Week of 5/9/2004

Dear EarthTalk: Are hybrid buses in my city really helping to reduce air pollution?

—Jennifer Cross, New York, NY

According to the Natural Resources Defense Council, 20 percent of U.S. air pollution comes from diesel buses—and many of them are concentrated in cities. The Environmental Protection Agency (EPA) currently runs a program called Clean School Bus USA, an effort to reduce both children"s exposure to diesel exhaust and the amount of air pollution created by diesel school buses. The EPA has also recently passed tougher standards for all diesel-powered vehicles, but they won’t go into effect until 2006. In the meantime, many cities are still trying to meet federal Clean Air Act rules, especially given rising rates of asthma, particularly in children. One of the ways cities can clean up their air is by employing alternatives to traditional diesel engines for both public and school buses.

"Retrofitting" (modifying) older buses, which includes adapting them to use cleaner-burning fuels and incorporating pollution controls, can reduce emissions, but hybrid buses offer increased benefits. A Department of Energy study reports that hybrid buses, which combine a diesel engine with an electric motor, outperform regular diesel buses in a variety of categories, offering 10 percent higher fuel economy, 19 percent lower carbon dioxide emissions and a whopping 97 percent reduction in carbon monoxide emissions. John Powell, executive director of the Advanced Transportation Technology Institute, sees the dual-fueled hybrids as the optimal choice with the most benefits. Hybrids have already been successfully introduced in New York City, New Jersey, Connecticut, Minnesota, Washington state and Toronto, Canada.

However, many environmentalists would like to do away with using diesel fuel altogether: "Replacing diesel buses with those fueled with natural gas or electricity will help to provide important health protections for people with lung disease," says Bonnie Holmes-Gen, assistant vice president for government relations with the American Lung Association of California. Some cities, like Boston, already run compressed natural gas buses. Still others are looking into blending hydrogen with natural gas to create a low-emission fuel for buses called "hythane." Whatever the alternatives, putting pressure on your local transit authority to buy hybrid vehicles or burn cleaner fuels will result in cleaner air for everyone.

CONTACTS: Natural Resources Defense Council, (212) 727-2700, www.nrdc.org; EPA"s Clean School Bus USA, www.epa.gov/cleanschoolbus; Advanced Transportation Technology Institute, (423) 622-3884, www.atti-info.org; American Lung Association of California, (510) 638-LUNG, www.californialung.org.


Dear EarthTalk: There are so many juices labeled "natural." Which ones are most healthful?

—Zenas Lu, Boston, Mass

The most healthful juice you can drink is made fresh, right before you drink it, from (preferably) organic fruits and vegetables with nothing added. The beneficial enzymes, vitamins and minerals are at their peak, and some health practitioners say that the water that comes from inside fruits and vegetables is the purest kind. When juices are packaged and pasteurized, they lose some of their nutritional value. Juices pack a nutritional punch, and are a good way to get part of your daily requirement of fruits and veggies. The American Dietetic Association calls orange juice a "nutrition powerhouse."

Obviously we don’t always have the time or money to drink fresh juice, and that"s when bottled juices are a good choice over soda or sugary iced teas. But buyer beware: Widely popular commercial "fruit drinks," with little to no real fruit juice, are largely artificially colored sugar water and contain minimal amounts of fruit juice.

According to the Center for Science in the Public Interest (CSPI), many fruit "drinks," "beverages," "ades" and "cocktails" are nothing more than non-carbonated soda pop. Fruitopia "Real Fruit Beverage" and Sunny Delight "Real Fruit Beverage," for example, contain only five percent juice. V8 "Splash" is about 25 percent juice and 75 percent sugar-water. CSPI says that, while Fruitopia has "100% vitamin C per serving" in flavors like Strawberry Passion Awareness, the product contains only about five percent strawberry juice and 95 percent high-fructose corn syrup. Similarly, Mystic Mango Mania Fruit Drink has mangoes pictured all over the label, but the product doesn’t contain any mango, except perhaps a small amount included in the "natural flavors." You"re getting roughly three percent white grape juice and 97 percent sugar water. The health website Lifeclinic.com argues that juice in such limited amounts does not have any health benefit.

Reading labels is the best way to ensure you are buying what"s best for you. If you"re buying off the shelf, try to avoid juices with artificial ingredients or preservatives and, quite simply, anything with less than 100 percent juice. Also, if you are watching your weight, many bottled juices can be high in calories, owing to natural fruit sugars. Drink water and eat whole fruit, which has fiber along with all the nutritional benefits.

CONTACTS: American Dietetic Association, (800) 877-1600, www.eatright.org; Center for Science in the Public Interest, (202) 332-9110, www.cspinet.org; Lifeclinic.com, (800)543-2850, www.lifeclinic.com.