Does night work put women's health at risk?

http://www.eurekalert.org/pub_releases/2012-06/ind-dnw061912.php

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The risk of developing breast cancer was 30% higher in women who had worked nights compared to women who had never worked nights. This increased risk was particularly marked in women who had worked nights for over four years, or in women whose working rhythm was less than 3 nights per week, because this led to more frequent disturbances between night and day rhythms.

Finally, the link between night work and breast cancer seemed to be more marked when we looked at women who had worked at night prior to a first pregnancy. An explanation for this result could be that the mammary cells, incompletely differentiated in women before their first pregnancy, are more vulnerable.

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