Because the Company’s Town Well being Officer in Chennai from 2006 to 2014, I used to be accountable for dealing with mosquito regulate actions within the town. At the moment, the foremost grievance of the contributors of the general public used to be the mosquito threat — the problem got here up again and again within the Company Council, complaint conferences and by means of petitions to the civic frame.
It is not uncommon wisdom that fifty% of mosquitoes breed in rivers and canals, some other 40% in stormwater drains and about 10% breed in person properties. Those mosquitoes that breed in home settings are chargeable for inflicting malaria and dengue, and subsequently, regulate calls for folks’s participation to achieve success. At that cut-off date, it used to be very tough and therefore we would have liked to make it folks’s motion as a way to get it to paintings.
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A few of the perennial resources of mosquito breeding within the town are the waterways like Cooum, and Adayar rivers, and canals like Buckingham, Otteri Nallah, and Virugambakkam Canal, all working for roughly 247 kilometres. The opposite supply is the stormwater drains flowing beneath the streets of Chennai Town for just about 2,100 kms, and facet drains for roughly 412 kms. They’re the water resources that let the breeding of what we name nuisance mosquitoes during the 12 months according to the volume of water stagnation. Those are culex mosquitoes, and they don’t purpose malaria or dengue however once in a while filariasis.
The stormwater drains within the town have over have about 3 lakh unlawful connections of sewers both deliberately broken through folks, or unintended breakage throughout the development of stormwater drains. The non-flowing sewer water stagnates during the 12 months.
My engineer pals would all the time be frustrated at me throughout the Commissioners’ overview on Saturdays once I used to record out the duration of SWD having stagnation — and thus properties for breeding mosquitoes. The stormwater drains which are meant to be dry throughout summer season had been 60% stuffed with sewage. They’re built just for floods in rain no longer for sewers. They have got no interconnections to empty out of town as they weren’t scientifically designed for this goal. Additionally like Mumbai, Chennai is positioned equivalent to or less than sea degree, therefore drainage is hard.
The answer for this might be like in Japan we want to set up deep charging bores or wells in lots of portions of town which is not going to handiest cut back flooding however lift the bottom degree water. They might additionally fill the temple tanks and lakes in and across the town offering connecting pipelines from the puts of heavy water stagnations.
The real factor that troubled the well being officers used to be the breeding of the opposite varieties of mosquitoes — those who breed in transparent water handiest — anopheles and aedes — inflicting malaria and dengue.
Dry day in per week
The home resources of mosquito breeding are family open overhead tanks, open wells, open sumps, temple tanks, lakes and septic tanks beside family garage of water throughout water shortage.
Brief resources of breeding at each and every space come with previous tyres, used disposables like tea cups, tins, coconut shells, unused grinding stones, damaged bathroom wares (when water collects in them), stagnant water on asymmetric terrace, tree leaves clogging within the pipe strains and sun shades and many others.
We determined to organise Dry Days for the OHTs as soon as per week within the housing colonies, as a way to take the message of home breeding of mosquitoes and the right way to save you them to the general public.
Rivers and canals
We’d get signals about expanding mosquito nuisance from MLA Quarters close to the Cooum and Ministers Quarters close to Adyar river. Right away the PWD division was asked to dredge the day by day collecting sand bar on the mouth of those rivers on day by day foundation until the court cases prevent.
The company in most cases spends just about ₹10 crore annually to spray pesticides, (malaria larvicide oils from oil firms) in those waterways, particularly at the edges and the banks of canals which in most cases have wild furry crops; just about 20 fibre boats and catamarans with fishermen had been used for spraying pesticides and removing of huge plastic waste in those rivers.
The water coming from the outskirts of Chennai in most cases brings in new larvae to town and therefore I had steered our body of workers to erect larvae filtering nets throughout water techniques. This became out to be very helpful.
We realised that it’s the faulty engineering measures which might be the causative elements for mosquito breeding within the town. In truth, we gave a suggestion to the PWD to expand an everlasting construction to put in angled pipelines around the mouth of rivers in the other way of sea waves to make sure the unfastened go with the flow of seawater into the rivers with out sand bar formation. Its efficient implementation on the river mouth may just no longer handiest cut back the price of mosquito regulate to the minimal however a great deal cut back the mosquito density and everlasting reduction for Chennaites from mosquito nuisance.
The suggestions had been technically made and supported through Oceanographic Engineers of IIT, Madras (Prof. Dr. Mani). I need to explain that opposite to not unusual trust, seawater doesn’t impact the groundwater. In truth, it used to be accomplished throughout the British rule with mechanical lockers close to the mouths to carry and steadiness sea water within the canals and rivers for shipping and to prevent mosquito breeding with saline infusion.
We gave a suggestion in 2010 to shop for a Norway-made and popularly used amphibian car costing ₹1 crore to dredge dust and trim the perimeters of the waterways to permit the unfastened go with the flow of water, and it used to be later bought. Its efficient day by day application with the dredging of sand on the river mouth would no longer handiest cut back the price of mosquito regulate to the minimal however a great deal cut back the mosquito density and nuisance.
Regulatory punitive movements
Last of the OHTs and wells which used to be technically referred to as “Hermetical sealing and Clinical closure of wells and OHT” used to be mandated through issuing a understand beneath TNPHACT 1939, SEC 83,84 and entailed prosecution within the courtroom of regulation for noncompliance.
The unlawful sewer connections to the stormwater drains weren’t allowed beneath Sec 17 to 36 of TNPH ACT 1939. Notices had been issued and the ones accountable for building websites the place water used to be allowed to stagnate had been punished.
“Mosquitoes are engineering drawback; malaria, dengue are clinical drawback”
Evolved countries in addition to the WHO have again and again steered that the breeding of mosquitoes remains to be an engineering drawback, and handiest remedy of malaria and dengue is the well being drawback. However in our set-up, each mosquito and malaria regulate is being undertaken through the well being division, arguably no longer essentially the most clinical approach of dealing with the issue.
College Well being Ambassador
Some other software that used to be used successfully within the regulate of home mosquito breeding (with the beef up of the general public) is college scholars.
Just about 5 lakh scholars had been concerned, sensitised in this factor and named as Well being Ambassadors, and had been additionally given an ID card.
They had been motivated to show their circle of relatives and neighbours about breeding zones of their properties, resulting in an expanding mosquito inhabitants, inflicting illness as smartly. Some faculties gave them assignments; they had been proven the reside mosquitoes within the prayer assembly and exhibitions had been carried out to determine the problems and varieties of mosquitoes.
After a 3-week, sustained pressure, the grownup mosquito/larval density had come right down to the minimal thereby decreasing the nuisance and the prevalence of illnesses.
Sector regulate way
All through the dengue epidemic in 2011, when alarming deaths had been witnessed on the nationwide degree, Chennai town recorded not up to 300 instances; I steered my crew to not depend on fogging (diesel combined artificial pyrethroid which is anticipated to knock down mosquitoes through neural poisoning) and spraying by myself, however slightly on 100% aid of breeding resources within the person properties.
There have been about 17.5 lakh families within the town then; my crew used to be steered to investigate cross-check 100 properties/day, 500 properties /week completely through box staffers, to take away the breeding resources, particularly tyres and put them at the streets for removing through the conservancy and to give them consciousness about mosquitoes and the illnesses they unfold.
Those 500 properties had been regarded as a cluster and referred to as a sector. 3,500 employees had been deployed on a freelance foundation after quick coaching. In truth, we had been stunned that simply this easy measure lowered the larva/mosquito density when each and every house used to be measured through entomologists for guy hour density later.
It’s prime time that public well being professionals and directors within the State, technically and rationally revised the present vector regulate program which suffers from insufficient manpower, equipment, and equipment. It might be instructed to drop our previous typical strategies in favour of recent, trendy and up to date vector regulate analysis and implementation.
Atmosphere proper elementary engineering flaws, at the same time as we envisage new plans for Singara Chennai 2.0 and proper engineering selections as part of crucial the town making plans job will likely be recommended for town. That’s the handiest factor that may, in a extra everlasting and urban approach, make certain that our waterways stay unfastened from breeding mosquitoes.
(Dr. P. Kuganantham used to be the previous well being officer of the Chennai Company. He can also be reached at drkugan@yahoo.com)
