As Delhi and the National Capital Region saw a sharp decline in air quality levels, the Indian Medical Association (IMA) declared the city in a public health emergency state.

As Delhi and the National Capital Region saw a sharp decline in air quality levels and recorded 'very poor' air quality, the Indian Medical Association (IMA) declared the city in a public health emergency state and urged schools to stop all outdoor activities to keep children out of hazardous air pollution levels.

While talking to ANI, IMA president KK Aggarwal further suggested that schools must be shut and people must stop stepping out.

IMA declares Delhi in public health emergency state,schools shld be shut & ppl must avoid stepping out-IMA Pres Dr.KK Aggarwal #AirPollution pic.twitter.com/mJ3SbVlGft — ANI (@ANI) November 7, 2017

India Today accessed a copy of the IMA letter addressed to Chief Minister Arvind Kejriwal and Delhi minister Manish Sisodia and Aggarwal wrote, "children are more prone to harmful effects of air pollution as their lungs are still growing... Breathing polluted air can hamper the growth of their lungs leading to breathing problems later on in life."

The IMA also appealed to Kejriwal to issue an advisory for all schools in Delhi-NCR, which should be disseminated through different media such as radio, print and social media.

Following this, the chief minister requested Sisodia to consider shutting down schools for a few days, CNN-News18 reported.

The IMA also requested Kejriwal to cancel the Airtel Delhi Half Marathon scheduled for 19 November, according to DNA.

"The air quality is particularly poor in the early morning when pollution is extremely high. This is also the time when the proposed Half Marathon is scheduled to start. The hazardous pollution levels may have disastrous health consequences, even for the healthy participants," said the letter, according to the DNA report.

India Today further reported that the letter said when the Air Quality Index crosses 200, time spent outdoors should be restricted.

The city's air has witnessed a rise in the air pollutant level with Delhi's average Air Quality Index (AQI) being 411 at 9 am on Tuesday morning, as per News18. According to reports, visibility dropped to 200 metre at 8.30 am. Mathura Road was at 441, which is one of the highest in the city.

In Noida, AQI was 430 at 9.30 am. Low visibility in the city resulted in slow traffic, reported Hindustan Times while adding that long traffic queues were seen on the Delhi-Noida-Delhi Flyway and Noida-Greater Noida expressway.

Over 20 flights were delayed or affected due to runway closure and smog at Indira Gandhi International Airport, reported ANI.

The Central Pollution Control Board (CPCB) said high moisture level in the air has trapped emissions from local sources and hanging low over the city in the absence of wind. Dipankar Saha, CPCB's air lab chief, told PTI that air from neighbouring Punjab and Haryana, where paddy stubble burning is in full swing, is not entering the city as of now. When it starts, the situation is expected to deteriorate further. The CPCB recorded 'very poor' air quality in the national capital. Neighbouring Noida and Ghaziabad, however, recorded 'severe'air quality.

According to the graded response action plan, when AQI hits severe levels, agencies are supposed to take counter measures, reported Hindustan Times. These include, enhancing public transport services with differential pricing to encourage off-peak hour travel, and increasing the frequency of mechanized cleaning of roads and sprinkling of water on roads.

With inputs from PTI