Urban pollution in wealthy world still adding to heart damage, study finds

{"text":[[{"start":8.45,"text":"Long-term exposure to urban air pollution damages the heart even at the relatively low levels found in many developed countries, a cardiac imaging study in Canada has found."}],[{"start":18.85,"text":"Researchers at the University of Toronto analysed CT heart scans from 11,000 people, linking their home addresses to pollutants recorded locally over the previous 10 years by the Ontario government’s network of air-monitoring stations."}],[{"start":32.45,"text":"While dirty air kills most people in the developing world, the study provided evidence that it remained a threat in wealthier countries where increasingly strict rules had lowered pollution in recent years, said Kate Hanneman, the senior author of the study published in the journal Radiology. "}],[{"start":49.5,"text":"The average exposure to polluting particles in the study group was well below the local air quality standard, she noted."}],[{"start":56.6,"text":"“The fact that we can detect a measurable signal in coronary atherosclerosis at these levels suggests there may be no clear, safe threshold for cardiovascular harm from air pollution, and that even populations in countries with relatively clean air face meaningful cardiovascular risk from environmental exposure,” she said."}],[{"start":76.2,"text":"The study found a significant correlation between coronary artery disease and exposure to two key types of pollution: extremely fine particles called PM2.5 and nitrogen dioxide gas."}],[{"start":89.55,"text":"The particulate matter, so-called PM2.5 because it measures 2.5 microns across, comes from vehicle exhaust, industrial emissions and increasingly from wildfires. Their diameter is 30 times less than a human hair, so they penetrate deep into the lungs and then into the bloodstream, damaging organs around the body."}],[{"start":null,"text":""}],[{"start":null,"text":""}],[{"start":109.55,"text":"The study concluded that an increase of 15 per cent in long-term exposure to the microscopic particles raised build-up of harmful calcium in coronary arteries by 11 per cent, plaque formation by 13 per cent and obstructive disease by 23 per cent. The effect was stronger in women than in men."}],[{"start":128.05,"text":"“We plan to continue our research by looking further at the associations between air pollution in men and women — and why they differ,” said Hanneman."}],[{"start":136.4,"text":"“While this was an observational study and can’t prove cause and effect, the findings are consistent with what we already know about how air pollution can damage the heart over time,” commented Sonya Babu-Narayan, clinical director of the British Heart Foundation, a UK charity not involved in the research."}],[{"start":154,"text":"“Seeing these associations at pollution levels typical of many urban areas is concerning and reinforces that there may be no truly safe level of air pollution when it comes to our heart health,” she added. “Whilst there has been some progress in reducing air pollution, this study supports the need for even stricter limits.”"}],[{"start":173.05,"text":"The World Health Organization estimates that 4.2mn deaths a year globally are linked to ambient, or outdoor, air pollution, with cardiovascular deaths accounting for about half the total. It also contributes to chronic obstructive pulmonary disease, dementia, lung cancer and respiratory infections. "}],[{"start":191.55,"text":"The connection between air pollution and climate change was noted by the study: “Because fossil fuel combustion drives both air pollution and greenhouse gas emissions, policies that improve air quality can deliver simultaneous benefits for cardiovascular health and the planet.”"}],[{"start":null,"text":"

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