In recent months, there has been heightened concern over the number of people who have been coming down with dengue, and this year's dengue outbreak is set to be Singapore's worst on record (2020 dengue outbreak set to be worst on record, July 3).

While more frequent mosquito fogging may look like action is being taken to crack down on the flying pests, it is not actually very effective.

Fogging has no effect on mosquito larvae. Routine, indiscriminate fogging is not a sustainable measure in the battle against dengue outbreaks.

The National Environment Agency (NEA) has emphasised repeatedly that source reduction of the Aedes aegypti mosquito is the primary focus of its control actions.

And it has formulated guidelines on fogging which are shared with the pest control industry.

The NEA has also clarified that fogging is not mandatory, and should be used judiciously and not as a routine mosquito control measure.

The frequency of mosquito fogging in my area has increased to up to two times a week.

When I approached the vector control person to ask if the fogging operation was made known to NEA in advance via the electronic fogging submission system, I was shown an "exemption" notice.

I hope the NEA can clarify its position on the seemingly routine and indiscriminate fogging operations in my area.

Wong Chung Keong