Background:Arsenic(As)is a toxic element that can lead to various health issues in humans.The primary exposure to As is through the consumption of water contaminated with high As levels,particularly in Bangladesh.Previous studies have shown that urinary arsenic(UAs)concentration can reflect As exposure and metabolism in individuals.However,little is known about how other factors,such as age,sex,and socioeconomic status,may affect UAs concentrations in children. Objective:This study aimed to investigate the influence of factors such as age,sex,and socioeconomic status on UAs concentrations in children,in addition to the impact of drinking water arsenic(WAs)levels. Methods:We conducted our study on elementary school-going children aged 8-11 years from rural Araihazar in Bangladesh.We measured UAs(available for a subset of 391 children)and WAs levels and collected information on demographic and socioeconomic characteristics.We employed regression analysis and t-tests to analyze the data. Results:Our findings revealed that younger children(β=197.95,95％confidence interval[CI]:111.97 to 283.94),female children(β=93.95,95％CI:8.49 to 179.40),and children with less educated fathers(β=138.03,95％CI:26.47 to 249.58)had higher UAs levels,particularly when they consumed water with high As content. Conclusion:The study concludes that children's As exposure and UAs concentration may vary depending on their age,sex,and socioeconomic status.Therefore,these factors should be considered when assessing the health risks associated with As.