So? Just because something is natural doesn't ,mean it's safer ( and we know the cancer risks of tanning excessively) and just because bleaching is not natural doesn't mean it is always unsafe.

Here's an example:

Niacinamide (topical) is actually a very safe way to lighten "that works by inhibiting melanosome transfer from melanocytes to keratinocytes" and actually provides many other benefits such as acne reduction, and improving wrinkles.

Source: http://www.ncbi.nlm.nih.gov/pubmed/12100180

So lightening this way can actually improve overall skin health.

Just trying to educate people who always use the "but tanning is natural" excuse to try to justify why people shouldn't bleach but say tanning is okay. (not saying your are, just in general).