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The authorities need to look at all the factors contributing to the rise in mosquito-borne diseases.NSTP/SALHANI IBRAHIM

FOLLOWING close on the heels of the rainy season are the mosquito fogging operations carried out by contractors engaged by the Ministry of Health and state Health Departments.

We put up with these malodorous operations even though we know that fogging is ineffective and provides a false sense of security.

Fogging is a popular way to control mosquitoes because it is visible and creates the impression that the authorities are doing something to combat mosquito-borne diseases.

However, studies have shown that fogging is effective only when the chemicals come in direct contact with the mosqui-toes.

I have witnessed how the mosquitoes fly up to my apartment window screens when fogging is carried out at ground level and fly back down when the coast is clear.

There are concerns that frequent fogging may even increase mosquitoes’ resistance to insecticides, giving rise to strains of super mosquitoes that are hard to destroy.

Fogging does not reduce mosquito populations because it does not kill mosquito larvae or pupae. If fogging was an effective mosquito-control method, we would see a decrease and not an increase in dengue cases in Malaysia.

Fogging is not only ineffective in controlling mosquito populations but potentially harmful to human health.

The chemicals used in fogging and spraying are neurotoxins that can affect the nervous systems of humans, companion animals and birds.

It kills beneficial insects such as ladybirds, and pollinators such as butterflies and bees.

Frequent fogging operations can harm biodiversity and cause ecological imbalance.

There are inexpensive and pesticide-free methods of mosquito control advocated by biologists and researchers.

These often involve getting premises owners and cleaning contractors to identify and eliminate mosquito breeding sites, including less-expected breeding sites such as bracts of flowers and plants, septic tanks, gutters and damp bathroom floors.

Increasing biodiversity in parks and gardens by bringing in native fish, frogs, dragonflies and bats that feed on mosquitoes and their larvae can reduce mosquito populations and restore degraded ecosystems.

The release of genetically-modified mosquitoes to either suppress pathogen infection or mosquito reproduction also seems to bear results, although it may be a few years before we can attest to their safety and effectiveness, and their impact on ecosystems.

In the meantime, the best and safest method of mosquito control is still the elimination of breeding opportunities.

I often find municipal rubbish bins, recycling bins and construction waste bins filled with stagnant water and mosquito larvae.

There should be a requirement for all these bins to have drainage holes at the bottom to allow water to flow out.

Local councils should ensure that abandoned vehicles are removed.

Construction sites and illegal dumpsites should be cleared regularly as these spaces often trap water and create places for mosquitoes to breed.

Address the role of single-use plastics and other disposable packaging in creating breeding grounds for mosquitoes, besides being a blight on the environment.

A ban, combined with a bottle and can deposit system, will reduce litter, encourage recycling, and keep these mosquito nurseries out of the environment and landfills.

There is also a link between deforestation and the rise in mosquito-borne diseases.

The Journal of Emerging Infectious Diseases has documented the steep increase in malaria cases in areas in Sabah and Sarawak where forested land has been cleared for agriculture.

Larvae-sustaining puddles are formed where there are no longer tree roots to control soil erosion and water runoff, and mos-quitoes and other pathogens proliferate in forest edges where the boundaries between human habitation and forested areas become blurred and primates and other disease carriers wander into human habitation.

To protect citizens from mosquito-borne diseases, the authorities need to look at factors contributing to a rise in the disease, and carry out policies that may include banning the clearing of forests, practising shade and mixed cultivation, and increasing biological pest-control measures, such as bringing back native fishes, frogs, bats, and birds to degraded areas.

We need to focus on disease prevention and implement measures to identify and eliminate mosquito-breeding sites and opportunities.

It’s time we stopped pretending that fogging is effective and redirect our resources to actual solutions.


Petaling Jaya, Selangor

The views expressed in this article are the author’s own and do not necessarily reflect those of the New Straits Times

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