Table 1.
Characteristics of epidemiological studies examining flame retardants and cognition, behavior, and/or neuroimaging in children published from 2015 to 2020
| First Author (Year), Country | Study Design | Sample Size | Flame Retardant Assessment | Neurodevelopment Assessment | Findings | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Prospective Cohort | Cross-sectional | PCBs | PBDEs | HBCD | Timing | Matrix | Age | IQ | Behavior | Neuroimaging | ||||
| Cowell (2015), United States [101] | ✔ | 210 | ✔ | Delivery | Cord Serum | 3–7 y | ✔ | Positive associations were observed between cord BDE-47 and BDE-153 and attention problems at age 4 years. However, no significant associations were present between cord PBDEs and attention problems at age 6 years. | ||||||
| Ding (2015), China [104] | ✔ | 232 | ✔ | Delivery | Cord Serum | 1 y 2 y |
✔ | A 10-fold increase in cord BDE-47 was associated with a decrease of 1.89-points (95% CI −3.75, −0.03) in the social domain developmental quotient, indicating poorer social skills. | ||||||
| Donauer (2015), United States [96] | ✔ | 349 | ✔ | 16±3 w | Maternal Serum | 5 w | ✔ | Null associations were reported between prenatal PBDEs and neurobehavioral infant profiles at 5 weeks, including hypotonic and social/easygoing, and high arousal/difficult. | ||||||
| Neugebauer (2015), Germany [88] | ✔ | 117 | ✔ | 32 w 2 w after delivery |
Maternal Serum Breast Milk |
8–9 y | ✔ | Positive association between maternal PCBs and omission error, inverse association between maternal and breast milk PCBs and ADHD related behaviors. | ||||||
| Nowack (2015), Germany [91] | ✔ | 116 | ✔ | 32 w | Maternal Serum | 9–10 y | ✔ | Inverse association between maternal PCB concentrations and Social Responsiveness Scale scores, mainly in girls. | ||||||
| Sagiv (2015), United States [102] | ✔ | 622 | ✔ | 26.7±2.6 w Delivery 9 y |
Maternal Serum Cord Serum Child Serum |
9 y 10.5 y 12 y |
✔ | Prenatal ∑PBDEs (BDE-47, −99, −100, and −153) were associated with poorer attention at ages 9–12 years, while no associations were observed between ∑PBDE concentrations in child serum and measures of attention in school-age children. | ||||||
| Sovcikova (2015), Slovakia [89] | ✔ | 307 | ✔ | 8–9 y | Child Serum | 8–9 y | ✔ | Positive association between serum PCB concentrations and parameters μ and τ of the ex-Gaussian distribution of simple reaction time. | ||||||
| Verner (2015), United States [86] | ✔ | 441 | ✔ | Delivery 0–12m | Cord Serum Estimates for postnatal |
8 y | ✔ | Positive associations between cord serum PCB-153 and ADHD-related behaviors in quantile regression at 75th percentile. Association for postnatal PCB-153 was attenuated. | ||||||
| Verner (2015), Canada [87] | ✔ | 98 | ✔ | Delivery | Cord Plasma | 5 y | ✔ | Null association between cord plasma PCB-153 and inattention, but estimated PCB-153 levels at 2 months were associated with increased duration of inattention. | ||||||
| Wang (2015), China [105] | ✔ | 98 | ✔ | 4–5 y | House Dust | 4–5 y | ✔ | BDE-209 and total-BDEs (BDE-99, BDE-153, and BDE-209) were positively associated with depressive behavior problems and lower social development quotients. | ||||||
| Caspersen (2016), Norway [83] | ✔ | 1024 | ✔ | 22 w | Food Frequency Questionnaire | 3.5 y | ✔ | ✔ | Estimated PCB intake during pregnancy was related to lower language skills in girls but not boys. Null association with ADHD, IQ, or executive function. | |||||
| Forns (2016), Norway [99] | ✔ | 548 | ✔ | Median: 32 d | Breastmilk | 12 m | ✔ | In a mixture model of 6 persistent organic pollutants that were selected by elastic net and Bayesian model averaging, null associations were noted between BDE-28 and BDE-47 and behavioral problems at 12 months. | ||||||
| Braun (2017), United States [92] | ✔ | 346 | ✔ | 16±3 w | Maternal Serum | 1–8 y | ✔ | ✔ | Prenatal BDE-47 was associated lower MDI scores at ages 1–3 years and decreased FSIQ at ages 5 and 8 years. Positive associations were also reported between prenatal BDE-47 and externalizing behaviors. | |||||
| Castorina (2017), United States [108] | ✔ | 310 | ✔ | 26 w | Maternal Urine | 7 y | ✔ | ✔ | Inverse associations between DPHP and Full Scale IQ and Working Memory. Positive association between ip-PPP and hyperactivity scores. |
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| Lipscomb (2017), United States [100] | ✔ | 72 | ✔ | ✔ | 3–5 y | Silicone Passive Sampler | 3–5 y | ✔ | ∑PBDEs (BDE-28, −33, −47, −49, −99, −153, and −154) were not associated with externalizing problems in preschool children, while there was a positive relationship with ∑OPFRs (TDCIPP, TPHP, TCPP, and TCEP). | |||||
| Rosenquist (2017), Greenland and Ukraine [85] | ✔ | ✔ | 23–25 w First 12 months after delivery |
Maternal Serum Pharmacokinetic model for postnatal PCBs |
5 and 9 y | ✔ | Pooled adjusted ORs between prenatal and postnatal PCB-153 and abnormal behavior scores for Greenland and Ukraine cohorts did not reveal a statistically significant relationship. | |||||||
| Vuong (2017), United States [103] | ✔ | 214 | ✔ | 16±3 w 1,2,3,5, and 8 y |
Maternal Serum Child Serum |
8 y | ✔ | ✔ | No statistically significant associations were reported between prenatal or postnatal PBDE concentrations and measures of inattention or impulsivity in children at age 8 years. | |||||
| Vuong (2017), United States [93] | ✔ | 208 | ✔ | 1,2,3,5, and 8 y | Child Serum | 8 y | ✔ | ✔ | Postnatal PBDEs were associated with decreased FSIQ and increased hyperactivity and aggressive behaviors at age 8 years. | |||||
| Zhang (2017), United States [94] | ✔ | 239 | ✔ | 16±3 w | Maternal Serum | 8 y | ✔ | ✔ | A 10-fold increase in prenatal ∑PBDEs was associated with a decrement of 5.3-points (95% CI −10.6, −0.02) in FSIQ. Prenatal BDE-153 were associated with increased externalizing problems in children at age 8 years. |
|||||
| Berghuis (2018), Denmark [82] | ✔ | 101 | ✔ | ✔ | ✔ | 35 w | Maternal Serum | 13–15 y | ✔ | ✔ | Prenatal HBCD was associated with decreased total intelligence in children 13–15 years. While PBDEs were not associated with cognition, BDE-153 was observed to decrease sustained auditory attention. | |||
| Kim (2018), South Korea [95] | ✔ | 59 41 |
✔ | Not specified | Maternal Serum Breastmilk |
13–24 m | ✔ | ✔ | Maternal serum BDE-47 was associated with more externalizing behaviors among infants. No associations were noted between PBDEs and MDI. | |||||
| Oulhote (2018), United States [97] | ✔ | 333 | ✔ | 6–13 w | Maternal Serum | 6.9±0.9 m | ✔ | Increased concentrations of prenatal PBDEs were associated with more negative vocalizations in infants. Delayed physical reactivity was also noted with higher PBDEs, but only among boys. | ||||||
| Bernardo (2019), Canada [90] | ✔ | 546 | ✔ | First Trimester | Maternal Plasma | 3–4 y | ✔ | Highest PCB-153 quartile was associated with increased risk of having Social Responsiveness Scale score > 60. | ||||||
| de Water (2019), United States [107] | ✔ | 34 | ✔ | 12.2±2.8 w | Maternal Serum | 5 y | ✔ | Prenatal PBDEs were associated with increased global efficiency in areas of the brain that are involved with visual attention at age 5 years. Increased global efficiency in this area of the brain is associated with more executive function problems. | ||||||
| Doherty (2019), United States [109] | ✔ | 227 149 |
✔ | 27 w | Maternal Urine | 2–3 y | ✔ | Inverse associations between maternal ip-PPP concentrations and MSEL Cognitive Composite Scores and MB-CDI Vocabulary scores. | ||||||
| Doherty (2019), United States [110] | ✔ | 199 | ✔ | 27 w | Maternal Urine | 3 y | ✔ | Positive associations between maternal urinary BDCIPP concentrations and Behavioral Symptoms Index and Externalizing Problems. Inverse association between maternal urinary ip-PPP concentrations and Internalizing Problems. | ||||||
| Ji (2019), China [98] | ✔ | 199 307 |
✔ | Delivery | Cord Serum | 2 y 4 y |
✔ | Cord PBDEs were not associated with externalizing problems, but there was an increase in aggressive behaviors at age 2 years. Cord PBDEs were positively associated with emotional reactivity and internalizing behaviors, but only among girls. | ||||||
| Ruel (2019), Netherlands [84] | ✔ | 181 | ✔ | ✔ | ✔ | 35 w | Maternal Serum | 18 m 30 m |
✔ | Prenatal PCB-153 was associated with a delayed MDI score at 18 months. No associations were observed between PBDEs or HBCD and MDI. | ||||
| Margolis (2020), United States [106] | ✔ | 33 | ✔ | 12.2±2.8 w | Maternal Serum | 5 y | ✔ | Inverse associations were reported between prenatal PBDEs and global efficiency of the reading network. Increased global efficiency of the reading network was associated with improved word reading, suggesting prenatal PBDEs may be involved in reading development. | ||||||
Abbreviations: BDCIPP, bis(1,3-dichloro-2-propyl) phosphate; d, days; DPHP, diphenyl phosphate; ip-PPP, isopropylphenyl phenyl phosphate; m, months; MB-CDI, MacArthur-Bates Communicative Development Inventories; MDI, mental development index; MSEL, Mullen Scales of Early Learning; TCEP, tris(2-chloroethyl) phosphate; TCPP, tris(1-chloro-2-propyl), TDCIPP, tris(1,3-dichloro-2-propyl) phosphate; TPHP, tri-phenylphosphate; w, weeks; y, years