Concerned over the harmful effects of the chemical used in fogging, particularly on field workers, the Union Health Ministry is conducting an efficacy study to replace it with a friendly one.
The National Vector Borne Disease Control Programme is carrying out extensive fogging in NDMC area with the new chemical - synthetic pyrathroid. Once successful, this chemical will be sprayed in other parts of the city.
"Malathion Organophosphorous Poison (MOP) which is at present being used for fogging in Delhi is highly toxic, not environment-friendly, harms the sprinkler on job and also people in the same area," an MCD official said.
There are 35 to 40 lakh houses in the city where fogging is carried out every year.
"Fogging exposure with MOP should not be more than three times a year. Studies have proved that excessive exposure affects the digestive system and harms the reasoning faculty. It was also seen that pilots who have sprayed it in foreign countries have died due to motor accident as it harmed their reasoning process," the official said.
"Deaths are being reported among field workers even before they retire. As per the rules, fogging is carried out in areas that have reported vector-borne diseases but it was done unnecessarily in residential areas and all Commonwealth Games venues where no such case was reported," he said.
The new synthetic pyrathroid fumigation was carried out in foreign countries where vector borne diseases are highly prevalent. It proved to be effective and least harmful to humans. The NVBDCP is yet to approve this chemical for use in Delhi, he said.
"People here insist that fogging be carried out in their areas on a regular basis without realising that it has bad effects on health. The flight range of a mosquito is almost 400 metres and fogging should be carried out within this range. If people check mosquito breeding in their coolers and overhead tanks, fogging process would not be needed at all," he said.