(i) Effect of Human Health:
(a) Mercury compounds in waste water in converted into methyl mercury by
Bacterial action which causes numbness of limbs, lips and tongue, deafness blurring of vision and mental derangement.
1. Mina Mata disease (Crippling deformity) of Japan detected in 1952 due to Consumption fish contaminated with mercury.
2. Consumption of cadmium contaminated water lead to itai itai disease and also known as ouch-ouch disease (a painful disease of bones and joints) and cancer of lungs and lever.
3. Compounds of lead cause anemia, headache, loss of muscle power and bluish line around the gum.
(ii) Effect of aquatic life:
(a) Biocides, polychlorinated biphenyls (PCBS) and other heavy metals such as Hg, Pb, Cd, Cu, as etc directly eliminate certain species of animals.
(b) An organic and inorganic waste in water decreases the dissolved oxygen (D.O.) content of water.
(c) Inorganic nutrients like phosphorus, Nitrogen form animals, plants and fertilizers causes eutrophication of lakes.
(iii) Biological magnification:
The phenomenon through which certain pollutants get accumulated in to the tissues in increasing or at ration along the food chain is called biological magnification.
E.g. Accumulation of DDT and other pesticides, radio nuclides in the tissues of aquatic animals.
(iv) Eutrophication:
Addition of waste water containing phosphorus and nitrogen compound and decomposition of grams wastes in water bodies increases the nutrient content in water which causes excessive growth of gae especially blue green.
(v) Hazards of ground water pollution:
Due to seepage from industrial wastes and agricultural run off, ground water get contaminated.
(1) Presence of excess nitrate in drinking water is dangerous for human health because it reacts with hemoglobin to form non-functional met hemoglobin, and impairs oxygen transport. It is called blue baby syndrome.
(2) Excess fluoride in drinking water causes teeth deformity, hardening of bones and stiff and painful joints (skeletal Fluor sis).
(3) Over exploitation of ground water may lead to leaching of arsenic from soil and rock sources which will contaminate ground water.
(vi) Effect of land and soil pollution:
(1) Industries manufacturing paper, textile, steel, fertilizers etc. release many organic and inorganic pollutants in the soil.