Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. 
Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. What was reviewed?
This invited commentary critically reviews the historical development, scientific rationale, and ongoing debates regarding the safety of the World Health Organization’s (WHO) provisional guideline of 10μg/L for arsenic in drinking water. The focus keyphrase, “arsenic in drinking water,” is central to the discussion as the authors assess epidemiological evidence linking chronic arsenic exposure to numerous adverse health effects, including various cancers and systemic diseases. The review scrutinizes the evolution of regulatory thresholds, the uncertain nature of low-dose toxicity, and the methodological challenges in assessing health risks at or below the current guideline. The commentary further evaluates the practicalities of risk modeling, analytical limitations, and the divergence in regulatory approaches internationally. It underscores the complexities of defining a health-based standard for arsenic in drinking water, highlighting both scientific uncertainties and technological constraints that influence policy and industry practices.
Who was reviewed?
The review synthesizes findings from a broad array of epidemiological studies, regulatory documents, and case studies involving human populations exposed to arsenic in drinking water. The populations covered include communities in high-arsenic regions such as Bangladesh, Chile, and Taiwan, where significant epidemiological data have been gathered on the health impacts of chronic arsenic exposure. Additionally, the commentary references regulatory experiences from Western Europe and North America, including detailed case examples from Denmark, New Jersey, and the Netherlands regions, where arsenic in drinking water occurs at lower concentrations. The review also considers the perspectives of regulatory authorities, water utilities, and health agencies that have shaped or implemented arsenic standards. By integrating evidence from diverse populations and regulatory contexts, the commentary provides a comprehensive perspective on the global challenges of managing arsenic in drinking water.
Most important findings
| Critical Points | Details |
|---|---|
| Historical evolution of standards | The WHO guideline for arsenic in drinking water has progressively lowered from 200μg/L in 1953 to the current provisional value of 10μg/L, reflecting increasing concern over carcinogenicity and other health effects. |
| Health effects at high vs. low concentrations | Chronic exposure to arsenic above 10μg/L is well-established as a cause of skin, lung, bladder, kidney, and liver cancers, as well as dermatological, neurological, cardiovascular, immunological, and endocrine effects. However, health risks at or below 10μg/L remain uncertain due to limitations in epidemiological evidence and risk modeling at low doses. |
| Risk assessment challenges | The commentary highlights uncertainty in the dose-response relationship for low-level arsenic exposure. Debates persist over whether arsenic has a threshold below which it is not harmful, or if any exposure carries risk due to its genotoxicity. This impacts the derivation of tolerable daily intakes and acceptable risk levels. |
| Analytical and treatment limitations | The 10μg/L provisional guideline is influenced not only by health risk models but also by the practical detection limits and treatment capabilities of water utilities at the time the standard was set. Some countries have since achieved lower targets (e.g., 5μg/L in Denmark and New Jersey, <1μg/L in the Netherlands), indicating technological progress. |
| Regulatory implications and global diversity | There is significant variation in acceptable risk levels and regulatory responses globally. The commentary emphasizes that while mathematical models can set ambitious targets, actual standards are determined by technological feasibility and local risk management priorities. |
Key implications
For the heavy metal certification program, the review of arsenic in drinking water underscores the need for continuous improvement in detection and removal technologies, as well as the adoption of precautionary approaches. Regulatory standards may lag behind scientific understanding, so certification should prioritize achieving the lowest reasonably achievable arsenic levels, reflecting global best practices.
Citation
Ahmad A, Bhattacharya P. Arsenic in Drinking Water: Is 10μg/L a Safe Limit? Curr Pollution Rep. 2019;5:1–3. doi:10.1007/s40726-019-0102-7
Arsenic is a naturally occurring metalloid that ranks first on the ATSDR toxic substances list. Inorganic arsenic contaminates water, rice and consumer products, and exposure is linked to cardiovascular disease, cognitive deficits, low birth weight and cancer. HMTC’s stringent certification applies ALARA principles to protect vulnerable populations.
Arsenic is a naturally occurring metalloid that ranks first on the ATSDR toxic substances list. Inorganic arsenic contaminates water, rice and consumer products, and exposure is linked to cardiovascular disease, cognitive deficits, low birth weight and cancer. HMTC’s stringent certification applies ALARA principles to protect vulnerable populations.
