Our study, conducted within a New York City-based cohort, identified novel interactions between maternal PAH exposure and maternal and newborn genetic haplotypes in key B[a]P metabolism genes on B[a]P-DNA adducts in paired cord blood samples.
Polycyclic aromatic hydrocarbons (PAH) are a class of chemicals common in the environment. Certain PAH are carcinogenic, although the degree to which genetic variation influences susceptibility to carcinogenic PAH remains unclear. Also unknown is the influence of genetic variation on the procarcinogenic effect of in utero exposures to PAH. Benzo[a]pyrene (B[a]P) is a well-studied PAH that is classified as a probable human carcinogen. Within our New York City-based cohort, we explored interactions between maternal exposure to airborne PAH during pregnancy and maternal and newborn haplotypes (and in one case, a single-nucleotide polymorphism) in key B[a]P metabolism genes on B[a]P-DNA adducts in paired cord blood samples. The study subjects included non-smoking African-American (n = 132) and Dominican (n = 235) women with available data on maternal PAH exposure, paired cord adducts and genetic data who resided in the Washington Heights, Central Harlem and South Bronx neighborhoods of New York City. We selected seven maternal and newborn genes related to B[a]P metabolism, detoxification and repair for our analyses: CYP1A1, CYP1A2, CYP1B1, GSTM3, GSTT2, NQO1 and XRCC1. We found significant interactions between maternal PAH exposure and haplotype on cord B[a]P-DNA adducts in the following genes: maternal CYP1B1, XRCC1 and GSTM3, and newborn CYP1A2 and XRCC1 in African-Americans; and maternal XRCC1 and newborn NQO1 in Dominicans. These novel findings highlight differences in maternal and newborn genetic contributions to B[a]P-DNA adduct formation, as well as ethnic differences in gene–environment interactions, and have the potential to identify at-risk subpopulations who are susceptible to the carcinogenic potential of B[a]P.
Exposure to traffic-related air pollutants, including polycyclic aromatic hydrocarbons (PAHs) from traffic emissions and other combustion sources, and childhood obesity, have been implicated as risk factors for developing asthma. However, the interaction between these two on asthma among young urban children has not been studied previously.
Exposure to early childhood PAHs was measured by two week residential indoor monitoring at age 5–6 years in the Columbia Center for Children's Environmental Health birth cohort (n=311). Semivolatile [e.g., methylphenanthrenes] and nonvolatile [e.g., benzo(a)pyrene] PAHs were monitored. Obesity at age 5 was defined as a body mass index (BMI) greater than or equal to the 95th percentile of the year 2000 age- and sex- specific growth charts (Center for Disease Control). Current asthma and recent wheeze at ages 5 and 7 were determined by validated questionnaires. Data were analyzed using a modified Poisson regression in generalized estimating equations (GEE) to estimate relative risks (RR), after adjusting for potential covariates.
Neither PAH concentrations or obesity had a main effect on asthma or recent wheeze. In models stratified by presence/absence of obesity, a significant positive association was observed between an interquartile range (IQR) increase in natural log-transformed 1-methylphenanthrene (RR [95% CI]: 2.62 [1.17–5.88] with IQRln=0.76), and 9-methylphenanthrene (2.92 [1.09–7.82] with IQRln=0.73) concentrations and asthma in obese children (n=63). No association in non-obese (n=248) children was observed at age 5 (Pinteraction < 0.03). Similar associations were observed for 3-methylphenanthrene, 9-methylphenanthrene, and 3,6-dimethylphenanthrene at age 7.
Obese young children may be more likely to develop asthma in association with greater exposure to PAHs, and methylphenanthrenes in particular, than non-obese children.
Childhood obesity; methylphenanthrenes; polycyclic aromatic hydrocarbons; asthma; nonatopic children
Prior research reports inverse associations between maternal prenatal urinary phthalate metabolite concentrations and mental and motor development in preschoolers. No study evaluated whether these associations persist into school age.
In a follow up of 328 inner-city mothers and their children, we measured prenatal urinary metabolites of di-n-butyl phthalate (DnBP), butylbenzyl phthalate (BBzP), di-isobutyl phthalate (DiBP), di-2-ethylhexyl phthalate and diethyl phthalate in late pregnancy. The Wechsler Intelligence Scale for Children, 4th edition was administered at child age 7 years and evaluates four areas of cognitive function associated with overall intelligence quotient (IQ).
Child full-scale IQ was inversely associated with prenatal urinary metabolite concentrations of DnBP and DiBP: b = −2.69 (95% confidence interval [CI] = −4.33, −1.05) and b = −2.69 (95% CI = −4.22, −1.16) per log unit increase. Among children of mothers with the highest versus lowest quartile DnBP and DiBP metabolite concentrations, IQ was 6.7 (95% CI = 1.9, 11.4) and 7.6 (95% CI = 3.2, 12.1) points lower, respectively. Associations were unchanged after control for cognition at age 3 years. Significant inverse associations were also seen between maternal prenatal metabolite concentrations of DnBP and DiBP and child processing speed, perceptual reasoning and working memory; DiBP and child verbal comprehension; and BBzP and child perceptual reasoning.
Maternal prenatal urinary metabolite concentrations measured in late pregnancy of DnBP and DiBP are associated with deficits in children’s intellectual development at age 7 years. Because phthalate exposures are ubiquitous and concentrations seen here within the range previously observed among general populations, results are of public health significance.
Polycyclic aromatic hydrocarbons are widespread urban air pollutants from combustion of fossil fuel and other organic material shown previously to be neurotoxic.
In a prospective cohort study, we evaluated the relationship between Attention Deficit Hyperactivity Disorder behavior problems and prenatal polycyclic aromatic hydrocarbon exposure, adjusting for postnatal exposure.
Materials and Methods
Children of nonsmoking African-American and Dominican women in New York City were followed from in utero to 9 years. Prenatal polycyclic aromatic hydrocarbon exposure was estimated by levels of polycyclic aromatic hydrocarbon- DNA adducts in maternal and cord blood collected at delivery. Postnatal exposure was estimated by the concentration of urinary polycyclic aromatic hydrocarbon metabolites at ages 3 or 5. Attention Deficit Hyperactivity Disorder behavior problems were assessed using the Child Behavior Checklist and the Conners Parent Rating Scale- Revised.
High prenatal adduct exposure, measured by elevated maternal adducts was significantly associated with all Conners Parent Rating Scale-Revised subscales when the raw scores were analyzed continuously (N = 233). After dichotomizing at the threshold for moderately to markedly atypical symptoms, high maternal adducts were significantly associated with the Conners Parent Rating Scale-Revised DSM-IV Inattentive (OR = 5.06, 95% CI [1.43, 17.93]) and DSM-IV Total (OR = 3.37, 95% CI [1.10, 10.34]) subscales. High maternal adducts were positivity associated with the DSM-oriented Attention Deficit/Hyperactivity Problems scale on the Child Behavior Checklist, albeit not significant. In the smaller sample with cord adducts, the associations between outcomes and high cord adduct exposure were not statistically significant (N = 162).
The results suggest that exposure to polycyclic aromatic hydrocarbons encountered in New York City air may play a role in childhood Attention Deficit Hyperactivity Disorder behavior problems.
Airborne polycyclic aromatic hydrocarbons (PAHs) are pollutants generated by combustion of fossil fuel and other organic material. Both prenatal PAH exposure and maternal psychological distress during pregnancy have each been associated with neurodevelopmental problems in children. The goal was to evaluate potential interactions between prenatal exposure to airborne PAHs and maternal psychological distress during pregnancy on subsequent behavioral problems in children.
In a longitudinal birth cohort study, 248 children of nonsmoking white women in the coal-burning region of Krakow, Poland, were followed from in utero until age 9. Prenatal PAH exposure was measured by personal air monitoring during pregnancy, maternal demoralization during pregnancy by the Psychiatric Epidemiology Research Instrument–Demoralization, and child behavior by the Child Behavior Checklist.
Significant interactions between maternal demoralization and PAH exposure (high versus low) were identified for symptoms of anxious/depressed, withdrawn/depressed, social problems, aggressive behavior, internalizing problems, and externalizing problems. The effects of demoralization on syndromes of anxious/depressed, withdrawn/depressed, rule-breaking, aggressive behavior, and the composite internalizing and externalizing scores were seen only in conjunction with high PAH exposure. Fewer significant effects with weaker effect sizes were observed in the low-PAH-exposure group.
Maternal demoralization during pregnancy appears to have a greater effect on child neurobehavioral development among children who experienced high prenatal PAH exposure. The results provide the first evidence of an interaction between prenatal exposure to maternal demoralization and air pollution on child neurobehavioral development, indicating the need for a multifaceted approach to the prevention of developmental problems in children.
prenatal; PAH; air pollution; child behavior; maternal psychological distress; demoralization
Our prior studies of lung cancer suggested that a novel biomarker (pro-surfactant protein B or pro-SFTPB) might serve as a predictive marker for this disease. We aimed to determine the potential utility of pro-SFTPB for distinguishing lung cancer cases from matched controls as a risk marker.
Study subjects were drawn from the longitudinal Physicians’ Health Study (PHS). Cases (n = 188) included individuals who were cancer-free at study enrollment but developed lung cancer during follow-up. Controls (n = 337) were subjects who did not develop lung cancer. Cases and controls were matched on date of study enrollment, age at enrollment, and smoking status and amount. Baseline plasma samples drawn at enrollment were analyzed for pro-SFTPB using ELISA to detect differences in protein expression levels for cases and controls.
Pro-SFTPB-non-detectable status was significantly associated with lung cancer risk (OR = 5.88, 95% CI 1.24, 27.48). Among subjects with detectable levels of the protein, increasing plasma concentration of pro-SFTPB was associated with higher lung cancer risk (OR = 1.41 per unit increase in log pro-SFTPB, 95% CI 1.08, 1.84).
These results suggest a non-linear, J-shaped association between plasma pro-SFTPB levels and lung cancer risk, with both non-detectable and higher levels of the marker being associated with lung cancer.
These results show promise of a risk marker that could contribute to predicting risk for lung cancer development and to narrowing the high risk population for low-dose computed tomography (LDCT) screening.
Proteomics; cancer risk; biomarker; lung cancer
Background: Studies suggest that phthalate exposures may adversely affect child respiratory health.
Objectives: We evaluated associations between asthma diagnosed in children between 5 and 11 years of age and prenatal exposures to butylbenzyl phthalate (BBzP), di-n-butyl phthalate (DnBP), di(2-ethylhexyl) phthalate (DEHP), and diethyl phthalate (DEP).
Methods: Phthalate metabolites were measured in spot urine collected from 300 pregnant inner-city women. Children were examined by an allergist or pulmonologist based on the first parental report of wheeze, other respiratory symptoms, and/or use of asthma rescue/controller medication in the preceding 12 months on repeat follow-up questionnaires. Standardized diagnostic criteria were used to classify these children as either having or not having current asthma at the time of the physician examination. Children without any report of wheeze or the other asthma-like symptoms were classified as nonasthmatics at the time of the last negative questionnaire. Modified Poisson regression analyses were used to estimate relative risks (RR) controlling for specific gravity and potential confounders.
Results: Of 300 children, 154 (51%) were examined by a physician because of reports of wheeze, other asthma-like symptoms, and/or medication use; 94 were diagnosed with current asthma and 60 without current asthma. The remaining 146 children were classified as nonasthmatic. Compared with levels in nonasthmatics, prenatal metabolites of BBzP and DnBP were associated with a history of asthma-like symptoms (p < 0.05) and with the diagnosis of current asthma: RR = 1.17 (95% CI: 1.01, 1.35) and RR = 1.25 (95% CI: 1.04, 1.51) per natural log-unit increase, respectively. Risk of current asthma was > 70% higher among children with maternal prenatal BBzP and DnBP metabolite concentrations in the third versus the first tertile.
Conclusion: Prenatal exposure to BBzP and DnBP may increase the risk of asthma among inner-city children. However, because this is the first such finding, results require replication.
Citation: Whyatt RM, Perzanowski MS, Just AC, Rundle AG, Donohue KM, Calafat AM, Hoepner LA, Perera FP, Miller RL. 2014. Asthma in inner-city children at 5–11 years of age and prenatal exposure to phthalates: the Columbia Center for Children’s Environmental Health Cohort. Environ Health Perspect 122:1141–1146; http://dx.doi.org/10.1289/ehp.1307670
Over the last decades many epidemiologic studies considered the morbidity patterns for respiratory diseases and lung function of children in the context of ambient air pollution usually measured in the postnatal period. The main purpose of this study is to assess the impact of prenatal exposure to fine particulate matter (PM2.5) on the recurrent broncho-pulmonary infections in early childhood.
The study included 214 children who had measurements of personal prenatal PM2.5 exposure and regularly collected data on the occurrence of acute bronchitis and pneumonia diagnosed by a physician from birth over the seven-year follow-up. The effect of prenatal exposure to PM2.5 was adjusted in the multivariable logistic models for potential confounders, such as prenatal and postnatal ETS (environmental tobacco smoke), city residence area as a proxy of postnatal urban exposure, children’s sensitization to domestic aeroallergens, and asthma. In the subgroup of children with available PM2.5 indoor levels, the effect of prenatal exposure was additionally adjusted for indoor exposure as well. The adjusted odds ratio (OR) for incidence of recurrent broncho-pulmonary infections (five or more spells of bronchitis and/or pneumonia) recorded in the follow-up significantly correlated in a dose-response manner with the prenatal PM2.5 level (OR = 2.44, 95%CI: 1.12 – 5.36).
In conclusion, the study suggests that prenatal exposure to PM2.5 increases susceptibility to respiratory infections and may program respiratory morbidity in early childhood. The study also provides evidence that the target value of 20 μg/m3 for the 24-hour mean level of PM2.5 protects unborn babies better than earlier established EPA guidelines.
birth cohort study; fine particulate matter; prenatal and postnatal exposure; bronchitis; pneumonia
Despite growing concern over potential health effects associated with exposures to the endocrine disruptor, bisphenol A (BPA), insufficient information is available on determinants of BPA concentrations among minority populations in the US.
To describe concentrations and predictors of BPA in an inner-city longitudinal birth cohort.
We analyzed spot urines for total BPA collected during pregnancy and child ages 3, 5, and 7 years from African Americans and Dominicans (n=568) enrolled in the Columbia Center for Children’s Environmental Health birth cohort and residing in Northern Manhattan and the South Bronx. Adjusting for specific gravity, generalized estimating equations were used to compare BPA concentrations across paired samples and linear regression analyses were used to determine relationships between BPA, season of sample collection, socio-demographic variables and urinary concentrations of phthalate metabolites.
BPA was detected in > 94% of samples. Prenatal concentrations were significantly lower than postnatal concentrations. Geometric means were higher among African Americans compared to Dominicans in prenatal (p=0.008), 5 year (p<0.001) and 7 year (p=0.017) samples. Geometric means at 5 and 7 years were higher (p=0.021, p=0.041 respectively) for children of mothers never married compared to mothers ever married at enrollment. BPA concentrations were correlated with phthalate metabolite concentrations at prenatal, 3, 5 and 7 years (p-values <0.05). Postnatal BPA concentrations were higher in samples collected during the summer.
This study shows widespread BPA exposure in an inner-city minority population. BPA concentration variations were associated with socio-demographic characteristics and other xenobiotics.
Bisphenol A; Urine; Child; Prenatal; Minority
Adolescents are often cited as having poor rates of compliance with medical regimens and research protocols. We quantified compliance in a cohort of urban adolescents participating in a complex research protocol in which measures were obtained without direct supervision by research personnel.
A total of 54 early adolescents ages 10–13 were asked to wear a vest containing a personal air pollutant exposure monitor for two 24-hour periods and to perform daily peak expiratory flow (PEF) for six consecutive days. Compliance with wearing the vest was measured by comparing accelerometer data from a device within the vest to one worn continuously on the child’s wrist. Daily PEF data were recorded using an electronic meter.
A priori definition of compliance was met by 85% of the adolescents by wearing the exposure monitoring vest and 72% by performing PEF.
These findings suggest that early adolescents can be compliant with complex research protocols that are needed to help bridge gaps in pediatric asthma research.
adolescents; teen compliance; asthma studies; exposure monitoring; peak expiratory flow; accelerometer; objective measurements; wearing compliance
Polycyclic aromatic hydrocarbons (PAH) are major toxic air pollutants released during incomplete combustion of coal. PAH emissions are especially problematic in China because of their reliance on coal-powered energy. The prenatal period is a window of susceptibility to neurotoxicants. To determine the health benefits of reducing air pollution related to coal-burning, we compared molecular biomarkers of exposure and preclinical effects in umbilical cord blood to neurodevelopmental outcomes from two successive birth cohorts enrolled before and after a highly polluting, coal-fired power plant in Tongliang County, China had ceased operation. Women and their newborns in the two successive cohorts were enrolled at the time of delivery. We measured PAH-DNA adducts, a biomarker of PAH-exposure and DNA damage, and brain-derived neurotrophic factor (BDNF), a protein involved in neuronal growth, in umbilical cord blood. At age two, children were tested using the Gesell Developmental Schedules (GDS). The two cohorts were compared with respect to levels of both biomarkers in cord blood as well as developmental quotient (DQ) scores across 5 domains. Lower levels of PAH-DNA adducts, higher concentrations of the mature BDNF protein (mBDNF) and higher DQ scores were seen in the 2005 cohort enrolled after closure of the power plant. In the two cohorts combined, PAH-DNA adducts were inversely associated with mBDNF as well as scores for motor (p = 0.05), adaptive (p = 0.022), and average (p = 0.014) DQ. BDNF levels were positively associated with motor (p = 0.018), social (p = 0.001), and average (p = 0.017) DQ scores. The findings indicate that the closure of a coal-burning plant resulted in the reduction of PAH-DNA adducts in newborns and increased mBDNF levels that in turn, were positively associated with neurocognitive development. They provide further evidence of the direct benefits to children's health as a result of the coal plant shut down, supporting clean energy and environmental policies in China and elsewhere.
Bisphenol A (BPA) is used widely to manufacture food container linings. Mouse models suggest exposure to BPA might increase allergic inflammation.
We hypothesized that BPA exposure, as assessed based on urinary BPA concentrations, would be associated with increased odds of wheeze and asthma and increased fraction of exhaled nitric oxide (FENO) values in children.
The Columbia Center for Children’s Environmental Health recruited pregnant women for a prospective birth cohort study (n = 568). Mothers during the third trimester and children at ages 3, 5, and 7 years provided spot urine samples. Total urinary BPA concentrations were measured by using online solid-phase extraction, high-performance liquid chromatography, isotope-dilution tandem mass spectrometry. Wheeze in the last 12 months was measured by using questionnaires at ages 5, 6, and 7 years. Asthma was determined by a physician once between ages 5 and 12 years. FENO values were measured at ages 7 to 11 years.
Prenatal urinary BPA concentrations were associated inversely with wheeze at age 5 years (odds ratio [OR], 0.7; 95% CI, 0.5–0.9; P = .02). Urinary BPA concentrations at age 3 years were associated positively with wheeze at ages 5 years (OR, 1.4; 95% CI, 1.1–1.8; P = .02) and 6 years (OR, 1.4; 95% CI, 1.0–1.9; P = .03). BPA concentrations at age 7 years were associated with wheeze at age 7 years (OR, 1.4; 95% CI, 1.0–1.9; P = .04) and FENO values (β = 0.1; 95% CI, 0.02–0.2; P = .02). BPA concentrations at ages 3, 5, and 7 years were associated with asthma (OR, 1.5 [95% CI, 1.1–2.0], P = .005; OR, 1.4 [95% CI, 1.0–1.9], P = .03; and OR, 1.5 [95% CI, 1.0–2.1], P = .04, respectively).
This is the first report of an association between postnatal urinary BPA concentrations and asthma in children.
Bisphenol A; asthma; wheeze; children; exhaled nitric oxide; IgE; cohort study
Sensitization to cockroach is one of the strongest identified risk factors for greater asthma morbidity in low-income, urban communities; however, the timing of exposures relevant to development of sensitization has not been elucidated fully. Further, exposure to combustion byproducts, including polycyclic aromatic hydrocarbons (PAHs), may augment the development of allergic sensitization.
To test the hypotheses that domestic cockroach allergen measured prenatally would predict cockroach sensitization in early childhood, and that this association would be greater for children exposed to higher concentrations of PAHs.
Dominican and African-American pregnant women living in NYC were enrolled. In the third trimester, expectant mothers wore personal air samplers for measurement of 8 nonvolatile PAHs and the semi-volatile PAH pyrene, and dust was collected from homes for allergen measurement. Glutathione-s-transferase mu (GSTM1) gene polymorphisms were measured in children. Allergen-specific IgE was measured from the children at ages 2, 3, 5 and 7 years.
Bla g2 in prenatal kitchen dust predicted cockroach sensitization at age 5–7 years [adjusted relative risk (RR) 1.15; P = 0.001; n = 349]. The association was observed only among children above [RR 1.22; P = 0.001], but not below [RR 1.07; P = 0.24] median sum of 8 nonvolatile PAH levels. The association was most pronounced among children with higher PAH and null in the GSTM1 gene [RR 1.54; P = 0.001].
Prenatal exposure to cockroach allergen was associated with a greater risk of developing allergic sensitization. This risk was increased by exposure to nonvolatile PAHs, with children null for the GSTM1 mutation particularly vulnerable.
Domestic exposure to cockroach allergen measured prenatally predicted sensitization to cockroach at age 5–7 years.
Cockroach allergen predicted sensitization only among children also exposed to higher levels of airborne non-volatile polycyclic aromatic hydrocarbons, indicating that these combustion byproducts may act as adjuvants in the development of cockroach sensitization in urban environments.
These findings suggest that targeting either allergen or combustion sources with primary prevention could be successful in reducing the development of cockroach sensitization.
Bla g2; cockroach; polycyclic aromatic hydrocarbon; IgE; allergy; inner-city; GSTM; GSTP
Prenatal exposure to chlorpyrifos (CPF), an organophosphorus insecticide, has long been associated with delayed neurocognitive development and most recently with decrements in working memory at age 7. In the current paper, we expanded the previous work on CPF to investigate how additional biological and social environmental factors might create or explain differential neurodevelopmental susceptibility, focusing on main and moderating effects of the quality of the home environment (HOME) and child sex. We evaluate how the quality of the home environment (specifically, parental nurturance and environmental stimulation) and child sex interact with the adverse effects of prenatal CPF exposure on working memory at child age 7 years. We did not observe a remediating effect of a high quality home environment (either parental nurturance or environmental stimulation) on the adverse effects of prenatal CPF exposure on working memory. However, we detected a borderline significant interaction between prenatal exposure to CPF and child sex (B (95% CI) for interaction term = −1.714 (−3.753 to 0.326)) suggesting males experience a greater decrement in working memory than females following prenatal CPF exposure. In addition, we detected a borderline interaction between parental nurturance and child sex (B (95% CI) for interaction term = 1.490 (−0.518 to 3.499)) suggesting that, in terms of working memory, males benefit more from a nurturing environment than females. To our knowledge, this is the first investigation into factors that may inform an intervention strategy to reduce or reverse the cognitive deficits resulting from prenatal CPF exposure.
chlorpyrifos; neurodevelopment; working memory; HOME inventory; sex-specific
Exercise-induced wheeze (EIW) may identify a distinct population among asthmatics and give insight into asthma morbidity etiology. The prevalence of pediatric asthma and associated urgent medical visits varies greatly by neighborhood in New York City and is highest in low-income neighborhoods. Although increased asthma severity might contribute to the disparities in urgent medical visits, when controlling for health insurance coverage, we previously observed no differences in clinical measures of severity between asthmatic children living in neighborhoods with lower (3%–9%) versus higher (11%–19%) asthma prevalence. Among these asthmatics, we hypothesized that EIW would be associated with urgent medical visits and a child’s neighborhood asthma prevalence.
Families of 7- to 8-year-old children were recruited into a case-control study of asthma through an employer-based health insurance provider. Among the asthmatics (n = 195), prevalence ratios (PRs) for EIW were estimated. Final models included children with valid measures of lung function, seroatopy, and waist circumference (n = 140).
EIW was associated with urgent medical visits for asthma (PR, 2.29; P = .021), independent of frequent wheeze symptoms. In contrast to frequent wheeze, EIW was not associated with seroatopy or exhaled NO, suggesting a distinct mechanism. EIW prevalence among asthmatics increased with increasing neighborhood asthma prevalence (PR, 1.09; P = .012), after adjustment for race, ethnicity, maternal asthma, environmental tobacco smoke, household income, and neighborhood income.
EIW may contribute to the disparities in urgent medical visits for asthma between high- and low-income neighborhoods. Physicians caring for asthmatics should consider EIW an indicator of risk for urgent medical visits.
asthma; allergy; exercise; emergency department; exercise-induced bronchoconstriction
Despite data associating exposure to traffic-related polycyclic aromatic hydrocarbons (PAH) in asthma, mechanistic support has been limited. We hypothesized that both prenatal and early postnatal exposure to PAH would increase airway hyperreactivity (AHR) and that the resulting AHR may be insensitive to treatment with a β2AR agonist drug, procaterol. Further, we hypothesized that these exposures would be associated with altered β2AR gene expression and DNA methylation in mouse lungs. Mice were exposed prenatally or postnatally to a nebulized PAH mixture versus negative control aerosol 5 days a week. Double knockout β2AR mice were exposed postnatally only. Prenatal exposure to PAH was associated with reduced β2AR gene expression among nonsensitized mice offspring, but not increases in DNA methylation or AHR. Postnatal exposure to PAH was borderline associated with increased AHR among sensitized wildtype, but not knockout mice. In the first study that delivers PAH aerosols to mice in a relatively physiological manner, small effects on AHR and β2AR gene expression, but not β2AR agonist drug activity, were observed. If confirmed, the results may suggest that exposure to PAH, common ambient urban pollutants, affects β2AR function, although the impact on the efficacy of β2AR agonist drugs used in treating asthma remains uncertain.
Previously we reported that airborne concentrations of cis-permethrin, but not trans-permethrin, measured during pregnancy in an inner city pediatric cohort was associated with cough by age 5. However, the effect of subsequent exposures to both permethrins during early childhood, and to piperonyl butoxide (PBO, a synergist for residential pyrethroid insecticides) remains to be elucidated. We hypothesized that prenatal and age 5-6 year measures of PBO and permethrins would be associated with cough at age 5-6 years in this cohort. Further, we explored the associations between these pesticides measures and wheeze, asthma, seroatopy, and fractional exhaled nitric oxide (FeNO).
PBO and permethrins were measured in personal air during the third trimester of pregnancy and indoor residential air at age 5-6 years (n=224). Health outcome questionnaires were administered to the mothers of 5-6 years old children. Indoor allergen specific and total immunoglobulin (Ig) E production was measured from sera collected at age 5, and FeNO was measured at 5-6 years. The hypotheses were tested using regression models adjusting for common confounders.
Noninfectious cough was reported among 14% of children at age 5-6 years. Measures of prenatal PBO, but not age 5-6 year PBO or permethrins, increased the odds of cough [OR (95% CI): 1.27 (1.09-1.48), p<0.01; n=217]. No significant associations were found for other measured health outcomes.
Prenatal PBO exposure was associated with childhood cough. It is unclear whether the observed effect is due mainly to PBO itself or residential pyrethroids of which PBO is an indicator.
prenatal pesticide exposure; cough; piperonyl butoxide; permethrin
Rationale: Phthalates are used widely in consumer products. Exposure to several phthalates has been associated with respiratory symptoms and decreased lung function. Associations between children’s phthalate exposures and fractional exhaled nitric oxide (FeNO), a biomarker of airway inflammation, have not been examined.
Objectives: We hypothesized that urinary concentrations of four phthalate metabolites would be positively associated with FeNO and that these associations would be stronger among children with seroatopy or wheeze.
Methods: In an urban ongoing birth cohort, 244 children had phthalate metabolites determined in urine collected on the same day as FeNO measurement. Repeated sampling gathered 313 observations between ages 4.9 and 9.1 years. Seroatopy was assessed by specific IgE. Wheeze in the past year was assessed by validated questionnaire. Regression models used generalized estimating equations.
Measurements and Main Results: Log-unit increases in urinary concentrations of metabolites of diethyl phthalate (DEP) and butylbenzyl phthalate (BBzP) were associated with a 6.6% (95% confidence interval [CI] 0.5–13.1%) and 8.7% (95% CI, 1.9–16.0%) increase in FeNO, respectively, adjusting for other phthalate metabolites and potential covariates/confounders. There was no association between concentrations of metabolites of di(2-ethylhexyl) phthalate or di-n-butyl phthalate and FeNO. There was no significant interaction by seroatopy. The BBzP metabolite association was significantly stronger among children who wheeze (P = 0.016).
Conclusions: Independent associations between exposures to DEP and BBzP and FeNO in a cohort of inner-city children were observed. These results suggest that these two ubiquitous phthalates, previously shown to have substantial contributions from inhalation, are positively associated with airway inflammation in children.
airway inflammation; asthma; diethyl phthalate; butylbenzyl phthalate; fractional exhaled nitric oxide
Our primary purpose was to assess sex-specific fetal growth reduction in newborns exposed prenatally to fine particulate matter. Only women 18–35 years of age, who claimed to be non-smokers, with singleton pregnancies, without illicit drug use and HIV infection, free from chronic diseases were eligible for the study. A total of 481 enrolled pregnant women who gave birth between 37 and 43 weeks of gestation were included in the study. Prenatal personal exposure to fine particles over 48 h during the second trimester was measured using personal monitors. To evaluate the relationship between the level of PM2.5 measured over 48 h in the second trimester of pregnancy with those in the first and the third trimesters, a series of repeated measurements in each trimester was carried out in a random subsample of 85 pregnant women. We assessed the effect of PM2.5 exposure on the birth outcomes (weight, length and head circumference at birth) by multivariable regression models, controlling for potential confounders (maternal education, gestational age, parity, maternal height and prepregnancy weight, sex of infant, prenatal environmental tobacco smoke, and season of birth). Birth outcomes were associated positively with gestational age, parity, maternal height and prepregnancy weight, but negatively with the level of prenatal PM2.5 exposure. Overall average increase in gestational period of prenatal exposure to fine particles by about 30 μg/m3, i.e., from 25th percentile (23.4 μg/m3) to 75th percentile (53.1 μg/m3) brought about an average birth weight deficit of 97.2 g (95% CI: −201, 6.6) and length at birth of 0.7cm (95% CI: −1.36, −0.04). The corresponding exposure lead to birth weight deficit in male newborns of 189 g (95% CI: −34.2, −343) in comparison to 17 g in female newborns; the deficit of length at birth in male infants amounted to 1.1 cm (95% CI: −0.11, −2.04). We found a significant interrelationship between self-reported ETS and PM2.5, however, none of the models showed a significant interaction of both variables. The joint effect of various levels of PM2.5 and ETS on birth outcomes showed the significant deficit only for the categories of exposure with higher component of PM2.5. Concluding, the results of the study suggest that observed deficits in birth outcomes are rather attributable to prenatal PM2.5 exposure and not to environmental tobacco smoke. The study also provided evidence that male fetuses are more sensitive to prenatal PM2.5 exposure and this should persuade policy makers to consider birth outcomes by gender separately while setting air pollution guidelines.
Cohort study; Prenatal exposure; Air pollutants; Fine particles; Gender; Fetal growth deficits
While exposures to urban fine particulate matter (PM2.5) and soot-black carbon (soot-BC) have been associated with asthma exacerbations, there is limited evidence on whether these pollutants are associated with the new development of asthma or allergy among young inner city children. We hypothesized that childhood exposure to PM2.5 and the soot-BC component would be associated with the report of new wheeze and development of seroatopy in an inner city birth cohort.
As part of the research being conducted by the Columbia Center of Children’s Environmental Health (CCCEH) birth cohort study in New York City, two-week integrated residential monitoring of PM2.5, soot-BC (based on a multi-wavelength integrating sphere method), and modified absorption coefficient (Abs*; based on the smoke stain reflectometer) was conducted between October 2005 and May 2011 for 408 children at age 5–6 years old. Residential monitoring was repeated 6 months later (n=262) to capture seasonal variability. New wheeze was identified through the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaires during up to 3 years of follow-up and compared to a reference group that reported never wheeze, remitted wheeze, or persistent wheeze. Specific immunoglobulin (Ig) E against cockroach, mouse, cat, and dust mite and total IgE levels were measured in sera at ages 5 and 7 years.
PM2.5, soot-BC, and Abs* measured at the first visit were correlated moderately with those at the second visit (Pearson r > 0.44). Using logistic regression models, a positive association between PM2.5 and new wheeze was found with adjusted odds ratio [95% confidence intervals] of 1.51 [1.05–2.16] per interquartile range (IQR). Positive but nonsignificant association was found between the development of new wheeze and soot-BC and (OR 1.40 [0.96–2.05]), and Abs* (OR 1.57 [0.91–2.68]); Significantly positive associations were found between air pollutant measurements and new wheeze when restricting to those participants with repeat home indoor measurements 6 months apart. Associations between pollutants and IgE levels were not detected.
Our findings suggest that childhood exposure to indoor air pollution, much of which penetrated readily from outdoor sources, may contribute to the development of wheeze symptoms among children age 5 to 7 years.
indoor air pollution; long-term exposure; PM2.5; black carbon; wheeze; asthma; young children
Impaired fetal development is associated with a number of adult chronic diseases and it is believed that these associations arise as a result of the phenomenon of “epigenetic programming”, which involves persisting changes in structure and function of various body organs caused by ambient factors during critical and vulnerable periods of early development. The main goal of the study was to assess the association between lung function in early childhood and prenatal exposure to fine particulate matter (PM2.5 ), which represents a wide range of chemical compounds potentially hazardous for fetal development. Among pregnant women recruited prenatally to the study personal measurements of PM2.5 was performed over 48 hours in the second trimester of pregnancy. After delivery, infants were followed over five years and the interviewers visited participants at their homes to record children’s respiratory symptoms every three months in the child’s first two years of life and every 6 months later. In the fifth year of the follow-up, children were invited for standard lung function testing and quantified by FVC, FEV1 and FEV05 levels. Material consisted of 176 children of nonsmoking mothers, who performed at least two acceptable spirometry measurements. Multivariable linear regression model showed a significant deficit of FVC at the highest quartile of PM2.5 exposure (beta coefficient = − 91.9 , P = 0.008), after adjustment for covariates (age, gender, birth weight, height and wheezing). Also FEV1 level in children was inversely correlated with prenatal exposure to PM2.5, and the average FEV1 deficit amounted to 87.7 ml (P = 0.008) at the higher level of exposure. Although the effect of PM2.5 exposure on FEV05 was proportionally weaker (−72.7, P = 0.026) it was significant as well. The lung function level was inversely and significantly associated with the wheezing recorded over the follow-up. The findings showed that significant lung function deficits in early childhood is associated with prenatal exposure to fine particulate matter, which may affect fetal lung growth.
prenatal exposure; air pollution; birth cohort; lung function; preschool children
DNA methylation changes have been implicated in many common chronic diseases leading to the hypothesis that environmental and age-related DNA methylation changes within individuals are involved in disease etiology. Few studies have examined DNA methylation changes within an individual over time and all of these studies have been conducted in adults. Here, we aim to characterize how global DNA methylation changes from birth to age three within a longitudinal birth cohort study and to determine whether there are consistent predictors of DNA methylation levels measured three years apart. We measured global DNA methylation in the same children at birth (cord blood) and again at three years of age among 165 children, using an immunoassay. We found that on average, DNA methylation was significantly higher in blood at age 3-years than in cord blood (p<0.01). However, for any individual child, the difference was less than would be expected by chance. We found that pre-pregnancy BMI was negatively predictive of both cord and three-year DNA methylation, even after statistical adjustment to account for the correlation between cord blood and three-year DNA methylation. The biologic implications of small changes in global DNA methylation are unknown. However, the observation that global DNA methylation levels persist within an individual from birth to age three supports the belief that factors that influence global DNA methylation, including pre-pregnancy BMI, may confer long-term effects.
The main goal of the study was to assess the effect of exclusive breastfeeding on the neurodevelopment of children over a seven-year follow-up period and to test the hypothesis that the observed cognitive gain in breastfed children in the first years of life is a strong predictor of their cognitive development trajectory, which may be continued in later life.
The analysis is based on data from the seven-year follow-up of 468 term babies (>36 weeks of gestation) born to non-smoking mothers participating in an ongoing prospective cohort study. The cognitive function of children was assessed by psychometric tests performed 5 times at regular intervals from infancy through the preschool age. The study included valid neurodevelopmental assessment of the children – 443 participants were evaluated least twice, 425 – three times and 307 five times in the follow-up period. The association between the cognitive achievements of preschool age children and exclusive breastfeeding of various duration was performed using the GEE (General Estimation Equation) longitudinal model, adjusted for major confounders such as maternal education, gender, parity, and weight gain in pregnancy.
Children breastfed exclusively for up to 3 months had IQs that were on average 2.1 points higher compared to the others (95%CI: 0.24 – 3.9); children breastfed for 4 – 6 months scored higher by 2.6 points (95%CI: 0.87 – 4.27); and the benefit for children breastfed even longer (>6 months) increased by 3.8 points (95%CI: 2.11 – 5.45). Other predictors were maternal education, gender of the child, having an older sibling, and weight gain during pregnancy.
The results of the study support the WHO expert recommendations on exclusive breastfeeding for six months; moreover, they provide evidence that even a shorter duration of exclusive breastfeeding in early infancy produces beneficial effects on the cognitive development of children. The breastfeeding-related IQ gain observed already at the age of 1 was sustained through preschool age and the difference in terms of IQ score between breastfed children and the reference group (mixed breastfeeding) held constant over the whole preschool period.
breastfeeding; cognitive function in early childhood; prospective birth cohort study
In a birth cohort study, we have assessed the dose-response relationship between individual measurements of prenatal airborne PAH exposure and specific PAH-DNA adducts in cord blood adjusted for maternal blood adducts and season of birth. The study uses data from an earlier established birth cohort of children in Krakow. The final analysis included 362 pregnant women who gave birth to term babies and had complete data on personal exposure in the second trimester of pregnancy to eight airborne polycyclic aromatic hydrocarbons (PAH) including benzo[a]pyrene (B[a]P), as well as DNA adducts, both in maternal and cord blood.
The relation between cord blood PAH-DNA adducts and airborne prenatal PAH exposure was non-linear. While cord blood PAH-DNA adducts were significantly associated with the B[a]P exposure categorized by tertiles (nonparametric trend z = 3.50, p < 0.001), the relationship between B[a]P and maternal blood adducts was insignificant (z = 1.63, p = 0.103). Based on the multivariable linear regression model we estimated the effect of the prenatal airborne B[a]P on the level of cord blood adducts. In total, 14.8% of cord blood adducts variance was attributed to the level of maternal adducts and 3% to a higher prenatal B[a] exposure above 5.70 ng/m3. The calculated fetal/maternal blood adducts ratio (FMR) linearly increased with the B[a]P exposure (z = 1.99, p = 0.047) and was highest at B[a]P concentrations exceeding 5.70 ng/m3.
In conclusion, the results support other findings that transplacental exposure to B[a[P from maternal inhalation produces DNA damage in the developing fetus. It also confirms the heightened fetal susceptibility to prenatal PAH exposure that should be a matter of public health concern particularly in the highly polluted areas because DNA adducts represent a pro-carcinogenic alteration in DNA The continuation of this birth cohort study will assess the possible health effects of fetal DNA damage on health of children and help in establishing new protective guidelines for newborns.
prenatal exposure; polycyclic aromatic hydrocarbons; biomarkers of exposure; PAH-DNA adducts; birth cohort study
This summary provides a synopsis of talks included in a symposium entitled “Current Needs and Future Directions of Occupational Safety and Heath in a Globalized World”. The purpose of the symposium was to (1) highlight national and international agencies with occupational health related activities; (2) address electronic (e-)waste issues in developing countries where exposures are secondary to the handling and scavenging of scrap; and (3) discuss the effects of hazardous materials, such as polycyclic aromatic hydrocarbon (PAH) and tobacco smoke on child intelligence quotient (IQ) in developing countries.