Polluted Air Can Trigger Cardiac Arrests

Air pollution affects our body, but it is mainly linked to the risk of cardiac arrests in a large part of the population.

This was the discovery of scientists in Singapore, who have been studying this problem for several decades. Specifically, the study published in the journal The Lancet Public Health highlights that increased concentrations of tiny particles in the air can trigger cardiac arrests.

For this research, the scientists collected data between 2009 and 2018 and found that the levels of tiny particles in polluted air would be 25 times smaller than the width of a human hair. These particles are known as PM2.5 (2.5 micrometers in diameter). Due to their tiny size, they can be inhaled very easily. But that is not all — they are also associated with certain health problems, including autoimmune diseases.

Air Pollution and Cardiac Arrests

The lead researcher, Joel Aik, an epidemiologist at the Duke-NUS Medical School at the National University of Singapore, stated:

We have provided clear evidence of a short-term association of PM2.5 with out-of-hospital cardiac arrest, which is a catastrophic event that usually causes sudden death.

To reach that conclusion, he and his team studied more than 18,000 reported cases of out-of-hospital cardiac arrest from the period 2009–2018. These were compared with daily air pollutant levels over the same period. They then determined that 492 of the cases could be attributed to increases in PM2.5 concentrations.

The data showed that daily PM2.5 concentrations averaged 18.44 micrograms per cubic meter. When testing hypothetical reductions in air pollution, the researchers found that a drop of 1 microgram per cubic meter correlated with an 8% reduction in cardiac arrest events. While a drop of 3 micrograms per cubic meter produced a 30% reduction. Those reductions would translate to 39 and 149 fewer heart attacks, hypothetically speaking.

In addition, the study found a clear decrease in the risk of suffering a heart attack 3 to 5 days after exposure to higher levels of pollution. This suggests that the effects of pollutant particles are short-term.

Therefore, many lives could be saved and hospital strain reduced if city air were cleaned up. On this, Aik says:

These findings highlight that efforts to reduce air particulate levels in the range of 2.5 micrograms or less, and protective measures against exposure to these particles, could help reduce sudden cardiac arrests in Singapore’s population, while also reducing the burden on health services.

But polluted air is not only a problem in Singapore — it affects many cities around the world. Therefore, it is important that the same air-cleaning measures be carried out in those cities to save even more lives.

Reference:

Air quality and the risk of out-of-hospital cardiac arrest in Singapore (PAROS): a time series analysis