Had New York not sprayed, more people would have likely have suffered. In contrast, in counties outside the city that waited to spray until a later date, people continued to contract West Nile. Actually, nature has always posed the greatest challenges to the survival of mankind, while chemicals are key to our survival. In fact, despite the increase of manmade chemicals, the average worldwide human life span has increased from around 30 years at the turn of the century to more than 60 today, and it continues to rise. Chemicals have played a crucial role in that progress by making possible such things as pharmaceuticals, safe drinking water, and, yes, pest control.
Biological pathogens remain a far more serious challenge to public health than do chemicals.
In the United States, it is true that such vector risks are relatively low, but that's in large part thanks to pesticide use. In contrast, the pesticide risks are negligible. More importantly, West Nile can serve as a reminder that there are potentially larger problems related to increased transmission of deadly infectious diseases. Just last year, two Boy Scouts contracted malaria on Long Island. Fortunately, the county government found the breeding ground, treated it, and destroyed the malaria-carrying mosquitoes.