Even ‘safe’ levels of air pollution can trigger heart attacks – and you could be dead within an hour of breathing dirty air, research warns
EXCLUSIVE: US Researchers Monitor Nitrogen Dioxide Levels For 15 Years, Increase Risk Of Heart Attack As Pollutant Concentration Increases
Even ‘safe’ levels of air pollution can cause heart attacks, a study suggests.
Researchers have also found that people can die within just one hour of breathing polluted air.
Stricter air quality standards are now urgently needed, experts claim.
Levels of nitrogen dioxide (NO2) – mainly emitted by cars – were tracked in nine US cities over 15 years.
The Columbia University scientists then compared this to heart attack hospitalization rates, allowing them to isolate any possible link.
Even ‘safe’ levels of air pollution can cause heart attacks, a study suggests. Researchers have also found that people can die within just one hour of breathing polluted air
Air pollution increases the risk of several conditions including heart attack, stroke and diabetes
What is nitrogen dioxide?
Nitrogen dioxide (NO2) is a gas produced mainly during the combustion of fossil fuels.
Short-term exposure to high concentrations of NO2 can cause airway inflammation and increase susceptibility to respiratory infections and allergens.
NO2 can exacerbate symptoms in people who already have lung or heart disease.
As the concentration of the pollutant increased, so did the risk of heart attack just 60 minutes after NO2 levels rose.
Heart attack risk increased when NO2 levels were below the current US national standard of 100 parts per billion (ppb).
This threshold means that for every billion units of air, 100 units of NO2 are considered acceptable.
They are in line with the World Health Organization and UK air standards that hourly concentrations should not exceed 200 micrograms of NO2 per cubic meter of air (µg/m³). 100 ppb NO2 equals 191 µg/m³.
UK laws currently stipulate that hourly levels of toxic NO2 should not exceed that threshold more than 18 times a year.
However, air quality tracking equipment shows that these limits are regularly breached in parts of London.
Writing in the journal Environment International, the academics said: ‘Our study suggests that current hourly standards may be insufficient to protect cardiovascular health.’
Studies have repeatedly shown that air pollution, especially from traffic, can lead to heart attacks.
That’s because inhaling pollutants — which can be so small that they travel deep into the lungs and into the bloodstream — can restrict blood flow to the heart and force the organ to work harder than usual.
Illustrated, is a graph showing three measurements of nitrogen dioxide, a pollutant primarily produced by engines and burning fossil fuels. In 2020 the annual average of urban background (purple) decreased by almost a quarter (23 percent).
However, it is not clear when the risk of heart problems begins after exposure to pollution and how long it lasts.
The Columbia University team used hourly NO2 concentration data for cities in New York state between 2000 and 2015.
The study also included data on hospitalizations for 8.9 million people, including 350,000 for heart attacks.
The average hourly NO2 concentration stood at about 23.3ppb.
But every 10ppb increase apparently increased heart attack risk by 0.2 percent.
And the risk of heart attack was highest in the first hour of exposure, when it increased by 0.21 percent.
Risk was elevated for six hours after a spike in NO2 rates across all cities, and up to 24 hours in some.
About 100,000 Britons and 800,000 Americans have heart attacks each year.
The WHO has claimed that countries need to take drastic measures as evidence is building on the health risks of micro-pollutants, which are also linked to dementia and cancer.
According to the United Nations agency, poor air quality is estimated to cause 7 million deaths each year and reduce millions of healthy years of life.