Human Health Risk Assessment Based on Lead (Pb) Exposure from Drinking Water and Aquatic Food in Pontianak, Indonesia

Abstract

Lead (Pb) exposure through drinking water and aquatic food remains a serious public health issue, particularly in tropical urban areas. This study aims to identify the main sources of Pb exposure in the community of Pontianak City through analysis of rainwater, refill water, tilapia, shrimp, shellfish, and fish-based processed foods. The study was conducted using a cross-sectional observational design, involving 37 rainwater samples, 23 refill water samples, and 60 food samples. Analysis using the AAS method showed that the average Pb level in rainwater reached 0.093 mg/L (0.040–0.160 mg/L) with 100% of samples exceeding the WHO threshold (0.01 mg/L), while in refilled water the average was 0.012 mg/L (0.009–0.020 mg/L) and 39.1% exceeded the standard. In food, shellfish had the highest Pb content at 0.42 mg/kg (0.20–0.68 mg/kg) with 42.9% exceeding the Codex standard (0.3 mg/kg), followed by shrimp at 0.35 mg/kg (36.7%), tilapia at 0.22 mg/kg (13.6%), and fish nuggets 0.05 mg/kg (0%). Daily intake estimates show that rainwater consumption contributes 0.186 mg/day, much higher than refill water (0.024 mg/day). The combination of rainwater and shellfish resulted in a total Pb intake of 0.228 mg/day (81.6% from water, 18.4% from food), while the combination of refilled water and shellfish was only 0.066 mg/day. The highest Estimated Weekly Intake (EWI) value reached 26.6 µg/kg bw/week, approaching the international reference threshold. The results of the study confirm that collected rainwater is the dominant route of exposure, while shellfish and shrimp are significant additional sources. These findings underscore the urgency of mitigation through improvements in rainwater harvesting quality, enhanced monitoring of refill depots, and control of consumption of certain aquatic foods.