GRAP stands for Graded Response Action Plan, which is a framework designed to combat air pollution in the Delhi-NCR region. It is a set of emergency action plans implemented in four stages depending on the severity of air pollution, which is determined by the Air Quality Index (AQI) . The AQI scale ranges from 0 to 500, with 0-50 considered good, 51-100 satisfactory, 101-200 moderate, 201-300 poor, 301-400 very poor, and 401-500 severe. The different stages of GRAP are as follows:

• Stage I: This stage is imposed when the overall air quality is in the "poor" category (AQI 201-300). Under this stage, the government imposes a heavy fine on garbage burning and sweeping without sprinkling water, ensuring proper implementation of guidelines on dust mitigation measures, ensuring regular lifting of municipal solid waste, construction and demolition waste, and hazardous wastes from dedicated dumping sites, and enforcing guidelines on the closure of brick kilns.

• Stage II: This stage is imposed when the overall air quality is in the "very poor" category (AQI 301-400). Under this stage, additional measures are taken, such as stopping the use of diesel generators, increasing parking fees by 3-4 times, and increasing the frequency of metro and bus services.

• Stage III: This stage is imposed when the overall air quality is in the "severe" category (AQI 401-500). Under this stage, additional measures are taken, such as stopping construction activities, closing brick kilns, and increasing the frequency of mechanized cleaning of roads.

• Stage IV: This stage is the most severe and is implemented when the AQI crosses 500. Under this stage, additional measures are taken, such as stopping entry of trucks into Delhi, closing schools, and implementing the odd-even scheme for private vehicles.

The Commission for Air Quality Management (CAQM) in NCR and adjoining areas oversees the implementation of GRAP, collaborating with the Ministry of Environment, Forest and Climate Change (MoEFCC) . GRAP is pivotal ...