Association of arsenic exposure with PDGF-BB in vitro and in a South Texas population exposed through drinking water.

Exposure to arsenic (As) from drinking water is a global public health concern, as As is a recognized carcinogen. Groundwater in South Texas, particularly in areas with Gulf Coast aquifers, contains high levels of As. Private wells are neither regulated nor regularly monitored, leaving residents vulnerable to arsenic exposure. This study aimed to investigate potential biomarkers of health effects for long-term, low-level As exposure among private well users in South Texas and to cross-validate findings using an in vitro model. Among 74 private well users, the association between urinary As levels and urinary LDH and 16 cytokine levels was assessed. After adjusting for covariates, linear regression analysis showed weak but significant associations between urinary total inorganic As levels and LDH (β = 0.37, p < 0.01, R(2) = 0.23) and PDGF-BB (β = 0.22, p = 0.02, R(2) = 0.17). However, no significant associations were found with other cytokines. To compare findings from the population study, SV-HUC-1 uroepithelial cells were exposed to 0.1 or 0.5 μM NaAsO₂ subchronically for 5 weeks, corresponding to total arsenic levels of 7.5 and 37.5 μg/L in drinking water. As exposure was not cytotoxic at either dose, as indicated by lactate dehydrogenase (LDH) activity. However, platelet-derived growth factor (PDGF)-BB protein levels showed a statistically significant increase at a lower concentration of 0.1 μM. These findings suggest that PDGF-BB may serve as a potential biomarker for low-level As exposure, but further studies are required for confirmation.