Frisbie & Mitchell 2022 — Global arsenic drinking water regulations
Frisbie and Mitchell systematically collated arsenic (As) drinking water regulations from 176 countries worldwide, finding that 136 have maximum allowable concentrations of 10 µg/L or less while 40 permit more than 10 µg/L; regulations for 19 countries could not be found. The WHO’s provisional 10 µg/L guideline, set in 1993 on the basis of analytical achievability rather than health-based risk assessment, is shown to be inadequate, and the authors argue that lower, more protective standards are both scientifically warranted and technologically feasible for countries at all income levels.
Key numbers
Standards identified for 176 countries. Range of maximum allowable concentrations: 1–500 µg/L. Mode: 10 µg/L. Countries permitting more than 10 µg/L: 40 (constituting 32% of global population). Countries with regulations at or below 10 µg/L: 136. Countries with no evidence of any regulation: 19. WHO provisional guideline: 10 µg/L (set 1993, rationale updated 2011 to add “treatment performance” proviso but health-based value not revised). Risk assessments cited indicate a lower health-protective threshold is warranted. High-income countries disproportionately meet the WHO guideline; low-income countries are more likely to use the older 50 µg/L standard (originally set by WHO in 1963).
Lowest national standard found: 1 µg/L (possibly a typographical error). Highest: 500 µg/L (several low-income countries). Countries still using 50 µg/L include Angola, Benin, and others citing the 1963 WHO standard.
Methods: systematic search of national government sources (Law Library of Congress, FAOLEX, official gazettes), Google Scholar, and direct contact with regulatory agencies; data cross-checked against prior partial surveys. Analysis performed in R 4.1.1. Population and GDP data sourced from the World Bank (2019).
Methods (brief)
Systematic review of primary legislation and secondary evidence for drinking water As regulations globally. No analytical measurements of water As concentrations; the paper analyzes regulatory limits, not measured concentrations. No LOD/LOQ applicable.
Implications
Certification: This paper establishes that a large share of global population lives under inadequate As drinking water protections, directly relevant to the HMT&C framework for establishing defensible exposure baselines. The WHO 10 µg/L provisional guideline cannot be used as a safe-level claim; the paper explicitly argues it is insufficiently health-protective.
Courses: Foundational context for any module on arsenic exposure pathways, regulatory frameworks, and the gap between current standards and health-based targets.
App: Drinking water is a significant As exposure route (especially in Bangladesh, India, Argentina, Mexico, Vietnam); app risk models for populations in high-prevalence regions should not assume regulatory compliance equals safety.