When you smoke a cigarette, you create a cloud of up to 4,000 chemicals including tar, carbon monoxide, pesticides and formaldehyde. Part of this cloud goes into your lungs, coating the cilia with a sticky layer of chemicals containing 43 known carcinogens. The other part of this toxic cloud spreads out into your environment, coating walls, carpets, furniture and plants. Just as cigarettes are harmful to humans, cigarette smoke harms plants' growth by interfering with their respiration, photosynthesis and nutrition uptake.
Plants breathe oxygen through small pores under their leaves called stomata. When someone smokes around plants regularly, the cigarette smoke leaves a fine layer of particles all over the plant's surface. If a lot of this smoke dust builds up on the leaves, the stomata can get clogged and make the plant's respiration less effective. Another part of plant respiration is absorbing carbon dioxide and releasing oxygen. When the leaves and stem are covered in cigarette smoke dust, they cannot release oxygen properly, preventing them from absorbing new carbon dioxide.
Photosynthesis is the process plants use to create nutrients from light. Plants absorb light through the surface of their leaves. If the leaves are covered with a layer of cigarette smoke, the plant receives less light and begins to starve. Growth and development are affected as the plant begins to compensate for the nutritional deficiencies.
In addition to the nutrition they create from light, plants take nutrition from the soil through their roots. The carbon monoxide in cigarette smoke harms beneficial microorganisms in the soil and affects root function. Carbon monoxide can interfere with the plant's ability to absorb nitrogen by killing the bacteria that fix nitrogen in the soil. Roots can absorb carbon monoxide, resulting in less oxygen and fewer nutrients for the plant.
If a plant doesn't get enough oxygen, it can cause poor root growth or make the plant weak and discolored. Plants with root damage may not be able to take water effectively and can wilt. Plants that suffer from lack of light can lose their leaves, turn yellow, or grow tall and spindly as they try to grow closer to the light source. Lack of adequate nutrition slows plants' growth and might stop them from blooming. The effects of chemicals in cigarette smoke are not immediately noticeable, but if a plant becomes heavily coated with cigarette smoke, it can slowly die from starvation, oxygen deprivation and lack of water. If there is a smoker in your house, you can help your plants by wiping their leaves clean once a week to remove smoke particles and dust.