Shortening Telomeres – A New Consequence of Air Pollution

Impact of Coal-burning Power Plants on Newborn Health

Coal Power Plant in Tongliang, China – Source:

In 2004, a major coal-burning power plant in Tongliang, China was closed. A study was conducted on children conceived and born before and after the closure to observe the health effects of the air pollution resulting from the power plant. This study, completed by Columbia University’s Mailman School of Public Health, measured telomere length in the umbilical cord blood of 255 newborns (with half being born before the plant closure and half conceived and born after). Telomeres are regions of repetitive DNA found at the end of chromosomes. These telomeres serve an important function, as they protect the chromosome from deterioration. Without telomeres, the cell may lose ends of chromosomes (which contain important genetic information) when they divide. Additionally, these telomeres can protect against cancer by preventing the cell’s chromosomes from fusing with each other. Shortened telomere length has also been linked to heart disease, cognitive issues, aging, and premature death.

The research team found that children born before the closure had shorter telomeres than those conceived and born after the closure. They found higher levels of PAH-DNA cord adducts, which is a marker for exposure to polycyclic aromatic hydrocarbons (PAHs). High levels of these adducts in cord blood were associated with shorter telomeres. These shorter telomeres may influence the chid’s risk for certain diseases and conditions in adulthood.

But what are PAHs?

Examples of PAHs – Source: 

PAHs are a series of hydrocarbons that arise from incomplete combustion and can be present in the air, water, and soil. The smoking of tobacco, burning of wood and coal, and the exhaust of gasoline (especially diesel) can release PAHs into the environment. In this case, PAHs are released from the production of coal into gaseous fuel. The structure of PAHs also plays an important role in its toxicity, with those having a “bay region” (found in Chrysene above) being the most potent carcinogens.

Overall, it is important that the potential health consequences of large, coal-burning power plants are continuously evaluated. This is especially true for countries like China, who is the largest producer and consumer of coal in the world. Additionally, following up with these children in adulthood may further illuminate long lasting health effects of PAH exposure (and the resulting shorter telomeres) from these coal-burning power plants.


1. Article Cited: tps://


3. Baird, C. et al. Environmental chemistry 5th Edition; W H Freeman & Co: New York, 2012.



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