27 March 12 The Straits Times
THE guidelines on fogging were formulated in 2006 by our association, the National Environment Agency (NEA) and relevant organisations ('Frequent fogging and insecticide concerns in mosquito control' by Dr Ong Siew Chey, last Tuesday; and 'Condos must change mindset' by PestBusters, last Friday.)
The NEA circulated the guidelines to pest control operators in January 2007, which advocate the judicious use of fogging.
The guidelines do not recommend fogging unless there is an increased presence of adult mosquitoes, or during an outbreak to eliminate infective mosquitoes immediately. When fogging is necessary, proper procedures are in place to protect the public and the environment. In line with the NEA's directive, we have consistently advised the public to place greater emphasis on inspection and source reduction in mosquito treatment; supplemented by fogging only when necessary.
With the NEA's directive in place, health and industry officials are fully aware of the consequences of widespread and indiscriminate fogging.
The NEA's enforcement and our regular reminders will help in disseminating the message.
Fogging remains popular because the public generally believes that the visible fog generated is an effective indicator of mosquito treatment.
In reality, fogging has no residual effect and destroys adult mosquitoes only when they come into direct contact with the fog. Much of the insecticidal fog dissipates quickly into the atmosphere due to high ground temperature.
So fogging and misting should be reserved for use only when the adult mosquito density is high and when an outbreak occurs.
The reaction by certain sectors of the public to fogging is understandable.
However, there is no scientific evidence to date to conclude that fogging has destroyed most of the beneficial or non-target insect population.
It must be remembered that with urbanisation, the natural habitat of these insects has been affected as well.
The insecticides used in fogging are registered and approved by the NEA. If there is any adverse report on the insecticide used, it will be phased out promptly.
Ng Say Kiat
For Singapore Pest Management Association