Proximity to major roadways was associated with fat accumulation in the liver, in a recently published study from the Harvard Clean Air Research Center. Non-alcoholic fatty liver disease (hepatic steatosis) is a common condition, closely linked with indicators of cardiometabolic syndrome (cardiovascular disease and insulin resistance). Over 2,000 participants from the Framingham Offspring Study and Third Generation who had undergone CT scans were part of the analysis in Massachusetts, after exclusion of those consuming alcohol frequently. Living within 58 m (25th percentile) from a major road was associated with increased amounts of liver fat, and the prevalence of fatty liver disease was 16% higher compared to participants living more than 416 m away (75th percentile). These measures were not associated with total PM2.5 exposures, suggesting a possible role for traffic-related exposures.