When inhaled, crystalline silica can cause scar tissue to form on what organs?
a. eyes
b. heart
c. lungs
d. sinuses?

Option C, Lungs

Explanation:

When silica dust is inhaled it causes silicosis which in severe cases is disabling. When Silica enters the lungs , scar tissues are formed which lead to difficulty in taking oxygen. This problem usually arises when crystalline silica is inhaled continuously for a period of 15 to 20 years. Its symptoms are not visible and thus can only be determined through chest X-Ray. However, after prolonged exposure lung dysfunctions causes breathing problem, fatigue, chest pain or  respiratory failure

Hence, option C is correct

it takes hundreds of years to become stable.

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