These are the findings of researchers who studied the blood vessel function of 270 Boston-area residents exposed to various levels of pollutants in their surrounding air. They also found cardiovascular risk was greater in people with type 2 diabetes than people with type 1.
For a summary of the study:
People with Diabetes More Sensitive to Cardiovascular Effects from Air Pollution
For the study itself (abstract only, subscription required for full article):
Diabetes Enhances Vulnerability to Particulate Air Pollution–Associated Impairment in Vascular Reactivity and Endothelial Function