Why should healthy teens wear masks this Diwali? Because pollutants can cause irregular heart beats
Air pollution or breathing in particulate matter triggers an irregular heart rhythm among adolescents within two hours of exposure. And we know how reducing the risk of irregular heart rhythms — known as arrhythmias — during adolescence may reduce the risk of sudden cardiac death and developing heart disease in adulthood.
According to a recent research published in the journal of the American Heart Association, an open access, peer-reviewed publication, this study is the first to assess the impact of air pollution on teenagers in the general population. The negative cardiovascular effects of air pollution on adults has already been established.
“Our findings linking air pollution to irregular heart rhythms suggest that particulate matter may contribute to the risk of sudden cardiac death among the youth,” said Fan He, Ph.D., lead author of the study and an instructor in public health sciences at the Penn State College of Medicine in Hershey, Pennsylvania. “Since childhood and adolescent cardiovascular conditions can track into adulthood and affect risk of major cardiovascular disease later in life, identifying modifiable risk factors of cardiac arrhythmia that may cause sudden cardiac death among adolescents should be of great public interest.”
The investigators analysed the impact of breathing particulate matter pollution on two types of irregular heart rhythms characterised premature contraction in the heart muscle, often described as a “skipped heart beat.” As the report says, “In premature atrial contractions (PAC), the heartbeat originates from the atria (top chambers of the heart). This usually causes no symptoms or harm. However, frequent, premature atrial contractions have been related to an increased risk of atrial fibrillation — a severe form of arrhythmia in which the top chambers quiver instead of beating effectively, there raising the risk of blood clots and stroke. Premature ventricular contractions (PVC) occur when the heartbeat originates from one of the ventricles (lower chambers of the heart). These also raise the risk of later heart attack, stroke, heart failure or sudden cardiac death. If premature contractions cause no symptoms, they are not treated. However, if they occur often and lead to frequently feeling a skipped heartbeat, fast heartbeat or a pounding heart, treatment with medications, implantable devices or procedures may be advised.”
Interpreting the study, cardiolog and president, Public Health Foundation of India (PHFI), Prof K. Srinath Reddy, said, “It has been well-established that air pollution, in which a variety of toxic chemicals are carried into the lungs and thereon into the bloodstream, can cause electrical durbances in the heart muscle. These rhythm durbances are called arrhythmias. While some are irksome, others can be dangerous and life threatening. Heart attacks can also be precipitated air pollution. It is essential to reduce air pollution levels so that we can protect the heart health of everybody, young or old.”
Dr Aparna Jaswal, Director, Electrophysiology and Cardiac Pacing, Fortis Escorts Heart Institute, Okhla, New Delhi, feels the study shows how pollution damages the cardiovascular system and is not just about lung health. “Air pollution induces inflammation in the body, which is known to be a trigger for various problems like heart attacks and irregular heart beats. Whenever there is inflammation of the vascular system and the heart, it can cause abnormal heart beating. It can even cause the lining of the blood vessels to become abnormal, which in turn can result in heart attacks. For a long time, air pollution was associated with irritation of the lungs and anxiety over those who have lung diseases and asthma. The study shows that this could also impact the heart simultaneously.”
How the research quantified the effect of pollution
The study examined the impact of breathing fine particulate matter on heart rhythms of adolescents. “Fine particulates (PM 2.5) are less than 2.5 microns in size and can easily be inhaled deep into the lungs. They enter the bloodstream easily. Particles smaller than 2.5 microns are usually related to fuel combustion, such as particles from car exhaust or wildfires. Once inhaled, the pollutants irritate the lungs and blood vessels around the heart, and previous research has suggested that over time, pollutants increase the process of disease in the arteries,” the report says.
The average PM 2.5 concentration measured in the study was approximately 17 micrograms of particulate matter per cubic meter of air (µg/m3) per day, which is well-below the health-based air quality standard of 35 µg/m3 established the US Environmental Protection Agency (EPA).
The study found how 79 per cent of participants had at least one irregular heart rhythm during the 24-hour study period. Of that group, 40 per cent had only premature atrial contractions, 12 per cent had only premature ventricular contractions, and 48 per cent had both.
A 5 per cent increase in the number of premature ventricular contractions within two hours of exposure was noted for each increase of 10 µg/m3 in PM 2.5. No association was found between the concentration of particulate matter and the number of premature atrial contractions.
“It is alarming that we were able to observe such a significant impact of air pollution on cardiac arrhythmias when the air quality remained well within the health-based standards established the EPA. It may suggest that adolescents who live in highly polluted areas such as inner cities are at even higher risk,” said researchers.
Preventive measures
What does this finding mean for youngsters in the Diwali season? The researchers advise wearing face masks and avoiding vigorous physical activity on high pollution days, especially during early morning hours.
