Rapid pollution increases may be as harmful to the heart as absolute levels

February 15, 2018

Sophia Antipolis, Feb. 15, 2018: Rapid increases in pollution may be as harmful to the heart as sustained high levels, according to research published today in the European Journal of Preventive Cardiology,1 a European Society of Cardiology journal. The authors urgently call for confirmatory studies as even residents of clean air cities could be at risk.

There is longstanding evidence that exposure to high concentrations of air pollution increases the risk for several diseases including heart attacks and European Union (EU) statutory pollution limits are based on absolute upper values.

However, this study investigated whether rapid increases in pollution increase the risk of heart attack, independently of an absolute threshold. It also looked at whether an association between heart attacks and changes in air pollution exists in clean air cities where concentrations of air pollution vary but do not exceed EU limits.

The study was conducted in Jena, Germany, a city with 100,000 residents and only a few days over the last several years during which concentrations of some air pollutants exceeded EU daily limits. All patients living within 10 km of Jena who had a heart attack and were admitted to Jena University Hospital between 2003 and 2010 were included.

Each of the 693 patients served as his or her own control. Concentrations of air pollutants one, two, and three days before heart attack symptoms were compared to concentrations in the previous and following week. The researchers analysed whether there were rapid variations in air pollution before the heart attack.

Increases of nitric oxides of more than 20 μg/m3 within 24 hours were associated with a more than doubled risk of heart attack.

Senior author Dr Florian Rakers, a researcher and doctor at Jena University Hospital, said: "Our study suggests that the risk of heart attack associated with nitrogen oxides depends on the dynamics and extent of increases, and not only on exposure to high concentrations."

The researchers were surprised by the magnitude of the association. Dr Rakers said: "The risk of heart attack more than doubled after a 24 hour increase in nitric oxides of more than 20 μg/m3. The impact of rapid increases in air pollutants on heart health may be at least as important as absolute concentrations."

He continued: "The adverse effects of rapid rises in pollution can occur in smaller cities. Increases of nitric oxides by more than 20 μg/m3 within 24 hours happen more than 30 times per year in Jena, which is known as a 'clean air' city where statutory limits for nitric oxides are generally not violated."

Ground traffic and especially diesel cars are the primary source of nitric oxides in the EU. The study did not investigate the cause of rapidly changing pollution levels, but Dr Rakers said they could be due to irregular events that lead to more traffic than usual - for example the start of holidays or meteorological conditions associated with smog.

The researchers urgently called for larger studies to confirm the association between rapid increases of air pollution and cardiovascular risk.

The paper states: "Even though the ambient air in the city of Jena is comparably clean, the significant association between rapid changes in nitrogen oxides and onset of myocardial infarction (MI) suggests that the current EU statutory limits do not sufficiently protect against effects relating to the cardiovascular health of the population. A more specific definition and stricter implementation of statutory limits for rapid increases of nitrogen oxides are potentially needed to address this issue and to close this gap regarding the risk of MI."

Dr Rakers said: "Once our findings are replicated, the EU should discuss statutory limits on rapid increases of nitric oxides. This would require more efforts to reduce these air pollutants, such as banning diesel cars that exceed EU emission limits."
-end-


European Society of Cardiology

Related Heart Attack Articles from Brightsurf:

Top Science Tip Sheet on heart failure, heart muscle cells, heart attack and atrial fibrillation results
Newly discovered pathway may have potential for treating heart failure - New research model helps predict heart muscle cells' impact on heart function after injury - New mass spectrometry approach generates libraries of glycans in human heart tissue - Understanding heart damage after heart attack and treatment may provide clues for prevention - Understanding atrial fibrillation's effects on heart cells may help find treatments - New research may lead to therapy for heart failure caused by ICI cancer medication

Molecular imaging identifies link between heart and kidney inflammation after heart attack
Whole body positron emission tomography (PET) has, for the first time, illustrated the existence of inter-organ communication between the heart and kidneys via the immune system following acute myocardial infarction.

Muscle protein abundant in the heart plays key role in blood clotting during heart attack
A prevalent heart protein known as cardiac myosin, which is released into the body when a person suffers a heart attack, can cause blood to thicken or clot--worsening damage to heart tissue, a new study shows.

New target identified for repairing the heart after heart attack
An immune cell is shown for the first time to be involved in creating the scar that repairs the heart after damage.

Heart cells respond to heart attack and increase the chance of survival
The heart of humans and mice does not completely recover after a heart attack.

A simple method to improve heart-attack repair using stem cell-derived heart muscle cells
The heart cannot regenerate muscle after a heart attack, and this can lead to lethal heart failure.

Mount Sinai discovers placental stem cells that can regenerate heart after heart attack
Study identifies new stem cell type that can significantly improve cardiac function.

Fixing a broken heart: Exploring new ways to heal damage after a heart attack
The days immediately following a heart attack are critical for survivors' longevity and long-term healing of tissue.

Heart patch could limit muscle damage in heart attack aftermath
Guided by computer simulations, an international team of researchers has developed an adhesive patch that can provide support for damaged heart tissue, potentially reducing the stretching of heart muscle that's common after a heart attack.

How the heart sends an SOS signal to bone marrow cells after a heart attack
Exosomes are key to the SOS signal that the heart muscle sends out after a heart attack.

Read More: Heart Attack News and Heart Attack Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.