“The latest research about cannabis use indicates that smoking and inhaling cannabis increases concentrations of blood carboxyhemoglobin (carbon monoxide, a poisonous gas), tar (partly burned combustible matter) similar to the effects of inhaling a tobacco cigarette, both of which have been linked to heart muscle disease, chest pain, heart rhythm disturbances, heart attacks and other serious conditions,” said Page, a professor in the department of clinical pharmacy and physical medicine/rehabilitation at the University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences in Aurora, Colorado.