Week of 7/13/2008

Dear EarthTalk: I need to replace my old TV. Can you tell me which of the latest models is the greenest? I was told that the flat-screen/plasmas are real energy hogs. What do you recommend?

—Angela Montague, via e-mail

According to The Wall Street Journal"s Rebecca Smith, a 42-inch plasma TV set can draw more power than a large refrigerator, even if the TV is only used a few hours a day. This is partly because many newer models don"t turn off but go into "standby" mode so they can start up fast later with no warm-up period. "Powering a fancy TV and full-on entertainment system—with set-top boxes, game consoles, speakers, DVDs and digital video recorders—can add nearly $200 to a family’s annual energy bill," she adds.

Smith recommends green consumers consider the Liquid Crystal Display (LCD) models, which typically uses less energy than comparable plasma sets. According to the U.S. Environmental Protection Agency (EPA), a 28-inch conventional cathode-ray tube (CRT) set uses about 100 watts of electricity. A 42-inch LCD set might consume twice that amount, while plasma could use five times as much, depending on the model and the programming. For the largest screen sizes (60 inches and up), projection TVs are the most energy efficient, clocking in at 150-200 watts—significantly less than the energy a plasma set would use.

"What scares us is that prices for plasma sets are dropping so fast that people are saying, why get a 42-inch plasma set when you can get a 60-inch or 64-inch one," says Tom Reddoch of the non-profit Electric Power Research Institute. "They have no idea how much electricity these things consume."

Some flat screen TVs draw more power than a large refrigerator. Beginning in November 2008, "Energy Star" labels will begin appearing on televisions to help consumers identify greener choices.© Getty Images

For its part, the industry is taking some steps to make its products more efficient, and to improve disclosure of energy usage. In June 2008 Sony pronounced its new 32-inch Bravia KDL-32JE1 LCD model "the world"s most energy efficient television." Slated for sale in Japan in August 2008 for around $1,400, the new set utilizes fluorescent tubes to create higher levels of brightness with less energy consumption, but still delivers large resolution, a high contrast ratio and a wide viewing angle.

Beginning in November 2008, forward-thinking manufacturers will get a little boost from the U.S. government, which will start awarding the most energy efficient new TV sets "Energy Star" labels to help consumers identify greener choices. TVs bearing the Energy Star label must operate at least 30 percent more efficiently than standard models in both stand-by and active modes. Consumers can see which models qualify by visiting the televisions section of the EnergyStar.gov home electronics page. According to the EPA, if all TVs sold in the U.S. met Energy Star requirements, yearly energy savings would top $1 billion and greenhouse gas emissions would drop by the equivalent of taking a million cars off the road.

Of course, the greenest option of all (aside from getting out from in front of that tube and spending more time outdoors) is to keep or repair your existing CRT unit (a digital-to-analog converter will be needed after February 2009 when new signal specifications go into effect). Most CRT sets use less energy than any of the LCD or plasma models, and if it ain"t broke, why fix it? Buying a new TV, even a greener one, only generates more pollution in production and transport, and creates waste in junking the old model.

CONTACTS: U.S. Environmental Protection Agency; Energy Star; Electric Power Research Institute; Sony Corp.

Dear EarthTalk: I heard that children are reaching puberty at earlier ages now and that it may have to do with environmental toxins and even their TV viewing habits. Can you enlighten?

—Mark Abbot, via e-mail

Some researchers believe that the preponderance of synthetic chemicals in more developed societies are interfering with human endocrine development and essentially "tricking" kids
bodies into going through puberty prematurely.© Getty Images

To say that kids are growing up faster than ever these days may be more than just cliché. Recent studies have shown that children are reaching puberty at younger and younger ages, and researchers are starting to see links between this trend and other societal ills such as ubiquitous pollution and sedentary lifestyles.

In a 2007 report for the Breast Cancer Fund entitled "The Falling Age of Puberty in U.S. Girls: What We Know, What We Need to Know," ecologist Sandra Steingraber argues that unfettered access to computers and TVs over the last 30 years has led to an increasingly sedentary lifestyle among kids in the U.S. and beyond. Active kids produce more melatonin, a natural hormone that serves as the body"s internal clock and calendar. This could explain why sedentary kids are likely to go through puberty sooner: Their bodies think their decreased melatonin production is a trigger to move into puberty. "[Melatonin is] an inhibitory signal for puberty," says Steingraber. "The more melatonin you have, the later you go into puberty."

Of course, sedentary lifestyles are also linked to childhood obesity, a condition that often continues—along with the many health problems that can accompany it—into adulthood. A recent National Health and Nutrition Examination Survey (NHANES) found that, between 2001 and 2004, 17.5 percent of children ages six to 11 were overweight—an effective doubling of obesity rates three decades ago. A study by the non-profit Obesity Society came up with a slightly higher figure—20 percent—with the percentages higher for Hispanic, African-American and Native American children.

Obesity is certainly one factor in the surge in so-called "precocious" adolescence, but chemicals are also thought to play a role. According to Erin Barnes, writing in E — The Environmental Magazine, a study comparing the body mass index of Danish and American girls found that the former group hit puberty a full year later than the latter even though their weights were in the same range. Another study found that wealthy girls in South Africa reach puberty a full year after their African-American counterparts. "Many researchers," writes Barnes, "are studying the relationship between chemical pollutants like PCBs (polychlorinated bphenyls) and phthalates (commonly used plasticizers) and premature development."

Some researchers believe that the preponderance of synthetic chemicals in more developed societies are interfering with human endocrine development and essentially "tricking" kids" bodies into going through puberty prematurely. Also, precocious puberty in girls has been linked to breast cancer, as well as higher rates of drug abuse, violence, unintended pregnancies, problems in school and mental health issues.

"Shortening childhood means a shortening of the time before the brain"s complete re-sculpting occurs," says Steingraber. "Once that happens, the brain doesn"t allow for complex learning." She adds that the brain can only build the connections used to learn a language, play a musical instrument or ride a bike before it gets flooded with the sex hormones that come with the onset of puberty.

CONTACTS: Breast Cancer Fund; National Health and Nutrition Examination Survey; Obesity Society