A carcinogenic substance is?

A. asbestos dust
B. sawdust
C. nitrogen (II) oxide
D. carbon (II) oxide

Correct Answer:

Option A – asbestos dust

EXPLANATION:

The correct answer is A.A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substances are considered carcinogens, but their carcinogenic activity is attributed to the radiation, for example, gamma rays and alpha particles, which they emit. Common examples of non-radioactive carcinogens are inhaled asbestos, certain dioxins, and tobacco smoke.

Asbestos is a group of naturally produced chemicals composed of silicon compounds. It is used in insulation materials due to heat resistance. Human exposure is through inhalation (from disruption of materials containing asbestos) and ingestion (contaminated food/water). Tiny asbestos fibers in the air can get trapped and accumulate in the lungs. Asbestos is linked to an increased risk of lung cancer, and the development of mesothelioma (cancer of the thin lining surrounding the lung (pleural membrane) or abdominal cavity (the peritoneum) and laryngeal cancer. Cancer may appear 30 to 50 years after exposure. Asbestos is a known human carcinogen.