Final answer:
The long-term effects of tanning include premature aging of the skin, increased risk for skin cancer, and possible phototoxic reactions when combined with certain medications or cosmetics.
Step-by-step explanation:
The detrimental long-term effects of tanning that the school nurse teaches adolescents about include premature aging of the skin, an increased risk for skin cancer, and possible phototoxic reactions. While tanning can lead to a temporary enhancement in appearance, over time it can cause the skin to lose elasticity and result in premature wrinkles. The most serious consequence of excessive tanning is the significantly higher risk of developing skin cancers such as melanoma. Additionally, certain medications and cosmetics can cause phototoxic reactions when the skin is exposed to ultraviolet (UV) light during tanning.