Deon du Plessis

I wasn’t out to eavesdrop on a whole damn country. But somewhere along the line that’s what happened.

As a linguist I probably spend more time than most listening – really listening – to how people speak. It isn’t just about what they say, but about how they say it. It’s about how the air fills the space between their teeth and tongues.

I especially love vowels. Those sounds that fill the weight of our identity, upbringing, geography… In some of my research, they’ve been whispering stories of South Africa’s complex regional past. And its audible present.

I analysed South African English, a broad category of English that that assumes that it is spoken the same all over the country. Or worse, assumes that it’s “supposed” to sound like British English. The consensus reached by several mid-20^th century scholars, such as Anthony Traill and more extensively Len Lanham and Roger Lass, was that South African English “standardised” in the mid-20^th century and there was no more regional variation, no more dialects, especially among younger speakers.

This supposed “neutral” English, used in schools and on the news, was thought to have flattened out any trace of where people came from. (Of course, there has always been variation based on speakers’ social class, ethnicity, and that kind of thing, so please bear in mind that I am talking specifically about region and mother tongue speakers here.)

But the thinking goes that dialects would emerge again at some point in time. Language is often messier than we’d like to think.

I spoke with people from Cape Town, Durban, and Johannesburg and looked at the vowels in words like trap, dress, and kit. I recorded these interviews and plotted (as on a Cartesian plane) people’s vowels. I wanted to see if any of the earlier regional variation survived. Or resurfaced.

It did.

The interesting thing is that it seems in South African English, dialects are not only in the process of reemerging, but they are remarkably similar to what they were before being levelled into one, non-regional thing. This actually corresponds quite closely to what happened in Martha’s Vineyard, an island off the coast of Massachussets, USA, where people started speaking more like those on the mainland until they didn’t.

For example, Capetonians say the “a” sound like you get in the word trap markedly “lower”. In the International Phonetic Alphabet (IPA)’s terms, you’d write it [æ], and you could also say it sounds more like “a” and less like “e” (you can listen to what I mean here and here, but note that the difference is exaggerated a lot). And in Durban, people said the “i” in the word “kit” in the middle of their mouths, not the front like people mostly would (listen here and here).

These differences might seem subtle, but they are not meaningless. Regional differences in South African English have not been erased – they have only learned to be more subtle.

This kind of work always brings me back to the masters who laid the foundation. One is Raj Mesthrie, one of the greatest South African linguists. (It’s also worth saying, he’s just a really nice guy.) A few years ago I had the privilege of contributing to a volume, also known as a festschrift, in honour of Raj. The chapter I wrote drew heavily from Roger Lass’s (1990) work which was from 25 years earlier. Roger was a mentor of Raj’s. It’s a rule of thumb that there are around 25 years between different generations, so it was good that we could get that one-generation-depth.

People have thought that there is no more regional variation in South Africa, that there are no more dialects, but that seems to be wrong. Something that is undeniable is that how we use language, its variation and nuances, expresses who we are. Maybe that’s the most human thing about language. It’s never really settled. It’s always in motion. Like us.

Bveledzani Pertunia Makhado

South Africa is faced with many social development challenges such as safe water, clean energy and delivery of health services. With the increase in population, comes an increase in the demand for clean water. Currently, researchers are considering the application of nanostructured materials for water purification processes. Nanomaterials have gained significant attention in water treatment applications because of the benefits they offer. They can transform the filtration process towards cleaner and safer drinking water by removing numerous impurities. 

Nanomaterials are tiny particles, often smaller than the width of a human hair. Their size is measured in nanometers—a billionth of a meter. This minute size gives them unique properties, making them incredibly effective in water treatment. For instance, their large surface area relative to their volume allows them to capture and neutralize harmful contaminants in water, including heavy metals, bacteria, and viruses with greater efficiency than traditional methods such as chlorination, Ozonation, UV radiation. These nanomaterials can adsorb and eliminate contaminants from water, resulting in cleaner and safer water. In addition, nanotechnology can be used to construct improved filtration systems capable of removing even microscopic particles and germs from wastewater. 

Despite their impressive benefits, nanomaterials come with significant safety concerns. One of the primary concerns is that these tiny particles might be released from the filtration membranes and enter the water supply, which could be dangerous if the materials are toxic. The possibility of these nanomaterials being released during the filtration process poses a health concern due to the knowledge gap regarding the toxicity of nanomaterials to humans and other organisms. 

Reports have shown that some nanomaterials are hazardous, while others are not. The toxicity of nanomaterials is influenced by their chemical composition. Understanding the toxic effects of these nanomaterials is crucial for understanding associated risks and formulating appropriate regulations and guidelines for their safe application and monitoring in wastewater treatment.

Scientists often overlook the side effects of the use of nanomaterials in water filtration processes, but it is essential to avoid secondary pollution. There has been a lack of research in this area, possibly due to the focus on short-term experiments performed on membranes that have not yet been applied at a commercial scale. Therefore, the research focus may need to shift to studying the release of nanoparticles from water filtration membranes, as well as the resulting environmental effects and risks to human health once these membranes are commercialized. 

To address these concerns, scientists and regulatory agencies are working to develop guidelines for the safe use of nanomaterials in water treatment. They use advanced techniques such as mass spectroscopy, UV-Vis spectrometry, and electron microscopy to study how these nanomaterials interact with pollutants and detect any potential leakage of nanoparticles into the filtered water and their toxic effect on human health and the environment. Organizations such as the Organization for Economic Co-operation and Development (OECD) and the International Organization for Standardization (ISO) are involved in setting safety standards. These standards help ensure that any exposure to nanoparticles remains within safe limits, protecting public health. 

Understanding the toxicological effects of nanomaterials is important for implementing and monitoring their use in various industries. This helps ensure their safe utilization and minimizes potential adverse effects. Understanding these effects also plays a key role in developing safer and more efficient methods for incorporating these materials into wastewater treatment processes. Continued research and regulation are crucial in ensuring the safe and responsible use of nanomaterials. As our understanding of the potential risks and benefits of these materials deepens, we can develop more effective and safer water treatment solutions. Through responsible research and regulation, we can fully exploit the potential of nanotechnology, creating a safer and healthier future for everyone. My research examines the release of nanomaterials from water filtration membranes during membrane fabrication, cleaning, and water filtration and how they can be optimized for safer and more efficient water treatment. We also investigate the toxicological effects of these nanomaterials on human health using in vitro studies. This work aims to contribute to the development of safer and more effective water treatment technologies that harness the benefits of nanomaterials while mitigating their risks.