Developmental Fluoride Neurotoxicity: Choi et al. Respond
Anna L. Choi1, Philippe Grandjean1, Guifan Sun2, Ying Zhang2
1Harvard School of Public Health, Boston, Massachusetts, E-mail: email@example.com; 2China Medical University, Shenyang, China
Environ Health Perspect 121:a70–a70 (2013). http://dx.doi.org/10.1289/ehp.1206192R [Online 1 March 2013]
The author declares they have no actual or potential competing financial interests.
Sabour and Ghorbani’s comments about the reported mean difference in IQ (intelligence quotient) scores reported in our article (Choi et al. 2012) suggest a misunderstanding of the scale unit we used and the public health significance of even a small decrease in the average IQ associated with exposure. We appreciate this opportunity to clarify the factual information about the reported IQ measure.
The standardized weighted mean difference (SMD) in IQ score between exposed and reference populations was –0.45 (95% confidence interval: –0.56, –0.35) using a random-effects model (Choi et al. 2012). We used the SMD because the studies we included used different scales to measure the general intelligence. The SMD is a weighted mean difference standardized across studies, giving the average difference in standard deviations for the measure of that outcome. For commonly used IQ scores with a mean of 100 and an SD of 15, 0.45 SDs is equivalent to 6.75 points (rounded to 7 points). As research on other neurotoxicants has shown, a shift to the left of IQ distributions in a population will have substantial impacts, especially among those in the high and low ranges of the IQ distribution (Bellinger 2007).
Bellinger BC. 2007. Interpretation of small effect sizes in occupational and environmental neurotoxicity: individual versus population risk. Neurotoxicology 28:245–251.
Choi AL, Sun G, Zhang Y, Grandjean P. 2012. Developmental fluoride neurotoxicity: a systematic review and meta-analysis. Environ Health Perspect 120:1362–1368.
New Search FunctionWe're pleased to present our improved search page. Try it, and let us know what you think!
CEHN September 2014 Article of the Month“Prenatal Polybrominated Diphenyl Ether Exposures and Neurodevelopment in U.S. Children through 5 Years of Age: The HOME Study” (Environ Health Perspect; DOI:10.1289/ehp.1307562) has been selected by the Children’s Environmental Health Network (CEHN) as its September 2014 Article of the Month. These CEHN summaries discuss the potential policy implications of current children’s environmental health research.
Register Today for PPTOX IVEnvironmental Stressors in Disease and Implications for Human Health
October 26–29, 2014
Boston Marriott Long Wharf Hotel
Join the Endocrine Society for the fourth international summit of Prenatal Programming and Toxicity (PPTOX), a premiere conference series dedicated to cutting-edge discussion of environmental hazards during early life and long-term consequences.* Housing deadline: Monday, October 6
For more information, visit the Endocrine Society website.
Sign Up to Receive E-mail Alerts
Recent Advance Publications
Asthma in Inner-City Children at 5-11 Years of Age and Prenatal Exposure to Phthalates: The Columbia Center for Children’s Environmental Health Cohort
Comparative Assessment of the Effects of Climate Change on Heat- and Cold-Related Mortality in the United Kingdom and Australia
Proximity to Natural Gas Wells and Reported Health Status: Results of a Household Survey in Washington County, Pennsylvania
Green and Blue Spaces and Behavioral Development in Barcelona Schoolchildren: The BREATHE Project
Aerial Application of Mancozeb and Urinary Ethylene Thiourea (ETU) Concentrations among Pregnant Women in Costa Rica: The Infants’ Environmental Health Study (ISA)
Pyrethroid Pesticide Exposure and Parental Report of Learning Disability and Attention Deficit/Hyperactivity Disorder in U.S. Children: NHANES 1999–2002
Household Cooking with Solid Fuels Contributes to Ambient PM2.5 Air Pollution and the Burden of Disease
- CareerOpp: Asst prof of global climate change & env health, Env & Earth Sci Dept, Willamette Univ, Salem, OR http://t.co/GV9kc9JRqv
- EHPNoonNews: EPA proposes changing worker protection standards for pesticides http://t.co/RMq3OUUr7E @cjonline
- EHPNoonNews: DNA patterns predict epigenetic changes http://t.co/scBYPKN06u @eurekalertaaas
- EHPNoonNews: Food makers to revamp additive safety process http://t.co/jGhnJakTZ9 @cenmag
- EHPNoonNews: Maine uniquely positioned to feel impact of climate change http://t.co/nKasREbtrE @bostonglobe