I don't know where people travel when they go to India, but it sure as hell isn't in New Delhi. I have been to some pretty filthy places in the world, but New Delhi is by far the worse.
In a way, I had expected the extreme poverty and was quite curious about it when I was there...I did not expect the air to be as polluted as it was. All of my pictures look hazy and bluish because the light would reflect off of the smog and dilute the colors of where we were.
My lungs ached the entire time I was there and I would hang out with the smokers because the smoke felt better on my lungs than the regular air that I was breathing. When I blew my nose, it was black. Literally black. In Turkey, kicking up all of the dirt on the dig, you would become accustomed to brown in your tissue, but never black.
After sight-seeing my exposed skin was covered in gritty soot. It was truly nasty.
If I go back to India, I will not stay in New Delhi....and I recommend that you don't as well... Trust me, your lungs will sing my praises.