Occurrence, spatial variation and risk assessment of pharmaceuticals and personal care products in urban wastewater, canal surface water, and their sediments: A case study of Lahore, Pakistan.

Due to the lack of wastewater treatment facility in Pakistan, the wastewater is directly discharged via urban drains, which might cause a high load of contaminants of emerging concerns and potential environmental risks. The present study focused on the occurrence and risk assessment of 52 pharmaceuticals and personal care products (PPCPs) of diversified classes in the water and sediment samples of urban drains and canal of Lahore, Pakistan. Non-steroidal anti-inflammatory drugs were the predominant PPCPs detected in the wastewater of urban drains and surface water of canal. The highest concentration was observed for acetaminophen, with median concentration of 13,880 ng/L followed by caffeine with median concentration of 6200 ng/L. Antibiotics were the predominant PPCPs in the sediment samples with highest concentration of ofloxacin (median value of 1980 μg/kg) followed by ciprofloxacin and oxytetracycline. Spatial variation showed that the population density has significant correlation with the level of many PPCPs in surface water while one of the drainage systems is affected by the direct wastewater discharge from the nearby industrial area. Ecological risk assessment in terms of risk quotient revealed that most of the PPCPs may cause high risk to the aquatic community. This high risk may lead to further contamination of food and crops, therefore enforcement of environmental legislations for treatment of wastewater is recommended.