star.gif (2664 bytes)A Down To Earth Supplement
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                   No.19,  July  15, 2001
Gobar means animal dung in Hindi. All of rural India uses it in a variety of ways. Ways that exemplify sustainable existence. That's why we use it, too.

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"KILLTHEM!" Easier said than done

The war between man and mosquito continues. The main weapons till now have been lethal chemicals. While these kill mosquitoes initially, they return stronger and more resistant than ever before. Then a stronger substance has to be made to carry on the fight. The chemicals get absorbed in every step of the food chain, killing us slowly but surely. Are there no other safe ways to stop the mosquito menace?

ddt.jpg (7178 bytes)SPRAY THEM
...and you poison everything else

In the early to mid 1950s, DDT became one of the most widely used pesticides. This was when it was thought to be completely harmless to human beings. In the 1960s, concern arose about its effects on humans. A study in 1968 showed that Americans were consuming an average of 0.025 milligrams of DDT per day! When DDT gets into our bodies, it is stored in fatty organs as the adrenals, testes, and thyroid. It is also stored in smaller concentrations in the liver and kidneys. DDT concentrations are especially high in human milk.

CONTROLLING ADULTS
Residual Insecticides: The main method of attacking adult mosquitoes in houses is spraying the inside surfaces of the walls and roof or ceiling with a residual insecticide. The intention here is that mosquitoes will rest on the insecticide deposit and remain long enough to pick up a lethal dose.

Treated bednets: Impregnating bednets with an insecticide adds a chemical barrier to the physical barrier of the net. In the world's largest treated bednet programme, in Sichuan Province, China, up to 2.25 million bednets have been treated annually. Bednets are impregnated by dipping in a pyrethroid, drying and re-hanging them.

CONTROLLING LARVAE
Larval control can make a significant contribution to malaria control, and can be done in a variety of ways. See how in the article on Bioenvironmental Control below.

tp.jpg (6119 bytes)USE REPELLANTS
...and the chemicals harm you

A survey carried out by the Malaria Research Centre (MRC), Delhi, reveals that mosquito repellents are harmful and should be avoided.

The most common complaint was breathing problem, followed by eye irritation, often accompanied by bronchial irritation, headache or skin reaction. Of those using repellent cream, 11.4 per cent reported skin reaction and itching. Of the 286 doctors covered in the survey, 165 or 57.6 per cent reported acute toxicity following use of repellents. Even those who do not immediately feel any adverse effects may be in long term danger. Mosquito nets, a "neem cream" made up of 5 parts neem oil and 95 parts coconut or mustard oil, or burning neem oil in kerosene are safe alternatives.

GENETIC CONTROL
The idea of creating genes for a harmless Anopheles has attracted much attention from biologists. This can be done by introduction of genes which make them non-susceptible to Plasmodium or help in diverting them from biting humans to biting animals.

buster.gif (1874 bytes) THESE TERRORS CAN BE CONTROLLED
With no chemicals, little money, team work and some help from you

Says who? Says a number of cases from across the country. From Panaji in Goa to Khera in Gujarat, the Malaria Research Centre (MRC) had carried out plenty of experiments in Bioenvironmental Control (BC), as this is known. Everywhere, malaria cases fell by about 60% to 80%. In other words, mosquitoes were controlled.

The National Malaria Eradication Programme (NMEP) failed miserably with residual insecticide sprays and chemotherapy. Soon after this, India’s own Mosquito Man, VPSharma went to survey a malaria epidemic in Gujarat in 1983. This saw the birth of BC in India. The MRC was founded and for five years, Sharma fought without a single chemical. The results clearly showed success. "In Karnataka, 300 villages are now free from malaria and mosquito-borne diseases. Ahmedabad city is also another example", says V P Sharma. "In Gujarat, where we started the project, the first year saw a 92% decline in malaria".

1. Don’t let ‘em lay eggs.
Mosquitoes lay eggs. And if you read about their life cycle, you will know that their eggs grow up into larva. Since eggs and larvae cannot move far, it is easy to control them. BC tells us: Do not allow mosquitoes to breed (lay eggs) at all. Any place that has even an inch of stagnant water is a good place for laying eggs.

  • Fill large pitches, low-lying areas with fly ash, soil or burnt coke ash
  • Construct cemented standpies and proper drainage of waste water around community taps
  • Construct soak pit for domestic waste water
  • Construct cemented drains with proper slope to allow waste water to flow properly
  • Empty domestic water containers at regular intervals
  • Clean (desilt) and flush blocked drains with saline water.

2. Kill those wrigglers!
In places where water has to remain, we can kill larvae in a number of ways:

  • Rear fishes like Gambusia and Guppy in irrigated fields or ponds. These eat up mosquito larva.
  • Cover wells with polystyrene beads. These stop larvae from getting air.
  • Cover overhead tanks with mosquito-proof covers
  • Kill mosquito larva with the help of biological pesticides and predatory mosquito larva called toxorhyncites.
  • Irrigation can be carried out according to a plan so that fields are dried once a week and larval life cycles cannot be completed.

3. Protect yourself.

  • Use treated bednets
  • Use neem oil on yourself as a repellent

Wonder of wonders, BC is also a source of income. For example, the fish reared to eat up the mosquito larvae can be sold for large sums of money.

So, why is malaria still a number one killer? Why do mosquitoes haunt us every day (and night)? DDT has been recognised as a killer chemical but it is still being used against mosquitoes. Ask government officials why and they will say because it is so cheap. (Cheap?? What price is our lives and health?) On the other hand, Sharma says, "Bioenvironmental control is the cheapest way of controlling malaria, cheaper than DDT". As against Rs 7.1 per capita cost for BC, it is Rs 9.91 for DDT. So why is DDT still being sprayed? (And it is going to be sprayed in India for the next five years!)

Finally it is up to local communities to fight back their mosquitoes themselves, rather than wait for government officials to come with their DDT guns."There are plenty of ways in which children can work against malaria", says Sharma. And what are the ways?

dot.gif (88 bytes)Practice BC in whatever way you can

dot.gif (88 bytes)Study malaria. "Malaria is a wonderful subject", says our own Mosquito Man. "No matter what branch you come from, be it remote sensing, chemistry, biology, molecular biology, GIS, and so on, malariology will have a connection". No idle words these for a man who has spent more than 30 years in this. Malaria is already part of the Goa Board curriculum for school students. (see Dropin)

dot.gif (88 bytes)Recognise the fact that malaria is a killer disease. Children below five years of age and pregnant mothers are at special risk. Suppose you or someone at home have recurring fever with chills, get your blood tested. Dengue is also on the rise, so get your blood tested for dengue too.

So, is your colony or neighbourhood a BC friendly neighbourhood? Are you with the Mosquito Man?

vpsh.jpg (6669 bytes)"Bioenvironmental control is the cheapest way of controlling malaria, cheaper than DDT"


V P Sharma
Winner of the 2001 Down to Earth ‘Green Scientist Award’ for his work on Malaria eradication
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"There are plenty of ways in which children can help prevent Malaria"