Pesticides and fertilisers are used intensively in South African agriculture in an effort to increase crop yields and prevent crop failure. However, environmental experts warn that these substances are often transported and contaminate water, both ground and fresh.
According to environmental advisor, Dr Anthony Turton, pesticides and residues (also nitrates and phosphates) can easily make their way into water sources, posing a risk to irrigation crops and animals. This is especially the case in rural areas.
“At least 65% of our (SA) water resource is contaminated. Irrigation and animal production from contaminated water are at risk,” Turton told Food For Mzansi.
According to a report by the Food and Agriculture Organisation of the United Nations, agriculture, which accounts for 70% of water abstractions worldwide, plays a major role in water pollution.
Microcystin poses a toxic threat
Farms discharge large quantities of agrochemicals, organic matter, drug residues, sediments and saline drainage into water bodies. The resultant water pollution poses demonstrated risks to aquatic ecosystems, human health and productive activities.
“The big issue to be aware of is microcystin, which is the toxin that comes from blue-green algae, that is known to transmit into produce via irrigation,” Turton said.
Blue-green algae build up in fresh or marine water if water temperatures, light conditions and nutrient levels increase and water flows are low. It is toxic and can affect humans and animals.
However, Turton said the exact nature and quantum of the risks to crops, animals and humans is not known yet.
Rural areas at risk
Another major problem is that there is still a significant amount of rivers and dams with untreated water. If the government and other role players’ slow pace in addressing the increasing sewage spillages into rivers and dams continues, Turton said he feared that matters could only get worse.
A report by the Water Research Commission on the contamination of resources by agricultural chemicals indicated that while the sector continues to be the biggest employer, it was also contributing to the pollution of water.
According to the report, pesticides are used intensively in South Africa and widespread occurrence of different agricultural chemicals in water resources has been identified.
“The major concern is the fact that humans and animals living in most rural and some urban areas are still dependent on untreated water for drinking.”
The problem with pesticides
“Most of the pesticides which are being applied are of high qualities and highly toxic, which end up in the streams and expose many ordinary people,” the report stated.
Pesticides are potentially toxic to humans and can have both acute and chronic health effects, depending on the quantity and the ways in which a person is exposed.
Furthermore, the report stated that based on the movement rating of each pesticide, almost two-thirds of pesticides have the potential to reach water resources such as surface and groundwater.
“Pesticides which put human health at more risk are those pesticides which have high weighted toxic potential and are highly mobile,” the report said.
What does the law say?
Can farmers be penalised if found contaminating natural resources?
Yes, in fact, there is legislation built around this but because of the poor water quality in South Africa, implementation of the legislation is poor, Turton explained.
“Legislation is in existence, but the state as regulator has failed. This means that the legislation is no longer capable of protecting the consumer or the farmer,” he said.
Turton said the long-term effect of contamination is the impact it will have on the economy and food security.
“We are aware that agriculture is the biggest employer and thus losing those thousands of jobs could be detrimental for the country,” he said.
Turton has made a fresh call to new entrants in agriculture to reduce the number of chemicals they expose to natural water resources. It is important that farmers learn and adopt safety standards when it comes to the use of pesticides and fertilisers, he added.
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