According to Tobacco Atlas, a partnership between the American Cancer Society and Vital Strategies, 5.7 trillion cigarettes are sold worldwide each year. That’s more than 15 billion cigarette butts every day, 65% of which are intentionally thrown away, according to Keep America Beautiful.
These inch-long, non-biodegradable filters, along with the tobacco in a cigarette, contain more than 7,000 chemicals, according to the US Surgeon General’s 2014 report on tobacco and health. More than 50 of them are carcinogenic. And a study by Imperial College London showed that they contribute more than a million tonnes of microplastic waste each year. Research also shows that these toxic substances eventually find their way into our food and water supply, with negative impacts on human health and the environment.
Just having them on the ground is dangerous, according to Thomas Novotny, a medical epidemiologist and executive director of the Cigarette Butt Pollution Project.
“These filters act like a little tea bag where the chemicals seep out,” Novotny said. “If they have leftover tobacco on them, it’s even worse.”
When a cigarette butt gets into the environment, it can kill. In a laboratory study, eight cigarette butts were soaked in about 8½ cups of water for 24 hours. The fish were placed in this leachate stock and by the fourth day half of them were dead.
On land, children and pets often pick up cigarette butts from the ground and ingest them. Poison Control has received more than 700 calls nationwide regarding cigarette butt ingestion in the past three years; nearly 90% of these incidents occurred in children under 2 years of age. Eating a single cigarette butt can be toxic to a child under 6, says Poison Control
These chemicals can seep into the soil and contaminate soil and groundwater. Heavy metals such as cadmium are dangerous and cannot be destroyed, but are easily taken up by plants such as root and leafy vegetables.
“It’s a vicious circle, what we do every day with our environment,” said Ana Navas-Acien, professor of environmental health sciences at Columbia University’s Mailman School of Public Health. “We eat, breathe and drink toxic products, leading to premature death and disease.”
Chemicals from cigarette butts can also build up in animals’ bodies, which means they can work their way through the entire food chain.
“Chemicals are leached into an aquatic environment,” Novotny said. “Animals down the food chain such as microorganisms are absorbed by filtration by a clam or an oyster. Then the birds eat that, and it becomes food for another animal, and maybe even for us.
Birds are known to incorporate discarded filters into their nests. Novotny said it had two results. First, the bird has fewer parasites or fleas because nicotine is a natural pesticide. Unfortunately, he said, cigarette butts also cause DNA damage.