Dear EarthTalk: Years ago I read that children should be kept at least two feet
Contrary to popular myth, TV screens do not
from the television because of harmful electronic emissions. Is this still relevant? Is there a difference regarding this between older and new flat-screen models? -- Horst E. Mehring, Oconomowoc, WI
Luckily for many of us and our kids, sitting “too” close to the TV isn’t known to cause any human health issues. This myth prevails because back in the 1960s General Electric sold some new-fangled color TV sets that emitted excessive amounts of radiation—as much as 100,000 times more than federal health officials considered safe. GE quickly recalled and repaired the faulty TVs, but the stigma lingers to this day.
But even though electronic emissions aren’t an issue with TVs made any time after 1968 (including today’s LCD and plasma flat screens), what about causing harm to one’s vision? Dr. Lee Duffner of the American Academy of Ophthalmology isn’t concerned, maintaining that watching television screens—close-up or otherwise—“won’t cause any physical damage to your eyes.” He adds, however, that a lot of TV watching can surely cause eye strain and fatigue, particularly for those sitting very close and/or watching from odd angles. But there is an easy cure for eye strain and fatigue: turning off the TV and getting some rest. With a good night’s sleep, tired eyes should quickly return to normal.
Debra Ronca, a contributor to the How Stuff Works website, argues that some parents might be putting the cart before the horse in blaming close-up TV watching for their child’s vision issues. “Sitting close to the television may not make a child nearsighted, but a child may sit close to the television because he or she is nearsighted and undiagnosed,” she reports. “If your child habitually sits too close to the television for comfort, get his or her eyes tested.”
Of course, excessive TV viewing by kids can cause health problems indirectly. According to the Nemours Foundation’s KidsHealth website, children who consistently watch TV more than four hours a day are more likely to be overweight, which in and of itself can bring about health problems later. Also, kids who watch a lot of TV are more likely to copy bad behavior they see on-screen and tend to “fear that the world is scary and that something bad will happen to them.” Nemours also finds that TV characters often depict risky behaviors (like smoking and drinking) and also tend to reinforce gender-role and racial stereotypes.
There has also been much debate in recent years on the effects of TV viewing on infants. A 2007 Seattle Children’s Research Institute study found that for every hour per day infants spent watching baby DVDs and videos they learned six to eight fewer new vocabulary words than babies who never watched the videos. But a 2009 study by the Center on Media & Child Health at Children's Hospital Boston found no negative cognitive or other impacts whatsoever on those infants exposed to more television than less.
While it may be inevitable that your kids will watch TV, the key, experts say, is moderation. Limit kids’ exposure to screens of any kind, and monitor what they are allowed to watch. As KidsHealth points out, parents should teach their kids that the TV is “for occasional entertainment, not for constant escapism.”
CONTACTS: American Academy of Ophthalmology, www.aao.org; How Stuff Works, www.howstuffworks.com; KidsHealth, www.kidshealth.org; Seattle Children's Research Institute, research.seattlechildrens.org; Center on Media & Child Health, www.cmch.tv.
Dear EarthTalk: What’s better for the local ecology, sewers or septic tanks? --
Most people, given a choice, prefer to be on a
Image Courtesy of "Trish Thornton, courtesy Flickr."
T.H., Darien, CT
You probably won’t have much choice as to whether that home you’re thinking of buying is on sewer or septic. Most likely it’s a done deal, unless the neighborhood is presently all on septic but is considering a petition to the town to switch to sewers (in which case you can usually agree to hook up or stay put).
There are pros and cons to each in regard to the environment. Both types of systems are designed to handle and treat so-called “blackwater” (wastewater from toilets) and “graywater” coming from our sinks, showers, dishwashers and laundry machines. On-site septic and community-wide sewer systems work in similar ways, utilizing micro-organisms to filter out bacteria, viruses and other disease-causing pathogens before releasing the cleansed water back into the environment.
In general, most people prefer to be on a shared sewer system if they have a choice, as the burden of keeping the system running smoothly falls on the local government, which presumably has the money and expertise to ensure that wastewater is properly treated across the region. Also, in a shared sewer system, wastewater is whisked away to a centralized treatment facility; anyone who has ever experienced a septic system backup on their property can appreciate what a benefit off-site wastewater treatment can be.
Another advantage to a shared sewer is that such systems are usually built to withstand heavy loads and can better accommodate periods of heavy precipitation or storm surges that might overwhelm smaller, poorly conceived or maintained home-based septic tanks, which are by virtue of their size and the laws of physics more prone to overflow and send contaminants into nearby surface and ground waters.
Septic systems have their proponents, though, who say that a professionally designed, installed and maintained system should hold up in even the biggest of storms. The University of Minnesota Extension (UMNE), which publishes the useful online “Septic System Owner’s Guide,” says vigilance is key: “The only way to guarantee effective treatment is to have a trained professional ensure adequate unsaturated and suitable soil exists below the soil treatment area to allow for complete wastewater treatment.”
When homeowners don’t take care of their septic systems properly, though, they can become a nuisance for the surrounding ecosystem. Wastewater that is not properly treated can contaminate surface and groundwater and threaten public health. According to UMNE, improperly treated sewage can be the culprit behind the spread of hepatitis, dysentery and other diseases resulting from pathogens in drinking water, while also compromising the purity of lakes and streams. Additionally, flies and mosquitoes that are attracted to and breed in wet areas where sewage reaches the surface can also spread disease.
Improperly treated sewage can also lead to increased nitrates in local water supplies, which is dangerous for infants, pregnant women and those with already compromised immune systems. In and around lakes and streams, this influx in nitrates can lead to plant growth out of whack with the local ecosystem’s ability to handle it, resulting in oxygen-free “dead zones” devoid of marine and riparian life altogether.
CONTACT: Septic System Owner’s Guide, www.extension.umn.edu/distribution/naturalresources/dd6583.html.