A new study has found more link between light at night (LAN) and cancer. Previous studies have shown that living in areas that have more night time illumination increases risk of prostate cancer for men and breast cancer for women.
The study examined four groups of lab mice that were injected with cancerous cells. Each group was exposed to different duration of light. The group that was exposed to the least amount of light had the least cancerous growth (0.85 cu cm, average), the group that was exposed to more light had a little more cancerous growth (1.84 cu cm, average) and the group that was exposed to the most light had even more growth (5.92 cu cm, average).