Assessment of Neurobehavioral Function with Computerized Tests in a Population of Hispanic Adolescents Working in Agriculture

doi:10.1006/enrs.2000.4105

Environmental Research

Volume 85, Issue 1, January 2001, Pages 14-24

https://doi.org/10.1006/enrs.2000.4105 Get rights and content

Abstract

In recent years there has been heightened concern over the potential of occupational or environmental exposures to affect neurological function in children and adolescents. The current study was designed to develop computerized tests to effectively assess neurobehavioral function in Hispanic adolescents working in agriculture and to evaluate those tests in Hispanic youths working in agriculture and in a non-agricultural group. After exclusions, 96 adolescents currently working in agriculture (AG) and 51 adolescents currently non-migratory and not working in agriculture (Non-AG) were tested. Neurobehavioral tests were selected from the computerized Behavioral Assessment and Research System. AG test performance was significantly below Non-AG performance on the cognitive tests. However, educational and cultural differences between the AG and Non-AG groups may explain this difference. Repeat testing of the AG group revealed substantially improved performance, further supporting educational or cultural differences as an explanation for the group differences. Together, these results expose the limitations in case-control or cross-sectional designs for testing migrant worker populations in the United States. Longitudinal or cross-sectional designs with repeat testing offer more promise and may be essential for drawing accurate conclusions in migrant worker groups where there are no truly equivalent comparison or control groups.

References (36)

R.W. Amler et al.
Selective approaches to basic neurobehavioral testing of children in environmental health studies
Neurotoxicol. Teratol.
(1996)
W.K. Anger et al.
Human behavioral assessment in neurotoxicology: Producing appropriate test performance with written and shaping instructions
Neurotoxicol. Teratol.
(1996)
W.K. Anger et al.
Human neurobehavioral research methods: Impact of subject variables
Environ. Res.
(1997)
B.H. Choi
The effects of methylmercury on the developing brain
Prog. Neurobiol.
(1989)
D.A. Otto et al.
Neurobehavioral Evaluation System (NES): Comparative performance of 2nd-, 4th-, and 8th-grade Czech children
Neurotoxicol. Teratol.
(1996)
M.G. Paule
Use of the NCTR Operant Test Battery in nonhuman primates
Neurotoxicol. Teratol.
(1990)
M.G. Paule et al.
Operant test battery performance in children: Correlation with IQ
Neurotoxicol. Teratol.
(1999)
D.S. Rohlman et al.
Computerized neurobehavioral testing: Techniques for improving test instructions
Neurotoxicol. Teratol.
(1996)
L. Rosenstock et al.
Chronic central nervous system effects of acute organophosphate intoxication
Lancet
(1991)
American Friends Service Committee, 1975, School Days, Saturdays, Sundays and Fiestas (Children Who Work in Commercial...

W.K. Anger

Worksite behavioral research: Results, sensitive methods, test batteries, and the transition from laboratory data to human health

Neurotoxicology

(1990)

T.A. Arcury et al.

Occupational and environmental health risks in farm labor

Hum. Organ.

(1998)

T.A. Arcury et al.

Chronic agricultural chemical exposure among migrant and seasonal farmworkers

Soc. Natural Resources

(1998)

P.A. Baghurst et al.

Environmental exposure to lead and children's intelligence at the age of 7 years. The Port Pirie Cohort Study

Epidemiology

(1992)

D. Bellinger et al.

Antecedents and correlates of improved cognitive performance in children exposed in utero to low levels of lead

Pediatrics

(1990)

B. Bracken et al.

State of the art procedures for translating, validating, and using psychoeducational tests in cross-cultural assessment

School Psychol. Int.

(1991)

R. Dahl et al.

Feasibility and validity of three computer-assisted neurobehavioral tests in 7-year-old children

Neurotoxicol. Teratol.

(1996)

Cited by (38)

Current evolution of neurobehavioral methods
2022, Advances in Neurotoxicology
Citation Excerpt :
Importantly, this has been evaluated for several neurobehavioral batteries (Arcia and Otto, 1992; Campbell et al., 1999; Chung et al., 2007; Farahat et al., 2003; Heaton et al., 2014; Lee et al., 2012; Lowe and Rabbitt, 1998; Lucero et al., 2019; Rohlman et al., 2000a; Sakong et al., 2007; Syvaoja et al., 2015; Taylor et al., 2020). Some samples have shown improved performance over time, for example the BARS (Rohlman et al., 2001b) or the Swedish Performance Evaluation System (Chung et al., 2007). The CANTAB showed practice effects that may inhibit its use in repeated measures designs (Lowe and Rabbitt, 1998) in an elderly population and the reliability could not be determined for all measures in a sample of children over a year-long period (Syvaoja et al., 2015).
Workplace exposures to neurotoxicants cause a variety of functional impairments, with the profile of deficits depending on the chemical nature, dose and duration of exposure, and individual characteristics that might confer susceptibility. The functional impairments, or neurobehavioral deficits, can include impairments in cognition, mood and mental state, motor or sensory function. Finland's Helena Hänninen was the first to systematize the process of evaluating patients with workplace exposures in the 1960’s, using multiple neuropsychological tests that formed a “battery.” Subsequently, several test systems were developed to assess nervous system deficits in a sensitive and reliable manner. Unlike neurological examinations, which are mainly qualitative (or semi-quantitative) in nature, neurobehavioral tests quantify the magnitude of nervous system deficits. Hence, neurobehavioral assessment is especially useful for detecting sub-clinical nervous system deficits in cross-sectional studies. Neurobehavioral methods are still evolving, with further validation of assessments for different subpopulations (e.g., different languages and cultures, socioeconomic status, and education level). Computerized testing became popular in the 1980s, given their consistency, ease, and economy of administration. Remote computerized testing will allow for the implementation of very large studies at a much lower cost than in-person assessments, but validation of those methods is needed. Neurobehavioral tests must dive deeper (e.g., mapping test results to brain mechanisms) and expand broadly to new frontiers (e.g., routine exams and telemedicine) to fulfill the promise that could only be imagined when the field first discovered the power of those tests to detect subtle, subclinical deficits due to occupational chemical exposures.
Thyroid hormones and neurobehavioral functions among adolescents chronically exposed to groundwater with geogenic arsenic in Bangladesh
2019, Science of the Total Environment
Groundwater, the major source of drinking water in Bengal Delta Plain, is contaminated with geogenic arsenic (As) enrichment affecting millions of people. Children exposed to tubewell water containing As may be associated with thyroid dysfunction, which in turn may impact neurodevelopmental outcomes. However, data to support such relationship is sparse. The purpose of this study was to examine if chronic water As (WAs) from Holocene alluvial aquifers in this region was associated with serum thyroid hormone (TH) and if TH biomarkers were related to neurobehavioral (NB) performance in a group of adolescents. A sample of 32 healthy adolescents were randomly drawn from a child cohort in the Health Effects of Arsenic Longitudinal Study (HEALS) in Araihazar, Bangladesh. Half of these participants were consistently exposed to low WAs (<10 μg/L) and the remaining half had high WAs exposure (≥10 μg/L) since birth. Measurements included serum total triiodothyronine (tT₃), free thyroxine (fT₄), thyrotropin (TSH) and thyroperoxidase antibodies (TPOAb); concurrent WAs and urinary arsenic (UAs); and adolescents' NB performance. WAs and UAs were positively and significantly correlated with TPOAb but were not correlated with TSH, tT₃ and fT₄. After accounting for covariates, both WAs and UAs demonstrated positive but non-significant relationships with TSH and TPOAb and negative but non-significant relationships with tT₃ and fT₄. TPOAb was significantly associated with reduced NB performance indicated by positive associations with latencies in simple reaction time (b = 82.58; p < 0.001) and symbol digit (b = 276.85; p = 0.005) tests. TSH was significantly and negatively associated with match-to-sample correct count (b = −0.95; p = 0.05). Overall, we did not observe significant associations between arsenic exposure and TH biomarkers although the relationships were in the expected directions. We observed TH biomarkers to be related to reduced NB performance as hypothesized. Our study indicated a possible mechanism of As-induced neurotoxicity, which requires further investigations for confirmatory findings.
Residential exposure to urban traffic is associated with the poorer neurobehavioral health of Ecuadorian schoolchildren
2019, NeuroToxicology
Citation Excerpt :
First, it used culturally adaptable and valid instruments to measure multiple functional outcomes of subtle NB effects. The Spanish version of the BARS was previously validated on sample of families who migrated from South American countries (Rohlman et al., 2001, 2007a). Second, the results demonstrated consistent evidence of PM-induced neurotoxicity across various functional domains such as visual memory, information processing speed, attention and behavior.
We investigated whether chronic traffic-generated air pollution containing fine and ultrafine particulate matter is associated with reduced neurobehavioral performance and behavioral dysfunction in urban Ecuadorian schoolchildren. Also, we examined the effect of child hemoglobin and sociodemographic risk factors on these neurocognitive outcomes.
A convenience sample of healthy children aged 8–14 years attending public schools were recruited in Quito, Ecuador. Child residential proximity to the nearest heavily trafficked road was used as a proxy for traffic-related pollutant exposure. These included high exposure (<100 m), medium exposure (100–199 m) and low exposure (≥ 200 m) from the nearest heavily trafficked road. The Behavioral Assessment and Research System (BARS), a computerized test battery assessing attention, memory, learning and motor function was used to evaluate child neurobehavioral performance. The Child Behavior Checklist (CBCL/6-18) was used to assess child behavioral dysfunction as reported by mothers. The data were analyzed using multiple linear regression.
Children with the highest residential exposure to traffic pollutants (< 100 m) had significantly longer latencies as measured by match to sample (b = 410.27; p = 0.01) and continuous performance (b = 37.90; p = 0.02) compared to those living ≥ 200 m away. A similar but non-significant association was observed for reaction time latency. Children living within 100 m of heavy traffic also demonstrated higher scores across all CBCL subscales although only the relationship with thought problems (p = 0.05) was statistically significant in the adjusted model.
The study findings suggest that children living within 100 m of heavy traffic appear to experience subtle neurobehavioral deficits that may result from fine and ultrafine particulate matter exposure.
Organophosphorus pesticide exposure and neurobehavioral performance in Latino children living in an orchard community
2016, NeuroToxicology
Citation Excerpt :
To assess the long-term health effects of OP exposure on these children, neurobehavioral data were collected using a battery of six computer-based tests from the Behavioral Assessment and Research System (BARS) and four individually administered tests (Table 1). The BARS has been used successfully in farmworker populations [29,30] and with Hispanic children [31]. Neurobehavioral testing was administered individually to each child in a private room at a community center or library.
Children living in agricultural communities have a greater risk from pesticides due to para-occupational pathways. The goal of this study was to assess the impact of exposure to organophosphorus pesticides on the neurobehavioral performance of school-aged Latino children over time. Two exposure measures were used to estimate children’s pesticide exposure: parent's occupation (agricultural or non-agricultural) and organophosphate residues in home carpet dust samples. During 2008–2011, 206 school-aged children completed a battery of neurobehavioral tests two times, approximately one year apart. The associations between both exposure measures and neurobehavioral performance were examined. Pesticide residues were detected in dust samples from both agricultural and non-agricultural homes, however, pesticides were detected more frequently and in higher concentrations in agricultural homes compared to non-agricultural homes. Although few differences were found between agricultural and non-agricultural children at both visits, deficits in learning from the first visit to the second visit, or less improvement, was found in agricultural children relative to non-agricultural children. These differences were significant for the Divided Attention and Purdue Pegboard tests. These findings are consistent with previous research showing deficits in motor function. A summary measure of organophosphate residues was not associated with neurobehavioral performance. Results from this study indicate that children in agricultural communities are at increased risk from pesticides as a result of a parent working in agricultural. Our findings suggest that organophosphate exposure may be associated with deficits in learning on neurobehavioral performance, particularly in tests of with motor function. In spite of regulatory phasing out of organophosphates in the U.S., we still see elevated levels and higher detection rates of several organophosphates in agricultural households than non-agricultural households, albeit lower levels than prior studies.
Meta-analysis on occupational exposure to pesticides - Neurobehavioral impact and dose-response relationships
2015, Environmental Research
Citation Excerpt :
Analyses on susceptibility were impeded by insufficient data on women and a large variability within data on adolescents. Disparities in intelligence and age may have contributed to the heterogeneity; Rohlman et al. (2001) for example addressed the difficulties of finding an intellectually comparable control group for adolescent workers. A one-year-difference in age seems negligible at the age of 34, it may be of great importance at the age of 15, where it may represent remarkable differences in the cognitive, emotional and social development.
While the health impact of high exposures to pesticides is acknowledged, the impact of chronic exposures in the absence of acute poisonings is controversial. A systematic analysis of dose–response relationships is still missing. Its absence may provoke alternative explanations for altered performances. Consequently, opportunities for health prevention in the occupational and environmental field may be missed.
Objectives were (1) quantification of the neurotoxic impact of pesticides by an analysis of functional alterations in workers measured by neuropsychological performance tests, (2) estimates of dose–response relationships on the basis of exposure duration, and (3) exploration of susceptible subgroups.
The meta-analysis employed a random effects model to obtain overall effects for individual performance tests. Twenty-two studies with a total of 1758 exposed and 1260 reference individuals met the inclusion criteria. At least three independent outcomes were available for twenty-six performance variables.
Significant performance effects were shown in adults and referred to both cognitive and motor performances. Effect sizes ranging from d_RE=−0.14 to d_RE=−0.67 showed consistent outcomes for memory and attention. Relationships between effect sizes and exposure duration were indicated for individual performance variables and the total of measured performances. Studies on adolescents had to be analyzed separately due to numerous outliers. The large variation among outcomes hampered the analysis of the susceptibility in this group, while data on female workers was too scant for the analysis.
Relationships exist between the impact of pesticides on performances and exposure duration. A change in test paradigms would help to decipher the impact more specifically. The use of biomarkers appropriate for lower exposures would allow a better prevention of neurotoxic effects due to occupational and environmental exposure. Intervention studies in adolescents seem warranted to specify their risk.
Chronic central nervous system effects of pesticides: State-of-the-art
2012, Revue d'Epidemiologie et de Sante Publique
Given the neurotoxic properties of pesticides, suggested by experimental results and clinical observations, many epidemiological studies have investigated neurological effects following acute or chronic exposure to pesticides. This review provides an overview of current knowledge about pesticide effects on the central nervous system: neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis), cognitive disorders, and psychiatric disorders (mood disorders, anxiety, depression and suicide).
Parkinson's disease, the most widely studied in relation with pesticide exposure, particularly with insecticides and herbicides, was observed to be a risk factor of the disease. Evidence is scarce for Alzheimer's disease and amyotrophic lateral sclerosis, but quite consistent. Cognitive and psychiatric disorders were often observed in relation with organophosphate insecticide exposure. Cognitive disorders were found associated with acute and chronic exposures, and psychiatric disorders mostly with poisonings. These epidemiologic studies were limited by a lack of detailed and reliable exposure assessment. The role of genetic susceptibilities has been recently observed, but must be further investigated.
Au vu des propriétés neurotoxiques de certains pesticides, observées expérimentalement ou lors de manifestations cliniques, de nombreuses études épidémiologiques se sont penchées sur les effets neurologiques en lien avec une exposition aiguë ou chronique à de telles substances. Nous proposons ici une revue de la littérature épidémiologique sur les troubles cognitifs, les maladies neurodégénératives (maladie de Parkinson, maladie d’Alzheimer et sclérose latérale amyotrophique), et les troubles psychiatriques (troubles de l’humeur, anxiété, dépression et suicide).
L’exposition aux pesticides a été beaucoup étudiée en lien avec la maladie de Parkinson, plus particulièrement l’exposition aux insecticides et aux herbicides, qui se sont révélés être des facteurs de risque de la maladie. Pour la maladie d’Alzheimer et la sclérose latérale amyotrophique, les arguments en faveur d’un tel lien sont moins nombreux, mais sont relativement cohérents. Les troubles cognitifs et psychiatriques ont été très souvent observés dans le contexte d’une exposition aux insecticides organophosphorés. Les troubles cognitifs ont été retrouvés associés à des expositions aiguës ou chroniques, et les troubles psychiatriques principalement aux intoxications. La plupart des études épidémiologiques restent en partie insuffisantes du fait d’une mesure de l’exposition limitée ou peu fiable. L’existence de susceptibilités génétiques a récemment été observée, ouvrant la voie à de nouvelles perspectives de recherche pour mieux comprendre la relation entre pesticides et troubles neurologiques.

View all citing articles on Scopus

View full text

Regular ArticleAssessment of Neurobehavioral Function with Computerized Tests in a Population of Hispanic Adolescents Working in Agriculture

Abstract

Neurotoxicol. Teratol.

Neurotoxicol. Teratol.

Environ. Res.

Prog. Neurobiol.

Neurotoxicol. Teratol.

Neurotoxicol. Teratol.

Neurotoxicol. Teratol.

Neurotoxicol. Teratol.

Lancet

Worksite behavioral research: Results, sensitive methods, test batteries, and the transition from laboratory data to human health

Neurotoxicology

Occupational and environmental health risks in farm labor

Hum. Organ.

Chronic agricultural chemical exposure among migrant and seasonal farmworkers

Soc. Natural Resources

Environmental exposure to lead and children's intelligence at the age of 7 years. The Port Pirie Cohort Study

Epidemiology

Antecedents and correlates of improved cognitive performance in children exposed in utero to low levels of lead

Pediatrics

State of the art procedures for translating, validating, and using psychoeducational tests in cross-cultural assessment

School Psychol. Int.

Feasibility and validity of three computer-assisted neurobehavioral tests in 7-year-old children

Neurotoxicol. Teratol.

Regular Article
Assessment of Neurobehavioral Function with Computerized Tests in a Population of Hispanic Adolescents Working in Agriculture