With the poisonous air in Delhi showing no signs of changing, a lot of the people, especially the kids and those with breathing problems have been resorting to the use of protective vog masks. However, uncomfortable the masks are many are still forced to use it because of the lack of options. But soon you may not have to wear protective masks to filter the air that you breath in. Alumni, professors and students of IIT-D or The Indian Institute of Technology Delhi, in collaboration with a startup have come up with a nano-respiratory filter that costs Rs 10.