A new Australian study warns that weak sunlight is not harmless. Even UV doses too low to produce visible redness or sunburn can damage DNA in skin cells, according to the researchers.
The damage occurs at the cellular level and may accumulate over time with repeated exposure. Over years, this buildup could increase the risk of developing skin cancer, even for people who never see obvious signs of sunburn.
The findings are described as landmark because they challenge the common assumption that only burning doses of sunlight require protection. The authors emphasize that duration of exposure matters: spending enough time outdoors under weak sun can still add up to significant harm.