Massachusetts State Board Esthetics Practice Exam

Which type of UV radiation is responsible for most skin aging?

1. UVB radiation

2. UVA radiation

3. UVC radiation

4. Visible light

The correct answer is: UVA radiation

UVA radiation is primarily responsible for most skin aging due to its ability to penetrate deeper into the skin layers. It leads to the breakdown of collagen and elastin, which are essential proteins that maintain skin structure and elasticity. This process results in premature aging signs such as wrinkles, fine lines, and loss of firmness. UVA rays are consistently present and can even penetrate clouds and glass, resulting in prolonged exposure over time. This characteristic makes them particularly concerning for skin health wherever there’s sunlight. Unlike UVB, which is more associated with sunburn and has a shorter wavelength, UVA’s long wavelengths can lead to cumulative damage and are a significant factor in photoaging. Other radiation types, such as UVC and visible light, do not play a significant role in skin aging; UVC radiation is mostly absorbed by the ozone layer and does not typically reach the earth's surface, while visible light is less impactful in terms of direct aging effects on the skin. Understanding the role of UVA in skin aging can help inform protective measures, such as using broad-spectrum sunscreens that block both UVA and UVB rays.