Day care protects against leukaemia

摘要

There is no association between exposure to electromagnetic fields and the risk of childhood leukaemia. But infants who attend day care are much less likely to develop leukaemia than those who do not mix with other babies, a large study in the UK shows. The results suggest that early exposure to a range of infections has a protective effect, somehow teaching the immune system to respond to infections in an appropriate way. Without this training, it appears that infections later in life are more likely to trigger leukaemia. This cancer is caused by the uncontrolled growth of white blood cells, which are part of the immune system.