Can infrared (IR) light cause damage that leads to skin cancer?

• A. No, because IR light is completely blocked by the Earth's atmosphere and never reaches the skin.
• B. Yes, because IR light is a form of ionizing radiation that can directly damage DNA.
• C. Yes, because IR light penetrates deeply and always causes mutations in skin cells.
• D. No, because IR light does not have enough energy to damage DNA and cause mutations leading to skin cancer.

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the nature of infrared (IR) light. IR light is a type of electromagnetic radiation with wavelengths longer than visible light but shorter than microwaves. It is non-ionizing radiation, meaning it does not have enough energy to remove electrons from atoms or molecules.
2. Step 2: Recall the concept of ionizing radiation. Ionizing radiation, such as X-rays and gamma rays, has high energy and can directly damage DNA by causing mutations. Non-ionizing radiation, like IR light, lacks this capability.
3. Step 3: Consider the energy of IR light. IR light has lower energy compared to visible light and ultraviolet (UV) radiation. UV radiation, particularly UVB, is known to cause DNA damage and mutations that can lead to skin cancer, but IR light does not have sufficient energy to do so.
4. Step 4: Evaluate the statement about IR light being blocked by the Earth's atmosphere. This is incorrect; IR light is not completely blocked by the atmosphere. In fact, IR light from the sun reaches the Earth's surface and contributes to heat, but it does not cause DNA damage.
5. Step 5: Conclude that IR light does not cause skin cancer because it lacks the energy required to damage DNA and induce mutations. This aligns with the correct answer provided in the problem.