Forum: Fogging should be used judiciously

We thank and agree with Mr Tan Lai Yong (

Fogging kills not only mosquitoes,

March 20).

Fogging and other chemical control methods such as misting should be used judiciously and not as a routine mosquito-control measure.

Indiscriminate use of chemicals can impact non-targeted insects and may also lead to insecticide resistance in the local mosquito population, rendering these insecticides ineffective for future outbreak control.

The National Environment Agency (NEA) emphasises source reduction of the Aedes mosquito as the primary focus of our dengue control efforts. Along with other measures, fogging may be carried out at dengue cluster areas where there are high mosquito populations to eliminate infected mosquitoes.

NEA has developed guidelines on fogging practices, which are shared with the pest control industry. All fogging operations must be notified to NEA in advance.

The public must also be informed of upcoming fogging operations by the pest control operator, managing agent or premises owner.

Vector control personnel are trained and licensed to handle pesticides. They are also required to follow proper procedures to protect the public and the environment.

However, the effects of fogging are transient as it does not eliminate the source of the mosquitoes. Thus, fogging, if performed, must be complemented with the removal of mosquito breeding habitats.

Everyone has a role to play in dengue prevention. Given the presence of the Aedes mosquito vector in Singapore, we urge all to regularly practise the B-L-O-C-K (Break, Lift, Overturn, Change, Keep) steps to prevent mosquito breeding, and the protective practice of S-A-W (Spray-Apply-Wear). Details are available at nea.gov.sg/dengue

By maintaining high standards of public hygiene together, we can combat dengue and contribute to a cleaner and greener Singapore for all.

Tony Teo
Group Director, Environmental Public Health Operations
National Environment Agency