PM2.5 linked to heart attacks

Summary: A study conducted by the Duke-NUS University of Singapore has proclaimed to produce clear evidence of a short-term association between out-of-hospital cardiac arrest and increased concentration of tiny particles in the air, i.e. a link between pollution and heart attacks in the Southeast Asian city.

Why this is important: More evidence of the link between climate change, human action and health.

The big theme: Achieving acceptable air quality has various significant investment and decision-making considerations. The most obvious are the implications on human health from a purely altruistic point of view. Decreasing pollution with the aim of decreasing human illness and suffering is (should be) a goal unto itself. In practice however, the focus is primarily on how such initiatives (that more often than not increase costs and dig into profits), will be beneficial to business in the long run, whether it be through decreased healthcare costs, increased health and productivity of the workforce, and reputational gains for such decisions.

Summary of a study published in The Lancet:

A study conducted in Singapore suggests that increased tiny particles in the air have the potential to cause out-of-hospital cardiac arrests (OHCAs). PM_2.5 particles are 2.5 micrometers in diameter or 25 times smaller than the width of a human hair and are easy inhaled. They have been previously linked to other significant health problems, including autoimmune diseases.

Just over 18,000 reported cases of OHCA, between July 2010 and December 2018, were tracked against pollution levels in Singapore. The study claimed that 492 of those cases could be ‘attributed to’ increased concentrations of PM_2.5 levels. The researchers claim to ‘have produced clear evidence of a short-term association of PM_2.5" with OHCA, although they did recognise that the study was observational and a causal relationship is still speculative at this point. Nevertheless, it still suggests that this is an area worth exploring further.

Let's look at why this is important...

Why this is important

Firstly, this is one of several studies that while not conclusive in themselves, support the value in further investigating the relationship between air pollution and health. During the period of the study, daily PM_2.5 concentrations averaged at 18.44 micrograms per cubic meter. The researchers modelled hypothetical reductions in PM_2.5 levels and found that a 1 microgram per cubic meter drop correlated to an 8% reduction in OHCAs. The effect appeared to be compounding, with a drop of 3 micrograms per cubic meter corresponding to a 30% reduction. That's the equivalent of 39 and 149 fewer heart attacks, respectively. Also encouraging is the short time frame in which results could be seen – heart attack risk dropped in just 3-5 days after exposure, meaning that efforts to reduce such particles (via a decrease in overall air pollution) could have a very quick and positive impact on morbidity and mortality, population health, worker productivity and strain on the healthcare system.

Climate change is already known to affect human well-being, with the UN citing a clear link between climate change and displacement of the world’s most vulnerable, stating ‘Weather-related crises have triggered more than twice as much displacement as conflict and violence in the last decade’ with ‘roughly 90% of refugees come from countries that are the most vulnerable and least ready to adapt to the impacts of climate change.’  

This is not just a ‘cardiac’ issue. We have previously discussed the implications of PM_2.5 particles as cancer causing agents, fuelling the discussion of the overall value of a longer term drive to decrease air pollution. And while the effects on cancer may be as well longer-term gained, the cardiac issue discussed here seems to be responsive in the short term, perhaps providing a ‘lowest hanging fruit’ to prove pollution decreasing measures are worthwhile.

From a business perspective, there could be holistic implications of targeted efforts to decrease emissions and pollution. Will companies hedge the initial investment eventually being offset by the increase in productivity of the current and future workforce? Historically one could argue that decisions have been based on an ‘acceptable’ amount of morbidity and mortality for the sake of profit. With better knowledge and a broader group of stakeholders with considerations beyond pure profit, that seems like a less likely route.

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