People whose fathers smoked during puberty seem to age faster than expected, according to research presented at the European Respiratory Society (ERS) Congress in Amsterdam, the Netherlands. The researchers found signs of faster biological ageing, compared to chronological age, in people whose fathers began smoking at age 15 or younger. They say smoking during puberty may create damage in boys’ developing sperm cells that can be passed on to their children. The researchers found that people whose fathers began smoking during puberty were around nine months to a year older than their chronological age on average. In people whose fathers began smoking later in life, researchers found only a small increase in biological age.