A cloth to cut the mercury risk from light bulbs
Compact fluorescent lamps last longer and use much less electricity than conventional bulbs. But they contain small amounts of the neurotoxin mercury. Compact fluorescents are supposed to be recycled so that the mercury (which is in vapour form) can be dealt with properly. But the tubes do occasionally crack or break, and the recycling rate is currently low, so mercury could be released in homes or elsewhere, posing a small risk to children. Robert H. Hurt, an engineering professor at Brown University, along with a student, Natalie C. Johnson, and others, set out to see what could be done to reduce the risk. They experimented with tiny particles of sulfur, copper, nickel and other elements to see how well mercury was absorbed onto them. Selenium, in particular, has a well-known affinity for mercury, and the researchers found that particles of it with a size from about 10 to 600 nanometers were capable of binding with almost all of the mercury from a lamp. The researchers say this “nanoselenium,” impregnated in cloth, could be used in packaging for new lamps or for cleaning up a broken lamp in the home.

Corals, already in danger, face new threat in algae grown by people
Off the palm-fringed white beach of the remote Pacific atoll of Butaritari, the view underwater is downright scary. Corals are being covered and smothered to death by a bushy seaweed that is so tough even algae-grazing fish avoid it. Eucheuma settles in the reef’s crevices that fish once called home, driving them away. “This is one of the most damaging seaweeds I have ever seen,” says Jennifer E. Smith of the National Center for Ecological Analysis and Synthesis at the University of California. The seaweed was originally farmed because, while not edible, it produces carrageenan, an increasingly sought-after binder and fat substitute used in the food industry, notably in ice cream. Today, Totie, the Butaritari traditional chief, says the only way to prevent Eucheuma from destroying the entire lagoon is for the seaweed company to offer to buy it.