Objective To ascertain the level of risk of cancer amongst adults severely exposed to environmental tobacco smoke at child hood.

Methods We conducted this study among 1,280 adults who were diagnosed for lung cancer for a period of 6 years from 2005–2011. We checked hospital records at childhood for frequent hospitalization related to tobacco effects like middle ear infections, pneumonia, bronchitis and worsened asthma conditions.

Results We were able to show the relationship between exposure to environmental tobacco smoke during childhood and cancer risk. Out of the total number of participants, 2.5% percent (32 adults) had been exposed to environmental tobacco smoke (ETS) at childhood. We found that the overall cancer risk was greater for individuals with exposures to environmental tobacco smoke during both childhood and adulthood than for individuals with exposure during only one period. When specific cancer sites or types were considered, it was found that leukemia and lymphoma among adults were significantly related to exposure to maternal passive smoke before 10 years of age.

Conclusion Results of epidemiologic studies including this one provide evidence that exposure of children to environmental tobacco smoke is associated with increased rates of lower respiratory illness and increased rates of middle ear effusion, asthma, and sudden infant death syndrome. Exposure during childhood to environmental tobacco smoke may also be associated with development of cancer during adulthood.