Micro plastics are found almost everywhere on Earth, from deep ocean sediments, to remote mountain lakes and in atmospheric fallout.
Professor Henk Bouwman and his team at the Unit for Environmental Sciences and Management at North West University found microplastics, too, in rivers running through developed parts of Gauteng and in the North West.
They collected and filtered 46 fresh water samples from various localities in and around Gauteng.
“High levels of plastic pollution were found in almost all samples. Up to 40 plastic particles per litre were found in the surface water of the Vaal River, a major river in the country’s largest drainage basin flowing through industrialised areas,” Bouwman and colleagues Carina Venter and Karin Minnaar write for a poster, “Cause and Effects of Plastics in SA as a Developing Country”.
These levels, they say, are comparable to high levels of microplastic pollution found in European rivers.
Microplastics are plastic particles less than 5mm long that have been found in a broad spectrum of locations across the globe, say the researchers. “Microplastics can be manufactured, for example, as microbeads, or formed by the breakdown of larger plastic pieces. Polymer fibres used in textiles are also fragmented due to mechanical breakdown and end up in aquatic systems when the textiles are washed.”
The team’s pioneering study, funded by the Water Research Commission (WRC), aims to quantify microplastic pollution in rivers running through developed areas in Gauteng and North West.
“This is the first freshwater study to our knowledge that quantifies microplastic pollution in South Africa and is the first riverine microplastic study in South Africa.”
In an article in the latest edition of The Water Wheel, a publication of the WRC, they reveal how they are investigating the presence of microplastics in the drinking water of four different municipalities - Ekurhuleni, Mbombela, Tshwane and Tlokwe.
“The preliminary results confirmed the presence of microplastics in the municipal water of all four cities, Bouwman states in the article.
“One municipality had the highest number of 15 particles per litre of tap water and another the lowest average of only four particles per litre. Water tested at the two other municipalities contained eight particles per litre.”
As South Africa is a water-scarce country, the researchers state in their poster that contamination of water with plastic could have a much greater effect on human and environmental health as the “dilution effect” is not as strong.
In a commentary piece last year on the current understanding of risks posed by microplastics in the environment, the team of local researchers note how when microplastics-contaminated water and soil are used for drinking and crop production, water and food security, as well as the well-being of the population, may be affected negatively.
“This direct link between the human population and the environment, now (most likely) also with an increasing microplastic burden, is of concern. South Africa and many other African countries still use persistent organic pollutants such as DDT for malaria control, especially in remote rural areas.
“The links between pollutants in microplastics and potentially more vulnerable rural populations need to be examined. Although the full impact of microplastics on the environment and biota is not yet understood, the potential threats should not be taken lightly.
“Another issue adding to the necessity of microplastics quantication and research in South African aquatic systems, both marine and freshwater, is the country’s rich natural biodiversity.
“Studies are being conducted on the impact of microplastics on biota, but the full extent of this relationship is yet to be understood.
“Recent ndings suggest that organisms at all trophic levels, with a variety of feeding strategies, have the potential to ingest microplastics. If the impact of microplastics on biota is as speculated, a great deal of work must be done in South Africa and the rest of the continent to ensure progress in the eld, and to reduce and/or eliminate sources of pollution.”
South Africa’s low water availability means it is of great importance to safeguard limited water resources, they argue.
“The growing plastics industry in South Africa requires excellence in clean-up and recycling to reduce the negative impacts on the environment and create a viable plastics sector.”
In 2017, the SA plastic industry grew by 1.9%. “The country’s recycling rate for 2016 was 41.8%, of which most was collected post-consumer,” the researchers state in their paper.
“Plastics SA has set an ideal of no plastics to landfills by 2030 and plans are being set in place to achieve this goal. Corporate initiatives to reduce SA’s plastic footprint are taken but efforts in terms of microplastics reduction are lagging.
“Inadequate waste disposal infrastructure and protocols, especially in informal settlements cause large quantities of unrecycled plastic to end up in aquatic systems and subsequently in the marine environment.
“Another obstacle facing the recycling industry is the separation of polymers in a single recyclable product and the costs involved Increasing public, industrial and government awareness will be the key to creating sustainable reduction and recycling efforts.”