Telomeres, the specialized regions of DNA found at each end of a chromosome, are discovered to be shorter for newborns that were exposed to air pollution before birth than those who were not. These telomeres are responsible for allowing the chromosomes to be copied exactly during cell division.
According to a study conducted in China, air pollution cause the telomeres to shorten every time a cell divides, and consequently, the genomic stability is progressively lost. Ultimately, this phenomenon is linked with health concerns such as cancer, heart diseases, cognitive decline, aging, and premature death.
“An individual’s telomere length at birth is known to influence their risk for disease decades later during adulthood. Further follow-up is needed to assess the role telomere length plays in health outcomes in the context of early life exposure to air pollution,” says Deliang Tang, professor of Environmental Health Sciences at the Columbia University’s Mailman School of Public Health.
Fourteen years ago, a coal-fired power plant in Tongliang, China was shut down by the government due to its alarmingly high level of air pollution, expecting that this action would improve the community’s health. This event opened an opportunity for scientists to study the difference between babies born before and after the shutdown.
The research team, led by Deliang Tang and Frederica Perera of the Mailman School of Public Health, studied the telomere length in the umbilical cord blood of 255 newborns. They are divided into two groups – babies who were conceived and born before the shutdown and those who were conceived and born after shutdown.
The ambient polycyclic aromatic hydrocarbons (PAH) levels, biomarkers, and health outcomes of the two groups were then compared and analyzed by the researchers. PAH is a toxic chemical compound found in air pollution produced by coal plants. Babies born prior the closure had higher levels of PAH found in the cord blood than those conceived and born after the shutdown. Increased levels of PAH in cord blood were linked with shorter telomeres and lower levels of brain-derived neurotrophic factor (BDNF), a protein involved in neuronal grown. Results are published in the journal Environment International.
“The new study adds to the evidence that closing this coal-burning power plant was beneficial to the health and future well-being of newborns there. Moreover, we know that lowering exposure to air pollution anywhere will be beneficial to children’s health and long-term potential,” says Perera, director of the Columbia Center for Children’s Environmental Health and professor of Environmental Health Sciences at the Mailman School of Public Health.