Prevalence and integrated risk assessment of antibiotics from River Chenab Pakistan; human and ecotoxicological prospectives

Abstract

Antibiotics are widespread consumed and released into the riverine ecosystem of Pakistan without proper treatment. This pioneering study investigated fluoroquinolones, macrolides, oxazolidinones and cephalosporins antibiotics from 11 sites of the Chenab River, Pakistan. Ecotoxicological and human health risk characterization was performed through GIS based geostatistical approaches, equipped with integrated risk modeling. Antibiotics were extracted via SPE, while analytical results were obtained through HPLC equipped with UFLC-PDA. Azithromycin was found most prevalent antibiotic across the study area (18.32 ± 2.69 μg/L). Ofloxacin, cefixime and ciprofloxacin were also detected in considerable concentration (6.70 ± 4.89, 1.67 ± 3.57 and 1.66 ± 2.93 μg/L, respectively). Single pollution index revealed the predominance of azithromycin throughout the study area, highlighting >62 % of areas as potential risk zones. Similar results were extracted through comparative pollution index, highlighting the Chenab River as polluted zone. Ecotoxicological risks characterization was determined by risk quotient (RQ), where RQ for azithromycin was18, which unveiled serious ecotoxicological threat. Health quotient (HQ_HH), health index (HI) and drinking water equivalent levels (DWEL) reflected that ofloxacin (chronic daily oral intake 1.8 × 10⁻⁴ and dermal 2.2 × 10⁻³) and ciprofloxacin exhibited potential risk to human health while azithromycin (chronic daily dermal exposure: 6.2 × 10⁻³) also posed considerable health risk to life. These results are the indication of possible risks associated with the prevalence of antibiotics in the Chenab River and needs to be considered a threat to be treated on priority basis by the concerned governmental authorities of the country.