23 May 2018
WEDNESDAY, May 23, 2018 (HealthDay News) — When you fire up the grill for your Memorial Day cookout, beware: Those tantalizing aromas hold an underestimated health risk. Grilling meats at a high temperature can produce cancer-causing compounds called polycyclic aromatic hydrocarbons (PAHs). You can be exposed to significant PAH levels simply by breathing in the sweet scent of barbecue. A new study from China suggests letting your skin come into contact with PAHs when you grill food is even more harmful than just savoring the aroma. And clothing won’t fully protect you against them. PAHs can cause lung disease and DNA mutations, the researchers said. Though eating barbecued meats is the most common source of exposure, just standing near a grill and breathing PAH-contaminated air can be risky, previous studies have shown. For the latest study, published May 23 in Environmental Science & Technology, a team led by Eddy Y. Zeng at Jinan University closely examined skin exposure to PAHs from barbecue fumes and particles. The researchers divided volunteers into groups based on various levels of exposure to grilled foods and smoke. Urine samples revealed the greatest PAH exposure came from eating grilled foods, but skin contact was in second place, followed by inhalation of barbecue fumes. Clothes can help protect you from the smoke, but only for a short period, the researchers noted in a journal news release. Once fabrics become saturated with contaminated smoke, the skin can absorb high PAH levels. To reduce your exposure to these toxic compounds, the researchers recommend laundering clothes immediately after you are around a grill. More information The U.S. National Cancer Institute provides more information on polycyclic aromatic hydrocarbons (PAHs).
09 January 2018
TUESDAY, Jan. 9, 2018 (HealthDay News) — NASA scientists say they have satellite evidence that the international ban on chlorine-containing chemicals called chlorofluorocarbons (CFCs) has helped heal the massive hole that was chewed in the Earth’s protective ozone layer. There now is roughly 20 percent less ozone depletion during the Antarctic winter than in 2005, a new study reports. “We see very clearly that chlorine from CFCs is going down in the ozone hole, and that less ozone depletion is occurring because of it,” said study lead author Susan Strahan. She’s an atmospheric scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md. Stratospheric ozone protects life on Earth by absorbing potentially harmful ultraviolet (UV) radiation from the sun. UV rays can cause skin cancer and cataracts, weaken the immune system and damage plant life. CFCs were used in everyday things from aerosols to air conditioners. In the 1970s, chemists warned they were accumulating in the upper atmosphere and would deplete atmospheric ozone. A hole in the ozone layer above Antarctica was detected in 1985. The 1987 Montreal Protocol and later amendments eliminated use of CFCs, but these chemicals linger in the atmosphere for decades. For the new study, researchers at NASA’s Goddard Space Flight Center used direct satellite observations to measure the chemical composition inside the ozone hole. The Aura satellite has been making measurements continuously around the globe since mid-2004. Measurements of microwave emissions showed that ozone-destroying chlorine is finally dissipating, according to the study. On average, total chlorine levels in the ozone hole fell by about 0.8 percent annually, the investigators found. During Antarctic winters, “temperatures are always very low, so the rate of ozone destruction depends mostly on how much chlorine there is,” Strahan said in a NASA news release. “This is when we want to measure ozone loss.” The study’s authors noted that the ozone hole should continue to shrink, but a more complete recovery is still decades away. Study co-author Anne Douglass, a fellow atmospheric scientist at Goddard, pointed out that “CFCs have lifetimes from 50 to 100 years, so they linger in the atmosphere for a very long time. As far as the ozone hole being gone, we’re looking at 2060 or 2080. And even then there might still be a small hole.” The study results were published online Jan. 4 in Geophysical Research Letters. More information The U.S. Environmental Protection Agency has more about the ozone layer.