In their sunscreen guide, the EWG association talk about sunscreen being just part of a toolbox when it comes to sun protection: "a good sunscreen can play a role in preventing sunburns – a major risk factor for melanoma – provided you use it correctly."
On regular days, the biggest risk is not sunburns coming from a prolonged exposure to UV-B rays: it’s the constant and sporadic exposure to UV-A, that penetrate deeper in the skin and even through glass, and hit us whenever we’re talking a walk outside or sitting behind a window at work.
In addition, many studies including coming from the same EWG, have alerted about the health consequences of the daily absorption of synthetic UV filters in the bloodstream: hormone disruption, infertility, skin allergies and cancer have been directly linked to filters commonly found in susncreen such as oxybenzone, avobenzone, homosalate, or zinc oxide.