Among the ingredients of commercially chalk, in addition to containing a metallic element, lead, manganese, barium content is low, the high content of the metal cadmium, cadmium inhaled, is stored in the liver, kidney, bone tissue, these organizationsobvious damage, long-term exposure to cadmium compounds caused lesions are emphysema and kidney damage, the condition can develop gradually, an early manifestation of weakness, lean, dizziness, insomnia, loss of appetite and symptoms of neurasthenia, and nasal bleeding,phenomenon of chronic pharyngitis, nasal mucosa atrophy and ulcers. Slow progress of emphysema, patients with progressive dyspnea into the market chalk the ingredients, in addition to containing a metallic element, lead, manganese, barium content is low, the high levels of the metal cadmium, cadmium inhaled, mainly lesions are stored in the liver, kidney, bone tissue, damage to these organizations clear that long-term exposure to cadmium compounds cause emphysema and kidney damage, the condition can develop gradually, an early manifestation of weakness, lean, dizziness, insomnia loss of appetite and symptoms of neurasthenia, and nasal bleeding, chronic pharyngitis, nasal mucosa atrophy and ulcers phenomenon. The slow progress of emphysema, patients with progressive dyspnea aggravating activities associated with palpitations. The cadmium also the most vulnerable to guide activities increase, accompanied by palpitations. The cadmium also the most easy to guide.

     Summary of chalk dust teachers so much solve the Environmental friendly issues, it is imperative!