Final answer:
Basal cell carcinoma and squamous cell carcinoma are the most common non-malignant types of skin cancer, and are generally curable. Melanoma is a more dangerous form that can metastasize. Protection from UV-B radiation, such as sunscreen use, can reduce the risk of developing skin cancer.
Step-by-step explanation:
The most common non-malignant types of skin cancer are basal cell carcinoma and squamous cell carcinoma. These are the cancers that originate from the epidermis of the skin, particularly from the stratum basale for basal cell carcinoma and from the stratum spinosum for squamous cell carcinoma. Compared to melanoma, which is a more dangerous and potentially lethal form of skin cancer likely to metastasize, basal and squamous cell carcinomas are highly curable and less likely to spread to other parts of the body.
Depletion of the ozone layer has led to increased exposure to UV-B radiation, which can damage DNA in skin cells, a process that significantly contributes to skin cancer development. While melanin in the skin provides some protection from the sun's damaging rays, it is often not enough to fully prevent DNA damage and the subsequent risk of cancer, especially with increased UV exposure due to environmental factors. It is important to wear sunscreen with a high SPF, wear protective clothing, and regularly check skin for any new or suspicious growths.