Plastic straws are getting all the attention lately, with cities like Vancouver and Seattle banning the use of them. Even major corporations like Starbucks and McDonald's have jumped on the environmental bandwagon and implemented their own plastic straw ban, citing ocean pollution.

But there is a worse polluter floating in the ocean, damaging habitats, poisoning fish and costing tax dollars for cleanup and disposal, according to environmental experts.

A report by NBC News named cigarette butts as the single greatest source of ocean pollution - surpassing plastic straws. The filters in cigarettes are made of tiny plastic particles that take decades or more to decompose. And they serve no use. According to a World Health Organization (WHO) report, cigarette filters were created in the 1950s by the tobacco industry in an effort to make smoking a "healthier" alternative to unfiltered cigarettes.

"As we now know, claims that filtered cigarettes were 'healthier' were fraudulent," the WHO said in its report. And while the banning of plastic straws is gaining momentum, some experts believe the focus should be on cigarette filters as well.

A campaign, called the Cigarette Butt Pollution Project, hopes to "eradicate" cigarette butts and tobacco waste from the environment. According to the project, out of the 5.6 trillion cigarettes that are made with these filters each year, almost two-thirds are dumped irresponsibly.

"Tossing a cigarette butt on the ground has since become one of the most accepted forms of littering globally and borders on a social norm for many smokers," the WHO said in its report, adding that around 680 million kilograms of tobacco waste litters the world each year.

Tobacco product waste also contains over 7,000 toxic chemicals, including known human carcinogens, which leach into and accumulate in the environment, the WHO stated.

"This toxic waste ends up on our streets, in our drains, and in our water. Research has shown that harmful chemicals leached from discarded butts, which include nicotine, arsenic, and heavy metals, can be acutely toxic to aquatic organisms," the report said.

In February of last year, California politician, Mark Stone introduced legislation that would prohibit cigarette butts that contain a filter.

"California has strong laws to deter people from littering, but in spite of the threat of having to pay up to 1,000 dollars in fines and cleaning up litter for up to 24 hours, people continue to discard cigarette butts on roadways, in parks, in gutters, and other places in their communities," the legislation stated. "In annual ocean cleanups in 2016, cigarette butts remained the top collected item of litter in California, in the United States, and internationally."

The bill was not passed, but despite this, Nick Mallos, director of the Trash Free Seas campaign for the Ocean Conservancy, said, it clearly indicates that the issue is moving forward.