While in pictures these malformed frogs were obviously eye catching for the environmentalist crowd, it turns out there’s actually a much more benign and biological explanation beyond all the fear mongering. The missing limbs and the extra limbs actually have two completely separate causes. While some scientists are still firmly entrenched in the “chemical cause” camp, biologists Stanley Sessions and Brandon Ballengee observed tadpoles in the wild for a few years, and noted that the tadpoles were actually being predated on by dragon fly nymphs.

The scientists observed back in their lab that the dragon fly nymphs would, more often than not, eat only parts of the tadpoles, usually just removing a limb. The tadpoles would then return back, and grow up, sans said limb. Despite missing parts of their bodies, many of the tadpoles were still able to grow up, metamorphosizing into frogs, who managed to live quite a long time.

While frogs with missing limbs have a rather mundane explanation, the frogs with extra limbs have a much more exotic explanation. Sessions established that the frogs had been infested by small parasitic flatworms called Riberoria trematodes. These works burrowed into the rapidly developing tadpoles and actually rearranged the cellular structure of the frogs as they were developing, resulting in their leg precursor cells to actually spawn multiple limbs.

Of course, the fact that this problem turned out not to be our fault doesn’t mean we’re off the hook. Pollution is still a problem, even if its effects aren’t as obvious as a three-legged frog.

With global warming dominating so many headlines today, it’s no surprise that many of us are looking to reduce the amount of carbon dioxide and other greenhouse gases our activities produce.

By assessing how much pollution each of your individual actions generates-be it setting your thermostat, shopping for groceries, commuting to work or flying somewhere for vacation-you can begin to see how changing a few habits here and there can significantly reduce your overall carbon footprint. Luckily for those of us who want to see how we measure up, there are a number of free online carbon footprint calculators to help figure out just where to start changing.

One of the best is the University of California at Berkeley’s Cool Climate Calculator. The free web-based tool takes into account daily driving mileage and grocery and electricity expenses, among other factors, to assign a carbon score, which users can compare to similar households across the 28 largest urban areas in the U.S. Some of the results are surprising. For example, residents of eco-aware San Francisco tend to have bigger carbon footprints than those in more conservative Tampa, Florida. The reason: San Francisco has a higher cost of living and colder, wetter winters (requiring more fossil-fuel derived heat).

Another great carbon footprint calculator is available at EarthLab.com, an online “climate crisis community” that has partnered with Al Gore’s Alliance for Climate Protection and other high-profile groups, companies and celebrities to spread the word that individual actions can make a difference in the fight against global warming. Users just take a three-minute survey and get back a carbon footprint score, which they can save and update as they work to reduce their impact. The site provides some 150 lifestyle change suggestions that will cut carbon emissions-from hanging your clothes to dry to sending postcards instead of letters to taking the bike instead of the car to work a few days a week.

“Our calculator is an important first step in educating people about where they are, then raising their awareness about what they can do to make easy, simple changes that will lower their score and positively impact the planet,” says Anna Rising, EarthLab’s executive director. “Our goal isn’t about convincing you to buy a hybrid or retrofit your house with solar panels; our goal is to introduce you to easy, simple ways that you as an individual can reduce your carbon footprint.”

Other websites, green groups and corporations, including CarbonFootprint.com, CarbonCounter.org, Conservation International, The Nature Conservancy and British Oil Giant BP, among others, also offer carbon calculators on their websites. And CarbonFund.org even allows you to assess your carbon footprint-and then offers you the ability to offset such emissions by investing in clean energy initiatives.

CONTACTS: Cool Climate Calculator, www.berkeley.edu/calculator.html; EarthLab, www.earthlab.com; CarbonFootprint.com, www.carbonfootprint.com; CarbonCounter.org, www.carboncounter.org; Conservation International, www.conservation.org; The Nature Conservancy, www.nature.org; BP, www.bp.com.

Dear EarthTalk: Why are some environmental groups jumping on the immigration issue? What does immigration have to do with the environment?  – Ginna Jones, Darien, CT

What to do about booming legal and illegal immigration rates is one of the most controversial topics on Americans’ political agenda these days. More than a million immigrants achieve permanent resident status in the U.S. every year. Another 700,000 become full-fledged American citizens. The non-profit Pew Research Center reports that 82 percent of U.S. population growth is attributable to immigration.

Meanwhile, the U.S. Census Bureau estimates that U.S. population will grow from 303 million people today to 400 million as early as 2040. While many industrialized nations, including Japan and most of Western Europe, are experiencing population growth slowdowns due to below replacement birth levels and little immigration, the U.S. is growing so fast that it trails only India and China in total numbers.

Advocates for U.S. population stabilization, including some environmental organizations and leaders, fear that this ongoing influx of new arrivals is forcing the nation to exceed its “carrying capacity,” stressing an already overburdened physical infrastructure. David Durham of Population-Environment Balance says that Americans who care about the environment should insist on reducing immigration, to recognize “ecological realities such as limited potable water, topsoil and infrastructure.” He also cites studies showing that a permissive U.S. immigration policy drives up fertility rates in the sending countries “which is the last thing these sending countries need.”

To others the problem is larger than immigration itself. “People don’t just materialize at our border, or at any border,” says John Seager of Population Connection. “When you talk about immigration, you’re talking about the second half of a process that begins when people decide to leave their homes.” And they are usually leaving their homes because of hunger, lack of work, oppression, or any number of other often-desperate reasons. Seager and many others argue that by helping poor nations better address the economic and family planning needs of their citizens, Americans can not only help improve the lot of millions of people living in dire poverty, but also slow down the tide of immigration.

Groups focusing on the immigration-environment nexus are keen to get their voices heard, but many mainstream green groups shun the highly divisive topic, preferring instead to encourage Americans, who are infamous around the world for their huge homes, gas-guzzling cars and extravagant consumption habits, to curb their unsustainable lifestyles, which they see as more fundamental to U.S. environmental problems than population pressures. With just five percent of the world’s people, Americans use a quarter of the world’s fossil fuels, own more private cars than drivers with licenses, and live in homes that are on average 38 percent larger today than they were in 1975. By scaling back, Americans can take a big bite out of pollution, sprawl and other environmental problems, while also setting a good example for those who land in the U.S. every year, lowering the nation’s collective carbon footprint significantly in the process.

CONTACTS: Pew Research Center, www.pewresearch.org; Population-Environment Balance, www.balance.org; Population Connection, www.populationconnection.org.

GOT AN ENVIRONMENTAL QUESTION? Send it to: EarthTalk, c/o E/The Environmental Magazine, P.O. Box 5098, Westport, CT 06881; submit it at: www.emagazine.com/earthtalk/thisweek/, or e-mail: earthtalk@emagazine.com. Read past columns at: www.emagazine.com/earthtalk/archives.php.

Thanks in part to pressure from non-profits like Greenpeace International-which has published quarterly versions of its landmark “Guide to Greener Electronics” since 2006-computer makers now understand that consumers care about the environmental footprints of the products they use.

The latest version of Greenpeace’s guide gives high marks to Toshiba, Lenovo, Sony and Dell for increasing the recyclability of their computers and reducing toxic components and so-called “e-waste” (refuse from discarded electronic devices and components). The group also credits Apple, HP and Fujitsu for making strides toward greener products and manufacturing processes, but emphasizes that even such top ranked companies have lots of room for improvement when it comes to the environment.

PC Magazine, the leading computer publication for consumer and business users, recently assessed dozens of personal computers according to environmental standards it developed in-house based on energy efficiency, recyclability and the toxicity of components. The publication also factored in various “green” certification schemes such as the U.S. Environmental Protection Agency’s EnergyStar program, the European Union’s Restriction of Hazardous Substances (RoHS) directive, Taiwan’s Greenmark and the computer industry’s own Electronic Products Environmental Assessment Tool (EPEAT).

The top choices for green desktop computers, according to PC, are Apple’s Mac Mini, Zonbu’s Desktop Mini, HP Compaq’s 2710p and dc7800, Lenovo’s ThinkCentre a61e, and Dell’s OptiPlex 755. As for laptops, the greenest current models include Dell’s Latitude D630, the Everex Zonbu, Fujitsu’s LifeBook S6510, and Toshiba’s Tecra A9-S9013.

Perhaps more important than the green-ness of your new computer is what you do with the old one. Stuffing it into the trash or setting it out for curbside pick-up may be the worst thing you can do with an outdated computer, as heavy metals and other toxins inevitably get free and get into surrounding soils and water. If the machine still works, donate it to a local school that can put it to use, or to Goodwill or the Salvation Army, either of which can re-sell it to help fund their programs. Another option is to donate it to the National Cristina Foundation, which places outdated technology with needy non-profits.

Once you’ve gotten rid of an old computer and outfitted yourself with a spiffy new green one, you might just want to score a few green accessories. Brooklyn, New York’s Verdant Computing, which bills itself as a purveyor of “the greenest computer products on the web,” sells remanufactured ink and toner cartridges, laptop cases made from recycled plastic, GreenDisk CDs packaged in recycled plastic jewel cases, solar-powered MP3 accessories, energy-saving printers and even a software program, GreenPrint, which modifies the print programs on your computer to economize on paper and ink/toner use. Verdant also has most products shipped to consumers directly from the manufacturers to save re-shipping.

CONTACTS: Greenpeace International, www.greenpeace.org; PC Magazine, www.pcmag.com; National Cristina Foundation, www.cristina.org; Verdant Computing, www.verdantcomputing.com.

Dear EarthTalk: Are there any efforts underway to green the air travel industry? It seems to me that it must be one dirty business from a pollution standpoint. — Elias Corey, Seattle, WA

Environmental battles over the siting and expansion of airports are as old as the air travel industry itself, but only in recent years have the airlines themselves been under pressure to go green.

And there’s no time like the present for the industry to take some action: Air pollution from commercial jets is a growing concern among scientists, as is air travel’s role in climate change because of the more acute warming effect of emissions when they are disbursed so much closer to the upper atmosphere.

According to the Royal Commission on Environmental Pollution, an independent group of scientists that advises the British government, emissions from aircraft will likely be one of the major contributors to global warming by the year 2050. According to USA Today, on a flight from New York to Denver, a commercial jet generates between “840 to 1,660 pounds of carbon dioxide per passenger. That’s about what an SUV generates in a month.”

Despite still gloomy times for the industry post-9/11, a few are actually responding to the call. Virgin is blazing new trails as part of a $3 billion investment in energy efficiency. The company is experimenting with biodiesel and ethanol-fuels derived from crops-and has invested hundreds of millions of dollars in ethanol-related businesses. But don’t expect to ride on a biofuel-powered jet anytime soon.

Airplane makers are getting in on the act, too. Boeing successfully flew the world’s first hydrogen-powered, fuel cell airplane in April 2008. A company spokesperson called the plane-a small one-seater-”full of promises for a greener future.” Boeing is working to develop a commercial version, but uncertainties about hydrogen production and distribution put this advancement well into the future, too.

So what can consumers do to fly greener today? Sharon Beaulaurier of GreenLight magazine suggests choosing airlines with newer, more fuel-efficient fleets such as JetBlue, Singapore Airlines or Virgin.

She adds that direct flights are better than those with stopovers, as frequent take-offs and landings use more fuel than when the planes are cruising. She also recommends avoiding airlines and airports with bad track records for delays, which leave planes idling and spewing greenhouse gases for hours unnecessarily.

The National Air Traffic Controllers Association (NATCA) runs AvoidDelays.com, which helps fliers choose airlines and airports based on on-time departures. Airlines with poor records include American, Atlantic Southeast, ExpressJet, Mesa and United, according to NATCA, which also calls Chicago’s O’Hare, New York’s LaGuardia, Newark, Philadelphia and San Francisco the worst airports for catching on-time flights.

Meanwhile, the European Union wants to require airlines touching down in Europe to participate in continent-wide carbon reduction programs already in place. Backers hope it will cut Europe’s exponential growth in airline emissions in half by 2020. Some carriers oppose the plan and are fighting it in court.

CONTACTS: Virgin Group, www.virgin.com; Boeing, www.boeing.com; AvoidDelays.com, www.avoiddelays.com.

GOT AN ENVIRONMENTAL QUESTION? Send it to: EarthTalk, c/o E/The Environmental Magazine, P.O. Box 5098, Westport, CT 06881; submit it at: www.emagazine.com/earthtalk/thisweek/, or e-mail: earthtalk@emagazine.com. Read past columns at: www.emagazine.com/earthtalk/archives.php.

“Gas consumption – and prices – historically rise with the temperature as more people drive for work or pleasure during the warmer months,” says Sue Pinera, environmental programs director of the Hertz Corp., leaders in the rental car industry.”

But you can definitely drive green and save yourself some money without having to trade in your reliable, reasonably priced family vehicle for a new one that features the latest eco-friendly technology.”

Summer vacations often mean extra driving, either to your destination in your own vehicle or, if you fly, in a rental car once you’re there. “Of all summer driving, vacation driving can be the most costly and least green,” Pinera points out. “Whether it’s spending time stuck in traffic or driving in circles looking for an attraction site in an unfamiliar location, there are plenty of opportunities to waste gas.”

Car rental agents, who work in tourist areas across the country leasing a variety of vehicles, have seen everything that works – and doesn’t work – when it comes to conserving gas, saving money and preserving the environment while vacation driving. Here are some tips from agents at Hertz for smart vacation driving:

In Your Own Car

* Have your car thoroughly checked out before going on a long vacation road trip. Be sure tires are properly inflated, oil and oil and air filters are fresh, and the air-conditioning is working properly. “Just $100 in preventative maintenance can save you real dollars in terms of fuel efficiency and a great deal of aggravation if you happen to catch a potentially serious problem before you break down on the roadside,” Pinera says.

* Drive smoothly and considerately. Aggressive driving – fast starts, excessive speed, abrupt maneuvers and constant braking – is not only dangerous, it significantly increases your vehicle’s fuel consumption. “You’ll enjoy the ride more and spend less on gas if you just drive friendly,” Pinera says.

* Only use premium fuel if your car’s manufacturer specifically recommends it for your engine type. Regular fuel costs less and premium will not improve your fuel efficiency in anything but a high-performance engine.

* Look for gas stations that offer pumps with vapor-recovery nozzles. They look like black plastic accordions attached to the nozzle. These curb emissions. Likewise, never try to “top off” your tank with these nozzles. They’re designed to shut off when the gas tank is at its optimum fullness. Continuing to pump could lead to overfilling and spilling.

* Try to pack light and avoid putting anything on top of your vehicle. Rooftop storage may increase the risk of rollover in some types of vehicles, and increases drag, which lowers fuel efficiency in all kinds of autos.

In a Rental Car

* Whenever possible, choose a fuel-efficient model, such as a subcompact, compact or economy car. The good news is that these are usually the least expensive to rent from any company.

* Consider renting a hybrid. Hertz, for example, offers a “Green Collection” of rental cars that includes fuel-sipping hybrids like the Toyota Prius or other environmentally friendly vehicles like the Toyota Camry or Hyundai Sonata, which feature an average Environmental Protection Agency (EPA) highway fuel efficiency rating of 31 miles per gallon.

* Paying the extra fee for a navigation system can go a long way towards saving you time (and money) driving around lost. “Navigation systems can help you find your way in unfamiliar territory, helping you reach your list of attractions with a minimum of time and gas lost,” Pinera says. “How you entertain the kids in the back seat, however, is entirely up to you.”

For more green driving tips, visit www.greencars.org or www.epa.gov/air/actions/drive_wise.

Courtesy of ARAcontent

Environmentalists consider litter a nasty side effect of our convenience-oriented disposable culture. Just to highlight the scope of the problem, California alone spends $28 million a year cleaning up and removing litter along its roadways. And once trash gets free, wind and weather move it from streets and highways to parks and waterways. One study found that 18 percent of litter ends up in rivers, streams and oceans.

Cigarette butts, snack wrappers and take-out food and beverage containers are the most commonly littered items. Cigarettes are one of the most insidious forms of litter: Each discarded butt takes 12 years to break down, all the while leaching toxic elements such as cadmium, lead and arsenic into soil and waterways.

The burden of litter cleanup usually falls to local governments or community groups. Some U.S. states, including Alabama, California, Florida, Nebraska, Oklahoma, Texas and Virginia, are taking strong measures to prevent litter through public education campaigns, and are spending millions of dollars yearly to clean up. British Columbia, Nova Scotia and Newfoundland also have strong anti-litter campaigns.

Keep America Beautiful (KAB), the group known for its “crying Indian” anti-litter TV ads of bygone days, has been organizing litter clean-ups across the U.S. since 1953. KAB has a strong track record of success in litter prevention, though it has been accused of doing the bidding of its industry founders and supporters (which include tobacco and beverage companies) by opposing many mandatory bottle and can recycling initiatives over the years and downplaying the issue of litter from cigarettes. Nonetheless, 2.8 million KAB volunteers picked up 200 million pounds of litter in KAB’s annual Great American Clean-up last year.

A more grassroots-oriented litter prevention group is Auntie Litter, which started in 1990 in Alabama to help educate students there about the importance of a healthy and clean environment. Today the group works internationally to help students, teachers and parents eliminate litter in their communities.

In Canada, the nonprofit Pitch-In Canada (PIC), founded in the late-1960s by some hippies in British Columbia, has since evolved into a professionally run national organization with a tough anti-litter agenda. Last year 3.5 million Canadians volunteered in PIC’s annual nationwide Cleanup Week.

Doing your part to keep litter to a minimum is easy, but it takes vigilance. For starters, never let trash escape from your car, and make sure household garbage bins are sealed tightly so animals can’t get at the contents. Always remember to take your garbage with you upon leaving a park or other public space. And if you’re still smoking, isn’t saving the environment a compelling enough reason to finally quit? Also, if that stretch of roadway you drive everyday to work is a haven for litter, offer to clean it up and keep it clean. Many cities and towns welcome “Adopt-A-Mile” sponsors for particularly litter-prone streets and highways, and your employer might even want to get in on the act by paying you for your volunteer time.

CONTACTS: Keep America Beautiful, Auntie Litter, Pitch-In Canada.

Dear EarthTalk: My uncle worked for over a decade on the top floor of an office building with cell phone towers directly above him. He was recently diagnosed with cancer. Is there any scientific evidence of links between exposure to cell phone tower radiation and cancer? — Jennifer L., Wellesley, MA

No one doubts that cell phone towers give off low-level radio-frequency radiation (similar to the microwave oven in your home), but scientists are still debating the health effects of long-term exposure. Some people are genetically predisposed to certain types of cancers, while others are not (for example, some lifelong smokers get lung cancer while others don’t). And with so many different chemicals, pollutants and other substances around us in our air, food and water, it is very difficult to determine with certainty if a particular environmental influence (such as a cell phone tower) is the culprit when health problems, such as cancer, arise in a particular locale or among certain populations.

But that hasn’t stopped many communities from worrying about this issue and taking cautionary measures. In San Francisco, for instance, concerned individuals and neighborhood groups have formed the San Francisco Neighborhood Antenna-Free Union (SNAFU) for the purpose of preventing “the placement of wireless antennas on or near residences, schools, health care centers, day care centers, senior centers, playgrounds, places of worship, and other inappropriate locations…”

SNAFU is worried that San Francisco is “already immersed in a sea of electromagnetic radiation” from, among other sources, some 2,500 licensed cell phone antennas at 530 locations around the city. The group is distributing petitions calling on local public officials to increase “restrictions on the number and location of cellular phone antennas and other wireless transmitters.” Other controversies have erupted in communities in Connecticut and elsewhere over churches renting their rooftops and steeples to cell phone companies for placement of antennas. And parents in Ossining, New York waged an unsuccessful battle in 2000 to ban revenue-generating cell towers from school grounds.

Still, the American Cancer Society (ACS) does not seem concerned, stating that limited epidemiological evidence suggests no link between cancers and living or working near a cell phone tower. ACS says that the energy level of radio waves coming off cell towers is too low to cause any noticeable human health impacts, and that a person would have to stand right in front of an antenna to pick up even trace amounts of radiation. And unlike X-rays or gamma rays, radio-frequency electromagnetic radiation is “non-ionizing,” meaning it lacks the gusto to break the bonds that hold molecules (like DNA) in cells together.

Still, cell phones and their towers are a fairly new technology, and very few studies of their health effects have yet been conducted. And the bulk of the research cited by the American Cancer Society has focused on direct and prolonged exposure to radio-frequency electromagnetic radiation in general, not on cell towers and their effects specifically. SNAFU reports that “no systematic attempt has been made to determine what current cumulative exposures to this radiation are….” Lingering public concerns about the issue surely means that more research on the topic is to come.

CONTACTS: American Cancer Society, San Francisco Neighborhood Antenna-Free Union (SNAFU).

GOT AN ENVIRONMENTAL QUESTION? Send it to: EarthTalk, c/o E/The Environmental Magazine, P.O. Box 5098, Westport, CT 06881; submit it at: www.emagazine.com/earthtalk/thisweek/, or e-mail: earthtalk@emagazine.com. Read past columns at: www.emagazine.com/earthtalk/archives.php.

Where indeed? The January/February 2008 issue of E – The Environmental Magazine (now posted at www.emagazine.com) reports that climate change is already affecting many of our most beloved winter sports, from ice-skating to skiing to maple sugaring. It’s not surprising, considering that 2006 was the warmest year on record in the U.S., and 1998 was the second warmest. While winter is still highly unpredictable (a week before E’s issue made it to newsstands, the country was hit with epic snowfalls and low temperatures) the warming trend is clear.

E’s cover package also includes some colorful reminiscing about the historic snowfalls many of us remember from childhood, plus an SOS from some of the country’s leading winter athletes, who are having to venture far and wide to find seasonal snow. Pro snowboarder Gretchen Bleiler, who has won more halfpipe competitions than any other female snowboarder, is watching the shorter, milder winters in her hometown of Aspen, Colorado, the deteriorating snowbanks on worldwide slopes and the last-minute cancellations of major snowboarding events.

“We moved to Aspen when I was 10,” says Bleiler. “I remember the first year we went to school there were avalanche danger days. The snow would rise so high in the valley. Then this past season they had to cancel the Grand Prix in New Jersey because it was too warm to even make snow.”

By the end of the century, temperatures in the Northeastern states are likely to rise by eight to 12 degrees Fahrenheit (at which time snow-covered days will have been reduced to half of what we traditionally experience). A 2007 Northeast Climate Impacts Assessment report, prepared by the Union of Concerned Scientists, says that under some higher-emission scenarios, “Only western Maine is projected to retain a reliable ski season by the end of the century, and only northern New Hampshire would support a snowmobiling season longer than two months.”

Consider these facts:

• Snowmobile sales slid 12 percent in the most recent accounting from the International Snowmobile Manufacturers Association. Total sales of 79,814 in 2006 contrasted sharply with the 170,325 sold in 1997.
• Cliff Brown of the University of New Hampshire notes that the state had 65 downhill ski areas in the 1970s, but only 20 remain. New Hampshire winters warmed 3.8 degrees Fahrenheit in the 20th century, and snowmaking alone hasn’t saved the day, especially for the low-lying family facilities. The surviving resorts, Brown says, are larger, tend to be corporate owned, and are located at higher elevations. To stay in business, the resorts have also diversified from skiing. On a recent fall day, the lower slopes at Bromley Mountain in southern Vermont looked more like an amusement park than a ski area.
• Northern New England’s climate was once ideal for maple sugaring, but as temperatures rise the industry is inexorably migrating north. Over the past four decades, the traditional mid-February to April maple sugaring season has slowly gotten shorter. According to a University of Vermont study, it now starts a week early and ends 10 days early, with a net loss of three production days. Long-time tappers worry that, by 2100, there may no longer be a maple sugar industry in New England.

The warming changes already visible are, to cite a particularly apt cliche, “the tip of the iceberg.” In the next few decades, global warming will be shaped by many different factors, with relatively unpredictable results. But the scientific consensus is near unanimous that the loss of predictable and comforting winter patterns will be a major consequence. Nostalgia for snowy winters past and “the way it was” will be a major growth industry, even as skiing, skating, snowman building and maple syrup-making gradually recede into our collective memory.

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Air fresheners are a $1.72 billion industry in the United States. An estimated 75 percent of homes use them regularly. According to a September 2007 report released by the Natural Resources Defense Council (NRDC), most common household air fresheners contain potentially noxious chemicals that degrade the quality of indoor air and may even affect hormones and reproductive development, particularly in babies.

As part of its “Clearing the Air” study, NRDC researchers tested 14 brands of common household air fresheners and found that 12 contained chemicals known as phthalates. Only two, Febreze Air Effects and Renuzit Subtle Effects, contained no detectable levels of phthalates. Products testing positive included ones marketed as “all-natural” and “unscented.” None of the brands tested listed phthalates on their labels.

Phthalates are “hormone-disrupting” chemicals that can be particularly dangerous for young children and unborn babies. Like some other man-made chemicals, phthalates can affect normal hormonal processes—those that control brain, nervous and immune system development, reproduction, mental processing and metabolism—by blocking them altogether, throwing off the timing or “mimicking” natural hormones and interacting with cells themselves, with very unhealthy consequences. The State of California notes that five types of phthalates—including one commonly used in air freshener products—are “known to cause birth defects or reproductive harm.”

Despite these issues, the U.S. Food and Drug Administration (FDA) does not regulate the use of phthalates or require the labeling of phthalate content on products. Other governments take the phthalate threat more seriously. The European Union forbids the most harmful phthalates in cosmetics or toys, and California Governor Arnold Schwarzenegger is expected to soon sign similar legislation for his state.

NRDC bemoans the fact that the U.S. government does not test air fresheners for safety or require manufacturers to meet specific health standards. “More than anything, our research highlights cracks in our safety system,” says Dr. Gina Solomon, a senior NRCD scientist. “Consumers have a right to know what is put into air fresheners and other everyday products they bring into their homes,” she says, adding that the government should keep a watchful eye on potentially dangerous products.

In conjunction with the study, NRDC—along with the Sierra Club, the Alliance for Healthy Homes and the National Center for Healthy Housing—is petitioning federal agencies to start assessing the risk air fresheners pose to consumers by testing all products now on the market. And NRDC has already begun working directly with some manufacturers to find ways to eliminate phthalates from these products.

NRDC recommends that consumers be selective and purchase only air fresheners that have the least amount of phthalates. Better yet, the group suggests consumers first try to reduce household odors by tending to their root causes or improving ventilation rather than masking them. “The best way to avoid the problem is to simply open a window instead of reaching for one of these cans,” concludes Solomon.

CONTACTS: Natural Resources Defense Council, www.nrdc.org/health/home/airfresheners.asp.

Dear EarthTalk: Are there any efforts underway to lessen the environmental impact—which must be considerable—of all the “18 wheelers” and other large vehicles that are numerous on our highways? — Sadie Strauss, Madison, WI

According to the Union of Concerned Scientists, although large trucks account for just six percent of total highway miles driven in the U.S., they are responsible for a host of environmental threats. These include over half the soot and a quarter of the smog-causing pollution generated by highway vehicles, six percent of the nation’s global warming pollution, and more than a tenth of the country’s oil consumption.

A typical diesel-powered 18-wheeler can emit as much nitrogen oxide and fine particulates—key elements in the formation of asthma-inducing smog—as about 150 passenger cars. Although strict limitations on emissions of various pollutants from cars have been in place in the U.S. since the 1970s, trucks and other large transport vehicles have been allowed to emit as much as five times as much pollution per mile.

But thanks to new regulations put in place by the U.S. Environmental Protection Agency (EPA), new trucks coming off assembly lines in the years immediately ahead promise to be much cleaner and greener. Known collectively as the EPA’s Heavy-Duty Highway Diesel Rules, the new regulations mandate that trucks manufactured in 2007 or after produce 75-90 percent less nitrogen oxide and 90 percent fewer particulates than earlier models. Of course, with most of the trucks on the road made prior to 2007 and thus exempt from the new regulations, air quality improvements won’t happen overnight.

In the meantime, though, the federal government has also instituted new regulations mandating that diesel fuels contain 97 percent less sulfur, another primary component of smog, than previously required. This means that all diesel-powered vehicles in the U.S., new or old, will be polluting less. Regulators hope that the combination of greener trucks and cleaner fuel will eventually bring emissions from large trucks into parity per mile driven with cars and light trucks (SUVs, pickups and minivans).

Beyond making existing truck engines more efficient, new technologies promise to green the trucking industry even more. Biodiesel, a form of diesel fuel derived from renewable plant crops, is coming on strong. According to the U.S. Department of Energy, use of the most common blend, B20 (80 percent regular diesel and 20 percent biodiesel), cuts petroleum use by 19 percent, greenhouse gas emissions by 16 percent and hydrocarbon emissions by 20 percent.

Also, hybrid technologies popularized by the Toyota Prius are starting to show up in trucks. Federal Express is pioneering the use of hybrid technology in trucks by outfitting many of its new delivery trucks accordingly. And several U.S. cities now run hybrid diesel-electric buses. Environmental leaders hope such fuel- and emission-saving technologies will trickle down into the private trucking industry as well.

CONTACTS: Union of Concerned Scientists, www.ucsusa.org; EPA’s Heavy-Duty Highway Diesel Program, www.epa.gov/otaq/highway-diesel.

GOT AN ENVIRONMENTAL QUESTION? Send it to: EarthTalk, c/o E/The Environmental Magazine, P.O. Box 5098, Westport, CT 06881; submit it at: www.emagazine.com/earthtalk/thisweek/, or e-mail: earthtalk@emagazine.com. Read past columns at: www.emagazine.com/earthtalk/archives.php.