Air pollution can trigger potentially fatal condition in teens

By Mark Waghorn via SWNS

Air pollution can trigger a potentially fatal irregular heartbeat in healthy teenagers, according to new research from Penn State University.

Kids' hearts can skip a beat within two hours of exposure to smog - increasing their risk of a heart attack.

Tiny toxic particles reach the bloodstream after being breathed into the lungs. Less than a 50th the width of a human hair, they fuel inflammation.

They come from diesel fumes, brake pads, tires and road dust. Known as PM2.5s, they have been linked to cardiovascular disease in adults.

The study in the Journal of the American Heart Association is the first to show they cause irregular heart rhythms, or arrhythmias, in youngsters.

Lead author Dr. Fan He, of Penn State University in the United States, said: "While relatively rare, irregular heart rhythms can lead to sudden cardiac death in otherwise healthy adolescents and young adults.

"Our findings linking air pollution to irregular heart rhythms suggest that particulate matter may contribute to the risk of sudden cardiac death among youth.

"Since childhood and adolescent cardiovascular conditions can track into adulthood and affect the 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."

Once inhaled, pollutants irritate the lungs and blood vessels around the heart. Over time they increase the process of disease in the arteries.

An analysis of 322 adolescents found eight-in-ten (79%) had at least one irregular heart rhythm during a 24-hour study period.

Dr. He said: "It is alarming 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 by the EPA (Environmental Protection Agency).

"It may suggest that adolescents who live in highly polluted areas such as inner cities are at even higher risk."

Results were consistent with data previously obtained in adults using similar methods from the same team and others.

Reducing risk may help combat the world's biggest killer. Cardiovascular disease claims almost 18 million lives a year.

Dr. He said: "Our study found air pollution increases the risk of cardiovascular diseases and sudden cardiac death - even among healthy adolescents.

"Protective measures, such as wearing masks and avoiding vigorous physical activities, may be warranted on days that particulate matter concentration is high, especially during early morning rush hours."

The team analyzed the impact of PM2.5s on two types of irregular heart rhythms - often described as a 'skipped beat.'

In PAC (premature atrial contraction), it originates from the top chambers called the atria. This usually causes no symptoms or harm.

But frequent bouts may lead to atrial fibrillation, a severe condition in which they quiver - raising the risk of blood clots and stroke.

A premature ventricular contraction (PVC) occurs when the heartbeat originates from the lower chambers or ventricles.

In some cases, they cause heart attack, stroke, heart failure or sudden cardiac death.

Repeated incidence of either often requires medications, implantable devices, or surgical procedures.

The participants were aged 17 on average and living in central Pennsylvania. Air each breathed was measured using a device called a nephelometer for a day.

Tracings of heart rhythms were taken with a small wearable device called a Holter monitor.

The average PM2.5 concentration was approximately 17 micrograms of particulate matter per cubic meter of air (µg/m3) per day - well below the EPA's 35 µg/m3 limit.

A five percent increase in the number of PVCs within two hours of exposure was noted for each increase of 10 µg/m3 in PM2.5. No link was identified with PACs.

Prof Robert Brook, of the American Heart Association who was not involved in the study, called for more robust national-level air quality regulations.

He has co-authored several American Heart Association scientific statements on air pollution.

Prof Brook, of Wayne State University in Detroit, said: "PM2.5 levels have fallen dramatically since the 1970s-80s due to regulations that have been unquestionably linked to improved health effects and life expectancy.

"We outlined in a recent AHA scientific statement, titled Personal-Level Protective Actions Against Particulate Matter Air Pollution Exposure, strategies and activity or behavioral changes that may reduce pollution exposure, such as portable air cleaners, facemasks, respirators and exercising during non-peak hours.

"However, there have been no studies to show these measures can actually prevent adverse clinical health effects such as heart attacks."

Earlier this year a study found air pollution in urban areas across the globe contributed to 1.8 million excess deaths in 2019.

The AHA recommends further development of evidence-based policy approaches, continued investment in research and greater innovation and transformational partnerships to reduce the cardiovascular burden of ambient air pollutants in the U.S.

Prof Brook added: "The most interesting and significant aspect of this study is clearly that the results were found in healthy young adolescents.

"The study adds support for the concern that even healthy young people are not immune to adverse cardiovascular responses to PM2.5 and at exposure levels within National Ambient Air Quality Standards for 24 hours established by the EPA.

"It is plausible that the findings help explain the potential reason for the time of onset of arrhythmias and even sudden death in some susceptible young people."

Dr. He and colleagues are currently evaluating the impact of air pollution on other markers of cardiac electrical activity.