Effects of high fluoride and iodine combined exposure on thyroid nodules and goiter in school-age children in Jiangsu, China.

Introduction: With advancements in detection equipment and an increase in the frequency of examinations, thyroid nodules and goiter in children have garnered attention. Objective: This study aims to determine the effects of high iodine and fluoride exposure on thyroid nodules and goiter in school-aged children. Methods: We recruited children aged 8 to 12 from rural Jiangsu, China, based on the concentrations of iodine and fluoride in local drinking water and urine. Participants were divided into four groups: a group with high fluoride and iodine (HFHI), a group with high fluoride (HF), a group with high iodine (HI), and a control group (CONTROL). Fluoride levels in both drinking water and urine samples were measured using the ion-selective electrode method. Urinary iodine (UI) was assessed using inductively coupled plasma mass spectrometry, and children's thyroids were examined with portable ultrasound equipment equipped with a linear 7.5-MHz probe. Results: The detection rates of thyroid nodules in the HFHI, HF, HI, and CONTROL groups were 10.4 %, 6.5 %, 7.7 %, and 2.8 %, respectively. The goiter detection rates were 3.8 %, 2.9 %, 3.8 %, and 1.1 %, respectively. In the HFHI group, statistically significant correlations were found between urinary fluoride (UF) and thyroid nodules ( Conclusions: Combined high iodine and fluoride exposure may have an adverse effect on thyroid nodules in school-age children.