Going inside is safer, but it doesn’t completely protect a person from pollution: Ozone can creep into buildings and homes and still pose a threat because it irritates the lungs. Inside a building, levels are much lower than outside because ozone changes when it runs into something like furniture. A new study identified yet another layer of protection that keeps ozone out of our bodies — human skin.

Our bodies continuously shed flakes of skin hosting ozone-busting oils that accumulate in house dust and on surfaces.

Kudumomo/Flickr

Skin contains many different kinds of oils. It’s easy to see: Just press your finger against a sheet of glass and observe. Your fingerprint is outlined in oil. When ozone in the air meets the oils in human skin, there is a chemical reaction. That means that the molecules of ozone — and possibly the molecules of oil — change.

Ozone is a lot like the oxygen we breathe. The kind that we breathe is made of diatomic molecules, which means each molecule has two atoms. But ozone has an extra: It is made of three oxygen atoms connected together. This extra atom makes ozone behave differently than typical oxygen. Ozone is both poisonous and protective.

For the new study, the scientists gathered information about the dust in the bedrooms of 500 children who live on the Danish island of Fyn. This dust, the scientists found, contained many different chemicals. One was a phthalate, which is a controversial chemical found in many plastics and other materials and that might harm to the hormone balance in humans. The scientists weren’t surprised to find a phthalate because these chemicals are everywhere.

They were surprised to find large amounts of cholesterol and squalene. (Squalene is a fat that makes up about 10 percent of the oil in human skin.) Then the researchers realized that both of these things can be found in human skin. The human body regrows its outer layer of skin every two to four weeks, and bits and pieces of the old skin break off — to become dust.

In this study, the researchers determined that skin flakes on surfaces were covering those surfaces with squalene, thus making those windows, doors or couches break up ozone as well as skin does.

“We’ve known that the ozone indoors is being gobbled up,” Charles Weschler told Science News. “But we really didn’t know what’s doing the gobbling.” Now, he finds, “this squalene is just great at chewing up ozone.” Weschler, a scientist at the University of Medicine and Dentistry, New Jersey, in Piscataway, worked on the new study.

It may seem like good news that human skin helps indoor spaces fight off dangerous ozone. After all, if the ozone goes away, then a person won’t breathe it and face the bad health effects.

But that may not be the case: Emerging research suggests this battle with ozone might present its own dangers.

Regions that host crowds stand to accumulate the most squalene, and any toxic pollutants that form during its reactions with ozone.

Kuchingboy/Flickr

In a different experiment, scientists in Austria mixed together ozone and skin oils in the laboratory. They found that, even though this mixing gets rid of ozone, it also creates new kinds of pollution. One in particular, called 4-oxopentanal (or 4-OPA), might be particularly dangerous. Until now, scientists have not analyzed 4-OPA to see how toxic it is, but that’s changing.

Yet another team of scientists are working on this chemical at the National Institute for Occupational Safety and Health in Morgantown, W.V. In early studies, the researchers found evidence that 4-OPA may be even worse than ozone. In other words, the ozone may be gone — but what’s left in its place may be even worse for human health.

In the end, scientists want to know exactly what’s going on with the molecules that we breathe — and they hope this information will help us find new ways to protect our health. But the scientific journey from the first experiment (in the children’s bedrooms) is long, requiring study after study by scientists who can learn from each other.

Going Deeper:

* Raloff, Janet. 2010. “The skinny on indoor ozone,” Science News, March 25. http://www.sciencenews.org/view/generic/id/57596/title/Science_%2B_the_Public__The_skinny_on_indoor_ozone

Sohn, Emily. 2006. “Sun screen,” Science News for Kids, July 12. http://sciencenewsforkids.org/articles/20060712/Feature1.asp

The potential for misery might get even worse. A new study suggests that rising levels of the gas carbon dioxide in the atmosphere could make poison ivy grow faster and become more toxic.

Poison ivy grows unusually fast when carbon dioxide in the atmosphere reaches levels expected in forests by about the year 2050.

J. Blanchard

“Rising carbon dioxide can favor pests and weeds, those plants we’d least like to see succeed,” says climate-change ecologist Bruce Hungate of Northern Arizona University in Flagstaff.

Large doses of carbon dioxide (CO₂) get into the air when people burn coal, oil, natural gas, and other fossil fuels. Carbon dioxide is a greenhouse gas. As it accumulates, the atmosphere traps more heat, and Earth’s climate warms up.

Plants need CO₂ to grow. To test whether extra CO₂ in the environment leads to extra plant growth, scientists have set up circles of pipes as high as treetops around the world. These pipes spit out either regular air or extra CO₂ over a patch of ground. As a result, researchers can compare how plants respond to different atmospheric conditions.

For 6 years, scientists monitored plants that grew near some of these pipes in a Duke University pine forest. They found that, with about 50 percent more CO₂ around, poison ivy plants were able to make more food and use water with greater efficiency.

Poison ivy plants that got the CO₂ boost produced the same amount of toxic oil, called urushiol, as regular air-bathed plants. With extra CO₂, however, more of the urushiol was in a particularly toxic form and more likely to cause rashes.

Poison ivy’s success in the presence of extra CO₂ is just one example of how climate change might alter the dynamics of forest ecosystems, scientists say.

With more poison ivy around, it might also become harder to enjoy being in the woods. Lead researcher Jacqueline E. Mohan, for example, had never developed a rash from poison ivy before she started the study. “I get it now,” she says.—E. Sohn

Going Deeper:

Milius, Susan. 2006. Pumped-up poison ivy: Carbon dioxide boosts plant’s size, toxicity. Science News 169(June 3):339. Available at http://www.sciencenews.org/articles/20060603/fob1.asp .

Additional information about research in the Duke Forest can be found at www.env.duke.edu/forest/ (Duke University).

To learn more about the effects of poison ivy, go to kidshealth.org/kid/health_problems/skin/poison_ivy.html (KidsHealth for Kids).

Sohn, Emily. 2006. Plant gas. Science News for Kids (Jan. 18). Available at http://www.sciencenewsforkids.org/articles/20060118/Note2.asp .

______. 2005. Arctic algae show climate change. Science News for Kids (March 9). Available at http://www.sciencenewsforkids.org/articles/20050309/Note2.asp .

______. 2004. A change in climate. Science News for Kids (Dec. 8). Available at http://www.sciencenewsforkids.org/articles/20041208/Feature1.asp .

______. 2003. Slower growth, greater warmth. Science News for Kids (April 30). Available at http://www.sciencenewsforkids.org/articles/20030430/Note2.asp .

Science project idea: Grow different plants in chambers with higher-than-normal levels of carbon dioxide. What effect do elevated levels of carbon dioxide have on how different plants grow?