Trends in preschool lead exposure, mental retardation, and scholastic achievement: Association or causation?

Nevin, Rick

doi:10.1016/j.envres.2008.12.003

Cited by 65 publications

(26 citation statements)

References 31 publications

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“…Children are especially vulnerable to Pb exposure. Epidemiological studies confirm the strong correlation between Pb exposure during childhood and deficits in cognitive function, such as learning and memory impairment, intellectual function decline, and anxiety-like behavior; these deficits persist to adulthood [2,3].…”

Section: Introductionmentioning

confidence: 94%

Lead Exposure Impairs Hippocampus Related Learning and Memory by Altering Synaptic Plasticity and Morphology During Juvenile Period

et al. 2015

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Lead (Pb) is an environmental neurotoxic metal. Pb exposure may cause neurobehavioral changes, such as learning and memory impairment, and adolescence violence among children. Previous animal models have largely focused on the effects of Pb exposure during early development (from gestation to lactation period) on neurobehavior. In this study, we exposed Sprague-Dawley rats during the juvenile stage (from juvenile period to adult period). We investigated the synaptic function and structural changes and the relationship of these changes to neurobehavioral deficits in adult rats. Our results showed that juvenile Pb exposure caused fear-conditioned memory impairment and anxiety-like behavior, but locomotion and pain behavior were indistinguishable from the controls. Electrophysiological studies showed that long-term potentiation induction was affected in Pb-exposed rats, and this was probably due to excitatory synaptic transmission impairment in Pb-exposed rats. We found that NMDA and AMPA receptor-mediated current was inhibited, whereas the GABA synaptic transmission was normal in Pb-exposed rats. NR2A and phosphorylated GluR1 expression decreased. Moreover, morphological studies showed that density of dendritic spines declined by about 20 % in the Pb-treated group. The spine showed an immature form in Pb-exposed rats, as indicated by spine size measurements. However, the length and arborization of dendrites were unchanged. Our results suggested that juvenile Pb exposure in rats is associated with alterations in the glutamate receptor, which caused synaptic functional and morphological changes in hippocampal CA1 pyramidal neurons, thereby leading to behavioral changes.

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Section: Introductionmentioning

confidence: 94%

Lead Exposure Impairs Hippocampus Related Learning and Memory by Altering Synaptic Plasticity and Morphology During Juvenile Period

et al. 2015

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“…For example, there is evidence in the United States and internationally that broad social interventions, such as environmental lead abatement 27,28 and improved nutrition, [29][30][31] have done more to decrease the prevalence of ID than specific medical interventions. Differences in preconception risk factors, including substance abuse, continue to exacerbate health disparities.…”

Section: Discussionmentioning

confidence: 99%

Impact of Specific Medical Interventions in Early Childhood on Increasing the Prevalence of Later Intellectual Disability

Brosco

Sanders

Dowling³

et al. 2013

JAMA Pediatr

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Importance: For the past 100 years, medicine in industrialized nations has become increasingly focused on specific medical interventions designed to improve the health of individual patients. Substantial evidence suggests that broader improvements in public health, nutrition, and economic well-being are more salient than medical or surgical interventions for the remarkable decrease in infant and child deaths since 1900. Less is known about the impact of specific medical interventions on morbidity such as intellectual disability (ID).Objective: To explore the impact of medical interventions in early childhood on increasing the prevalence of later ID, as reported in the literature from 1950 through 2000. Design:We reviewed the medical literature and other data from 1950 through 2000 to construct estimates of the condition-specific prevalence of ID over time. We further explored the existing literature to document historically relevant influences on condition-specific prevalence, including the introduction of effective interventions, the timing of these introductions, and the likelihood of their widespread use.Setting: Twentieth century United States and Western Europe.Participants: Populations of children who received a life-saving intervention within the first 5 years of life and were evaluated for ID after 5 years of age.

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“…For example, Reyes (2007) noted that estimates indicate that the reduction in lead exposure in the 1970s is responsible for a 56% drop in violent crime in the 1990s and will likely produce further declines in the future, up to 70% drop in violent crime by the year 2020. (p. 36) Lead removal has also been estimated to cut in half the number of children who receive formal diagnoses of intellectual disability and are therefore eligible for special education (Nevin, 2009), confirming a prediction made two decades ago (Needleman, 1990;Weiss, 1988). A recent attempt to quantify educational costs in a single school district was undertaken in a study of the role of lead exposure and student:teacher ratios on student performance assessments in New Orleans schools (Zahran, Mielke, Weiler, Berry, & Gonzales, 2009).…”

Section: Economic and Social Costsmentioning

confidence: 99%

“…This single act has been estimated to have resulted in a halving of violent crime (Reyes, 2007) and of the number of individuals eligible for a diagnosis of mental retardation (Nevin, 2009), and many have argued that further action may have even greater benefits (Gilbert & Weiss, 2006). The addition of lead to gasoline in the 1930s imposed a massive societal cost, one that was difficult to detect in comparison with chemicals that cause functional deformities or cancer.…”

mentioning

confidence: 99%

Environmental health and behavior analysis: Contributions and interactions.

Newland¹

2013

APA Handbook of Behavior Analysis, Vol. 2: Translating Principles Into Practice.

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The heightened public awareness that environmental contaminants can act on the nervous system and have effects that appear in behavior presents a major challenge to behavioral scientists in all areas. They are being asked to conduct both hazard assessment (are there neurobehavioral effects of some chemical at any dose?) and risk assessment (what is the risk to a population at a specific level of exposure?) for behavioral effects that are not always well understood. The heavy metal lead provides an excellent example. Concern over lead poisoning lies in claims that it lowers scores on IQ tests, retards academic performance, and results in disruptive and even criminal behavior. The problems posed are daunting: How easy is it to detect a 5-point drop in scores on IQ tests? Can scientists predict these effects from experimental models using laboratory animals? Can they identify behavioral and neural mechanisms that account for these effects? What economic costs are incurred if the average IQ drops a few points, and how does this cost compare with that of reducing lead in the environment?These concerns are reflected in policymaking. Federal legislation and regulation of toxic substances specifically include behavior, including schedule-controlled operant behavior, as a regulatory endpoint (Tilson, 1990). The inclusion of nervous system damage in general, and its behavioral manifestations in particular, represents a sea change in public concern over unintended exposure to chemicals. Where cancer has been (and still is) a significant concern, the recognition that adverse behavioral effects follow certain types of chemical exposure is increasing. These effects carry over into a large number of domains. Environmental contaminants, even at very low exposure levels, contribute to disorders across the life span, including developmental disabilities and the hastening of age-related impairments. Behavioral scientists' understanding of how this happens not only has public policy implications but can also inform them about the behavior and neurobiology surrounding these disorders.

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Trends in preschool lead exposure, mental retardation, and scholastic achievement: Association or causation?

Abstract: This study shows that 1936-1990 preschool

Cited by 65 publications

References 31 publications

Lead Exposure Impairs Hippocampus Related Learning and Memory by Altering Synaptic Plasticity and Morphology During Juvenile Period

Lead Exposure Impairs Hippocampus Related Learning and Memory by Altering Synaptic Plasticity and Morphology During Juvenile Period

Impact of Specific Medical Interventions in Early Childhood on Increasing the Prevalence of Later Intellectual Disability

Environmental health and behavior analysis: Contributions and interactions.

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