Calf Muscles. 1  The calf muscles are six in number: the gastrocnemius, the soleus, the popliteus, the tibialis posterior, the flexor digitorum longus, and the flexor hallucis longus. 2  The gastrocnemius and the soleus run between the knee and the ankle. 3  One of the calf muscles, the soleus, has a special ability.
Ozone pollution is a form of pollution which is characterized by high concentrations of ozone, a form of oxygen, at ground level. Exposure to ozone can cause serious health problems in plants and people, and ozone pollution is a major problem in some regions of the world. It tends to increase during periods of high temperatures and sunny skies, which is why bad air advisories are often issued on seemingly nice days.
Ozone depletion describes two related phenomena observed since the late 1970s: a steady decline of about four percent in the total amount of ozone in Earth's stratosphere, and a much larger springtime decrease in stratospheric ozone around Earth's polar regions. The latter phenomenon is referred to as the ozone hole. There are also springtime polar tropospheric ozone depletion events in addition to these stratospheric phenomena. The main cause of ozone depletion and the ozone hole is man-made ch