A smoke-free advocacy group is calling for tobacco companies to be held legally responsible for parts of cigarettes that are unsafe for the environment.
New research in the Tobacco Control Journal shows 98 percent of all cigarettes contain filters made of plastic that is not biodegradable.
Smokefree Coalition executive director Prudence Stone said it was possible up to 4 trillion of those butts were discarded by smokers worldwide each year.
"Now the Ministry of Health can look to the Ministry for the Environment and see partnership there, in a framework that sees the damage done to our shared environment, it's not just a health issue anymore, tobacco is an environmental issue as well."
She said she wanted regulations that forced the tobacco industry to be legally responsible for the environmentally unsafe components of cigarettes.
Dr Stone said the Ministry of Health could join forces with the Ministry for the Environment over the issue.