First Thing, Daily Maverick's flagship newsletter

Join the 230 000 South Africans who read First Thing newsletter.

We'd like our readers to start paying for Daily Maverick

More specifically, we'd like those who can afford to pay to start paying. What it comes down to is whether or not you value Daily Maverick. Think of us in terms of your daily cappuccino from your favourite coffee shop. It costs around R35. That’s R1,050 per month on frothy milk. Don’t get us wrong, we’re almost exclusively fuelled by coffee. BUT maybe R200 of that R1,050 could go to the journalism that’s fighting for the country?

We don’t dictate how much we’d like our readers to contribute. After all, how much you value our work is subjective (and frankly, every amount helps). At R200, you get it back in Uber Eats and ride vouchers every month, but that’s just a suggestion. A little less than a week’s worth of cappuccinos.

We can't survive on hope and our own determination. Our country is going to be considerably worse off if we don’t have a strong, sustainable news media. If you’re rejigging your budgets, and it comes to choosing between frothy milk and Daily Maverick, we hope you might reconsider that cappuccino.

We need your help. And we’re not ashamed to ask for it.

Our mission is to Defend Truth. Join Maverick Insider.

Support Daily Maverick→
Payment options

Fish in major South African river have microplastics co...

Our Burning Planet


Fish in major South African river have microplastics coursing through them

The Vaal River at dusk. (Photo: Nana Cilliers)

Plastic particles are becoming vehicles for toxic elements and organic contaminants which subsequently rise through food chains.

We are living in the plastic age. Plastics are literally everywhere: clothes, furniture, computers, phones and more contain plastic materials. It’s no wonder, then, that the food we eat, the water we drink and even the air we breathe is contaminated with microplastics.

These tiny plastic particles are smaller than 5mm in diameter. Some, known as secondary microplastics, are formed from the breakdown of larger plastic items. In natural environments like rivers, plastics are exposed to different degradation processes driven by thermal, chemical, microbial and mechanical forces.

Primary microplastics, meanwhile, are manufactured at microscopic size to be used as fibres, films, foams and pellets, among other things. It is estimated that between 0.8 and 2.5 million tonnes of microplastics are released into the global marine system per year.

Once they’re in oceans, lakes, rivers and other bodies of water, microplastics absorb toxic elements and organic contaminants. Their small size and large surface area mean that microorganisms such as bacteria and fungi may also attach and colonise on them. This all makes microplastics a cocktail of contaminants.

Globally, microplastics research is still in its infancy as the scale of the problem has only become apparent in recent years. The knowledge gap is especially high across Africa. That’s worrying: the continent is home to some of the largest and deepest of the world’s lakes and notable rivers, but not much is known about the extent of microplastics in African freshwaters.

It is also difficult to assess the environmental and public health risks linked to microplastics. That’s because scientists are still learning about how microplastics move through various pathways and where people are most vulnerable to exposure.

In an attempt to bridge this gap, we recently studied common carp fish collected from South Africa’s Vaal River. It’s a major freshwater body of significant economic value that, the country’s Department of Water and Sanitation says, “supports almost 50% of South Africa’s gross domestic product”. The river supplies water for drinking, agriculture and industries and services to around 11 million people in the Gauteng, Mpumalanga, North West and Free State provinces.

Our findings were troubling. We took samples from 26 fishes’ digestive tracts and found a total of 682 particles — ranging from seven to 51 particles per fish. That means the river is considerably polluted with microplastics. This isn’t just potentially bad news for people’s health; it also has huge economic implications because the Vaal and similar water bodies are used for agriculture, breeding livestock and recreation.

Toxicity and risk

South Africa has a vibrant plastic manufacturing industry. Recycling, though, is limited. The country is ranked among the top 20 countries with the highest mass of mismanaged plastic waste — and a notable proportion of that enters the aquatic environment.

Many of the microplastics we recovered from our samples were small, coloured (dyed) and fibrous (the particles have a slender and elongated appearance). Those are worrying characteristics because studies have shown that several aquatic organisms are drawn to and consume small, coloured and fibrous microplastics, which resemble natural prey.

Their greater surface area means that smaller microplastics absorb more pollutants from the water that their larger counterparts, resulting in additional health risks. Research has also found that the smaller the microplastics the more likely they are to end up in aquatic organisms’ muscles and livers. That makes them more harmful to the animals. And their fibrous shape means they’re easily embedded in tissue. So they spend longer in an animal’s intestines and become more toxic.

Finally, coloured microplastics are particularly toxic because of the colouring agents used during the plastic manufacturing process.

Awareness and improved policies

Many people are simply not aware of what microplastics are, nor how they might cause harm. During sampling, we met some people who were fishing; others were cooking and eating fish along the banks of the Vaal River while they fished. They were interested to know what we were doing and admitted they’d not heard of this issue before.

Microplastics: An image of fish from the Vaal River being cooked.
People cooking freshly-caught fish on the banks of the Vaal River. (Photo: Dalia Saad)

This emphasises the importance of social awareness and public education. Public awareness strategies could include a wide range of activities designed to persuade and educate, perhaps beginning with early grade school curricula. It is important to extend the message beyond reuse and recycling to the responsible use and minimisation of waste. People should also be taught about the risks involved in using plastic for water or food storage.

Making people aware of these issues is key to creating public pressure to demand effective waste regulations. This is important because the negative effects of microplastic pollution are not limited to the bio-physical elements of the environment — they have implications for social and economic systems.

Rivers and lakes are used for transport, agriculture, breeding livestock and recreation. The productivity, viability, profitability and safety of these sectors are highly vulnerable to plastic pollution. Microplastics pollution is as much a social concern as it is a scientific one. DM

The author would like to acknowledge her students who conducted the study with her: Patricia Chauke, Gibbon Ramaremisa, and Michelle Ndlovu.

Dalia Saad is a researcher at the School of Chemistry, University of the Witwatersrand.

First published by The Conversation.

Absa OBP

Comments - share your knowledge and experience

Please note you must be a Maverick Insider to comment. Sign up here or sign in if you are already an Insider.

Everybody has an opinion but not everyone has the knowledge and the experience to contribute meaningfully to a discussion. That’s what we want from our members. Help us learn with your expertise and insights on articles that we publish. We encourage different, respectful viewpoints to further our understanding of the world. View our comments policy here.

No Comments, yet

Please peer review 3 community comments before your comment can be posted