Are the impacts from air pollution hiding in plain sight in the everyday aliments that so many of us suffer from? A new study, the largest of its kind, found that people living in polluted areas were more likely to have more than one long-term illness. Researchers looked at more than 360,000 people aged between 40 and 69 who had health data in the UK Biobank. They found greater chances of multiple neurological, respiratory, cardiovascular and common mental health conditions such as depression and anxiety, even having allowed for differences in income. These long-term problems affect people’s lives and place big burdens on our economy and health services. Earlier this month the UK government announced a target for the worst particle pollution in England in 2040. It means that England plans to meet the 2005 World Health Organization (WHO) guidelines in 18 years’ time, 35 years after the guidelines were set. The new health study found an extra 20% chance of multiple long-term illnesses for those living with particle pollution that is worse than the 2040 England target. Dr Ioannis Bakolis, from King’s College London, who led the study, said: “We will need to track people’s changing health over time to know for sure if air pollution caused these chronic health problems. If air pollution exposure indeed affects risk, it presents an opportunity to shape the epidemic of multiple long-term illness using environmental policy such as expanding low-emission zones or avoiding building care homes in pollution hotspots.” It may be decades before we get data on the progress of these chronic illnesses, but we can learn by looking into the past. Seventy years ago, London was coping with the deaths of about 12,000 people in the city’s worst ever smog. A subsequent Ministry of Health report reviewed past death records and found that smogs had been killing people over the previous 80 years. The evidence had been there all along. In 2016, a study looked at the health of Londoners who survived the 1952 smog as infants under one year old or in utero. They were left with a 20% greater chance of developing asthma in childhood, compared with those outside London. Although less clear in the data, the chances of them having adult asthma increased by about 10%. Recent analysis of first world war army records found that air pollution had been reducing the height and health of soldiers who grew up downwind of areas of intense coal use. This all adds to the evidence that air pollution can lead to a whole range of chronic illness. Putting this another way, the benefits of clean air could be even greater than we imagine.