Years of clinical studies have conclusively linked cigarette smoke, both primary and secondary, to heart and lung disease and widely varied cancers. Questions remain, however, regarding the impact of cigarette smoke on plants. Whether house plants suffer from living with smokers, or food crops from being tended by field workers who smoke, are relevant concerns.
According to the Lung Association, tobacco smoke contains more than 4,000 chemicals, many of them poisonous or carcinogenic. Among them are carbon monoxide, arsenic, hydrogen cyanide, ammonia, lead, sulphur compounds, formaldehyde and, of course, nicotine. Toxic to humans and other animals, these chemicals do not bode well for healthy plants.
NASA has discovered that house plants absorb pollutants, removing such cigarette-borne toxins as formaldehyde and carbon monoxide from the air. You and your family can breathe a little easier, but your leafy roommates will have to take one for the team. Over time, the contaminants plants absorb build up in the leaves, stems, roots and soil.
House plants constantly exposed to cigarette smoke accumulate a layer of particulate matter, which according to Cynthia Galloway, botany professor at Texas A&M, could potentially clog the stoma. These are the pores in the plants' leaves which absorb oxygen. Blocked stoma will contribute to the suffocation of a plant.
Few clinical studies are available documenting how cigarette smoke affects plants. But several students have published the results of their experiments on the internet. These classroom studies show consistently detrimental effects upon leaf growth over the long term. Observed problems in the exposed plants include fewer leaves, stunted leaves and mutated leaves. Leaves tended to wilt and brown sooner as well, leading the students to believe that plant death would occur if the experiments continued.
Though not transmitted by cigarette smoke itself, the tobacco mosaic virus can affect plants in a smoker's household. The virus can survive at least 50 years in dried plant material, making any tobacco product a potential carrier. Infected plants display a mottled pattern of discoloration and blemishes in leaf and fruit--the "mosaic" from which the virus gets its name.
There's no treatment, only prevention. If you smoke, don't do so while handling plants or tools for plant care. Wash your hands thoroughly after smoking. And, should your plants display signs of infection, get rid of them and any plants adjacent to them.