Arsenic contamination of drinking water is a major global health concern, including in parts of New Hampshire. Originating from both natural and anthropogenic sources, arsenic exposure is associated with severe health outcomes, although its precise mechanisms of toxicity remain incompletely understood. Tissue-specific vulnerability further complicates risk assessment, as certain organs may accumulate arsenic at higher levels than others. Environmentally relevant concentrations often do not cause immediate toxicity; however, arsenic readily crosses the placenta and has been linked to developmental defects in newborns. Despite these risks, few studies have quantified tissue-specific toxicity or somatic arsenic accumulation during long-term exposure. In this study, we employ laser ablation–inductively coupled plasma mass spectrometry (LA-ICP-MS) to quantify whole-body and tissue-specific arsenic accumulation in the model organism Daphnia under chronic exposure. Preliminary results indicate minimal short-term changes in whole-body accumulation, but elevated arsenic concentrations in tissues such as the brood pouch.