Mention substances that can be found in polluted water
Answers
Insecticides
Insecticides are chemicals that are sprayed onto crops to kill the insects that eat crops. One of the more controversial insecticides is DDT. The use of DDT on crops was used to control the malaria mosquito in South Africa. At certain levels (10 mg per kg) DDT can cause human poisoning with the following symptoms: dizziness, vomiting and convulsions. At lower levels, DDT can affect the development of babies and has been associated with cancer. DDT has been banned in South Africa. Another group of controversial insecticides are the organo-phosphates. These insecticides have been used in the place of DDT since it was banned. Some specialists believe that these insecticides have caused even greater environmental damage than DDT and that they are even more toxic to humans and other mammals.
Insecticides are easily washed by the rain into streams and groundwater where they poison fish and domestic animals. Many insecticides are stored for a long time in the bodies of animals and can end up in the meat, fish, egg and milk that you eat. Fruits and vegetables that have been sprayed with insecticides also remain poisonous for many days afterwards and must be washed very well before eating.
Ask questions about the use of insecticides in your area. Keep a look out for fish or birds that have been poisoned. Dead fish and birds provide a good indicator of chemical pollution. If you suspect pollution by insecticides then contact your local council as soon as possible.
Heavy Metals
Heavy metals such as nickel, molybdenum, zinc, cadmium and lead are mined and processed by the mining and ore-smelting industries, many of which occur in Gauteng. These metals are easily washed into streams and groundwater. Copper and mercury are another two heavy metals, which are found in fungicides. Fungicides are also sprayed on crops and easily washed into rivers. These heavy metals are toxic to biological life including the people who may have to drink from the polluted rivers. Crops that have been irrigated with polluted water can also be dangerous. In a similar way to DDT, heavy metals can also build up in the body causing symptoms of poisoning.
In the past, toxic waste products were dumped into the rivers or into landfill sites close to where people lived causing health problems and even death. Today all South Africans have a constitutional right to a clean and safe environment. Make sure that you remain informed and observant so that you can prevent toxic chemicals from being used in your environment. If you suspect water pollution in your area then contact your local council.
Problem Products
We can find pollutants, soil, chemicals, sewage, chemicals released from factories, some kinds of poisonous sobstances from the chemicals, infectious virus or bacteria, some kind of fungii, harmful microbes, etc.