Increased risk of heart attack due to rapid increase in nitrogen oxides
It has long been known that air pollution is a health hazard. Among other things, it can damage the lungs and increase the risk of cancer, respiratory and cardiovascular diseases such as heart attacks. Researchers have now found that the risk of heart attack also increases due to a rapid increase in nitrogen oxides.
Rapid increases in nitrogen oxide levels increase the risk of heart attack
It has long been known that environmental pollution is associated with a high health risk. For example, health experts point out the potential risk to life from nitrogen oxides, because high nitrogen oxide concentrations in the ambient air can increase the risk of heart attack. A current study by scientists from the University Hospital Jena showed that the short-term risk of a heart attack also increases if the nitrogen oxide content in the ambient air rises rapidly within 24 hours.
Years of life lost
As the University Hospital wrote in a communication, the European Environment Agency lists in its current report on air quality, among other things, the years of life that air pollution costs the population.
Accordingly, in 2016 the Europeans lost a total of over 800,000 years of life due to the pollution of the air with nitrogen dioxide - with conservative calculation.
In the European Union, this gas is generated primarily in the internal combustion engines of motor vehicles and especially diesel cars, as well as in heating systems. It has been proven that it irritates and damages the respiratory system and increases the risk of heart attack.
The limit values applicable throughout Europe, 200 micrograms per cubic meter of air as the maximum hourly value and 40 micrograms as an annual mean, are therefore monitored by a dense network of measuring points.
In a study now published in the specialist journal "European Journal of Preventive Cardiology", doctors and medical statisticians from Jena prove that the rapid increase in the nitrogen oxide content in the air can also have health effects.
To this end, the scientists looked at all patients who were treated with an acute heart attack from 2003 to 2010 in the University Hospital Jena.
Only the data of those patients who came from a radius of ten kilometers around the hospital and for whom the time at which the symptoms started could be precisely reconstructed were included in the evaluation.
The data of these almost 700 patients were then compared with the recordings of the immission data for nitrogen oxides (NOX / 2), ozone (O3) and particulate matter (PM10) from the Thuringian State Institute for the Environment and Geology, which recorded these parameters for air pollution in Jena.
The experts examined in detail whether the concentrations of the most important air pollutants changed abnormally over a period of 24 hours shortly before the first heart attack symptoms.
The scientists deliberately chose a 'clean' city as the place of study: In the eight years under review, the currently applicable European limit values for all measured air pollution parameters in Jena were met within a few days.
Connection almost linear
At the start of the study, the doctors suspected that the risk of heart attacks is related to the change in air quality. "The clarity of the connection surprised us, it is almost linear," says Dr. Florian Rakers, senior author of the study.
The Jena scientist and doctor focuses on the influence of environmental influences on the development of diseases.
Prof. Matthias Schwab, senior physician at the Clinic for Neurology and co-author of the study explains: "The acute heart attack risk in our study roughly doubled if the nitrogen oxide concentration increased by 20 micrograms per cubic meter within a day"
“Rapid increases in nitrogen oxide concentrations also occur in a supposedly clean city like Jena around 30 times a year. This is probably due to an unusually high volume of traffic or meteorological factors that promote smog development, ”Dr. Rakers further out.
The results were less clear for particulate matter and ozone. “A connection between a rapid increase in both air pollutants and the acute risk of heart attack could not be confirmed. Nevertheless, high concentrations of particulate matter and ozone are particularly harmful for patients with lung diseases, ”emphasizes Prof. P. Christian Schulze, Director of the Clinic for Internal Medicine I and co-author of the study.
With their investigation, the Jena scientists are expanding their knowledge of the harmful effects of nitrogen oxides.
"The risk of a heart attack obviously increases not only when people are exposed to high nitrogen oxide concentrations in the ambient air for a short or long period, but also when the nitrogen oxide content increases rapidly," says Dr. Florian Rakers.
"In this way, nitrogen oxides could also have a harmful effect in comparatively 'clean' air. Because of the clinical relevance of our results, investigations should be carried out on a larger scale and in other geographical regions in order to expand the EU limit values by a dynamic component if necessary. "(Ad)