Water usage pattern of peri-urban community in the river basin: analyzing crucial variables for human exposure model

Abstract

The human exposure model (HEM) is an important tool to predict the amount of contaminants carried by water to the community. Proper input variables play a crucial role in running the HEM, which is often scarce, particularly in low- and middle-income countries like Indonesia. To overcome that problem, we conducted a water demand survey of 10 water-related activities in a peri-urban community of the Upper Citarum River Basin. The survey resulted in three main variables of the exposure model from those activities, i.e. frequency, volume, and duration. This study aims to analyze if the contaminant uptakes from the HEM output were significantly different between groups (i.e.: male and female groups, 18 – 65 y.o. and ≥ 65 y.o. groups) and which exposure routes and water-related activities contribute the most to the contaminant’s total uptake by using statistical and proportional analysis. The output of carbofuran deterministic modelling showed the average total uptake was 1.06.E+00 ng/kg/day. The statistical analysis revealed a significant difference between oral and dermal uptake, but there was no significant difference in total uptake between gender and age groups. After conducting the proportional analysis, it was found that oral uptake contributed almost 99% to the total uptake of carbofuran. The analysis also showed that drinking and cooking were two activities contributing the most to the total uptake. This study’s results are necessary for health risk assessment and HEM development, especially in the field of river basin management.