A new study, conducted before and after the 2004 closure of a coal-burning power plant in China, found children born before the closure had shorter telomeres — specialized sections of DNA that allow chromosomes to be faithfully copied during cell division — than those conceived and born after the plant stopped polluting the air.
Perera et al find babies exposed in the womb to high levels of air pollution had shortened telomeres. Image credit: Chris LeBoutillier.
Columbia University’s Professor Deliang Tang and co-authors analyzed telomere length in the umbilical cord blood of 255 newborns, about half of whom were born before closure of the local coal burning power plant in Tongliang County, Chongqing Municipality, and half of whom were conceived and born after.
In babies born pre-closure, researchers found higher levels of PAH-DNA cord adducts, a biomarker for exposure to polycyclic aromatic hydrocarbons (PAH).
Elevated levels of these adducts in cord blood were associated with shorter telomeres — the first time this relationship has been tested — as well as with lower levels of brain-derived neurotropic factor (BDNF), a protein involved in neuronal grown.
However, telomere length was not associated with developmental scores in the subset of 210 children tested at age 2, although the finding doesn’t rule out telomere length-related neurodevelopmental problems at later ages.
“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,” Professor Tang said.
In May 2004, high levels of air pollution prompted the government to shut down the Tongliang power plant to improve community health.
This action, announced in advance, provided a unique opportunity to compare data on ambient PAH levels, biomarkers, and health outcomes in two successive cohorts of children, with and without prenatal exposure to emissions from the coal-fired power plant.
In previously published research on these cohorts, the authors reported newborns born after the plant closure had lower levels of PAH-DNA adducts, lower rates of various health outcomes, and increased levels of BDNF.
“Our study adds to the evidence that closing this coal-burning power plant was beneficial to the health and future well-being of newborns there,” said Columbia University’s Professor Frederica Perera.
“Moreover, we know that lowering exposure to air pollution anywhere will be beneficial to children’s health and long-term potential.”
The team’s findings are published in the journal Environment International.
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Frederica Perera et al. Shorter telomere length in cord blood associated with prenatal air pollution exposure: Benefits of intervention. Environment International, published online January 24, 2018; doi: 10.1016/j.envint.2018.01.005
