Cardiovascular Effects of Incremental Diesel Exhaust Inhalation in Middle-Aged Healthy GSTM1 Null Human Volunteers

Inclusion Criteria:

• Age 50-75 years old generally healthy male and female.
• Normal resting ECG.
• Oxygen saturation greater than 94% at the time of physical exam.

Exclusion Criteria:

• A history of angina, cardiac arrhythmias, and ischemic myocardial infarction or coronary bypass surgery.
• Cardiac pacemaker.
• Uncontrolled hypertension (> 150 systolic, > 90 diastolic).
• Neurodegenerative diseases such as Parkinson's and Alzheimer disease.
• A history of chronic illnesses such as diabetes, cancer, rheumatologic diseases, immunodeficiency state, known cardiovascular disease, chronic respiratory diseases such as chronic obstructive pulmonary disease or severe asthma.
• History of bleeding diathesis.
• Currently taking HMG-CoA reductase inhibitors for hyperlipidemia including lovastatin, pravastatin, simvastatin, and atorvastatin.
• Currently taking beta-blockers to control hypertension and/or arrhythmias.
• Use of oral anticoagulants.
• Participants must refrain from all over-the-counter NSAIDs for a period of two weeks prior to exposure. Low-dose aspirin will be acceptable. Medications not specifically mentioned here may be reviewed by the investigators prior to a participant's inclusion in the study.
• Subjects who are currently smoking or have smoking history within 1 year of study (defined as more than one pack of cigarettes in the past year).
• Subject is pregnant, attempting to become pregnant or breastfeeding.
• No exposure will be conducted within 4 weeks of a respiratory tract infection.