodiesel mixed with petroleum diesel fuels, can be used in nearly all diesel equipment. Higher blends, and even pure biodiesel, can be used in many diesel engines built since 1994 with little or no modification. Vehicles made before 1994 often have rubber components that can be degraded by biodiesel, warns NNB.
Dr. Rudolf Diesel's prediction may not be far off. According to a recent New York Times Magazine article, there are already more than 150 U.S. gas stations that now offer biodiesel. More than 15 million gallons of biodiesel were sold in 2002. The Energy Policy Act of 1992 has given biodiesel an edge by requiring the use of alternative fuels in certain fleets of official cars and trucks, and the U.S. military has become one of the largest consumers of biodiesel. According to the Alternative Fuel Price Report, published by the Department of Energy's Alternative Fuels Data Center, which lists refueling locations on its Web site, biofuel prices are currently only $.30 or $.40 more than regular diesel and gasoline.
Some advocates, such as the American Biofuels Association, think that with government incentives comparable to those that have been provided for ethanol, a corn-based fuel, biodiesel sales could reach about two billion gallons per year, or replace about eight percent of conventional highway diesel fuel consumption. The New York Times reports that "in Germany, where diesel engines power close to 40 percent of passenger cars, more than 1,000 gas stations offer biodiesel at the pump—at a competitive price, thanks to huge tax breaks and subsidies for alternative fuels."
CONTACT: National Biodiesel Board, 3337a Emerald Lane, PO Box 104898, Jefferson City, MO 65110-4898, (800) 841-5849, www.biodiesel.org, firstname.lastname@example.org; Alternative Fuels Data Center, www.afdc.doe.gov, (800) 423- ( Alternative Fuels Hotline); American Biofuels Association, 1925 N. Lynn Street, Suite 1050, Arlington, VA 22209, (703) 522-3392.