A comprehensive survey and analysis of international drinking water regulations for inorganic chemicals with comparisons to the World Health Organization’s drinking-water guidelines

Abstract

Background The World Health Organization (WHO) has published criteria for determining the quality of drinking water since 1958. Since 1984, these criteria were termed “guidelines” to emphasize that they are not national standards, but rather guidelines for nations to develop their own national standards, which may take into account local environmental, social, economic, and cultural conditions. When calculating guideline values (GVs), the WHO reviews the toxicological literature, calculates a health-based value (HBV), and determines whether the HBV should be adopted as a GV. The WHO also considers aesthetic aspects of drinking water quality, such as taste and the staining of plumbing fixtures, and additionally supplies aesthetic values (AVs) for certain drinking water contaminants. There is no central registry for national drinking water standards, so the degree of variation of national drinking water standards is not known. Methods We examined standards, guidelines, and background documents for all inorganic contaminants published by the WHO from 1958–2022. We also searched for national drinking water standards for all independent countries. Results We found the WHO currently has 16 GVs, six HBVs without GVs, and six AVs without HBVs or GVs for inorganic drinking water contaminants, excluding disinfection agents and their byproducts. More than half of the point of departure studies used to support these values were published in 2005 or earlier. Ninety-eight percent of the world’s population lives in jurisdictions with drinking water standards, and 14 countries directly link their national standards to the current WHO’s drinking water guidelines. Lack of transparency (standards available only through purchase) and typographical errors are common problems, especially for resource-limited countries. Conclusions The WHO drinking water guidelines are crucially important for drinking water safety; they are used for guidance or as official standards throughout the world. It is crucial that they be based on the best available science.

3D-Printed Fluorescent Hydrogel Consisting of Conjugated Polymer and Biomacromolecule for Fast and Sensitive Detection of Cr(VI) in Vegetables

“…10,11 Consequently, the World Health Organization (WHO) has established a stringent maximum tolerable level of 0.05 mg/L for Cr 2 O 7 2− in drinking water. 12 Thus, rapid, convenient, and accurate monitoring of Cr 2 O 7 2− concentration is crucial for devising a reasonable and feasible treatment plan.…”

“…Among various heavy metal ions, Cr 2 O 7 2– is a common yet extremely toxic pollutant, owing to its widespread use in industries such as textile, metal, leather tanning, water cooling, and electroplating. − Compared to other metal ions such as Fe 3+ , Cu 2+ , Hg 2+ , and Pb 2+ , the emission of Cr 2 O 7 2– is relatively low, contributing to a concealed effect that often goes overlooked. − However, Cr 2 O 7 2– is nonbiodegradable, which will persist, accumulate, and migrate in the environment. It not only adversely impacts plant growth and development, but also threaten ecological security, thus influencing the quality of agricultural products, and jeopardizing human health through the food chain, with reported risks of cancer from long-term and short-term exposure to Cr 2 O 7 2– . − Drinking water stands out as a particularly vulnerable resource to Cr 2 O 7 2– contamination, ascribing to the high solubility of Cr 2 O 7 2– in water. , Consequently, the World Health Organization (WHO) has established a stringent maximum tolerable level of 0.05 mg/L for Cr 2 O 7 2– in drinking water . Thus, rapid, convenient, and accurate monitoring of Cr 2 O 7 2– concentration is crucial for devising a reasonable and feasible treatment plan.…”