Sigh.

Brighter bedrooms during sleep directly related to breast cancer.

Back when the University of Haifa was just starting the study, I told several people about it. "This makes complete sense to me. The rise in breast cancer rates sharpened significantly alongside the rise in electric outdoor lighting, there's a much higher incidence of breast cancer in major cities than in the country, and we know that certain necessary neurochemicals and hormones are affected by light therapy, so it only stands to reason that darkness would *also* affect necessary neurochemicals and hormones." I would suggest that it was a bad idea to sleep with lights on, I'd bring a sleep mask to cons (and wear it at home when my room was nothing but windows), and when asked about it, I'd talk about this study. The responses were generally along the lines of "diet-pollution-genetics", raised eyebrow, and good-natured mockery for believing everything I read.

Obviously it's not *just* light. We know other things are directly related to breast cancer (diet, pollution, genetics, and who-knows-what-else they'll find). But the numbers here are pretty freakin' significant.

Scientists have known for years that rats raised in cages where lights are left on for much of the night have higher cancer rates than those allowed to sleep in darkness.

I have no doubt they're going to link not getting enough dark while sleeping to other forms of cancer as well.