Unlikely additives

Would you eat that powdered doughnut if you knew it was dusted in titanium nanoparticles? Whether it worries you or not, nanomaterials—involving particles a few billionths of a meter in size—are infiltrating the food industry. Titanium dioxide, a substance that enhances whiteness, is found in candy, gum, and toothpaste. Silver nanoparticles are used in food packaging for their antimicrobial properties. Other nanoscale additives make liquids creamy without adding fat.

Some food producers eschew nanotechnology, but a new report suggests many either don’t know whether their product supply chain contains the particles or are unwilling to admit it. As You Sow, an environmental and human-rights group, asked 2,500 companies in the food industry whether they used nanotechnology. Only 26 responded. Of those, two admitted their products contained nanoparticles, and 10 weren’t sure. As You Sow’s own study of powdered doughnuts found Dunkin’ Donuts Powdered Cake Donuts and Hostess Donettes both contained titanium dioxide less than 10 nanometers in size—though it’s not clear whether the particles were engineered or byproducts of manufacturing. (Hostess has since declared bankruptcy.)

Nanoparticles can be absorbed into the bloodstream after being inhaled or ingested, and are small enough to penetrate cells. Some studies have shown them to be harmful to rodents. Last April, the Food and Drug Administration said there wasn’t enough data to determine whether nanoscale food ingredients are safe. Meanwhile, the Environmental Protection Agency is studying the safety of titanium dioxide and four other nanomaterials: According to the As You Sow report, government agencies in 2012 spent 16 times as much on nanomaterial product development as on safety testing.

It may be a mistake to assume all nanomaterials are guilty until proven innocent, though. Andrew Maynard, director of the Risk Science Center at the University of Michigan, told me in 2011 that science indicates some nanomaterials cause harm, while others don’t: “You can’t put everything in the same bucket.”

By the numbers

12.3 billion

Median number of small mammals, such as chipmunks and rabbits, that die each year in the jaws of U.S. domestic cats, according to a new estimate. The nation’s 30 million to 80 million stray cats are responsible for most of the killings. Including household pets that occasionally roam outdoors, cats may kill more than 3 billion birds annually—ranking the purring predators as greater threats to bird and mammal wildlife than humans. (Nature Communications)

63 percent

Decrease in deaths among children under 5 in Rwanda between 2000 and 2011. Since the 1994 genocide that left 800,000 Rwandans dead, the country has become a healthcare success story, thanks in part to foreign aid, with life expectancy rising from 28 years to 56 years. Although childhood malnutrition remains high, deaths from childbirth, AIDS, tuberculosis, and malaria have plummeted over the past decade. (British Medical Journal)

2,600 feet

Depth of the borehole American scientists drilled in Antarctic ice while searching for life in a subglacial lake. The researchers found what appeared to be bacteria living in water samples collected from Lake Whillans, a shallow body of water sandwiched between the Antarctic continent and ice cap. They plan to confirm their novel discovery using DNA sequencing. —D.J.D.