Deteriorating air and water quality of Punjab region during 2017 to 2021, using ground and satellite data

Punjab, the agrarian state, located in northern part of India, is subdivided in three regions: Malwa, Majha and Doaba. It is the major producer of wheat, rice, sugarcane, cotton, maize and pulses. Excessive pumping of groundwater for irrigation and crop residue burning every year greatly affect the air and water quality of the region. The poor air and water quality poses serious threat to human health. Malwa region of Punjab has emerged as cancer capital of the state. We have analyzed air and water quality of Punjab using satellite and ground data (Central Groundwater Board (CGWB)) for the periods 2017-2021 to observe recent change in pollution levels. The aerosol optical depth (AOD) varies from 0.04 to 3.5 and angstrom exponent (AE) varies from 0.0 to 1.80 during 2017-2021. Higher values of AE attribute to smoke due to anthropogenic activities, and are observed in pre-monsoon (Feb-April) and post-monsoon (Sept-Nov) periods. Similarly, Methane (CH4) is increased from 1944.60ppbv in 2017 to 1953.91ppbv in 2021, Nitrogen dioxide (NO2) is increased from 9.27×1015 molecules/cm2 in 2017 to 9.56×1015 molecules/cm2 in 2021, and Carbon monoxide (CO) is increased from 194.06ppbv in 2017 to 209.78ppbv in 2021.

The spatial variation of groundwater quality shows that south-western part of Punjab is more polluted than other parts of the state. The districts that fall under this region are Bathinda, Faridkot, Fazillka, Fatehgarh Sahib, Mansa, Moga, Muktsar and Sangrur. Our study shows that ~92% of groundwater samples collected from Faridkot district have fluoride (F) concentration above permissible limit of 1mg/l. Furthermore, piper trilinear diagram shows that 67.8% of groundwater samples are HCO3 type in the year 2017 and it increased to 73.19% in the year 2020. Sodium Absorption Ratio (SAR) index, is calculated which shows that nearly 43% groundwater samples have SAR index higher than 3 in 2017 and it is increased to nearly 52% in the year 2020. Similarly, 18 groundwater samples have TDS, higher than 3000mg/l in the year 2017, and groundwater samples from 21 locations have TDS higher than 3000mg/l in the year 2020. This shows that air and water quality has deteriorated during 2017-2021 and if proper mitigation measures are not taken, then the environmental quality of Punjab will continue to degrade and affect the human health.