Fluoride exposure, dopamine relative gene polymorphism and intelligence: A cross-sectional study in China.

Background: Excessive fluoride exposure is related to adverse health outcomes, but whether dopamine (DA) relative genes are involved in the health effect of low-moderate fluoride exposure on children's intelligence remain unclear.

Objectives: We conducted a cross-sectional study to explore the role of DA relative genes in the health effect of low-moderate fluoride exposure in drinking water.

Methods: We recruited 567 resident children, aged 6-11 years old, randomly from endemic and non-endemic fluorosis areas in Tianjin, China.

The relationships between thyroid-stimulating hormone and/or dopamine levels in peripheral blood and IQ in children with different urinary iodine concentrations.

Environmental iodine deficiency or excess can lead to inappropriate iodine nutrition in the population. Little research has been performed to determine whether changes in thyroid-stimulating hormone (TSH) and/or dopamine (DA) concentrations in peripheral blood are involved in intellectual impairment caused by inappropriate iodine nutrition. 498 children aged 7-12 from areas with different water iodine concentrations were included in the study.