Sources and Variability of Petroleum Hydrocarbon Residues in Sediments of Chilika Lagoon, East Coast of India

Imprints of COVID-19 lockdowns on total petroleum hydrocarbon levels in Asia's largest brackish water lagoon

“…The TPHC concentrations in surface waters varied from 0.19 to10.61 μg L −1 , with an average of 2.33 ± 2.28 μg L −1 during the study period (S. T3). On comparing these TPHC levels with the levels reported by the limited number of previous studies conducted in India, we found that a significantly higher TPHC level was observed by Mohanty et al (2017) (S. T1) in the Chilika lagoon (0.45–44.03 μg L −1 ), whereas a similar range of TPHC had been reported from the coastal waters off Chennai ( Veerasingam et al, 2011 ) and a comparatively low TPHC level (0.04–1.58 μg L −1 ) was recorded in the coastal waters off Chilika in the Bay of Bengal ( Panigrahy et al, 2014 ). Overall, the TPHC concentrations in the surface waters of Chilika lagoon from the present study are well below the threshold limits (PHC > 100 μg L −1 ) prescribed for the sustainability of biotic life of aquatic and marine environments by the Central Pollution Control Board, Government of India ( CPCB, 1986 , CPCB, 1993 ), and the U.S Environmental Protection Agency (USEPA, 1986).…”

“…Assessment of TPHC and its derivatives in inland and estuarine aquatic environments has received considerable attention in recent times due to their toxic, mutagenic, and carcinogenic characteristics and because they readily transform into hydrophilic metabolites and accumulate into the aquatic environment (i.e., fish, shellfish, etc.) ( Mohanty et al, 2017 ; Hemalatha et al, 2020 ). Coastal lagoons are also vulnerable to TPHC and derivatives as they could be sourced from natural or anthropogenic activities that include point discharges and urban runoff, with a significant contribution from boat activities for fishery and tourism.…”

“…Expanded literature on the impacts and dynamics of TPHC in natural waters is provided in the Supplementary section and tables (S.1; S. T1 and S. T2). Several past studies from Indian coastal environments have studied TPHC magnitude and dynamics (Venkatachalapathy et al 2012; Mohanty et al, 2017 ; Hemalatha et al, 2020 ). However, so far, there have been no reports on the impact of the lockdown (due to the COVID-19 pandemic) on the variability of TPHC in those systems.…”