The study, conducted in Mexico City, found that the iron-rich nanoparticles produced by industry and vehicle emissions damage the heart’s muscle cells. It suggests that the particles could explain the link between air pollution and heart disease. In a previous study, the researchers found the same nanoparticles in human brains and linked their presence to Alzheimer’s-like damage—another disease associated with air pollution. (The Guardian)

Talking point: Over four million people die every year as a result of exposure to outdoor air pollution, according to the World Health Organization (WHO) (another 3.8 million die every year due to household exposure to pollution caused by cooking or burning fuels). And, some 91 per cent of the world’s population live in places where air pollution exceeds WHO limits. According to a 2018 United Nations report, two out of every three people will be living in cities by 2050, expanding the number of those exposed to air pollution, meaning cities will increasingly need to address both the physical and financial costs. A World Bank report puts the economic cost of air pollution on the 2013 global economy at US$225 billion in lost labour income.