Refinement Impairments of Verbal-Performance Intelligent Quotient in Children Exposed to Fluoride Produced by Coal Burning.

To explore the relationship between total intelligence quotient (IQ), verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ), and fluoride exposure in children aged 8-12 years in coal-burning fluorosis area of Dafang County, Guizhou Province, China. The Wechsler Intelligence Scale for Children Revised in China (WISC-CR) was used to test the total IQ, VIQ, and PIQ in 99 children aged 8-12 years (55 in dental fluorosis group and 44 in control group). The differences in the intellectual levels between the two groups were compared, and the correlation between the intellectual level of children exposed to fluoride and the exposure dose of fluoride was analyzed. The VIQ, PIQ, and total IQ in the dental fluorosis group were 85.64 ± 16.53, 94.87 ± 12.73, and 88.51 ± 12.77, respectively, and these were lower than those in the control group (94.34 ± 16.04, 99.23 ± 12.44, and 96.64 ± 11.70, respectively). Significant difference was observed in VIQ and total IQ between the two groups (P = 0.002, P = 0.01), but not in the PIQ (P > 0.05). Each item of VIQ impairment (common sense, similar, arithmetic, vocabulary, and understanding) was significantly lower than those without VIQ impairment in the dental fluorosis group (P < 0.05). There was a significant difference in two items of building blocks and decoding between PIQ impairment and normal group (P < 0.05). Children with fluorosis in coal-burning areas had impaired IQ and obviously had impaired VIQ. Thus, the language learning ability should be strengthened in children exposed to fluorosis.