Detergents threaten India s waterbodies
What are the dangers posed by detergents?
The detergents contain phosphates which pose a threat to the environment.
What are phosphates used for in detergents?
Phosphates perform many functions in washing powders and detergents.They soften hard water by bonding with calcium ions. This way they prevent the lime included in water from depositing or settling on the textile fiber. If the water is hard and contains dissolved lime, its ability to dissolve soap diminishes and the cleaning power deteriorates. Moreover, phosphates stabilize the alkalinity of the surfactants. They keep the dissolved dirt in the water and prevent it from penetrating back into the clothes.
How is the phosphate content in detergents a threat to the environment?
Phosphates cause eutrophication in natural waterbodies. Eutrophication is the process by which the nutrients in a waterbody increase. This results in an increased rate of productivity, generally of phytoplankton and of macrophytes in shallow waters The algae growth increases and when the algae dies and decomposes, it removes the oxygen from the water. This kills the fish in the water and increases pathogenic organisms. Eutrophication is usually caused by human activities near waterbodies.
What are the indicators of eutrophication?
A decrease in transparency, increasing alkalinity, reduction of dissolved oxygen concentration, increased chlorophyll content and plankton biomass indicate that eutrophication has set in.
What made you realise that the use of detergents was harming the waterbodies?
I have studied the impact of detergent use in the lakes of Canada. It was in the early 1950s and 1960s when scientists noticed eutrophication of the lakes in the country.
What kind of problems did detergents cause in Canada?
The great lakes of Canada are the largest freshwater system in the world, about 244,000 square km in size. Eutrophication had set in the system as well as streams, stretches of rivers and other waterbodies. The state of Lake Erie, the shallowest of the lakes, can be studied as an example of how stressed the waterbodies in Canada were and how they were revived.
In 1966-67, the total municipal human phosphorus load in the lake was 6,030 metric tonnes. The phosphorus loading from detergents was estimated at 11,980 metric tonnes. And the total loading that year was 27,299 metric tonnes. Between 1942 and 1970, the phosphorus load in the river had increased threefold. As expected, the tremendous increase in phosphorus led to increased algae growth. Consequently, the chlorophyll concentration in the lake waters rose. The oxygen levels in the hypolimnium, or the water close to the bottom of the lake was found to be as low as 2 miligramme per litre.
How did the Canadian authorities deal with the problem?
By the mid-1960s, the effects of the eutrophication were so substantial that it led to a public outcry. The Canadian and the us governments woke up to take action. They asked the Great Lakes Water Quality Board of the international Joint Commission ( ijc ) to carry out a detailed study to suggest remedial measures. It was realised that if phosphates were to be removed from the lakes, it would save nearly us $22 million. The ijc recommended in 1969 that the phosphates in detergents be brought to the minimum level required and be replaced with environmentally benign alternatives by 1972.
How did the detergent industry react?
Just as expected. The detergent manufacturers vehemently opposed ijc 's suggestions. They took the stand that in case of eutrophication, phosphates were not the controlling factor. Usually it is the nitrate-phosphorus balance that controls the level of eutrophication. However, in the case of Canadian waters it was conclusively proven that the phosphorus content had gone so high that nitrates had become the limiting factor. In 1970, the authorities passed regulations limiting the phosphorus content to 8.7 per cent. By 1973, it was brought down to just 2.2 per cent. us spent about us $ 7.8 billion on remedying the problem. By 1975, the phosphorus loading in lake Erie had been considerably reduced in both the us and Canada.
What's the situation today in Canada?
All the detergent manufacturers adhere to the limits laid down by the authorities. Strict control and public vigil ensures that the waterbodies in Canada remain safe and healthy.
How big is the problem of phosphates in India?
If you look at the market for detergents, whether it is in rural India or in urban India, the use of detergents is increasing fast. Some experts suggest that as much as 70 per cent of the