Jms. Vanmaanen et al., CONSUMPTION OF DRINKING-WATER WITH HIGH NITRATE LEVELS CAUSES HYPERTROPHY OF THE THYROID, Toxicology letters, 72(1-3), 1994, pp. 365-374
We studied the effect of nitrate contamination of drinking water on vo
lume and function of the thyroid in human populations exposed to diffe
rent nitrate levels in their drinking water. Two sets of low and mediu
m (tap) water, respectively medium and high (well) water nitrate expos
ure groups were compared. Drinking of nitrate-contaminated water was d
ose-dependently related with 24-h urinary nitrate excretion and saliva
ry nitrate levels. No iodine deficiency was observed in any of the nit
rate exposure groups. A dose-dependent difference in the volume of the
thyroid was observed between low and medium vs. high nitrate exposure
groups, showing development of hypertrophy at nitrate levels exceedin
g 50 mg/l. An inverse relationship was established between the volume
of the thyroid and serum thyroid stimulating hormone (TSH) levels.