People exposed to particulate matter (PM) emitted mainly from diesel used in vehicles may be at greater risk of developing heart attack, heart failure and death, researchers warned.

The findings showed that exposure to PM 2.5 from diesel can lead to systemic inflammation, vasoconstriction -- narrowing of blood vessels, and raised blood pressure, all of which can cause harmful changes to the structure and function of the heart.The combination of these factors can also increase the pressure in the heart, which enlarges to cope with the overload.Every 5 per cubic metre air or µg/m3 increase in exposure was associated with a 4-8 percent increase in left ventricular volume (structure) and a 2 percent decrease in left ventricular ejection fraction (function), the researchers said.

"The study 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," said lead author Nay Aung from the Queen Mary University of London. This may be due to an inflammatory response. The inhalation of PM2.5 causes localised inflammation of the lungs followed by a more systemic inflammation affecting the whole body, Aung added. 

For the study, presented at the annual conference EuroCMR 2017 in Prague, the team included 4,255 participants, 62 years old on average."Reducing PM 2.5 emission should be an urgent public health priority and the worst offenders such as diesel vehicles should be addressed with policy measures," Aung noted.