Prenatal exposure to synthetic phenols and phthalates and child respiratory health from 2 to 36 months of life

Associations of prenatal exposure to phthalates and their mixture with lung function in Mexican children

Early life phthalates exposure has been associated with adverse respiratory outcomes. However, evidence linking prenatal phthalates exposure and childhood lung function has been inconclusive. Additionally, few studies have examined phthalates exposure as a mixture and explored sexually dimorphic associations. We aimed to investigate sex-specific associations of prenatal phthalates mixtures with childhood lung function using the PROGRESS cohort in Mexico (N = 476). Prenatal phthalate concentrations were measured in maternal urine collected during the 2nd and 3rd trimesters. Children's lung function was evaluated at ages 8-13 years. Individual associations were assessed using multivariable linear regression, and mixture associations were modeled using repeated holdout WQS regression and hierarchical BKMR; data was stratified by sex to explore sex-specific associations. We identified significant interactions between 2nd trimester phthalates mixture and sex on FEV1 and FVC z-scores. Higher 2nd trimester phthalate concentrations were associated with higher FEV1 (β = 0.054, 95 %CI: 0.005, 0.104) and FVC z-scores (β = 0.074, 95 % CI: 0.024, 0.124) in females and with lower measures in males (FEV1, β = -0.017, 95 %CI: -0.066, 0.026; FVC, β = -0.014, 95 %CI: -0.065, 0.030). This study indicates that prenatal exposure to phthalates is related to childhood lung function in a sex-specific manner.

Maternal concentrations of environmental phenols during early pregnancy and behavioral problems in children aged 4 years from the Shanghai Birth Cohort

BACKGROUND

Prenatal exposure to environmental phenols such as bisphenol (BPs), paraben (PBs), benzophenone (BzPs), and triclosan (TCS) is ubiquitous and occurs in mixtures. Although some of them have been suspected to impact child behavioral development, evidence is still insufficient, and their mixed effects remain unclear.

OBJECTIVES

To explore the association of prenatal exposure to multiple phenols with child behavioral problems.

METHOD

In a sample of 600 mother-child pairs from the Shanghai Birth Cohort, we quantified 18 phenols (6 PBs, 7 BPs, 4 BzPs, and TCS) in urine samples collected during early pregnancy. Parent-reported Strengths and Difficulties Questionnaires were utilized to evaluate child behavioral difficulties across four subscales, namely conduct, hyperactivity/inattention, emotion, and peer relationship problems, at 4 years of age. Multivariable linear regression was conducted to estimate the relationships between single phenolic compounds and behavioral problems. Additionally, weighted quantile sum (WQS) regression was employed to examine the overall effects of the phenol mixture. Sex-stratified analyses were also performed.

RESULTS

Our population was extensively exposed to 10 phenols (direction rates >50 %), with low median concentrations (1.00 × 10-3-6.89 ng/mL). Among them, single chemical analyses revealed that 2,4-dihydroxy benzophenone (BP1), TCS, and methyl 4-hydroxybenzoate (MeP) were associated with increased behavior problems, including hyperactivity/inattention (BP1: β = 0.16; 95 % confidence interval [CI]: 0.04, 0.30), emotional problems (BP1: β = 0.11; 95 % CI: 0.02, 0.20; TCS: β = 0.08; 95 % CI: 0.02, 0.14), and peer problems (MeP: β = 0.10; 95 % CI: 0.02, 0.18); however, we did not identify any significant association with conduct problems. Further phenol mixture analyses in the WQS model yielded similar results. Stratification for child sex showed stronger positive associations in boys.

CONCLUSION

Our findings indicated that maternal phenol levels during early pregnancy, specifically BP1, TCS, and MeP, are associated with high behavioral problem scores in 4-year-old children.

Exposure to endocrine-disrupting plasticisers and lung function in children and adolescents: A systematic review and meta-analysis

Exposure to endocrine-disrupting plasticisers (EDPs), such as phthalates and bisphenols, has been associated with reduced lung function in children and adolescents. However, the existing literature yields conflicting results. This systematic review and meta-analysis aimed to assess the epidemiologic evidence investigating the association between EDP exposure and lung function in children and adolescents. A comprehensive search of five databases identified 25 relevant studies. We employed a random-effects meta-analysis on spirometry measures. The effect size of interest was the change in lung function in standard deviation (SD) units resulting from a two-fold increase in exposure levels. We found that certain phthalates marginally reduced lung function in children. Forced expiratory volume in 1 s (FEV1) was reduced by a two-fold increase in mono-benzyl phthalate (MBzP) (β = -0.025 SD, 95%CI: 0.042, -0.008), mono-ethyl-oxo-hexyl phthalate (MEOHP) (β = -0.035 SD, 95%CI: 0.057, -0.014) and mono-carboxy-nonyl phthalate (MCNP) (β = -0.024 SD, 95%CI: 0.05, -0.003). Forced vital capacity (FVC) was decreased by a two-fold increase in MBzP (β = -0.022 SD, 95%CI: 0.036, -0.008) and MEOHP (β = -0.035 SD, 95%CI: 0.057, -0.014) levels. A two-fold increase in MCNP levels was associated with lower FEV1/FVC (β = -0.023 SD, 95%CI: 0.045, -0.001). Furthermore, a two-fold increase in MEOHP levels reduced forced mid-expiratory flow (FEF25-75) (β = -0.030 SD, 95%CI: 0.055, -0.005) and peak expiratory flow (PEF) (β = -0.056 SD, 95%CI: 0.098, -0.014). Notably, associations were more pronounced in males. Given the potential for reverse causation bias, the association between childhood exposure to EDPs and lung function remains uncertain. Overall, our meta-analysis showed small reductions in lung function with higher phthalate exposure. However, future studies are warranted in younger age groups.