"We have to take this as a public health emergency as air pollution will have adverse health impact on all, particularly our children," he said in the letter.
Under these circumstances, he said, construction activities, hot mix plants and stone crushers in Delhi, Faridabad, Gurugram, Ghaziabad, Noida and Greater Noida will remain closed till the morning of November 5.
The EPCA also asked implementing agencies to take immediate stringent action to stop stubble-burning in the neighbouring states of Punjab and Haryana.
Stubble-burning in the neighbouring states has been one of the major contributors to pollution in the national
capital. On Thursday, stubble-burning in Punjab and Haryana contributed to 27 per cent pollution in Delhi, while on Wednesday the contribution was recorded at 35 per cent, the highest so far.
The Environment Pollution (Prevention and Control) Authority also directed the agencies to take strict action against biomass-burning in Delhi and the outer National
"The Environment Pollution (Prevention and Control) Authority has directed implementing agencies to take immediate stringent actions to stop stubble-burning in neighbouring states of Punjab and Haryana," according to a letter EPCA chief Bhure Lal wrote to the chief secretaries of the two states.
According to data from Punjab and Central Pollution Control Boards, the state has recorded a whopping increase of 7,842 fires -- from 12,027 on October 27 to 19,869 on October 30.
Haryana recorded an increase of 476 cases from 3,735 on October 27 to 4,211 on October 30.
An AQI between 0-50 is considered 'good', 51-100 'satisfactory', 101-200 'moderate', 201-300 'poor', 301-400 'very poor' and 401-500 'severe'. Above 500 falls in the 'severe-plus emergency' category.