Childhood leukemia has increased dramatically in the past century, and scientists believe that the increase in childhood leukaemia may be part due to increased light at night:
Whilst the link between leukaemia and light at night may, on the surface, seem surprising, it has a logical basis and there is considerable evidence pointing towards the association. Compared with 100 years ago we are exposed to considerable light at night (LAN) during the natural hours of darkness. LAN disrupts our natural circadian rhythm, suppressing the normal nocturnal production of the hormone melatonin.As Russel Reiter, Professor of Cellular and Structural Biology at the University of Texas, explains, a reduction in melatonin has been linked to cancer initiation as well as cancer progression. ‘As an anti oxidant, in many studies melatonin has been shown to protect DNA from oxidative damage. Once damaged, DNA may mutate and carcinogenesis may occur.’
A number of studies have shown that people in occupations that expose them to LAN (i.e. night workers) experience a higher risk of breast cancer and that blind people, who are not vulnerable to reduced melatonin levels through LAN, have a lower incidence of cancer.
(Hat tip to Mercola’s Health Blog.)