Do cigarette filters deliver what they promise?

"Filter" evokes cleanliness and safety. Many believe that these cigarettes components retain toxins and protect health. But the facts show otherwise.

A (very brief) history of cigarette filters

• They were first used in the USA in the 1860s to keep loose tobacco out of smokers' mouths.
• In the 1930s and 1940s, filters were marketed to protect smokers from "poisons" such as nicotine.
• Cigarette filters are mainly made of plant-based plastic (cellulose acetate) and are not easily degradable.
• It is estimated that around 0.3 million tonnes of cellulose acetate filters are disposed of worldwide every year. For decades, they have been the most frequently collected waste during beach and city clean-ups.

Do cigarette filters protect against harmful substances?

The harmful effects of cigarette smoking have been known for decades. The filter is at least a little reassurance for many smokers. However, the safety claims made by the tobacco industry do not stand up to scientific evidence.

A few facts:

• As early as the 1930s, cellulose acetate filters were evaluated by industry researchers. The results indicated there is hardly any difference in nicotine content between normal and filtered cigarettes.
• In an internal note from the Philip Morris company in 1958, scientists declared the selective filtration of harmful compounds to be "a thermodynamic impossibility".
• Nowadays, some filters contain activated carbon. Although it can remove some chemical substances, it cannot remove particles or carbon monoxide.
• Overall, there is growing evidence that "filters" are not able to eliminate toxic tobacco chemicals.

But the industry is resourceful. Another innovation to supposedly reduce the tar and nicotine content is filter ventilation in the form of small holes through which the smoke is supposed to be diluted. However, as smokers need to ingest enough nicotine to "get the kick", they draw all the more strongly on the ventilated filters (so-called compensatory smoking), which ultimately cancels out any (questionable) benefits of filtered cigarettes.

What is the impact of cigarette filters on the environment?

These findings alone are sobering enough. However, there is an even greater danger posed by cigarette filters that is only slowly being recognised by scientists and the public: the damage to the environment. Here, too, there are some insightful data:

A cigarette filter consists of 12,000 to 15,000 strands of cellulose acetate. With almost 6 trillion cigarettes sold worldwide every year and a market share of filtered cigarettes of 99.8 % (in the USA), that's a lot of rubbish. Carelessly disposed of in bodies of water and on land, the fibres can spread unhindered through ecosystems.

In a laboratory study of fresh and salt water washouts of cigarette butts, around 800 chemical components were detected. In addition to nicotine, these also included diacetin and triacetin, which are used as plasticisers in the manufacture and attachment of the filters. It is now also known that discarded cigarette butts are a significant source of microplastic waste in the environment.

In light of this, the study authors argue that the so-called "filters" should no longer be labelled as such, but as what they are: Product additives that can cause considerable damage.

A call for a ban on cigarette filters

The scientific community agrees that filtered cigarettes do not reduce the health risks of smoking and can also damage ecosystems. The WHO, public health researchers, and environmentalists are therefore calling for a ban on the sale of disposable cigarette filters. Nevertheless, the myth of the protective effect of filters persists. A lot of educational work is still needed here, including on the part of physicians.