Reducing Traffic Pollution Exposure Improves Blood Pressure

Inclusion Criteria: * The inclusion criterion was age 40-75 years. * There was a preference for people who were otherwise healthy, but overweight or obese. Exclusion Criteria: * A history of a major cardiovascular outcome (including myocardial ischemia (MI), stroke, angina) * Other serious health problems (current asthma or COPD) * Taking anti-hypertensive medications * Smoking or living with a smoker * Cognitive impairment * Working at a job with high combustion exposure (taxi/truck driver, restaurant cook) * High combustion exposure in the preceding 24 hours (driving on the highway, cooking in a restaurant, driving a truck) * Not speaking English or Chinese.