Question

Environmental Biochemistry

What are the major sources and types of pollutants in our environment, AND how do they enter living organisms? (Explain how they are able to enter living organisms and cells, and how this relates to their chemical and physical nature.)

Answer 1

• Domestic sources of pollution include toilets, latrines and wastewater from kitchens and bathrooms. If these wastes are properly contained and prevented from getting into the environment, they will not cause pollution. However, frequently this is not the case. Open defecation obviously releases human waste into the environment, which can then be washed into rivers and other surface waters. Solid wastes from households and also from shops, markets and businesses include food waste, packaging materials and other forms of rubbish. Domestic sources are also responsible for gaseous pollutants in the form of smoke and carbon dioxide from domestic fires.
• Pollution from the industrial sector has been on the rise, posing a serious problem to the environment. Many industrial processes produce polluting waste substances that are discharged to the environment, frequently through chimneys (to the air) or through pipes (to surface water) . Among the most polluting industries are food processing, tanneries and textiles with processing plants and factories that produce liquid effluents which are discharged into rivers, often without treatment. In practice, rivers frequently receive polluting discharges from many different sources all at the same time.
• Nowadays, agricultural activities use more pesticides and fertilisers. Fertiliser contains phosphate and nitrate and if these reach water bodies they can cause excessive plant growth .Agriculture is also responsible for gaseous pollutants in the form of methane produced by livestock and solid pollutants from crop residues, packaging materials and other wastes similar to those produced domestically. Animals also contribute to waste products and potential pollutants with their excrement.
• If you observe the tailpipe of diesel engine vehicles, you will have seen the black exhaust gas produced. The intensity of the black colour is greater for poorly maintained vehicles, to the extent sometimes that it makes the air hazy or smoky and causes coughs and eye irritation.