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.
The main cause of ozone depletion and the ozone hole is man-made chemicals, especially man-made halocarbon refrigerants, solvents, propellants, and foam-blowing agents (chlorofluorocarbon (CFCs), HCFCs, halons), referred to as ozone-depleting substances (ODS).