Iodine and Goitre in the Netherlands a Role for Nitrate Pollution?

Abstract

Iodized salt was introduced in The Netherlands in 1928 and the use was voluntary. In 1968 this preventive measure was replaced by the introduction of iodized bread salt. This salt was used by bakers in bread and contained 46 mg KI per kg salt. It became mandatory all over the country. The iodized salt (3–8 mg KI/kg) remained available for voluntary use. In 1974 the Ministery of Public Health decided that the iodized household salt was no longer necessary and the sale was stopped. During the seventies the consumption of bread per capita decreased. An epidemiological survey on goitre prevalence and urinary iodine excretion was carried out in 1976 by Tan et al¹. The main conclusion of this studie was that the existing level of iodine supplementation was insufficient to prevent endemic goitre especially in female adolescents. Based on these results a Committee of the National Health Board (1981) advised a revision of the goitre profylaxis measures¹, which were executed in 1982. Iodized household salt with a higher iodine content (23–29 mg KI/kg) was reintroduced and the iodine content of bread salt was raised from 46 to 60 mg KI per kg. In order to assess the effect of these revisions epidemiological surveys were carried out