Chronic air pollution increase in nitric oxide creates heart attack risk

Increased risk of heart attack due to rapid increase in nitric oxide

It has long been known that air pollution poses a threat to health. Among other things, it can damage the lungs, increase the risk of cancer, respiratory and cardiovascular diseases such as heart attack. Researchers have now found that the risk of heart attack is also increased by a rapid increase in nitric oxide.

Rapid increase in nitric oxide levels increases the risk of heart attack

It has long been known that pollution of the environment is associated with a high health risk. Health experts point out, among other things, the potential danger of death from nitrogen oxides, because a high nitrogen oxide concentration in the ambient air can increase the risk of heart attack. A recent study by scientists at the Jena University Hospital has now shown that the short-term risk of a heart attack also increases when the nitrogen oxide content in the ambient air rises rapidly within 24 hours.

It has been known for a long time that high nitrogen oxide concentrations in the ambient air damage health and, among other things, increase the risk of heart attack. Researchers have now shown that the short-term risk of a heart attack also increases when the nitrogen oxide content in the ambient air increases rapidly. (Image: Gina Sanders / fotolia.com)

Lost years of life

As the University Hospital writes in a communication, the European Environment Agency lists in its latest report on air quality, among other things, the years of life, which costs the population the air pollution.

As a result, Europeans lost a total of more than 800,000 years in 2016 because of the burden of nitrogen dioxide on the air - with conservative accounting.

This gas is produced in the European Union mainly in internal combustion engines of motor vehicles and in particular of diesel cars and in heating systems, it irritates and damages the respiratory organs and increases the risk of heart attack.

The Europe-wide limit values, 200 micrograms per cubic meter of air as the maximum hourly value and 40 micrograms a year, are therefore monitored with a dense network of measuring points.

Health effects

In a study now published in the journal "European Journal of Preventive Cardiology", physicians and medical statisticians from Jena demonstrate that the rapid increase in nitric oxide levels in the air can also affect health.

To this end, the scientists considered all patients who were treated with an acute myocardial infarction in the years 2003 to 2010 at 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 when the symptoms started were included in the analysis.

The data from these just under 700 patients were then compared with the records of the nitrogen oxide (NOX / 2), ozone (O3) and particulate matter (PM10) emissions data from the Thuringian State Institute for the Environment and Geology, which records these parameters for air pollution in Jena.

In detail, the experts examined whether the concentrations of the most important air pollutants changed unusually shortly before the first heart attack symptoms over a period of 24 hours.

As a place of study, the scientists deliberately chose a 'clean' city: In the eight years under consideration, the current European limit values ​​for all measured air pollution parameters in Jena were met, with the exception of a few days.

Context almost linear

The physicians suggested at the beginning of the study that the risk of heart attacks is related to the change in air quality. "The clarity of the connection surprised us then, it is almost linear," 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 of the Department of Neurology and co-author of the study explains: "The acute risk of heart attack in our study doubled in approximately when the nitrogen oxide concentration increased by 20 micrograms per cubic meter within one day".

"Rapid increases in nitric oxide concentrations occur even in a supposedly clean city like Jena about 30 times a year. This is probably due to an unusually high traffic volume or meteorological factors that promote smog development, "Dr. Rakers on.

For particulate matter and ozone, the results were less clear. "A correlation between a rapid increase in both air pollutants and acute myocardial infarction risk was not confirmed. Nevertheless, high concentrations of particulate matter and ozone are particularly detrimental to patients with lung diseases, "emphasizes Prof. P. Christian Schulze, Director of the Department of Internal Medicine I and co-author of the study.

With their investigation, the Jena scientists are expanding their knowledge of the harmfulness of nitrogen oxides.

"The risk of a heart attack does not only increase when people are exposed to high levels of nitric oxide in the ambient air for a short or long time, but also when the level of nitric oxide increases rapidly," Dr. Florian Rakers.

"In this way, nitrogen oxides could be detrimental even in comparatively 'clean' air. Because of the clinical relevance of our findings, urgent investigations should be carried out on a larger scale and in other geographic areas, and then, if appropriate, expand the EU limits by a dynamic component. "(Ad)