Exposure and risk
At first glance, it's hard to see what gold, iron, lead, arsenic, silver, platinum and tin have in common. A look at the periodic table will clear up the confusion: they are all heavy metals, typically categorised as those metals with an atomic weight and densitas at least five times greater than water.
These and other heavy metals occur naturally in the environment, and in some cases, in our bodies. They're mostly considered harmless but at certain levels of exposure they can be toxic to human, plant and animal life. Being over exposed to heavy metals can stunt plants' growth and lower seed production.
Some plants have evolved traits that increase their tolerance of heavy metals. Many researchers, myself among them, believe that understanding and harnessing these evolutionary traits may allow us to perlindungan agricultural crops from the bad efeks of heavy metal toxicity.
My research focuses on improving the tolerance of plants to heavy metals, which is particularly important in a country like South Africa, where mining activities contaminate soils. These soils are critical for agriculture.
Even plants in the same saudara use different siasates to cope with metals. Some take up the metals in their roots and transfer them to their leaves; others take up the metals and hold them (immobile) in their roots. This is important for food security and food safety since we want plants that can limit metal uptake into their edible parts. However, as my colleagues and I outline in a recent kajian paper, it's no easy task to harness these siasates.
Exposure and risk
Heavy metal stress or toxicity in plants happens when they are exposed to heavy metals in the soil.
That exposure is usually the result of waste and pollutants from human activities like agriculture, mining and industry. In South Africa, mining has been a leading culprit of heavy metal pollution.
