Inclusion Criteria:  Male or female current tobacco smokers with >= 20 pack years of self-reported smoking exposure and a current average use of >= 10 cigarettes/day Age >= 18 years Karnofsky performance scale >= 70% Leukocytes >= 3,000/microliter Absolute neutrophil count >= 1,500/microliter Platelets >= 100,000/microliter Total bilirubin =< 2 x institutional upper limit of normal (ULN) Aspartate aminotransferase (AST) (serum glutamic-oxaloacetic transaminase [SGOT])/alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase [SGPT]) =< .5 x ULN Creatinine =< 1.5 x ULN Fertile subjects must use adequate contraception (abstinence, barrier methods, or birth control pills) prior to study entry and for the duration of study participation. The effects of BSSE on the developing human fetus are unknown. For this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her study physician immediately Ability to understand and willingness to sign a written informed consent document  Exclusion Criteria:  History of invasive cancer within the past 2 years, except for excised and cured non-melanoma skin cancer or carcinoma in situ of the cervix. Participants who continue adjuvant treatment for an index cancer occurring > 2 years ago, such as adjuvant hormonal therapy for breast cancer, are excluded. Participants who are on anti-neoplastic treatment for a chronic malignancy, such as multiple myeloma or chronic myelogenous leukemia, are excluded Chronic, current or recent (within the past 2 weeks) use of systemic steroid doses equivalent to prednisone > 5 mg daily for continued use > 14 days. Use of inhaled steroids, nasal sprays, and topical creams for small body areas (< 10% body surface area) is allowed Participants may not be receiving any other investigational agents History of allergic reactions attributed to compounds of similar chemical or biologic composition to Avmacol ES (BSSE) Uncontrolled intercurrent illness including but not limited to: ongoing or active infection requiring systemic antibiotics or antifungals; symptomatic congestive heart failure; unstable angina pectoris; ventricular arrhythmia (e.g., ventricular tachycardia) or uncontrolled atrial arrhythmia (e.g., symptomatic atrial fibrillation with rapid ventricular response); or psychiatric illness/social situations that would limit compliance with study requirements Pregnant or lactating women