Explanation:

 National Green Tribunal has indicated on 10th Nov that when air pollution reaches severe levels, Delhi and neighbouring states will have to take the following measures:

Sprinkling water from choppers
Stopping construction activities
Shutting down polluting power plants and gen-sets
Passing a host of directions to tackling air pollution in Delhi and neighbouring states, the NGT also asked for the setting up of central and 5 state-level monitoring committee to check implementation of orders and form action plans to check pollution
When PM 2.5 and PM 10 levels cross 251 and 431 micrograms cubic metre, it is an environment emergent said the NGT chairperson Swantanter Kumar
The chairperson also said measures would have to be implemented to tackle the situation
Farmers must be given happy seeders-machines that sow wheat without burning paddy residues
This is to prevent crop fires.
During the period of severe air pollution, all construction, transport of construction material and stone crushing activities must be stopped
States will have to shut down power plants, hot-mixers, brick kilns, diesel generator sets whose emissions are above the prescribed limit, according to an interim order for NGT
The NGT also asked 4 neighbouring states of Delhi- Haryana, Punjab, UP and Rajasthan- to consider banning diesel vehicles older than 10 years while directing Delhi to ensure strict implementation of orders on diesel vehicles.
Tribunal also asked Delhi government why they did not install air filters in schools for children as instructed.