In the former mining area Herrerias in Andalusia, the deep waters of Pit Lake Guadiana show extremely high concentration of dissolved carbon dioxide (CO₂). 

Levels are so high that if it were to bubble up, human beings close-by would be jeopardized. To demonstrate a possible fix, scientists of the Spanish Institute of Geology and Mining, the University of the Basque Country (UPV/EHU, Bilbao) and the Helmholtz Centre for Environmental Research (UFZ) constructed a pilot plant for degassing.

A fountain pulls deep water through a pipe to the surface, where the gas can escape from the water. The buoyancy produced by the bubbles provides the energy required for driving the flow.

Hydrogen peroxide (H2O2) is a strong oxidizer. You may know it as a wound disinfectant or as a bleaching agent for hair and teeth but it is also created naturally in our bodies, as part of our cellular oxidation.

H2O2 belongs to a group of natural chemicals called reactive oxygen species (ROS) and when the process gets out of hand, too much oxidation can have a damaging effect on cells and their components. Unchecked free radicals, the most well-known ROS, are believed to play a role in carcinogenesis, degenerative diseases, and even aging. To prevent that, our cells also contain antioxidant enzymes known as peroxiredoxins that degrade H2O2 molecules. We don't want to have no H202, despite the chemophobia of environmental and food activists, we want just enough.

Though it has higher risks in older people, and those are well-known and cautioned against, prescription use of benzodiazepines increases steadily with age, despite the known risks for older people, according to a comprehensive analysis of benzodiazepine prescribing in the United States.

Benzodiazepines are a widely used class of sedative and anti-anxiety medications.  They are effective in relieving anxiety and take effect more quickly than antidepressant medications often prescribed for anxiety. However, the prevalence of anxiety disorders declines with age. Guidelines recommend non-pharmacologic approaches and antidepressants over benzodiazepines as first-line treatment in older people. 

Though deaths due to drug use and hepatitis C have gone up, falling death rates due to cancer and heart disease have resulted in a global life expectancy increase of 5.8 years in men and 6.6 years in women between 1990 and 2013, according to an analysis from the Global Burden of Disease Study 2013 (GBD 2013).

In high-income regions, falling death rates from most cancers (down by 15%) and cardiovascular diseases (down by 22%) have increased life expectancy, while rapidly declining death rates for diarrhea, lower respiratory tract infections, and neonatal disorders have helped extend life expectancy in low-income countries (see figure 7 page 14, and table 2 pages 15-23). 

Airline pilots can be exposed to the same amount of UV-A radiation as if they visited a tanning bed, because airplane windshields do not completely block UV-A radiation.

In 2009, researchers detected methane on Mars, suggesting the planet may be biologically or geologically active. 

Now NASA's Mars Curiosity rover has measured a tenfold spike in methane in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory's drill.