This article gives a short, uncited and unorthodox summary of UVA vs UVB effects. Most chemical effects may be unknown, but a few are well-characterized like py

This article gives a short, uncited and unorthodox summary of UVA vs UVB effects. Most chemical effects may be unknown, but a few are well-characterized like pyrimidine dimer related mutations from UVB that are also seen in skin cancer sequencing samples. UVB has therefore been thought to be directly carcinogenic (likely indirectly as well through other mechanisms), whereas UVA is often associated with photo aging (longer wavelength, penetrates deeper through epidermis into dermis leading to solar elastosis) and may have carcinogenic role that is less chemically obvious compared to the dimers.