Postnatal Cadmium Exposure, Neurodevelopment, and Blood Pressure in Children at 2, 5, and 7 Years of Age

Abstract

BackgroundAdverse health effects of cadmium in adults are well documented, but little is known about the neuropsychological effects of cadmium in children, and no studies of cadmium and blood pressure in children have been conducted.ObjectiveWe examined the potential effects of low-level cadmium exposure on intelligence quotient, neuropsychological functions, behavior, and blood pressure among children, using blood cadmium as a measure of exposure.MethodsWe used the data from a multicenter randomized clinical trial of lead-exposed children and analyzed blood cadmium concentrations using the whole blood samples collected when children were 2 years of age. We compared neuropsychological and behavioral scores at 2, 5, and 7 years of age by cadmium level and analyzed the relationship between blood cadmium levels at 2 years of age and systolic and diastolic blood pressure at 2, 5, and 7 years of age.ResultsThe average cadmium concentration of these children was 0.21 μg/L, lower than for adults in the National Health and Nutrition Examination Survey (NHANES), but comparable to concentrations in children < 3 years of age in NHANES. Except for the California Verbal Learning Test for Children, there were no differences in test scores among children in different cadmium categories. For children with detectable pretreatment blood cadmium, after adjusting for a variety of covariates, general linear model analyses showed that at none of the three age points was the coefficient of cadmium on Mental Development Index or IQ statistically significant. Spline regression analysis suggested that behavioral problem scores at 5 and 7 years of age tended to increase with increasing blood cadmium, but the trend was not significant. We found no significant associations between blood cadmium levels and blood pressure.ConclusionWe found no significant associations between background blood cadmium levels at 2 years of age and neurodevelopmental end points and blood pressure at 2, 5, and 7 years of age. The neuropsychological or hypertensive effects from longer background exposures to cadmium need further study.

Concentration of metals in blood of Maine children 1–6 years old

“…These findings suggest that blood may not be an optimal compartment for biomonitoring of these metals, at least in young children. In contrast, Cd was detected in approximately half the blood samples of children identified with high blood lead concentrations in a study in the United States (Cao et al, 2009), and was detected in the majority of German fourth-graders (Link et al, 2007), with average concentrations in both studies considerably higher than those in this study.…”

The Role of Heavy Metal Pollution in Neurobehavioral Disorders: a Focus on Autism

“…Moreover, cadmium concentration in urine (that may be used as a biomarker of exposure in early pregnancy), even at low doses, was associated to decreased IQ scores in children (Kippler et al 2012a). Cao et al (2009) did not observe any significant relationship between blood cadmium levels, as a result of postnatal exposure, and neurodevelopmental scores in children at 2, 5, and 7 years of age. Children 6-15 years of age who had higher urinary Cd concentrations showed an increased risk of learning disabilities; in contrast, the association with ADHD did not reach statistical significance (Ciesielski et al 2012) as previously observed through evaluation of Cd concentration in blood of school-aged children with ADHD (Yousef et al 2011).…”

“…High concentrations of Cd in the soil and water supply mean that it is readily detectable in meat, fish, vegetables, and fruits (Ishitobi et al 2007). In addition to diet (primarily cereals and vegetables), which represents the main source of cadmium intake in the non-smoking general population, exposure to Cd may also occur through environmental tobacco smoke, house dust, and active smoking (Järup et al 1998;Cao et al 2009). Once it entered the body, Cd accumulates in the liver and kidney, and the highest concentrations may be observed in the renal cortex (U.S. Environmental Protection Agency 1997; Cao et al 2009).…”

“…Though Mn cannot be considered an environmental pollutant, numerous evidence suggests the potential association between Mn exposure and intellectual impairment in school-aged children, who showed Prenatal cadmium exposure IQ deficits (4.5 years of age) Tian et al (2009) IQ deficits (5 years of age) Kippler et al (2012a) Postnatal cadmium exposure No significant effects on neurodevelopmental scores (2, 5, and 7 years of age) Cao et al (2009) Learning impairment (6-15 years of age) Ciesielski et al (2012);Yousef et al (2011) Social problems and attention deficits (7-16 years of age) Bao et al (2009) deficits in IQ and verbal domain (Bouchard et al 2007: Claus Henn et al 2010Bouchard et al 2011;Menezes-Filho et al 2011). Manganese exposure is further associated with an increased risk of behavioral disorders, including ADHD (Farias et al 2010;Yousef et al 2011).…”

Elevated Serum Polybrominated Diphenyl Ethers and Alteration of Thyroid Hormones in Children from Guiyu, China

“…The proportion of children with blood lead levels greater than 10 mg/dL was 88.0%, with 10.2% (147/167) having blood lead levels higher than 20.0 mg/dL. In addition, the blood cadmium levels observed in this study exceeded the current range of normal values (#0.2 mg/L) [34,35]. However, no different of blood lead and cadmium were found between male and female.…”