2nd hand smoke hurting my chest, what does that mean? bf of 10 months smokes and sometimes around me. how dangerous is this?

Second hand smoke: Second hand smoke can irritate the non smoker's lungs. Tobacco smoke contains more than 7000 chemicals including 70 that can cause cancer. You are more likely to have upper respiratory infections and lung infections if you are breathing in second hand smoke. Here are two articles about second hand smoke: http://www.lung.org/stop-smoking/smoking-facts/health-effects-of-secondhand-smoke.html https://www.cdc.gov/tobacco/data_statistics/fact_sheets/secondhand_smoke/general_facts/