What effect does UVA light have on the skin?

UVA light primarily affects the skin by oxidizing melanin, which leads to the browning effect that is often associated with tanning. When UVA rays penetrate the skin, they interact with existing melanin, causing it to oxidize and darken in color. This is why many individuals notice a darker skin tone following exposure to UVA light, as it enhances the appearance of tans that were already present or developing due to prior sun exposure.

The other options do not accurately describe the primary effects of UVA light. It does not typically cause immediate itching and irritation; rather, those symptoms are more commonly associated with sunburn or allergic reactions. While prolonged exposure to UVA can contribute to skin damage over time, it is not an immediate outcome, and discussing immediate effects clarifies how it fits into the tanning process. Additionally, UVA light does not prevent melanin production; instead, it stimulates the existing melanin to darken, which contributes to the tanning process.