Combined association of BTEX and material hardship on ADHD‐suggestive behaviours among a nationally representative sample of US children

Abstract

Background: Previous research shows that environmental and social factors contribute to the development of attention-deficit/hyperactivity disorder (ADHD). Objective:To determine the relationship between early-life exposure to common ambient air pollutants (benzene, toluene, ethylbenzene, and xylene, also known as BTEX), household material hardship (a measure of socio-economic status), and ADHD-suggestive behaviours in kindergarten-age children. Methods: Pollutant exposure estimated from the 2002 National Air Toxics Assessment at each child's residential ZIP code at enrolment was linked to the Early Childhood Longitudinal Study Birth Cohort (n = 4650). Material hardship was assigned as a composite score of access to food, health care, and housing. Kindergarten teachers rated children's behaviours and activity in the classroom using a five-point Likert scale. Children with summary scores in the bottom decile were classified as displaying ADHD-suggestive behaviours. Logistic regression models were constructed to estimate the association between both BTEX exposure and material hardship on ADHD-suggestive behaviours.Results: The odds of displaying ADHD-suggestive behaviours were greater in children with combined high-level exposure to BTEX and in those experiencing material hardship (odds ratio 1.54, 95% confidence interval [CI] 1.12, 2.11, and OR 2.12, 95% CI 1.25, 3.59, respectively), adjusting for covariates. These associations were stronger when restricting the study population to urban areas. There was no evidence of interaction between early life BTEX exposure and material hardship, although the effects of BTEX exposure were slightly greater in magnitude among those with higher material hardship scores.Conclusions: Children exposed to air toxics, material hardship, or both early in life are more likely to display signs of ADHD-suggestive behaviours as assessed by their kindergarten teachers. The associations between exposures to air pollution and to socio-economic hardship were observed in all children but were particularly strong in those living in urban areas. K E Y W O R D S air pollutants, air toxics, child behaviour, socio-economic status, urban environment | 483 DELLEFRATTE ET AL. S U PP O RTI N G I N FO R M ATI O N Additional supporting information may be found online in the Supporting Information section at the end of the article. How to cite this article: Dellefratte K, Stingone JA, Claudio L. Combined association of BTEX and material hardship on ADHD-suggestive behaviours among a nationally representative sample of US children. Paediatr. Perinat.

Inequalities in Exposure to Ambient Air Neurotoxicants and Disparities in Markers of Neurodevelopment in Children by Maternal Nativity Status

“…Individual and collective exposure measures were evaluated, but only isophorone displayed a crude association with BSF-R mental z-scores and was subsequently used for further assessments. To account for the rightly-skewed distribution, isophorone along with the other nine pollutants were dichotomized at the 75th quartile to obtain ‘high’ and ‘low’ exposure categories [ 32 , 36 ]. This approach reduces exposure measure susceptibility to overly influential outliers occurring when totaling the individual-level estimated exposure concentrations [ 32 ].…”

“…To account for the rightly-skewed distribution, isophorone along with the other nine pollutants were dichotomized at the 75th quartile to obtain ‘high’ and ‘low’ exposure categories [ 32 , 36 ]. This approach reduces exposure measure susceptibility to overly influential outliers occurring when totaling the individual-level estimated exposure concentrations [ 32 ]. Estimated isophorone exposures greater than the 75th quartiles (≥7.90 ng/m 3 ) were categorized as ‘highest quartile’ exposure and exposures below the 75th quartile (<7.90 ng/m 3 ) were deemed as ‘lowest quartile’ exposures.…”

“…Exposure to hazardous air pollutants (HAP), defined by the US Environmental Protection Agency (EPA) as “toxic air pollutants harmful to human health”, has been linked to adverse neurodevelopmental outcomes such as autism and attention deficit disorder (ADD) [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. In addition, many HAPS commonly found in urban environments have been identified as being disruptive to early brain development, including benzene, diesel, ethylbenzene, chloroform, toluene, styrene, manganese, polycyclic aromatic hydrocarbons (PAH)/polycyclic organic matter (POM), xylene, and isophorone [ 18 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. Growing evidence highlights prenatal exposures to HAPs contributing to the disruption of fetal brain development introducing vulnerabilities to adverse neurodevelopment in children [ 31 , 34 , 35 ].…”

Secondary Analysis of Existing Data Sets for Developmental Behavioral Pediatrics

“…Examples are studies about the effect of air pollution on child neurodevelopment that have been achieved by linking developmental assessments and child zip code in the Early Childhood Longitudinal Study to the 2002 National Air Toxics Assessment data. 15,16 Case Part 2: 3 Months Later The fellow conducts a background literature search that reveals key unanswered questions in the field. The fellow decides to advance her long-term research goals by conducting a secondary data analysis aimed at better understanding why some groups of children with special health care needs engage in self-management more than others.…”

“…Examples are studies about the effect of air pollution on child neurodevelopment that have been achieved by linking developmental assessments and child zip code in the Early Childhood Longitudinal Study to the 2002 National Air Toxics Assessment data. 15,16…”