Artificial light is essential for modern societies to function, but doctors fear our 24/7 culture could have unintended consequences for human health. The American Medical Association has just voted to (31) the recommendations of a report that recognizes exposure (32) light from street lamps to TV screens is linked to sleep (33) . The AMA added that is supported further study into the (34) link between keeping lights on all the time with cancer and obesity, as well as worsening of (35) diseases such as diabetes. Cancer epidemiologist Professor Richard Stevens from the University of Connecticut said, "It is a (n) (36) by a major health body, the American Medical Association, (37) this is an emerging environmental issue that has a (38) large impact on the health of society. Based on an accumulation of (39) , this august body is now making the statement: We take this seriously, (40) the public should take it seriously too." Professor Stevens is (41) with being the first to articulate the hypothesis that the increasing use of artificial light at night may be related to the high breast cancer risk in the (42) world."There’s no question that this light at night changes our (43) in the short term," Stevens says. "We know that artificial light (44) circadian rhythms. We’re learning more and more about the specifics of what that means. The clearest evidence is about the hormone melatonin. We’re lowering it; we’re even (45) it completely, depending on the amount of light." Melatonin has been shown to (46) breast cancer in laboratory rats. Stevens is careful to say that the changes in human physiology (47) artificial light have not been proven to cause cancer. The (48) of the AMA council report’s recommendations by the association could (49) more federal funding for studies into the health (50) of artificial light at night.