Melanin and Dermal Uptake of Thirdhand Cigarette Smoke

Inclusion Criteria: * Adult nonsmoker * Aged 18-50 * Skin reflectance scores below 150 or above 249 using the Mexameter 18 instrument * Healthy on the basis of medical history * Systolic blood pressure \<150 * Diastolic blood pressure \<100 * C-reactive protein \<3.1 mg/ml * Liver function (AST and ALT) in normal ranges * kidney function (BUN) in normal ranges * LDL\<131 * Blood glucose \<110 * Not exposed to tobacco SHS. Exclusion Criteria: * Dermal skin reflectance score between 150 and 249, as measured by the Mexameter 18 instrument. * Positive SARS-CoV-2 antibody test * Age 18 \< or \> 50 * Physician diagnosis of asthma, heart disease, hypertension, thyroid disease, diabetes, renal or liver impairment or glaucoma. * Unstable psychiatric condition (such as current major depression, history of schizophrenia or bipolar disorder) or current use of more than two psychiatric medications * Systolic blood pressure greater than or equal to 150 * Diastolic blood pressure greater than or equal to 100 * Blood glucose greater than or equal to 110 * LDL greater than or equal to130 * Pregnancy or breastfeeding (by urine hCG and/or history) * Alcohol or illicit drug dependence within the past 5 years * BMI \> 35 and \< 18 * Current illicit drug use (by history or urine test) * More than 1 pack year smoking history * Ever a daily marijuana smoker * Smoked anything within the last 3 months * Unable to hold allergy or other OTC medicines * Occupational exposure to smoke, dusts OR fumes * Concurrent participation in another clinical trial * Unable to communicate in English * No social security number