【Daily Question】A reward of 2 Wealth is given for participating in the assessment of occupational disease hazards. 5 Wealth for correct answers, July 27

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This post was last edited by zxz017 on 2015-7-28 08:52. Poisons that exist in the form of gases, vapors, mists, fumes, or dust can enter the human body through the respiratory tract. Once toxins enter the lungs, they quickly pass through the alveolar walls into the blood circulation and are transported throughout the body. Most larger dust particles can be filtered out by the nasal hairs, while the cilia in the trachea can transport the dust particles that have settled on the tracheal walls to the pharynx for elimination through mucus; only smaller dust particles can reach the lungs. The smaller the dust particles, the greater the harm they pose to the human body. Prolonged inhalation of a certain amount of dust can lead to various types of pneumoconiosis; for example, inhalation of coal dust causes coal pneumoconiosis, while inhalation of plant-based dust leads to plant pneumoconiosis. Dusts such as free silica and silicates can cause diffuse, fibrotic lesions in the lungs. The following statement regarding inhalation of substances containing free silica is true: it can cause ( ) occupational diseases. A. Coal silicosis B. Silicosis C. Coal worker’s pneumoconiosis D. Graphite pneumoconiosis Answer: B, Silicosis