Did you know that drinking a coke a day really isn't all that harmful, but drinking 2 or 3 litres a day can cause diabetes, obesity and possibly death? All fogging chemicals are mixed in dosages that are too small to affect the human body with the limited inhalation times that the fogging is in the air. The reason the workers doing the fogging are wearing masks is that they, unlike the general population are directly within the fogging cloud during the fogging operations where the fog cloud is the densest therefore are inhaling the fumes for much long and in much heavier concentration then the general public ever would.
Much the same as breathing oxygen, to much and you can get oxygen toxicity.
A common approach is a three pronged attack against vector borne diseases, chemical donuts in the water for the eggs not yet hatched, oiling to smother the existing larvae and fogging for the adult mosquito. Unfortunately, we are not allow to eradicate the biggest cause of vector borne diseases, man. If man would not allow stagnant water to stand, then the mosquito would not have a place to breed. So, maybe we should use stronger stuff when we have a dengue outbreak in a cluster and just wipe out all the humans there who allowed the breeding to happen in the first place.
Oh, yeah, Vector Control Workers have to go for blood tests every six months to ensure there is not any residual build up of the chemicals in the body. In 15 years, we've never had a bad blood test.
From one who watch his BiL almost die 4 years ago due to dengue, I'll chance the fumes of a fogger anyday. Not nearly as dangerous as walking down Orchard Road on a weekend with thousands of car idling along spewing out partially burnt hydrocarbons and other foul toxic chemicals and carbon monoxide.
