Teacher is standing in front of the blackboard needs to carry on the teaching of the crowd, they often demand chalk on the blackboard. Therefore, many teachers will suction too much chalk. Some teachers will worry, suction too much chalk is will cause I am sick. It is undeniable that dust particles will to human body form larger damage. Next, let's know chalk dust under the composition of it.

【 chalk composition 】

Chalk is made by gypsum. The composition of gypsum is calcium sulfate. Gypsum function safe, Environmental friendly. For thousands of years, the doctor of traditional Chinese medicine with plaster stone, rich in water of crystallization of calcium sulfate CaSO - 4 · 2 h2o) Fried uniform, exterior calcined gypsum (plaster of Paris) applied to the affected part. Thought can cool and refreshing antipyretic, fluids, thirst, give birth to the muscle gathered boils.

【 dust granule on person damage larger 】

In fact faculty use chalk writing blackboard writing, is gypsum powder coating on the blackboard. Scrub the blackboard, gypsum dust (chalk) in the air in the short time after floating fall in the blackboard adjacent object surface and the ground. The grain is bigger, more than 100 microns above, heavier, fall faster, floating in the air time is short.

According to the labor health related materials, produce and living environment of air dust particles, diameter in 10-20 microns above, the nose suction timely mostly be nose hair, nose, pharynx and throat obstruction, adhere to the mucosa small airway and alveolar. If for the body harmful substances (such as silica, asbestos), in the alveolar and small airway stored up in more, will be formed to human body damage.

By above knowable, chalk dust particles is bigger, it most likely will not suction to lower respiratory tract, and add gypsum itself to human body Environmental friendly, the medical profession has been there for suction chalk lead to lung disease report. Our country labor department of health, in the work the relevant provisions of the pneumoconiosis, also didn't will chalk as the etiology of lung.

Although faculty can not suction too much chalk, but there is no denying that chalk is still on the body formation damage, therefore, teacher long time in such an environment, is still more simple than others on disease.

Warm prompt: from above we know, dust particles to understand form will surely damage. In fact faculty to prevent intake of too much chalk, can choose use slide to teaching, except when necessary to use chalk blackboard writing, so that you can compare well away from the chalk.