Potential Neurotoxin Could Be in Our Food

# By Brandon Keim Email Author
# July 17, 2009 | 2:04 pm

Long after a potentially neurotoxic flame retardant is off the market, it could linger in our food chain.

One of the most comprehensive analyses yet of human exposure to PBDEs, or polybrominated diphenyl ethers, shows that the chemical — long used in everything from computers to sleeping bags — enters humans through their diets, not just their household.

“The more you eat, the more PBDEs you have in your serum,” said Alicia Fraser, an environmental health researcher at Boston University’s School of Public Health who headed the new study, published this month in Environmental Health Perspectives.

PBDEs are chemical cousins of polychlorinated biphenyls, or PCBs, which are known to cause birth defects and neurological impairments. PCBs were banned throughout the world by the mid-1970s, when PBDEs were gaining popularity as flame retardants. PBDEs were soon found in most plastic-containing household products.

By the late 1990s, trace amounts of PBDEs had been found in people all over the world, with the highest exposures measured in the United States. Researchers became nervous: Low doses caused neurological damage in laboratory animals, and the highest human PBDE levels were found in breast milk.

Whether PBDEs posed an immediate threat to humans was uncertain. Direct testing is unethical, and population-wide epidemiological studies are difficult to run. But there’s enough reason for concern that the European Union banned two of the three most common PBDE formulations in 2004.

The Environmental Protection Agency, which in January admitted that it lacked the ability to establish basic standards of chemical safety, has not followed suit, but three states — California, Washington and Maine — have banned PBDEs since 2007. Many manufacturers have either stopped or plan on stopping their use.

“They are persistent in the environment. They don’t get broken down. Therefore, it takes a really long time for the contamination to leave our environment and our bodies,” said Fraser. “Even though we don’t know the health effects at this point, most people would want policies that would stop us from being exposed to them.”

But though well-advised, these bans won’t eliminate the threat. Most PBDE exposure research has focused on how people can absorb it from dust and other indoor sources that would ostensibly be eliminated once PBDE-containing products were discarded. Much less attention has been paid to PBDEs in food.

Fraser’s team analyzed biological samples from 2,000 people, provided by the U.S. Centers for Disease Control and Prevention. The same data was used in 2004 to establish baseline estimates of PBDE exposure in Americans, but that study didn’t look for patterns in food consumption. Fraser’s team found that PBDE levels were 25 percent higher in meat-eaters than vegetarians.

Though the channels of food contamination by PBDEs haven’t been conclusively established, it’s possible that “the old products are being moved to landfills, and PBDEs could enter the environment that way,” said Fraser. Earlier this year, the National Oceanic and Atmospheric Administration announced that PBDEs were present in all U.S. coastal waters and the Great Lakes, with the highest levels found near urban and industrial areas.

That PBDEs would be highest in meat products makes sense, as the chemicals accumulate in fat, and it wouldn’t be hard for PBDEs to enter their feed and water.

Fraser suggested that the United States adopt chemical regulations similar to those in the European Union, which in 2007 mandated that chemicals be thoroughly tested and proven safe before used. That’s the opposite of the U.S. system, where chemicals are assumed to be safe until it’s proved otherwise.

“The industry is finding new products to use as flame retardants, and we don’t know the health and safety implications of those products either,” said Fraser. “We need to test the health and safety implications of products before they go into use, not after.”

Source: http://www.wired.com/wiredscience/2009/07/pbde/

Power Your Car With Pee

# By Ben Mack Email Author
# July 17, 2009

A scientist at Ohio University has developed a catalyst capable of extracting hydrogen from urine. That’s right. Urine. Now you can fill one tank while draining another.

Garardine Botte claims the device uses significantly less energy than is needed to extract hydrogen from water and says it could power hydrogen fuel cell vehicles in the near future. Her electrolyzer uses a nickel-based electrode to extract hydrogen from urea (NH2)2CO, the main component in urine. Hydrogen is less tightly bound to the nitrogen in urea than to the oxygen in water, so the electrolyzer needs just 0.37 volts across the cell to oxidize the urea, according to Botte. That’s less than half the amount of energy in an AA battery and considerably less than the 1.23 volts needed to split water.

One of hydrogen’s biggest stumbling blocks to use as an alternative fuel is the amount of energy needed to produce it. And then there’s the matter of distributing it. Botte says her gadget eliminates such problems because it’s small enough to integrate into an automobile. Urine is also readily available — your body produces two to three liters of it each day, and it is the most abundant form of waste on the planet. We could treat waste water while fueling our cars.

“Urea is the same stuff we use to fertilize our flower beds. It’s a solid that dissolves in water and is therefore easy to move,” Botte told Wired.com. “An electrolyzer built into a car would eliminate the need for a hydrogen storage tank, and with the right partnership, I believe we could have pee-powered cars capable of 60 miles per gallon on the road within a year.”

Botte’s current electrolyzer prototype is about the size of a pair of CD jewel cases and can produce up to 500 milliwatts of power. That’s pretty small, but Ohio University has patented the technology and Botte says it could be scaled up to power hybrid and electric vehicles or anything else running on electricity.

“We are currently working on the chemistry of the electrolyzer,” she said. “The next step is the engineering, which should flow just fine. It would involve increasing the size of the electrolyzer, making it more efficient and testing its long-term stability.”

She says the cost of developing the technology for conventional cars would all depend on what’s powering the car. The electrolyzer would have to pull energy from a power source like a battery in order to produce hydrogen for a fuel cell. Botte also is examining how the electrolyzer could draw the power it needs from a solar panel. Hooking it up to a rooftop solar panel — like the one on the 2010 Toyota Prius — could increase efficiency as much as 40 percent, she said.

Botte hasn’t gotten much in the way of federal funding for the project, though she is working with the Department of Defense to develop electrolyzer technology for military use.

“Years ago, the army pushed to develop hydrogen technology in order to eliminate the use of noisy generators when out in the field or in order to deal with what’s called the ’silent camp problem,’” Botte said. “The problem they were running into out in the desert was access to large amounts of clean water. The electrolyzer, however, eliminates the need for clean water other than drinking water and to transport fuel to remote areas.”

Photo: Flickr / RichPix

Source: http://www.wired.com/autopia/2009/07/pee-powered-cars/