Diesel fumes have negative effects on the heart according to a new study by researchers at Queen Mary University of London (QMUL).
“There is strong evidence that particulate matter (PM) emitted mainly from diesel road vehicles is associated with increased risk of heart attack, heart failure, and death,” said lead author Dr Nay Aung from the Advanced Cardiovascular Imaging Unit led by Professor Steffen Petersen at William Harvey Research Institute, QMUL.
“This may be driven by an inflammatory response – inhalation of fine particulate matter (PM2.5) causes both localised inflammation of the lungs and a more systemic inflammation.”
Using 4255 participants from the UK Biobank, the study examined whether PM2.5 may damage the heart directly.
The association between PM2.5 exposure and heart structure and function was estimated using multivariable linear regression, a form of statistical modelling which adjusts for potential factors that could influence the relationship such as age, gender, diabetes and blood pressure.
Dr Aung said: “We found that as PM2.5 exposure rises, the larger the heart gets and the worse it performs. Both of these measures are associated with increased morbidity and mortality from heart disease.”
The researchers also looked for potential factors that could modify the relationship. They found that those with a degree-level education were less prone to having a larger heart and had a smaller reduction in ejection fraction when exposed to PM2.5 than people with a lower level of education.
Dr Aung said: “This finding is consistent with previous research on the effect of air pollution on morbidity and mortality. This could be due to a number of factors including better housing and workplace conditions, which reduce pollution exposure. Educated people may also be more aware of their health, have healthier lifestyles, and have better access to healthcare.”
The negative effects of PM2.5 include systemic inflammation, vasoconstriction, raised blood pressure and increased risk of heart attack. A combination of these factors can impair the heart structure and function.
Dr Aung said: “We found that the average exposure to PM2.5 in our study cohort is about 10 µg/m3. This is below the European target of less than 25 µg/m3 and yet we are still seeing these harmful effects. This suggests that the current target level is not safe and should be lowered.”
He continued: “Our results suggest that PM2.5 is linked with negative changes in the heart structure and function that are associated with poor outcomes. Reducing PM2.5 emission should be an urgent public health priority and the worst offenders including diesel vehicles should be addressed with policy measures.”
In terms of what individuals can do to decrease their risk, Dr Aung said: “Sensible measures to reduce exposure to air pollution are recommended. These include avoiding times and places where there is a high level of pollution. If you want to cycle into work and there is heavy traffic around that time then try to find a quieter route away from the vehicles. Those with cardiorespiratory diseases should, if possible, limit the time spent outdoors during highly polluted periods such as rush hours.”
Dr Aung presented the abstract 'Impact of fine particulate matter air pollutant on cardiac atrial and ventricular structure and function derived from cardiovascular magnetic resonance (CMR) imaging – evidence from the UK Biobank' during the BEST Oral Abstracts session at EUROCMR 2017 on 26 May.