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Pesticides and chemical fertilisers are the silent killers in our food chain — and they’re wiping out wildlife


Dr Andrew Venter is the director of the Cambridge Institute for Sustainability Leadership’s operations in South Africa. Venter joined CISL SA from WILDTRUST, where he was chief executive for 19 years. Over this period, he led the development of WILDTRUST into one of South Africa’s largest and most influential environmental organisations.

In 1962, Rachel Carson exposed the environmental impact of DDT in her book, ‘Silent Spring’, catalysing one of the world’s first major environmental movements. Nearly 60 years later, our continued addiction to chemical fertilisers and pesticides continues to exact a terrible toll on wildlife and human health.

This article forms part of Roving Reporters’ The Future We Want Series. Read more at

I recently had the privilege of witnessing a biodiversity “spectacular” at the Karkloof Conservation Centre, nestled in the foothills of KwaZulu-Natal’s Karkloof Mountains.

As the sun sets, flocks of majestic wattled and sonorous grey-crowned cranes flew in from the surrounding countryside and settled in the shallow waters of a local pan. We were entranced by their beauty, their aerial prowess, distinctive calls and grace. The wattled crane is particularly majestic, with mature adults standing up to 1.7m.

We were joined by more than 10% of South Africa’s wattled crane population. The tragedy is this equated to about 30 birds.

Between 1970 and 2000, the South African wattled crane population crashed to fewer than 200 birds. To blame was the conversion of their habitat for agriculture, the use of toxic fertilisers and pesticides, and the proliferation of power lines across their airspace. Since 2000, intensive conservation efforts have led to a 50% recovery, with about 300 birds today, a notional success by any standard.

The wattled crane is our “canary” in the coal mine. Growing up, I was told stories of coal miners taking canaries with them underground. The birds were more vulnerable to toxic air than the miners and would die first, warning the miners to escape.

A century of bad farming practice, anchored by the indiscriminate use of toxic chemicals and the destruction of grasslands, forests and river systems, has transformed vast areas of our planet into sterile, unproductive and often toxic landscapes.

Many of us know about DDT (Dichlorodiphenyltrichloroethane), which was developed as an insecticide and is globally infamous for its environmental impacts. It was discovered by a Swiss chemist, Paul Hermann Muller, who was awarded a Nobel Prize in Physiology or Medicine in 1948 “for his discovery of the high efficiency of DDT as a contact poison against several arthropods”.

Contemporary scientists opined that DDT would lead to environmental destruction on a scale not seen before, but were ignored in the face of the early success of DDT in eradicating malaria and its ability to suppress insect activity. Widely touted as a miracle insecticide, its use grew exponentially, leaving a trail of long-term environmental destruction globally.

In 1962, Rachel Carson exposed the environmental impact of DDT in her book, Silent Spring, catalysing one of the first environmental movements anchored by a campaign to ban DDT.

Since then, clinical studies have demonstrated that DDT is not only environmentally destructive but also extremely dangerous to humans. Side effects range from decreased fertility to pancreatic cancer and autism in children whose mothers were exposed to the chemical during pregnancy. Tragically, it is still used widely in 14 countries, including India and China.

We’re addicted to using herbicides and pesticides, but don’t understand the toxic impact of these chemicals on our environment and personal health.

Any activities that put short-term yields and profits ahead of the long-term implications for the environment and public health will come undone – as they eventually undermine the resilience of our human and natural systems.

Perhaps the best known more recent example is Glyphosate. It was discovered in 1970 and is currently the world’s most widely produced herbicide by volume. This is despite growing scientific evidence of the risks it poses to human health and a series of US court cases that have found that Glyphosate causes cancer.

In South Africa, this chemical is used widely to suppress the growth of “weeds” and is actively promoted in association with the use of genetically modified (GM) cotton, soya and maize designed to withstand the impact of this chemical. As the body of evidence grows, demonstrating the impact of Glyphosate, we’re likely to see a reduction in its use, eventually condemning it to infamous celebrity “killer” status alongside DDT.

The question is… why are we willing to expose our lives and those of our loved ones to experiments of this kind?

Angus McIntosh, a well-known regenerative farming activist, is outspoken in this regard. He says glyphosate can be found “in every loaf of bread sold in every shop in this country” and “in all processed foods, tinned foods and ready-made meals”.

He points out that, in the form of Roundup, it is widely used as a weed killer beyond our farming community, mentioning its use by Kirstenbosch Botanical Gardens and the Johannesburg Zoological Gardens, to make his point.

We have to do better.

Before World War II, successful farmers were those who understood their natural environments, “listening” to their soil, “respecting” their water supplies and “honouring” the interconnectedness of their activities with the natural world.

Since then, we’ve seen the farmers that embrace these values sidelined by corporate interests — promoting “modern” farming anchored by the use of pesticides, herbicides and genetically modified crops. The impact has been devastating, through the poisoning of soils and water systems, and destruction of biodiversity.

As our society reflects on the journey forward, recovering from the Covid-19 pandemic and preparing for the system shocks that are coming as global warming accelerates, we have to find a better way to live on this planet.

Any activities that put short-term yields and profits ahead of the long-term implications for the environment and public health will come undone – as they eventually undermine the resilience of our human and natural systems.

We need to reflect on the majestic beauty of the wattled crane, its challenge to survive in the world we’ve created and the lessons we’ve learnt in our fight to save it. DM

This article is part of The Future We Want Series launched by the CISL and Roving Reporters in response to the Covid-19 pandemic.

Karkloof Conservancy has two hides, open from 5am to 6pm, seven days a week. Bookings are not necessary for the day, but are required for the evenings when the cranes come in to roost. To book email [email protected] or call 076 1476 686.


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