What does sunlight have in common with environmental chemicals that are believed to cause cancer?

Both sunlight and environmental chemicals that are believed to cause cancer can damage DNA.

Sunlight contains ultraviolet (UV) radiation, which is a type of ionizing radiation that can damage DNA by causing mutations. Environmental chemicals that are believed to cause cancer, such as benzene and formaldehyde, can also damage DNA by causing mutations.

DNA damage can lead to cancer if it occurs in genes that control cell growth and division. When these genes are damaged, cells can start to grow and divide uncontrollably, leading to the formation of a tumor.