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. Ground level or bad ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight.
Ozone is an air pollutant that can damage human health, vegetation, and many common materials. It is an ingredient of urban smog. Unlike most other air pollutants, ozone is not directly emitted from any one source. Ozone is formed near the surface by the interaction of sunlight, with hydrocarbons and nitrogen oxides.