The Herb

• Nicotine is a naturally occurring chemical in the leaves of the tobacco plant. Nicotine comprises 0.3 to 0.5 percent of the dry weight of tobacco leaves. It is produced in the roots and then transferred to the leaves. It is a neurotoxin that can be deadly in mammals if ingested, and it acts as a stimulant in smaller quantities. The leaves are cured and dried for use in cigarettes, chew and snuff. It is the most widely grown nonfood crop in the world.
  
  

Nicotine in the Environment

• Nicotine is a secondary metabolite, which means it has no primary function in a plant's metabolism. It does have an ecological role as defensive compounds against pests and has the ability to accumulate to some degree in the primary metabolites. Secondary metabolites are not widely available but do build up over time. However, nicotine has a half-life of only half a day in soil, which is not a convincingly long period for toxic buildup. In water, it persists for three days, and studies have shown it to have negative effects on aquatic life.
  
  

The Filter

• The filter may be the biggest problem with cigarette butts in soil and near plants. The filter is made of cellulose acetate, a type of plastic that doesn't degrade well. The purpose of the filter is to catch impurities and some of the toxins that result from smoking. The filter will have an accumulation of these toxins, which can leach into soil. These toxins may include but are not limited to formaldehyde, menthol, preservatives and any combination of 1,400 different potential additives, some of which are organic and others inorganic. It can take up to 15 years for a butt to degrade, and it will be leaching these chemicals into soil during this period.
  
  

Beneficial Affects of Nicotine in Plants

• Nicotine has been used as an insecticide since the 1600s. The substance is both a repellent and a toxin to some smaller life forms. It is compatible with other insecticides and fungicides and has little effect on beneficial insects. It is primarily used on sucking insects that affect crops. Nicotine is marketed in the United States as an alkaloid and sulfate. The alkaloid is a fumigant, and the sulfate is a liquid. Most of the nicotine processed for this use is produced in other countries, especially India.