Week of 06/13/10

Dear EarthTalk: What is "kenaf" paper? From what I’ve heard, it’s good for the environment. But what exactly are its benefits and where can I obtain some?

—Tiffany Mikamo, via e-mail

Kenaf, a fast-growing, non-invasive annual hibiscus plant related to cotton, okra and hemp, makes ideal paper fiber as well as great source material for burlap, clothing, canvas, particleboard and rope. Its primary use around the world today is for animal forage, but humans enjoy its high-protein seed oil to add a nutritious and flavorful kick to a wide range of foods. In fact, kenaf has been grown for centuries in Africa, China and elsewhere for these and other purposes, but environmentalists see its future in replacing slower-growing trees as our primary source for paper.

U.S. Department of Agriculture (USDA) research shows that kenaf yields some six to 10 tons of dry fiber per acre per year, which is three to five times more than the yield of Southern Pine trees—now the dominant paper pulp source in the U.S. And to top it off, researchers believe kenaf absorbs more carbon dioxide—the chief "greenhouse gas" behind global warming—than any other plant or tree growing. Some 45 percent of dry kenaf is carbon pulled down from the atmosphere via photosynthesis.

No wonder environmentalists are so bullish on kenaf for our common future. "The more kenaf we grow, we can not only absorb significant amounts of the carbon dioxide that is responsible for global warming," says Bill Loftus of the non-profit Kenaf Research Farm, "but also educate the world on how to be self-sustainable through kenaf’s many properties of providing food, shelter and economic opportunities."

U.S. Department of Agriculture research shows that kenaf yields some six to 10 tons of dry fiber per acre per year, which is three to five times more than the yield of Southern Pine trees, now the dominant paper pulp source in the U.S. Kenaf also absorbs more carbon dioxide than any other plant or tree. Pictured: Bill Loftus tends kenaf plants at the Kenaf Research Farm.© Kenaf Research Farm

As to its use for paper, 10 major U.S. newspapers have tested kenaf-based newsprint and were pleasantly surprised by how well it held up and how crisply it displayed text and pictures. And since it is already brighter than wood-based pulp, it requires less bleaching before it can be used to carry ink. But since kenaf is not mass-produced the way paper trees are on big plantations across the Southeast and West, it still costs more than regular paper and as such has not gone mass market, despite its environmental.

Also, while some policymakers and many environmentalists would like to see our paper feedstock switched from Southern Pine and other trees to kenaf, entrenched timber companies with big investments in tree farms (and who employ many a Washington lobbyist) do not. And with many timber companies already suffering economically, lawmakers are unlikely to mandate changes that could make matters worse.

Even if kenaf doesn’t become the paper of tomorrow, it may still have a bright future. The Kenaf Research Farm reports that Toyota is already using kenaf grown in Malaysia for insulation and interiors in some cars. Toyota is also experimenting with using kenaf to reinforce the sugarcane- and maize-based biopolymers it hopes can replace many of the plastic and metal parts in the vehicles it is designing today.

Your best bet for finding some kenaf paper is to try a specialty art supply or stationery store. One good online source is The Natural Abode. Photographers might try using kenaf photo paper, such as Pictorico’s ART Kenaf, in their ink jet printers to give their snaps a unique look and a green pedigree.

CONTACTS: USDA; Kenaf Research Farm; The Natural Abode; Pictorico ART Kenaf.

Dear EarthTalk: OK, so are cell phones emitting dangerous radiation or not? If so, which phones are safer that others and what do we do to minimize exposure?

—Luke Alderman, Santa Fe, NM

The jury is still out as to whether or not the radiation emitted by cell phones is dangerous, but some manufacturers are working to reduce the radiation emissions of the phones they make. Though it may make you look bionic, a safe bet is to use a headset or ear piece to create distance between the phone and your head when calling.© Thinkstock

The jury is still out as to whether or not the radiation emitted by cell phones can cause negative health effects for callers. Mobile phones emit signals to communicate with cellular towers via radio waves, which are comprised of radio-frequency (RF) energy, a form of electromagnetic radiation.

The U.S. Federal Communications Commission (FCC) limits the amount of radiation any phone sold in the U.S. can emit to what it considers a safe level of 1.6 watts per kilogram of body weight (a measure of the energy absorbed by the body when using a wireless device). But some health practitioners are concerned that even this level of exposure may be too high, resulting in people unwittingly exposing themselves to potentially harmful radiation every time they make or take a call.

Such radiation is known to heat up living tissue it comes into close contact with by a fraction of a degree, but this level of temperature increase is less than that caused by exposure to direct sunlight, and the brain’s blood circulation typically disperses this excess heat quickly by increasing local blood flow.

Some recent studies have found higher risks for brain and salivary gland tumors among people using cell phones for 10 years or longer, while other research has found little if any risk. Other research has looked at the reproductive, cognitive and sleep effects of RF energy at levels similar to what cell/smart phones emit. Results have been mixed. More studies are now underway to resolve whether or not cell phones are safe for people to use, but some electronics manufacturers aren’t waiting around to cut down on the radiation emissions of the phones they make and sell.

If you are in the market for a new cell phone, check out the nonprofit Environmental Working Group’s (EWG"s) rundown on which of the thousand or so popular cell/smart phone models give off the most and least radiation. Levels vary widely, from as little as 0.3 to the legal limit of 1.6 watts per kilogram of body weight. Sanyo’s Katana II, Samsung’s Rugby, Nokia’s 7710, and the Blackberry Storm, among others, get top marks from EWG for giving off lower amounts of radiation (in the 0.3 range). Meanwhile, more than a dozen different cell/smart phones (including some of the most popular models such as Motorola’s Droid, Blackberry’s Bold 9700, LG’s Chocolate Touch and HTC’s Nexus One by Google) are categorized as "worst" by EWG for giving off larger amounts of radiation (pushing the 1.6 limit). Apple’s iPhone 3Gs is in the middle of the spectrum, leaking between 0.52 and 1.19, depending on usage.

Regardless of which cell/smart phone you use, you can minimize your exposure to RF radiation by taking a few simple precautions. For one, using a headset (these give off significantly less radiation) or speaker phone keeps the phone itself away from your head. Also, your phone emits far less radiation when used to text instead of call—and the phone isn’t next to your brain when texting—so the more you tap (just not while driving, please!) instead of talk the better. Also, a poor signal (fewer bars) means that your phone has to work harder—and emit more radiation—to connect up to a wireless tower, so wait to make that call until you are somewhere with a stronger connection.

CONTACTS: FCC; Environmental Working Group.

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