Phthalate ester contamination in groundwater at the Himalayan-Potohar Interface: health risks in Rawalpindi, Pakistan

Phthalate esters (PAEs) are synthetic chemicals widely used as plasticizers, leading to their presence as environmental contaminants with potential health risks. This study investigates the occurrence and concentration of three phthalate esters (PAEs), dibutyl phthalate (DBP), diethyl phthalate (DEP), and dimethyl phthalate (DMP), in groundwater from Rawalpindi City, Pakistan. Fifteen samples were collected and analyzed using liquid-liquid extraction with dichloromethane and gas chromatography-mass spectrometry (GC/MS). DBP was the most frequently detected PAEs, followed by DEP, while DMP was not present in any sample. DBP concentrations ranged from < 0.042 to 0.170 μg/L, and DEP from < 0.011 μg/L, both below USEPA's maximum contaminant limits. Temperature and time were found to influence PAE migration in groundwater. Health risk assessments using the exposure index (EI) and hazard quotient (HQ) showed that all HQ values were below 1 (HQ < 1), indicating no carcinogenic risk. The estimated daily intake of DBP contributed up to 0.71% of the tolerable level for adults and 0.05% for children. The findings confirm that PAEs in the groundwater samples are within safe limits, posing no immediate health risks. However, ongoing monitoring is recommended to assess potential long-term exposure effects.