Ambient black carbon, PM2. 5 and PM10 at Patna: Influence of anthropogenic emissions and brick kilns

Particulate Matters like Black Carbon, PM2.5 and PM10 present in the atmosphere not only poses a threat to human health but also contributes to near-term regional and global atmospheric warming. There has been a large concern of this kind of pollutants in Indo-Gangetic Plains (IGP). Hence, an attempt has been made to see the impact in one of the highly developing city of IGP as Patna. This city has been ranked among the top 100 air polluted cities in the world. To establish the role of BC, PM2.5, and PM10 on local air quality, continuous measurements were conducted at seven locations of Patna from January to December 2015. The seasonal mass concentration of BC were 13.92 ± 3.48 μgm− 3 in the winter, 9.65 ± 3.0 μgm− 3 in the pre-monsoon, 5.83 ± 1.90 μgm− 3 in the monsoon and 7.86 ± 3.66 μgm− 3 in the post-monsoon. Similarly, the seasonal concentrations of PM2.5 (PM10) were 68.86 ± 18.83 μgm− 3 (108.13 ± 21.49 μgm− 3) in the winter; 64.62 ± 18.76 μgm− 3 (93.45 ± 18.42 μgm− 3) in the pre-monsoon; 37.83 ± 11.27 μgm− 3 (62.82 ± 14.81 μgm− 3) in the monsoon and 40.14 ± 16.66 μgm− 3 (64.72 ± 22.40 μgm− 3) in the post-monsoon. About 76.67% of PM2.5 and 87.78% of PM10 concentrations were greater than NAAQ Standards in the winter on a daily basis and 46.74% and 36.96% in the pre-monsoon season. The backward trajectory analysis was also carried out through HYSPLIT model which suggests that the additional source of these pollutants during the winter and pre-monsoon season from the northwest and northern region of Patna. The ratios of PM10/PM2.5 observed at brick kilns cluster monitoring locations during the brick manufacturing period were significantly higher (0.87–4.48 μg μgm− 3) than other monitoring sites and increase the level of these pollutants over the city.