Freshwater pollution is harmful to human health by causing intestinal illnesses, like malaria, cholera, schistosomiasis, typhoid, liver disease, hepatitis C and all sorts of dysentery, in addition to cases of intoxication. Petroleum, heavy metals and radioactive materials are among the most important pollutants of seawater, rivers, and groundwater. Petroleum contains cancer-causing substances such as benzo a pyrene and other chemicals that pollute the water, such as the pesticide DDT.
Microbial or chemical pollution of water
Microbial or chemical pollution of water is one of the most damaging contaminants to human health.
● Bacterial contamination of water
It has been proven beyond a reasonable doubt that wastewater, if not treated properly, causes serious human diseases, particularly if it enters the drinking water. Bacterial contamination of water is the cause of outbreaks of salmonella and hepatitis C in many countries around the world. Wastewater contains a large number of microorganisms like bacteria, viruses, and parasites, transmitting numerous diseases like cholera, typhoid, and polio. Microorganisms are involved in the transformation of methane, sulfur, phosphorus, and nitrates. Methane bacteria produce methane under aerobic and anaerobic conditions, and mold bacteria produce ammonia which oxidizes to nitrate, which is known as green water and occurs as a green layer of weeds on the surface of water reservoirs, lakes, and marine shorelines, often in stagnant water and causes an obstruction of oxygen leakage into water Increasing green grass causes blue eye disease in children.
● Chemical contamination of water
Water pollution from chemicals can be hazardous for the environment and human health. The main chemicals polluting the water can be summarised as follows:
1- Acidic or alkaline compounds: Acidic or alkaline compounds alter the pH of water. A high pH of the water negatively affects human health and leads to rust and corrosion in the pipes. Alkaline pollution creates salts such as carbonates, bicarbonates, hydroxides, and chlorides.
Calcium, magnesium, and bicarbonate are responsible for the hardness of water, and chloride and sulfate are responsible for the salinity of the water.
2- Nitrates and phosphates: These compounds are responsible for the phenomenon of green water. Green herbs consist of algae and are made up of carbon, nitrogen, and phosphorus elements. It should be noted that nitrate combines with hemoglobin and prevents oxygen from combining with it, causing choking.
3- Heavy metals: The most commonly used heavy metals in wastewater are lead and mercury. Lead leakage in water mains causes brain damage, particularly in children. Mercury is present in water in the form of mercury sulfide, which is insoluble and exists organically in the form of phenol and methyl, The most harmful of which is methylmercury, which causes paralysis of the nervous system and blindness. In fish, methylmercury accumulates at high concentrations due to pollution and passes from fish to humans.
4- Iron and magnesium: Iron and magnesium change the color of the water to rust-like color and are harmful only if they are in large quantities and are more prevalent in groundwater.
5- Organic compounds: Many organic compounds cause water pollution, including pollution by Petroleum and its derivatives, pesticides, fungicides, and other industrial chemicals.
6- Halogens: Chlorine and fluoride serve to sterilize water from harmful microbes. However, when organic substances or hydrocarbons are present in water, they react with chlorine to form cancer-causing HFCs.
7- Radioactive materials: Such as radium, which causes cancer, in particular bone cancer.