Detergent footprint in aquatic ecosystems

• Water pollution caused by detergents is now a big concern in the global context.
• The per capita detergent consumption in India is around 2.7 kilogram per year. It is around 3.7 kg in Philippines and Malaysia and 10 kg in the United States of America.
• Many of the chemical substances that are disposed of in water bodies are toxic and hazardous.

Detergents:

• A detergent is a surfactant or mixture of surfactants that has cleaning properties in dilute solution with water. A detergent is similar to soap.
• Surfactant detergents are used to enhance the wetting, foaming, dispersing and emulsifying properties of detergents.
• Surfactant detergent, when added to a liquid, reduces its surface tension, thereby increasing its spreading and wetting properties.
• Detergents are very widely used in both industrial and domestic premises like soaps and detergents to wash vehicles.

Detergents and pollution:

• Nonylphenol, a hazardous chemical present in detergents, is known to enter water bodies and the food chains.
• It bio-accumulates and can pose serious environmental and health risks.
• It has been detected in human breast milk, blood and urine, and is associated with reproductive and developmental effects in rodents.
• The detergents contain suspected carcinogens and ingredients that do not fully biodegrade.
• Many laundry detergents contain approximately 35 to 75% phosphate salts. Phosphates can cause a variety of water pollution problems.

• Some phosphate-based detergents can also cause eutrophication.
• Phosphate-enrichment can cause the water body to become choked with algae and other plants.
• Detergents also contain oxygen-reducing substances (ie, a chemical compound that readily transfer oxygen atoms) that may cause severe damage to the fishes and other marine animals.
• Detergents are capable of destroying the external mucus layers that protect the fish from bacteria and parasites, causing severe damage to the gills.
• A few more harmful components of detergents which are anthropogenic components such as herbicides, pesticides and heavy metal concentrations (like zinc, cadmium and lead) can cause the water to grow murky.

• This blocks out light and disrupting the growth of plants.
• Turbidity also clogs the respiratory system of some species of fishes.
• Pathogens from these toxic water bodies cause diseases, some fatal, in human or animal hosts diseases.

Bioaccumulation:

• It is a process of accumulation of chemicals in an organism that takes place if the rate of intake exceeds the rate of excretion.

Eutrophication:

• It is the process by which a body of water becomes enriched in dissolved nutrients (such as phosphates) that stimulate the growth of aquatic plant life usually resulting in the depletion of dissolved oxygen.