The BSDMA officials will assess climate change and its impact in the region, recent changes in the land use pattern and its impact on current pollution level in the city.

The study will be conducted by dividing the city into various zones based on their pollution levels and the proposed field survey will be conducted using modern and accurate techniques. The study will also include preparation of pollution-based mapping of different areas. Sources said the inception report on the study is targeted to be readied by June-end.

"Patna has lately emerged as one of the most polluted cities in the country, primarily with regard to air pollution. Since no in-depth climate related vulnerability and risk analysis currently exists for the state, it is felt pertinent that such an in-depth vulnerability and risk analyses should be carried out. Besides, environment degradation has recently been included in the definition of disaster. Hence, we are going to conduct this study," said Vyasji, vice-chairman of BSDMA.

Senior BSDMA officials said Patna has been adjudged as third most polluted state capital in India. Pollution from the known sources includes road transport, industries, diesel generator sets, open waste burning, dust, construction activities and aviation.

Preliminary assessment of BSDMA suggests that the overall environmental condition in Patna has deteriorated due to a situation driven by population growth, unplanned development, migration, industrialisation and increased improper vehicle traffic moderation, depletion of green covers and increased construction activities.

Patna was declared the sixth most polluted city in the world in terms of level of PM2.5 (levels of ultra-fine particles of less than 2.5 microns which invade human lungs and causes cancer) by WHO in its report released in May last year.

Patna is apparently quite a noisy city too. The sound levels at most places in the city are recorded higher than the permissible limits almost throughout the year. This is primarily due to needless honking.

The permissible sound level in industrial area is 75dB at day time and 70dB at night time, 65dB and 55dB respectively in commercial area, 55dB and 45dB in residential areas and 50dB and 40dB in silence zones.

Water pollution too is a grave issue in the city. According to recent estimates, Patna generates 290 million litres of waste water on daily basis. Of the total sewage generated by the city, approximately two-third, or about 140 MLD, flows directly into the Ganga, polluting the river. The rest seeps underground, polluting the ground sources.