This is an unfortunate story. There has been a big spike in the number of melanoma cases in young women and it has been linked to tanning bed used prior to special events like Prom or Homecoming.
I know the indoor tanning industry says that the product is perfectly fine but this is evidence that it is not. As cosmetic chemists, you will often be asked about all kinds of beauty topics and it makes sense for you to be well versed on a variety of topics. Indoor tanning is one of these topics.
The bottom line is that indoor tanning is not safe and it has been proven to cause melanoma. If someone tells you otherwise just have them look up what the American Academy of Dermatology has to say.