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Earth Alive: Focus on environment
Recycled plastic railroad ties
There are nearly a billion wooden railroad ties holding together the railroads and subways of the US. That’s a lot of wood, and thus a lot of trees. It’s also a lot of creosote, a preservative chemical used on wood and deemed by the US EPA “probably a human carcinogen.” The cost of wood coupled with insurance against creosote-related litigation is inspiring some rail operators to switch to ties made from recycled plastics and rubber – milk jugs, plastic bags, Styrofoam cups, and so forth.
Manufacturers claim that plastic ties are environmentally friendly, and that they last longer and resist humidity better than their wood counterparts. Makers of plastic ties now have less than one per cent of the market, but they anticipate a growing share in years to come.
Birds in decline across North America
According to a report, close to 30 per cent of bird species in North America are experiencing a “significant decline.” By analyzing data on 654 species, collected from 1966 to 2003, the group discovered that 36 per cent of shrub-land species are disappearing, along with 25 per cent of forest species, 23 per cent of birds in urban areas, 13 per cent in wetlands, and a whopping 70 per cent in North America’s grasslands.
The primary culprit, the report says, is loss of habitat. It calls for more habitat protections and increased preservation efforts by private landowners and homeowners.
Scientists discover singing iceberg in Antarctica
Scientists monitoring earth movements in Antarctica believe they have found a singing iceberg. Sound waves from the iceberg had a frequency of around 0.5 hertz, too low to be heard by humans, but by playing them at higher speed the iceberg sounded like a swarm of bees or an orchestra warming up, the scientists said.
The German Alfred Wegener institute for polar and marine research published the results of its study, done in 2002, in Science magazine. Between July and November 2002 researchers picked up acoustic signals of unprecedented clarity when recording seismic signals to measure earthquakes and tectonic movements on the Ekstroem ice shelf on Antarctica’s South Atlantic coast. Tracking the signal, the scientists found a 50 by 20 kilometre iceberg that had collided with an underwater peninsula and was slowly scraping around it.
“Once the iceberg stuck fast on the seabed it was like a rock in a river,” said scientist Vera Schlindwein. “The water pushes through its crevasses and tunnels at high pressure and the iceberg starts singing. The tune even goes up and down, just like a real song.”
Traffic causes heart attacks
Being stuck in traffic could substantially raise your chances of having a heart attack — and it’s not just the stress. The particulate pollution that hovers over traffic is the likely culprit, says a study in the New England Journal of Medicine, though “we can’t exclude that there is an interaction between stress and pollution,” says lead author Annette Peters.
And it doesn’t matter whether you’re in a car, aboard public transportation, or riding a bike; as long as you’re breathing the stuff, you’re at risk. So, although the researchers do recommend reducing stress, they acknowledge that the only real way to meliorate the problem is an overall reduction in air pollution.
Rocket-fuel chemical in lettuce and milk
Perchlorate, an explosive component of rocket fuel, was found in about 90 per cent of lettuce samples and 97 per cent of milk samples from around the US tested by the Food and Drug Administration. Health officials said the levels of contamination found shouldn’t be a problem for healthy adults, though nearly all the samples tested had perchlorate in higher concentrations than the US EPA’s preliminary recommendation for an acceptable level in drinking water.
Perchlorate can disrupt thyroid function, potentially leading to delayed development, mental retardation, impaired motor skills, hearing loss, or thyroid tumours, and it poses particular dangers for kids. The chemical makes its way into the food supply by tainting waters used for crop irrigation.
Studies on perchlorate contamination and what should be done about it, are continuing. In the meantime, both government officials and environmentalists agree that you should keep eating your veggies, as their salutary benefits outweigh their risks.
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