Spatio-temporal variations in fine particulate matter and evaluation of associated health risk over Pakistan

Human health and the environment are adversely affected by fine particulate matter. By utilizing standard deviation ellipse and trend analyses, we studied the spatial patterns and temporal trends of PM_2.5 over Pakistan from 1998 to 2016. The outcomes of these analyses indicated that PM_2.5 concentrations were considerably amplified in Pakistan, particularly in the provinces of Punjab and Sindh. The areal extent of PM_2.5 concentrations below 15 μg/m³ declined constantly, and the area with PM_2.5 concentrations above 35 μg/m³ increased significantly. The highly affected cities were Lahore, Faisalabad, Multan, Southern Gujranwala, Dera Ghazi Khan, Bahawalpur, Sukkur, and Larkana. Overall, the northwest-southeast axis experienced more rapid variations in the spatial pattern of PM_2.5 than the northeast-southwest axis; similarly, the east-north axis also experienced faster changes in the spatial distribution of this crucial pollutant than the west-south axis. To support nationwide air pollution control, a two-tier level was recommended for allocated regions in Pakistan depending on their PM_2.5 concentrations. From 1998 to 2016, health risks expanded and increased in Pakistan, particularly in Lahore, Karachi, Multan, Gujranwala, Faisalabad, and Hyderabad; these are Pakistan's most populated cities. The outcomes of this study suggest that human health is continuously affected by PM_2.5 in Pakistan, and that a plan of action to combat air pollution is immediately needed. Integr Environ Assess Manag 2021;17:1243-1254. © 2021 SETAC.