Air pollution caused 3.2 million new cases of diabetes worldwide in 2016, according to a new estimate. Fine particulate matter, belched out by cars and factories and generated through chemical reactions in the atmosphere, hang around as haze and make air hard to breathe. Air pollution has been linked to chronic conditions such as heart disease and diabetes (SN: 9/30/17, p. 18), but this study is one of the first attempts to quantify the connection for diabetes.