DECIPHERING THE EARTH’S ARSENIC ENIGMA: A COMPREHENSIVE EXAMINATION OF GLOBAL GROUNDWATER CONTAMINATION

Abstract

Background: Arsenic contamination in groundwater is a major global environmental and public health issue, affecting over 150 million individuals across more than 70 countries. Toxic inorganic arsenic species, arsenite (AsIII) and arsenate (AsV), significantly disrupt cellular processes, causing oxidative stress and leading to severe health risks such as arsenicosis, cardiovascular diseases, neurotoxicity, and multiple cancers. Major river basins and deltas, including the Bengal and Mekong Deltas, exhibit arsenic levels exceeding World Health Organization (WHO) guidelines of 10 ppb, impacting vulnerable populations disproportionately.

Objective: To comprehensively examine the sources, health effects, and mitigation strategies for arsenic contamination in groundwater on a global scale, with a focus on current challenges and regional disparities.

Methods: A systematic review was conducted, synthesizing data from over 100 peer-reviewed studies published in the last decade. Arsenic concentration data from affected regions were evaluated, alongside epidemiological studies on health outcomes. Mitigation strategies, including deep groundwater extraction, well switching, and oxidation methods, were analyzed for effectiveness and limitations based on field trials and global implementation reports.

Results: Groundwater arsenic levels varied widely, with concentrations ranging from <0.5 ppb to over 5000 ppb globally. In Bangladesh, over 45 million people are exposed to arsenic levels exceeding 50 ppb, compared to 20% of deep wells in Vietnam exceeding WHO guidelines. Health effects included a 30% increase in cardiovascular dysfunction and a 25% higher incidence of neurotoxicity in regions with elevated arsenic exposure. Mitigation strategies demonstrated regional variability, with deep tube wells reducing arsenic levels below 10 ppb in 95% of tested wells in Bangladesh, while oxidation achieved up to 99% arsenic removal under controlled laboratory conditions.

Conclusion: Arsenic contamination in groundwater remains a critical threat to global public health. Although existing mitigation strategies show promise, their effectiveness is challenged by high costs, regional variability, and socioeconomic disparities. Ongoing research, adaptive solutions, and international collaboration are essential to reducing the health and environmental impacts of arsenic exposure.