Story at a glance
- Exposure to air pollution, like secondhand smoke, can lead to lung problems and asthma.
- Children are especially vulnerable.
- Data from a longitudinal study suggests that grandchildren may have higher risk of asthma if their grandparents smoked.
Air pollution is detrimental to lung health, especially if it is indoors and constant. For example, exposure to secondhand smoke from cigarettes can trigger asthma attacks in children. New research suggests that the effects might even be felt one generation removed.
A study published in the European Respiratory Journal looks at data on 1,689 children who grew up in Tasmania from the Tasmanian Longitudinal Health Study, which goes back to 1968. They also had information about whether the children’s fathers were exposed to secondhand smoke from their parents when they were under the age of 15.
The researchers found that the risk of non-allergic asthma in children increased by 59 percent if their fathers were exposed to secondhand smoke in their childhood, compared to children whose fathers were not exposed. If the fathers were exposed to secondhand smoke and went on to smoke themselves, the risk for their children to have asthma was even higher at 72 percent.
They can’t be certain how the exposure to smoke could lead to the children’s asthma, but one theory is through epigenetic changes. “This is where factors in our environment, such as tobacco smoke, interact with our genes to modify their expression,” says Shyamali Dharmage at the University of Melbourne, in a press release. “These changes can be inherited but may be partially reversible for each generation.”
Epigenetic changes are like the cells taking notes and holding onto their responses to the environment. If these changes make it to cells that become sperm cells, those “notes” could be passed down to the next generation.
However, this is still a theory, and more studies will be needed to further understand the relationship between exposure to secondhand smoke and asthma in future generations. “We already know that smoking and being exposed to second-hand smoke can increase asthma risk,” says Jonathan Grigg, who is Chair of the European Respiratory Society’s Tobacco Control Committee and was not involved with the study, to News Medical. “This study adds to growing evidence that the damage caused by tobacco smoke can be passed on to children…We need to protect children from this damage with measures to discourage smoking and support to help smokers quit.”