Pharmaceuticals in water as emerging pollutants for river health: A critical review under Indian conditions

• Published in: Ecotoxicology and environmental safety Vol. 247; p. 114220
• Main Authors: Ranjan, Nitin, Singh, Prabhat Kumar, Maurya, Nityanand Singh
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.12.2022; Elsevier
• Subjects: And River Health Condition; Emerging Pollutants; Indicator Group Score; Pharmaceutical Pollutants; River Health Index; And River Health Condition; Indicator Group Score; Pharmaceutical Pollutants; River Health Index; Emerging Pollutants
• ISSN: 0147-6513; 1090-2414; 1090-2414
• DOI: 10.1016/j.ecoenv.2022.114220

The wastewaters from pharmaceutical manufacturing units, hospitals, and domestic sewage contaminated with excretal matters of medicine users are the prime sources of pharmaceutical pollutants (PPs) in natural water bodies. In the present study, PPs have been considered one of the emerging pollutants (EPs) and a cause of concern in river health assessment. Beyond the reported increase in antibiotic-resistant bacteria (ABRB), PPs have been found adversely affecting the biotic diversity in such water environments. Considering Algae, Macroinvertebrates, and Fishes as three distinct trophic level indicators, the present study puts forward a framework for showing River Health Condition (RHC) based on the calculation of a River Health Index (RHI). The RHI is calculated using six Indicator Group Scores (IGS) which individually reflect river health in a defined category of water quality characteristics. While Dissolved Oxygen Related Parameters (DORP), Nutrients (NT), and PPs are taken as causative agents affecting RHCs, scores of Algal-Bacterial (AB) symbiosis, Macroinvertebrates (MI), and Fishes (F) are considered as an effect of such environmental conditions. Current wastewater treatment technologies are also not very effective in the removal of PPs. The objective of the present study is to review the harmful effects of PPs on the aquatic environment, particularly on the chemical and biotic indicators of river health. Based on predicted no-effect concentrations (PNEC) for algae, macroinvertebrates, and fishes in the aquatic environment and measured environmental concentration (MEC) in the river, the estimated risk quotient (RQ) for norfloxacin in the Isakavagu-Nakkavagu stream of river Godavari, Hyderabad is found 293 for algae, 39 for MI, and 335 for fish. Among PPs, in Indian rivers, the presence of caffeine is the most frequent, with algae at the highest level of risk (RQmax= 24.5). Broadly six PPs, including azithromycin, caffeine, diclofenac, naproxen, norfloxacin, and sulfamethoxazole are found above PNEC values in Indian rivers. The application of IGS and RHI in understanding and presenting the river health condition (RHC) through colored hexagons has been demonstrated for the river Ganga near Varanasi (India) as an example. Identification of critical indicator groups, based on IGS provides a scientific basis for planned intervention for river health restoration to achieve an acceptable category. [Display omitted] •A framework to to determine the RHC has been proposed based on water quality parameters including PPs and biotic indicators.•The toxicity of PPs on aquatic organisms has been projected based on PNEC and critical threshold concentration.•Azithromycin, caffeine, diclofenac, naproxen, norfloxacin, and sulfamethoxazole have been found in concentrations much above their PNEC values for the aquatic environment.•The risk quotient ranges from a modest value of 1.65 (for naproxen on macroinvertebrates) to more than 300 (for norfloxacin on fish).•IGSs and RHI are tools used for river health improvements with time along its course.