Brushing away pollution

By: Dr Anas Hakimee Ahmad Ubaidillah, Dr Mohd Azmi Abdul Razak, Dr Nur Diyana Mohamed Radzi

Have you ever stopped to think about what happens to your toothbrush after you throw it away? This everyday item, used daily for maintaining our oral hygiene, often ends up in landfills, contributing to an increasing environmental crisis. The thing is, we use a lot of them!

Having professionals recommend changing toothbrushes every three to four months, imagine the amount of plastic waste this habit has produced. What is supposed to be a hygienic habit ends up polluting and hurting our planet more. If you missed out, June 5th marks the World Environment Day and as inhabitants of this planet, it’s crucial to reflect on the impact of our daily habits and consider how small changes can lead to significant environmental benefits.

Toothbrushes, typically made from plastic, are not biodegradable. The handle of the toothbrush is commonly made of polyethylene and polypropylene and its bristles are mostly made from nylon as the properties of the material itself can effectively remove plaque and food debris from the surface of the teeth. Once discarded, they can linger in the environment for hundreds to maybe even thousands of years. To put it simply, the toothbrushes you used as a child decades ago are still somewhere in landfills if not drifted away in the ocean. Your toothbrush may exist on this Earth longer than you would.

A recently published study mentioned that the amount of plastics that enters landfills and the environment is sufficient for rebuilding the currently standing Great Wall of China which is about 6000 kilometres long! An observation conducted by researchers from the Faculty of Dentistry, Universiti Malaya observed a significant number of discarded toothbrushes littering the beach of Pantai Marang, Terengganu. This issue is not unique to Malaysia; similar findings have been reported in the United States, where numerous toothbrushes were discovered during beach clean-up efforts. It is expected worldwide that billions of toothbrushes have been discarded to the environment and the numbers will keep on increasing.

So what is this invincible material that we call plastic and why should we care about what happens when we dispose of them? Plastics are made of a wide range of synthetic or semi-synthetic materials composed of polymer-containing compounds. Synthetic plastics are derived from natural gas, crude oil or coal. Plastics do not decompose the same as organic materials. Bacteria transform the organic materials in the soil into other useful compounds through a process known as biodegradation.

This process unfortunately does not happen with plastics. However, in 2008, a 17 year-old Eco-expert from Waterloo Collegiate Institute, Daniel Burd, shocked the world when he made a ground-breaking discovery that certain types of bacteria can break down plastics! His research concluded that plastics that would normally take hundreds of years to degrade can be degraded in as short as 6 weeks with the presence of this specific mixture of bacteria at a certain temperature. That’s good news! Right?

The process however, is not as straightforward as it seems. Not only have other researchers confirmed Burd’s findings, they have also identified several other plastic-eating bacteria. However, none have been effective in practical applications. Until waste treatment plants are equipped to implement these new processes to degrade plastics, the only other option to break down plastic is through photodegradation which is a type of decomposition that requires sunlight instead of bacteria. The sun’s UV rays are able to break the bonds between the long molecular chain that makes up the plastics. Over time, this process will turn big pieces of plastic into lots of smaller pieces. Plastics buried deep in landfills rarely see the light of day, but in the ocean, where a lot of plastics get discarded, bathes in as much light as it does water.

A group of researchers from Nihon University in Chiba, Japan, found that plastic, more specifically Styrofoam, a type of polystyrene plastic, can degrade in as little as a year in warm ocean water. Does that mean our plastic toothbrushes that end up in the ocean degrade faster? Technically, yes. Not as fast as Styrofoam or a grocery plastic bag would, but yes, the toothbrush would degrade faster floating in the ocean than it would be buried in the landfills.

The thing is, plastic never fully degrades. It breaks down into smaller particles which we call microplastics, an extremely persistent by-product. Many studies are coming up emphasizing the impact of microplastics to the environment citing that it may be harmful to the ocean and aquatic life and when these contaminants enter the food chain, it can give grave consequences to humans. Yet another major headache to environmentalists.

Fortunately, eco-friendly alternatives are available to help combat this issue. Bamboo toothbrushes, for instance, are biodegradable and have a much lower environmental impact. Some oral care manufacturers have also introduced innovative toothbrushes made from miswak, a natural, sustainable material traditionally used for oral hygiene in the Muslim community. Toothbrushes with replaceable heads will also reduce plastic waste by allowing users to retain the handle while only replacing the bristles.

These options not only reduce plastic waste but also offer culturally and religiously significant benefits, making them an appealing choice for a greener future. By making small changes in our daily habits, we can collectively reduce the environmental footprint of our oral hygiene routines.

This World Environment Day, themed “Our land. Our future. We are #GenerationRestoration,” serves as a timely reminder of the importance of reducing plastic waste in our daily lives. The day calls for global action to tackle the plastic pollution crisis and to restore the health of our planet. Let’s pledge to make more environmentally conscious choices and go for more sustainable alternatives. The next time you replace your toothbrush, consider the broader implications of your choice, and opt for a more environmentally friendly option

The authors are Lecturers and Restorative Dentistry Specialist in Faculty of Dentistry, Universiti Malaya. They may be reached at anashakimee@um.edu.my