•Consumption of formula reconstituted with fluoridated water can lead to excessive fluoride intake.•Breastfed infants receive very low intake of fluoride.•We compared IQ scores in 398 children who ...were formula-fed versus breastfed during infancy.•IQ scores were lower with higher levels of fluoride in tap water.•The effect was more pronounced among formula-fed children, especially for nonverbal skills.
Infant consumption of formula reconstituted with fluoridated water can lead to excessive fluoride intake. We examined the association between fluoride exposure in infancy and intellectual ability in children who lived in fluoridated or non-fluoridated cities in Canada.
We examined 398 mother-child dyads in the Maternal-Infant Research on Environmental Chemicals cohort who reported drinking tap water. We estimated water fluoride concentration using municipal water reports. We used linear regression to analyze the association between fluoride exposure and IQ scores, measured by the Wechsler Primary and Preschool Scale of Intelligence-III at 3–4 years. We examined whether feeding status (breast-fed versus formula-fed) modified the impact of water fluoride and if fluoride exposure during fetal development attenuated this effect. A second model estimated the association between fluoride intake from formula and child IQ.
Thirty-eight percent of mother-child dyads lived in fluoridated communities. An increase of 0.5 mg/L in water fluoride concentration (approximately equaling the difference between fluoridated and non-fluoridated regions) corresponded to a 9.3- and 6.2-point decrement in Performance IQ among formula-fed (95% CI: −13.77, −4.76) and breast-fed children (95% CI: −10.45, −1.94). The association between water fluoride concentration and Performance IQ remained significant after controlling for fetal fluoride exposure among formula-fed (B = −7.93, 95% CI: −12.84, −3.01) and breastfed children (B = −6.30, 95% CI: −10.92, −1.68). A 0.5 mg increase in fluoride intake from infant formula corresponded to an 8.8-point decrement in Performance IQ (95% CI: −14.18, −3.34) and this association remained significant after controlling for fetal fluoride exposure (B = −7.62, 95% CI: −13.64, −1.60).
Exposure to increasing levels of fluoride in tap water was associated with diminished non-verbal intellectual abilities; the effect was more pronounced among formula-fed children.
Organizational socialization is a crucial moment during employment, as employees learn the skills and behaviours needed to be successful in a new role. Researchers have historically relied on the ...organizational socialization tactics (OST) scale created by Jones (
1986
) to assess this phenomenon, despite its limitations. This research aimed to create an alternative measure of socialization focused on an employee’s perceptions of
sink or swim
, made up of the 3-factors: responsibility, effectiveness, and support. Study 1 used the academic literature and data from an industry survey to generate an initial item pool and then used subject matter experts (SMEs) to run a content validation assessment. Study 2 used a longitudinal survey design with two waves to assess the factor structure, psychometric properties, and predictive validity of the scale. The 3-factor structure was supported through an EFA and confirmed with a subsequent CFA and the refined scale indicated acceptable levels of construct validity and test-retest reliability. The predictive validity of the scale was supported through a series of regression analyses across separate employment outcomes. Overall, the finalized 17-item
Sink or Swim Scale (SSS)
demonstrated that it is a valid, practical, and shorter alternative to the OST scale. The subdivision of support also demonstrated the potential to act as a standalone measure of an employee’s socialization experience.
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