Use of iodine for water disinfection: iodine toxicity and maximum recommended dose.

Abstract

Iodine is an effective, simple, and cost-efficient means of water disinfection for people who vacation, travel, or work in areas where municipal water treatment is not reliable. However, there is considerable controversy about the maximum safe iodine dose and duration of use when iodine is ingested in excess of the recommended daily dietary amount. The major health effect of concern with excess iodine ingestion is thyroid disorders, primarily hypothyroidism with or without iodine-induced goiter. A review ofthe human trials on the safety ofiodine ingestion indicates that neither the maximum recommended dietary dose (2 mg/day) nor the mum recommended duration of use (3 weeks) has a firm basis. Rather than a clear threshold response level or a linear and temporal dose-response relationship between iodine intake and thyroid function, there appears to be marked individual sensitivity, often resulting from unmasking ofunderlying thyroid disease. The use of iodine for water disinfection requires a risk-benefit decision based on iodine's benefit as a disinfectant and the changes it induces in thyroid physiology. By using appropriate disinfection techniques and monitoring thyroid finction, most people can use iodine for water treatment over a prolonged period of time. Key worni goiter, iodine, thyroid disorders, thyroid hormones, water purification, water supply.

Iodine Nutrition: Iodine Content of Iodized Salt in the United States

“…In Spain, tablets containing 200 µg of iodine are made available to pregnant and lactating women through the national health system (79). Many travelers and others use iodine for water disinfection for which the recommended upper limit is 2 mg/day and a maximum period of 3 weeks (80).…”

Knowledge to Predict Pathogens: Legionella pneumophila Lifecycle Critical Review Part I Uptake into Host Cells

“…However, bromine is not recommended for potable drinking water, and there is controversy surrounding safe levels of consumption over an extended period with iodine [120,146]. While both are oxidizing agents similar to chlorine, neither is as effective as chlorine at inactivating L. pneumophila.…”

Iodine [MAK Value Documentation, 2006]

“…Case reports without exposure data are not described here; see the sources mentioned above and reviews (Backer and Hollowell 2000;Pennington 1990). Table 1 summarizes exemplary data for repeated treatment with iodine at known exposure levels.…”

“…This daily dose, however, does not take into account sensitive groups (such as thyroid patients suffering, for example, from thyroiditis, hyperthyroidism, hypothyroidism or goitre, or persons taking medication containing iodine such as amiodarone, an agent for cardiac arrhythmia) (ATSDR 2004;Backer and Hollowell 2000;Pennington 1990). …”