Bryan Adams' silhouette could easily be seen in the dusty air above the venue in Gurugram

The sight of Bryan Adams' silhouette in the dusty air above Gurgaon's Leisure Valley Park on Sunday might have been the only positive side-effect of the heavy, toxic smog that has engulfed the National Capital Region with the onset of the winter chill. However, with the pollution across Delhi-National Capital Region hitting "very poor" levels - that is over six times above the safe limit - residents have begun bracing themselves for the consequences it could have on their health.

Several mothers began reaching out to doctors, particularly cancer specialists.

"We are living in a very dangerous environment. If women who are expecting get exposed to this poor quality air, it will have an impact on the unborn child," said Anupam Sibal, group medical director, Apollo hospitals.

Experts say that children and pregnant mothers are the most vulnerable. They strictly warn against going outside and say that schools must do away with assembly or sports on days with poor air quality.

"Children start breathing in poison from the moment they are born and nobody bothers. This has to become an election issue. Everybody has to hit the streets. We have to make it difficult for our leaders because I really don't know what I am paying taxes for," said Jyothi Thyagarajan, development director, Ardee schools.

After his concert, Mr Adams posted a photo on Instagram, saying, "New Delhi, India you we're incredible tonight. In this photo, if you look carefully you can see my shadow silhouetted in the dust and smoke of the venue over the audience. I've never seen that before. Magical India. Namaste."

Last year, pollution levels climbed to 12 times above the recommended limit and the Indian Medical Association had declared a public health emergency. The government took a number of steps such as offering to pay up to 80 percent of certain farm equipment, such as a Straw Management System that attaches to a harvester and shreds the residue.

Despite these measures, crop-burning continues in several parts of Haryana and Punjab, mainly because the subsidy given for the Straw Management System and mulching machines wasn't covering the costs of the equipment and the labour involved. It was still much cheaper and easier to burn the residue.

With air quality across Delhi-National Capital Region worsening, the emergency Graded Response Action Plan (GRAP) to combat air pollution came into force on Monday and the Badarpur thermal power plant was shut down.

The overall air quality index (AQI) recorded at 4 pm Monday was 218 which falls in the poor category, according to Centre-run System of Air Quality and Weather Forecasting and Research (SAFAR).

However in some parts of Delhi and the National Capital Region, it was in the "very poor" category. According to the Central Pollution Control Board website, Anand Vihar recorded an AQI of 318, and Jahangirpuri recorded an AQI of 311

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'.

(With inputs from Reuters and PTI)