Rats were exposed to nitrate (NO3-) in drinking water, to phenylmercuryacetate (PMA) by gavage and to NO3- and PMA together during 4 different experiments. PMA impaired kidneys, NO3- thyroid gland, and NO3- and PMA together both organs. In the last case a synergistic effect on the thyroid gland was shown. The lowest effective concentration of NO3- was 40 mg/l. It resulted in histomorphological changes of the thyroid epithelial cells. That low effective dose of NO3- and possible synergistic effects should give a further impulse to take into consideration not only a low iodide intake but also goitrogenic environmental chemicals when evaluating the endemic goitre prevalence.

Two different experiments on rats were carried out: an acute intoxication causing clinical symptoms and a subchronical intoxication without any symptoms. After the acute experiment an increase of hemoglobin- and hematocrite values as well as of the mean corpuscular hemoglobin concentration was found. These differences are interpreted to be an increased erythropoiesis after hypoxia. Following the subchronical experiment the parameters mentioned above had decreased. These results linked up to anisocytosis, poikilocytosis and/or polychromasia in 30% of the treated animals and allow to assume a disorder of erythropoiesis. The results require to take in consideration a prophylactic hematological survey of long-term exposed people.

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