Nicotine or smoke particles that have clung to residential walls and carpets for years can still have harmful effects on infants, observed a recent study by researchers at the Cincinnati Children’s Hospital Medical Centre, US. The researchers said that this thirdhand smoke can increase the risk of respiratory and infectious illnesses, including asthma, bronchiolitis and pneumonia, alongwith damaging the DNA within the cells of exposed tissue. The findings of the study, published in JAMA Network Open, pointed out that children are at particular risk as they get the smoke particles on their fingers and later involuntarily ingest it, even if they are from “smoke-free” homes at the moment. The study highlighted that children in the lowest income families had higher levels of nicotine particles on their hands, totaling 14 nanograms per wipe in non-smoking homes.