Pumpkins Carve Environmental Niche, Elevision Makes Distress Call, Diamond Mine in Montana, More on Nitrogen

• Pumpkins carve environmental niche
• Television makes distress call
• Diamond mine in Montana
• More on nitrogen

Pumpkins carve environmental niche

When pumpkins are not being used as decorations for Halloween, it's possible they could be cleaning the environment. Researchers at the Royal Military College of Canada have discovered that the lowly pumpkin is good at sucking up contaminants right out of the soil.

In greenhouse experiments, chemist Ken Reimer and colleagues took soil that was contaminated with DDT, used decades ago to control mosquitoes, and grew a selection of plants, including ryegrass, tall fescue, zucchini, and pumpkin. The plant that removed the most DDT was pumpkin, followed by zucchini. The researchers speculate that the large mass and volume of these plants account for their effectiveness.

In further studies, Reimer found that pumpkins also can remove polychlorinated biphenyls (PCBs) from soils.

Low-level, persistent contaminants such as DDT, PCBs, some pesticides, and dioxins are difficult to remove from soils because they are not water soluble. The most effective method for cleanup is to place the soil in a landfill or incinerate it.

Reimer says pumpkin growing is not likely to replace traditional methods of soil cleanup anytime soon, but it might offer an inexpensive and environmentally friendly alternative, especially in small communities where money is a concern and the cleanup is not urgent. If pumpkins are used, they could not be eaten, of course. The plants and vines would be cut down after they ripen, then disposed of in landfills or incinerated.

The full report on Reimer's work will be in the Nov. 15 issue of Environmental Science & Technology.

Television makes distress call

Recent news accounts describe an eerie occurrence in Oregon. A man's flat-screen television set was discovered to be sending out an international distress signal. The signal was so strong that it was picked up by a satellite and routed to an Air Force rescue center in Virginia, which dispatched a search-and-rescue team to the man's apartment. The surprised owner was advised to keep his set turned off or face a $10,000 fine for "willingly broadcasting a false distress signal." The TV's manufacturer, Toshiba, has offered to replace the year-old set.

No one knows why the TV was sending the 121.5-MHz signal, but the quality of this year's television programs could be a reason the TV was distressed.

Diamond mine in Montana

A surprise diamond mine may have been found in Montana. Deposits of the diamond-bearing green mineral kimberlite have been found on an 80-acre site known as the Homestead property, and a sample has turned up a microscopic diamond.

Although a few diamonds have been found in Montana, they are believed to have been carried there by streams or glaciers many years ago. The Homestead diamonds would be the first ones to actually have been made in Montana.

The site is being explored by the Kentucky firm Delta Mining & Exploration Corp. The firm is excited because kimberlite, which is normally found in tubes that were formed by volcanoes far below ground, has been pushed to the surface in Montana, making the ore accessible. This will reduce excavation costs and also mitigate environmental damage to the surrounding prairie.

More on nitrogen

More readers are finding advertisements for using dry nitrogen gas to fill auto tires in place of air (C&EN, Oct. 25, page 88). And the concern about the rationale for this continues as well, particularly the claim that nitrogen doesn't leak out of tires because it is larger than oxygen. Physical chemist David Yang writes to point out that the oxygen-oxygen double bond is about 1.2 Å long and the nitrogen-nitrogen triple bond is about 1.1 Å. "They may have better luck inflating with a really large molecule such as helium," Yang jokes.

This week's column was written by David Hanson . Please send comments and suggestions to newscripts@acs.org.