Healthy teens are more prone to having irregular heartbeats after breathing in fine particulate air pollution, according to the first major study of its impact on otherwise young, healthy individuals.
The alarming findings have raised concern among researchers because heart arrhythmias appear to be triggered even when air pollution is within standard air quality limits. Heart arrhythmias can increase the risk of sudden cardiac death and heart disease, according to Heart.org.
Doctors monitored the air breathed and the heart activity of more than 300 healthy American teenagers over 24-hour periods. Doctors found that higher concentrations of fine particles called PM2.5s increased teens' risk of irregular heartbeats for the next two hours. Similar effects have been found previously in older adults.
Healthy teens having irregular heartbeats due to air pollution
The researchers wrote in the Journal of the American Heart Association that this is the first study that reports the association between cardiac arrhythmias and PM2.5 air pollution among otherwise healthy adolescents.
Vehicle exhausts and combustion in the construction and manufacturing industries are major sources of PM2.5s, which are particles smaller than 2.5 microns. Once PM2.5s are inhaled, these particles can reach deep into the lungs and even the blood vessels, where they can cause inflammation that drives disease.
Dr. Fan He, the lead author of the study at Penn State College of Medicine, said that the results were striking, given that healthy teenagers are usually considered low risk for cardiovascular diseases. He added that their findings suggest air pollution could trigger arrhythmias and contribute to sudden cardiac death among the youth, devastating events for their families and larger communities.
Participants given heart monitors and mobile air sampling kits
The researchers examined the impact of particulate air pollution on 322 healthy teens about seven years after enrolling, aged 6 to 12, in the Penn State Child Cohort study. The participants were given mobile air sampling kits, and heart monitors to carry around for 24 hours, whether outside or indoors, active or sedentary.
The monitors provided to the participants captured two types of arrhythmia that can make people feel their heart has skipped a beat. The first one is driven by premature contraction of the heart's upper chambers. The second one is driven by a sudden contraction of the lower chambers or ventricles. While premature ventricular contractions are rarely treated unless they cause symptoms, they can raise the risk of stroke, heart failure, heart attacks, and sudden cardiac death later in life.
According to the study, the risk of premature ventricular contractions within two hours of exposure increased by 5 percent for every ten micrograms per cubic meter increase in PM2.5. He told the Guardian that the effect was alarming as it was seen even at an average daily PM2.5 level of 17 micrograms per cubic meter. An intermediate daily level of 35 micrograms per cubic meter is considered low-level pollution in the United Kingdom.
