Hundreds of millions worldwide, primarily in low and middle-income countries, rely on groundwater for drinking and cooking, especially in coastal regions. An estimated 300 million people live in these vulnerable coastal areas. This groundwater source is increasingly threatened, posing a significant and largely unaddressed public health risk. The core issue centers around potential contamination of this water supply, which could lead to increased instances of high blood pressure and related mortality. This silent threat requires urgent investigation and mitigation strategies to protect these at-risk populations. Further research is needed to determine the extent of contamination and develop sustainable solutions for safe water access. Failure to address this issue could have devastating consequences for global public health.