Migration of people to cities like Chennai has put enormous pressure on the infrastructure in terms of water and sanitation('Pot Luck', Down To Earth, December 31, 2004). Had Chennai been located by the side of a perennial river, the situation could have been managed better, but that is not to suggest that Chennai should move out to the vicinity of the Cauvery.
To clarify other aspects, the Centre for Water Resources (cwr) is an autonomous research institute within Anna University. The centre is strong not only in technical aspects of tank rehabilitation, but also in the institutional and policy arena of tank rehabilitation. cwr is trying to restore water bodies through people's participation and even got the Government of Tamil Nadu to award tank rehabilitation contracts to the Water Users Association (wua) despite bureaucratic roadblocks.
Regarding evaporation reduction, these measures will be successful only when the water is available. In the early 1980s, the centre had carried out experimentation of suppression of evaporation loss through application of chemicals, of which we submitted reports to the government.
Centre for Water Resources
Anna University, Chennai...
The prevalence of massive arsenic poisoning in West Bengal is well known, but it's the government's lack of concern that stalls workable solutions. The origin of arsenic in a hand pump can be traced to the design details of its components. Copper-zinc alloys (brass) exhibit serious corrosion, especially with prolonged exposure to aerated water high in chloride ions. As arsenic in brass (0.04 per cent to .45 per cent in weight), is highly effective when it comes to preventing dezincification, the addition of arsenic to brass increases its resistance to stress corrosion cracking in various acidic solutions. Arsenic in brass inhibits corrosion in chloride solution by being oxidised to arsenite or arsenate anions in solution and chemisorbed on the surface of brass components. It is this that becomes the source of arsenic in hand pump water.
The other factor that contributes to arsenic is iron. Although iron components that come in contact with water are supposedly anti-corrosive, these do get corroded over time. As a result, poisonous pollutants get released into the water. Hand pumps that get used only for a little while each day are more prone to pollutants, especially for the initial few buckets.
Millions of our rural and urban poor are facing slow poisoning. The solution could be to use hand pumps with food grade plastic coatings and non-arsenic additives like aluminium or boron. If not, switch to open wells.
H S GOYAL
Motilal Nehru National
Institute of Technology
Allahabad, Uttar Pradesh...
The world needs water
cse has highlighted the issue of contaminated water at various fora. When it comes to accessing potable water, Team b , which is around 30 per cent of the people on the planet, can afford bottled water on a regular basis. Most of this segment has very little idea of what it means to be without water or power even for a spell and leave quality issues of the water they consume to their supermarkets and the government.
But when it's about water, you cannot ignore the problems of Team a, virtually the rest of the world, that cannot get basic access to drinking water. Besides the lack of adequate supply, the quality of the water available is also a problem. Healthy water with enough oxygen is a basic human right.
I have been working on developing and promoting solar-based-technology to purify water. At present, there are applications to treat water for human consumption through humidification and dehumidification by sun and gravitation alone. Low technology methods can produce high quality de-silted water, without the need to use generators, electricity or chemicals. But it takes more investment to get started and more time to be profitable.
For instance, to produce or sustain 20,000 litres of water per day by solar power, costs around us $320,499. To produce or sustain the same number of litres on conventional osmosis-based technologies, would cost around us $76,919 or less, plus us $7,691.99 per year for filters and chemicals and us $2,564.80 for maintenance. In addition, there are problems like power and quality of water. But both systems together can do wonders for quantity. This is a critical factor as, according to the un Agenda 2015, the world now needs two million litres per day, to serve 400,000 people. So in the long run, we all need to look at more sustainable methods.
HELMUT G SCHUSTER
The lung index
Nowhere are global standards more necessary ('World class products', Down To Earth, February 28, 2005) than for gasoline and diesel. Europe is introducing tighter controls on fuel quality, which would go some way in slowing down the death rate from cancer (one in three urban citizens are expected to get cancer in 2005 and one in two by 2005). But in India, we are still to adopt these standards. Instead, we seem to take pride in picking up the old norms cast off by the European Economic Commission. Nor are the state oil companies trying to change the status quo.
Fuel quality must be seen not only as an industry concern but also in the context of the price we're all paying, as cancer becomes a household epidemic in India. For instance, benzene in vehicular fuels is a known carcinogenic that causes havoc with our collective health, yet there are no controls on it.
Technical teams within the oil industries -- foreign and local -- want to supply the best fuel possible, but unless the government regulates the fuel quality, it's not a viable option for them. Imposing standards may mean that the industry has to import fuel for a period of time, while local refineries make the modifications.
Polluting industries that use synthetically-produced dyes ('Ecological distemper', Down To Earth, February 28, 2005) cause immense harm to the ecology. Hair dyes and cosmetics are among many products commonly used with consumers unaware of the harm. Let us hope that more alert users can deter the manufacturers from using harmful colouring material.
Pick of the Postbag
All smoke and no fire?Theus study on the carcinogenic effects of tobacco smoke ('How smoking causes cancer', Down To Earth, March 15, 2005) is typical, with all promises having conditional parameters. Obviously, us studies on lung cancer (Science, April 30, 2004 or New Complete Medical and Health Encyclopedia , JG Furguson, Volume 4, 1986) have failed to get anywhere in the 'war' against lung cancer, either on 'early' detection, prevention or cure.
Then, no two cancers, even in the same individual, have ever been alike. So how can a single 'drug' (ag-1478) ever prevent, forget cure, a host of cancers that appear in the aero-digestive tract? Also, why are a host of cancers that appeared in the aerodigestive tract being linked to tobacco smoking? Isn't it because 're-searchers' failed to establish any relation between lung cancer and smoking?
According to the "pioneering" work of the Medical Research Council (uk) in 1962, out of 740 heavy smokers, one gets lung cancer. The onus is therefore on science to explain how the other 739 escaped lung cancer. Nor has science any explanation for those getting lung cancer despite not smoking or being around a smoker. For the statistical proof that tobacco causes cancer, there is a parallel body of evidence that tobacco habitus have a lower incidence of bowel cancer, brain cancer, Parkinson's and Alzheimer's, as compared to those who stay away from tobacco. So the next time you ask someone to give up smoking, you may actually be precipitating these four diseases.
Finally, the 1998 study (see Economist, March 14, 1998) by who concluded that non-smokers married to, working with or growing up with smokers were not at significantly more risk from lung cancer than anyone else.
A Mukherjee and J N Mukherjee
Down To Earth replies
Contrary to your contention (unsupported by statistical evidence) about tobacco habitus having "a lower incidence of bowel cancer, brain cancer, Parkinson's and Alzheimer's as compared to those who stay away from tobacco", several reports talk of the types of cancers caused by tobacco smoke (see Lancet 2003, Vol. 362, September 13, p 847-852).
According to the World Health Organization ( who ), tobacco use kills one person every 6.5 seconds. 11,000 people a day die worldwide and by 2020, tobacco use will end up killing 10 million people a year. As many as 70 per cent of them live in the developing world.
Apropos passive smokers not being affected, studies show that cancer has also occurred in non-smokers and in those who have given up smoking for over 10 years ( British Medical Journal , Vol 330, February 5, 2005).
Secondly, the drug ag 1478 does not act on cancer cells but inhibits the very production of cox -2 and egfr tyrosine kinase. In this study both these proteins have been linked to the development and progression of cancer....
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.