Longitudinal effect of phthalates exposure on allergic diseases in children.

BACKGROUND: Environmental chemicals, such as phthalates, phenols, and parabens, may affect children's immune development and contribute to the risk of atopic diseases and asthma. OBJECTIVE: To evaluate the associations between prenatal and childhood phthalate exposure and atopic diseases in children at the age of 9 years. METHODS: This analysis is restricted to 145 mother-child pairs from the prospective Polish Mother and Child Cohort Study. Phthalate metabolite levels were assessed in the urine samples collected from mothers during the third trimester of pregnancy and from children at age of 2 and 9 years. For the appropriate recognition of children's health status, a questionnaire was administered to the mothers and completed with information from the medical record of each child. The clinical examination was performed by a pediatrician/allergist in the presence of the mother or a relative. RESULTS: A higher urine concentration of mono-2-ethyl-5-oxohexyl phthalate increased the risk of food allergy in children at the age of 9 years (odds ratio [OR], 1.75; 95% CI, 1.19-2.57; P = .004) and decreased the risk of atopic dermatitis (OR, 0.49; 95% CI, 0.27-0.87; P = .02). For mono-2-ethyl-5-hydroxyhexyl phthalate, an increased risk of atopic dermatitis was observed (OR, 1.90; 95% CI, 1.18-3.05; P = .008). A higher urine concentration of mono-benzyl phthalate increased the risk of asthma in children (OR, 1.67; 95% CI, 1.08-2.58; P = .02), but the risk of asthma decreased when the concentration of mono-2-ethylhexyl phthalate was higher (OR, 0.64; 95% CI, 10.43-0.97; P = .04). CONCLUSION: Our study has not provided clear evidence of the negative effect of phthalate exposure during pregnancy and within the 9 years after birth on allergic diseases in children.

Fathers and sons: Physiological stress in male Zaisan mole voles, Ellobius tancrei.

The social environment can be stressful for at least some group members, resulting in elevated levels of glucocorticoid stress hormones (GC). Patterns of the relationships between social rank and GC levels vary between species. In carnivores, primates and birds that live in permanent cooperative groups, helpers do not usually display physiological indicators of stress. Very little is known about status-related GC differences within cooperative groups of rodents. In this laboratory study, we compared GC concentrations in dominant (fathers) and subordinate (natal sons) males of a cooperative subterranean vole, Ellobius tancrei. The assessment of adrenocortical activity by measuring urine glucocorticoid metabolites (UGM) was previously validated for this species through an ACTH challenge test. We observed clear peaks of UGM in the second or third urine samples taken after the administration of ACTH (lag time equal to 2.5-3 h). Thus, UGM is suitable to estimate physiological stress in Ellobius. Postpubertal sons living in natal groups had significantly higher UGM concentrations than their fathers. The average UGM levels of sons were positively associated with their ages and paternal body masses, and negatively associated with paternal ages. Hence, son-father interactions rather than just younger ages of sons appear to contribute to GC differences. The revealed pattern was not consistent with that reported for most cooperative species from other taxa, highlighting the importance of comparative studies.

Associations of early life urinary triclosan concentrations with maternal, neonatal, and child thyroid hormone levels.

BACKGROUND: Triclosan, an antimicrobial agent used in some consumer products, reduces endogenous thyroid hormone concentrations in rodents. Despite ubiquitous triclosan exposure and the importance of thyroid hormones for normal fetal development, few human studies have examined the impact of triclosan exposure on maternal, neonatal, or child thyroid hormones. METHODS: In the HOME Study, a prospective cohort from Cincinnati, OH, we measured urinary triclosan concentrations up to three times in pregnant women between 16weeks and delivery, and up to three times in children between age 1-3years. We quantified serum concentrations of thyroid stimulating hormone and total and free thyroxine and triiodothyronine in mothers at 16-weeks gestation (n=202), neonates at delivery (n=274), and children at age 3years (n=153). We estimated covariate-adjusted differences in thyroid hormones with a 10-fold increase in triclosan using linear regression and multiple informants models. RESULTS: Triclosan was not associated with thyroid hormones during pregnancy. We observed a few associations of triclosan concentrations with thyroid hormone concentrations in neonates at delivery and children at age 3years. Higher gestational triclosan, particularly around the time of delivery, was associated with lower cord serum total thyroxine (ß: 0.3µg/dL; 95% CI: -0.6, -0.0). Childhood triclosan, particularly at age 1year, was positively associated with total thyroxine at age 3years (ß: 0.7µg/dL; 95% CI: 0.3, 1.2). CONCLUSION: Our findings suggest that triclosan exposure may influence some features of neonatal and early child thyroid function. Given the large number of comparisons we made, these findings should be replicated in other cohorts.

Maternal and infant inflammatory markers in relation to prenatal arsenic exposure in a U.S. pregnancy cohort.

INTRODUCTION: Accumulating evidence indicates that arsenic (As), a potent environmental toxicant, may increase cardiovascular disease risk and adversely affect endothelial function at high levels of exposure. Pregnancy is a vulnerable time for both mother and child; however, studies examining the association between prenatal As exposure and plasma biomarkers of inflammation and endothelial function in mothers and newborns are lacking. METHODS: We examined maternal urinary As levels at gestational weeks 24-28 and levels of inflammatory biomarkers in plasma from 563 pregnant women and 500 infants' cord blood. We assessed a multiplexed panel of circulating inflammatory and endothelial function markers, including tumor necrosis factor alpha (TNFα), monocyte chemoattractant protein 1 (MCP1), intercellular adhesion molecule (ICAM1) and vascular cell adhesion molecule (VCAM1). RESULTS: Compared with the bottom tertile, the highest tertile of maternal urinary As during pregnancy was associated with a 145.2ng/ml (95% CI 4.1, 286.3; p=0.04) increase in cord blood ICAM1 and 557.3ng/ml (95% CI -56.4, 1171.1; p=0.09) increase in cord blood VCAM1. Among mothers, the highest tertile of maternal urinary As during pregnancy was related to a 141.8ng/ml (95% CI 26.1, 257.5; p=0.02) increase maternal plasma VCAM1 levels. Urinary As was unrelated to MCP1 or TNFα in maternal plasma and cord blood. In structural equation models, the association between maternal urinary As and infant VCAM was mediated by maternal levels of VCAM (ßmediation: 0.024, 95% CI: 0.002, 0.050). CONCLUSION: Our observations indicate that As exposure during pregnancy may affect markers of vascular health and endothelial function in both pregnant women and children, and suggest further investigation of the potential impacts on cardiovascular health in these susceptible populations.

An Observational Study to Evaluate Associations Between Low-Level Gestational Exposure to Organophosphate Pesticides and Cognition During Early Childhood.

Prenatal exposure to organophosphate pesticides, which is ubiquitous, may be detrimental to neurological development. We examined 327 mother/infant pairs in Cincinnati, Ohio, between 2003 and 2006 to determine associations between prenatal exposure to organophosphate pesticides and neurodevelopment. Twice during pregnancy urinary concentrations of 6 common dialkylphosphates, nonspecific metabolites of organophosphate pesticides, were measured. Aggregate concentrations of diethylphosphates, dimethylphosphates, and total dialkylphosphates were calculated. Bayley Scales of Infant Development, Second Edition-Mental and Psychomotor Developmental indices were administered at ages 1, 2, and 3 years, the Clinical Evaluation of Language Fundamentals-Preschool, Second Edition, at age 4, and the Wechsler Preschool and Primary Scale of Intelligence, Third Edition, at age 5. Mothers with higher urinary total dialkylphosphate concentrations reported higher levels of socioeconomic status and increased fresh fruit and vegetable intake. We found no associations between prenatal exposure to organophosphate pesticides and cognition at 1-5 years of age. In our cohort, exposure to organophosphate pesticides during pregnancy was not associated with cognition during early childhood. It is possible that a higher socioeconomic status and healthier diet may protect the fetus from potential adverse associations with gestational organophosphate pesticide exposure, or that dietary exposure to the metabolites is innocuous and not an ideal measure of exposure to the parent compound.

Urinary 3-phenoxybenzoic acid (3-PBA) levels among pregnant women in Mexico City: Distribution and relationships with child neurodevelopment.

BACKGROUND: In recent years, pyrethroid pesticide use has increased in Mexico, the United States, and elsewhere, resulting in extensive human exposure. There is growing concern that pregnant women may be a particularly vulnerable population, as in utero fetal exposure during critical periods of development could adversely affect long-term neurobehavioral function. METHODS: We measured maternal urinary 3-phenoxybenzoic acid (3-PBA) concentrations during the third trimester of pregnancy as a measure of in utero pyrethroid exposure to the fetus among participants in an established Mexico City birth cohort (n=187). In a subset of mothers, we measured 3-PBA during the first, second, and third trimester (n=21) to assess variability across pregnancy. We examined associations between third trimester 3-PBA concentrations and children's scores on the Mental Development Index (MDI) and Psychomotor Development Index (PDI) from the Bayley Scales for Infant Development (BSID-IIS) at 24 and 36 months of age. RESULTS: 3-PBA was detected in 46% of all urine samples, with similar detection rates and geometric mean concentrations across pregnancy among the 21 participants who provided repeat samples. Participants in the medium and high 3-PBA categories (≥LOD) had lower MDI scores at 24 months compared to those in the low 3-PBA category (

Prenatal Second-Hand Smoke Exposure Measured with Urine Cotinine May Reduce Gross Motor Development at 18 Months of Age.

OBJECTIVE: To evaluate the association of second-hand smoke exposure of pregnant mothers using urine cotinine with the neurodevelopment of their children at 18 months of age in the mother-child cohort in Crete (Rhea Study). STUDY DESIGN: Selected participants were Greek mothers with singleton pregnancies, had never smoked, and had available urine cotinine measurements in pregnancy, and their children for whom a neurodevelopmental assessment was completed. We performed face-to-face interviews twice during pregnancy and postnatally, and assessed children's neurodevelopment at 18 months of age using the Bayley Scales of Infant and Toddler Development, Third Edition. We used linear regression and generalized additive models. RESULTS: Of 599 mothers, 175 (29%) met the inclusion criteria. Maternal urine cotinine levels were low (mean: 10.3 ng/mL, SD: 11.7 ng/mL). Reported passive smoking from different sources was strongly associated with urine cotinine levels. A negative association was observed between cotinine levels in pregnancy and child's gross motor function (beta = -3.22 per 10 ng/mL, 95% CI -5.09 to -1.34) after adjusting for factors potentially associated with neurodevelopment; results were similar in both sexes. A negative association was also observed for cognitive and receptive communication scales but the effect was small and not statistically significant. CONCLUSIONS: Maternal exposure during pregnancy to second-hand smoke measured through urine cotinine was associated with a decrease in gross motor function among 18-month-old children, even at low levels of exposure.

Neonatal thyroid function born to mothers living with long-term excessive iodine intake from drinking water.

OBJECTIVE: The effects of long-term excessive maternal iodine intake on neonatal thyroid function are less known. This study aimed to assess the effects of maternal excessive iodine intake from drinking water on thyroid functions of both mothers and their neonates. DESIGN AND METHODS: This observational study was performed in high iodine (HI) areas and adequate iodine (AI) intake areas, including 384 healthy pregnant women in late gestation (mean week 39·3 ± 1·6 weeks) and their newborns. Blood and urine samples were obtained from pregnant women, while cord blood samples were obtained from neonates. Urinary iodine concentration (UIC) and thyroid function were evaluated. RESULTS: The median maternal UIC was 1241 and 217 µg/l in HI and AI areas, respectively (P < 0·001). The concentrations of serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT3) and free thyroxine (FT4) in neonates in HI areas were 7·33 mIU/l (range 5·47, 11·06 mIU/l), 2·93 ± 0·59 and 15·03 ± 1·92 pmol/l, respectively, while that were 4·71 mIU/l (range 3·96, 6·04 mIU/l), 2·31 ± 0·28 and 16·50 ± 1·35 pmol/l in AI neonates (P < 0·05). Similar changes were also observed in neonates in HI areas when excluding the effect of maternal thyroid autoimmunity. Cord blood TSH concentration (r = 0·31, P = 0·001) and FT3 concentration (r = 0·43, P = 0·001) were positively correlated with maternal UIC. Cord blood FT4 concentration was negatively correlated with maternal UIC (r = -0·25, P = 0·001). Mothers living in HI areas (ß = 0·296, 95% CI: 0·163, 0·255) and with subclinical hypothyroidism (ß = 0·360, 95% CI: 0·034, 0·175) contributed to elevated cord blood TSH concentration in neonates, while male neonates were more likely to present with higher TSH concentration compared with female infants (ß = -0·760, 95% CI: -0·119, -0·033). CONCLUSIONS: Excessive iodine intake during pregnancy was associated with an increased rate of hyperthyrotropinaemia in neonates and their mothers, especially in male neonates.

Low-level prenatal mercury exposure in north China: an exploratory study of anthropometric effects.

In order to investigate anthropometric effects of mercury (Hg) exposure, we examined the status of human prenatal exposure to Hg species, including total mercury (THg), methylmercury (MeHg) and inorganic mercury (IHg), in North China, as well as their potential effects on fetal and infant growth. Hg concentrations in various bioindicators were measured from 50 Chinese women and newborns in 2011. The participants were followed for 12 months to collect anthropometric information. Linear and two-level regression analyses were performed to determine the associations between Hg levels and body growth. The geometric mean levels of THg in the placenta, cord blood, fetal hair, and maternal blood, hair, and urine were 25.88 µg/kg dry wt, 2.73 µg/L, 572.98 µg/kg, 2.29 µg/L, 576.54 µg/kg, and 0.58 µg/g creatinine, respectively. Nearly 100% of Hg presented as IHg in urine, and the percentage of IHg in other bioindicators was 14.86-48.73%. We observed significantly negative associations between Hg levels in some matrixes and anthropometry of neonates (weight and height) and infants (height) (p < 0.05). THg levels in maternal hair were also negatively associated with infant growth rate of weight during 12 months after delivery (p = 0.017). This study suggests that low-level prenatal Hg exposure could play a role in attenuating fetal and infant growth, and the effects of MeHg and IHg are different.

Phthalate exposure and reproductive hormone concentrations in pregnancy.

Some phthalate chemicals can affect hormone physiology in utero, resulting in adverse reproductive health outcomes in animal models. It is unknown whether these exposures are related to circulating maternal hormone concentrations during pregnancy. We used multivariate linear regression to estimate associations between phthalate metabolite concentrations and concurrent serum-free and total testosterone and estradiol (E2) levels in 180 pregnant women in the Study for Future Families. We also examined associations between prenatal serum hormone concentrations and anogenital outcome in infants. All analyses were adjusted for appropriate confounding variables. Total testosterone, free testosterone, and E2 concentrations ranged from 8 to 406 ng/dl, 0.03 to 1.2 ng/dl, and 529 to 40 600 pg/ml respectively. We observed an inverse association between log-sum di-2-ethylhexyl phthalate (DEHP) metabolite concentrations and lower log-total testosterone concentrations (-0.15, 95% CI -0.26, -0.04) and log-free testosterone (-0.15, 95% CI -0.27, -0.03). This relationship persisted regardless of fetal sex. Similarly, we observed an inverse association between log monobutyl phthalate (MBP) concentrations and log-total and -free testosterone concentrations in women carrying male fetuses. Monoethyl phthalate (MEP) concentrations were positively associated with log-total and -free testosterone concentrations in women carrying male fetuses (0.09, 95% CI 0.003, 0.17 and 0.10, 95% CI 0.01, 0.19 respectively). Prenatal hormone concentrations were not significantly associated with infant anogenital outcomes. Our preliminary data suggest that DEHP metabolite, MBP, and MEP exposures during pregnancy are associated with prenatal sex steroid hormone concentrations, but sex steroid hormone concentrations were not associated with infant reproductive outcomes.

Relationship between body mass index of offspring and maternal smoking during pregnancy.

OBJECTIVE: To examine the relationship between maternal smoking during pregnancy and the body composition of offspring. SUBJECTS: Grade 4 elementary school children (n=1366; boys/girls, 724/642; 9-10 years old) were enrolled in this study. All parents answered a lifestyle questionnaire, and children underwent passive smoking tests. Urinary cotinine measurement and lifestyle screening test parameters (that is, body weight, body length, body mass index (BMI), obesity index (OI), blood tests for liver function and lipid profile and questions regarding maternal smoking and lifestyle) were evaluated in terms of their relationship with maternal smoking. In addition, urinary 8-hydroxydeoxyguanosine (8-OHdG) concentration was measured in 80 randomly selected children to assess its relationship with oxidative stress. RESULTS: Both BMI and OI were significantly higher in children whose mothers smoked during pregnancy than in those whose mothers never smoked (BMI: 17.2±2.7 vs 16.9±2.5 kg m(-2), P=0.016; OI: 2.7±14.3% vs 0.4±14.0%, P=0.003). The degree of elevation was positively correlated with the duration of maternal smoking. The increases in BMI and OI resulted from increased body weight and reduced height. The confounding factors-'breakfast with family', 'watching television at dinner', 'eating and drinking before sleep', 'watching television for >2 h', 'sleep duration <8 h' and 'playing sports'-were statistically significant. BMI and OI were significantly high in children whose mothers smoked during pregnancy in these six confounders. On the other hand, urinary 8-OHdG concentration was negatively correlated with BMI in children who had >1.3 ng ml(-1) urinary cotinine, suggesting that it may be related to basal metabolism due to oxidative stress. CONCLUSION: Maternal smoking is a risk factor for higher BMI and OI in 9- to 10-year-old children whose mothers smoke during pregnancy and may be independent of other confounding factors.

Maternal gestational androgens are associated with decreased juvenile play in white-faced marmosets (Callithrix geoffroyi).

Exposure to androgens during prenatal development shapes both physiological and behavioral developmental trajectories. Notably, in rhesus macaques, prenatal androgen exposure has been shown to increase rough-and-tumble play, a prominent behavioral feature in males during the juvenile period in primates. While macaques are an Old World, polygamous species with marked sexually dimorphic behavior, New World callitrichine primates (marmosets and tamarins) live in cooperative breeding groups and are considered to be socially monogamous and exhibit minimal sexual dimorphism in social play, which suggests that androgen may affect this species in different ways compared to macaques. In addition, we previously described considerable variation in maternal androgen production during gestation in marmosets. Here we tested the association between this variation and variation in offspring rough-and-tumble play patterns in both males and females. We measured testosterone and androstenedione levels in urine samples collected from pregnant marmoset mothers and then observed their offspring's play behavior as juveniles (5-10 months of age). In contrast to findings in rhesus macaques, hierarchical regression analyses showed that higher gestational testosterone levels, primarily in the second semester, were associated with decreased rough-and-tumble play in juveniles, and this relationship appears to be driven more so by males than females. We found no reliable associations between gestational androstenedione and juvenile play behavior. Our findings provide evidence to suggest that normative variation in levels of maternal androgen during gestation may influence developmental behavioral trajectories in marmosets in a way that contradicts previous findings in Old World primates.

Prenatal phthalate exposures and autism spectrum disorder symptoms in low-risk children.

BACKGROUND: Prenatal exposure to environmental chemicals has been associated with Autism Spectrum Disorder (ASD) symptoms in some, but not all, studies, but most research has not accounted for other childhood behavior problems. OBJECTIVES: To evaluate the specific associations of prenatal phthalate exposures with ASD symptoms in children (ages 3-6) accounting for other behavior problems, and to assess sex differences in these associations. METHODS: We measured phthalate metabolites in prenatal urine samples. Mothers completed the Social Responsiveness Scale-2nd edition (SRS-2) to assess child ASD symptoms and the Child Behavior Checklist (CBCL) to assess general behavior problems. We assessed associations of the sum of di-(2-ethylhexyl) phthalate metabolites, monobutyl phthalate, mono-isobutyl phthalate, and monoethyl phthalate (mEP) with ASD symptoms, adjusting for other behavior problems, using linear regression models (n=77). RESULTS: Most associations were null, and the sample size limited power to detect associations, particularly in the stratified analyses. After adjusting for internalizing and externalizing problems from the CBCL, ASD symptoms increased for each doubling of prenatal mEP concentration among boys only. CONCLUSIONS: Further investigation of maternal prenatal urinary phthalate metabolite concentrations and ASD symptoms while adjusting for other behavioral problems is warranted.

Maternal consumption of artificially sweetened beverages during pregnancy is associated with infant gut microbiota and metabolic modifications and increased infant body mass index.

Artificial sweetener consumption by pregnant women has been associated with an increased risk of infant obesity, but the underlying mechanisms are unknown. We aimed to determine if maternal consumption of artificially sweetened beverages (ASB) during pregnancy is associated with modifications of infant gut bacterial community composition and function during the first year of life, and whether these alterations are linked with infant body mass index (BMI) at one year of age. We studied 100 infants from the prospective Canadian CHILD Cohort Study, selected based on maternal ASB consumption during pregnancy (50 non-consumers and 50 daily consumers). BMI was higher among ASB-exposed infants. Infant stool (16S rRNA gene sequencing) and urine (untargeted metabolomics) were acquired in early (3-4 months) and late (12 months) infancy. We identified four microbiome clusters, of which two recapitulated the maturation trajectory of the infant gut bacterial communities from immature (Cluster 1) to mature (Cluster 4) and two deviated from this trajectory (Clusters 2 and 3). Maternal ASB consumption did not differ between clusters, but was associated with community-level shifts in infant gut bacterial taxonomy structure and depletion of several Bacteroides sp. in Cluster 2. In the complete dataset, urine succinate and spermidine levels at 3 months were higher in ASB-exposed infants, and urine succinate was positively associated with BMI at one-year-old. Overall, gestational exposure to ASB was associated with gut microbiota structure in infants from Cluster 2, and gut microbiota structure was associated with infant BMI. Gestational exposure to ASB was positively associated with infant urine succinate and spermidine. Succinate was found to mediate 29% of the effect of ASB exposure on BMI at one-year-old, revealing a potential role of this metabolite in increased infant weight linked to gestational ASB consumption. As we face an unprecedented rise in childhood obesity, future studies should evaluate the causal relationships between maternal ASB consumption (a modifiable exposure), gut microbiota and metabolites, infant metabolism, and body composition.

Associations of prenatal exposure to phthalates with measures of cognition in 7.5-month-old infants.

BACKGROUND: Phthalates are endocrine disrupting chemicals that have been associated with adverse neurobehavior, but little is known about their influence on infant cognition. METHODS: A visual recognition memory task was used to assess cognition in 244 7-8-month-old infants (121 females; 123 males) from a prospective cohort study. Phthalate metabolites were quantified in maternal urines pooled from across pregnancy. The task included familiarization trials (infant shown 2 identical faces) and test trials (infant shown the now familiar face paired with a novel one). Half of the infants saw one set of faces as familiar (set 1) and half saw the other set as familiar (set 2). During familiarization trials, average run duration (time looking at stimuli before looking away, measure of processing speed), and time to familiarization (time to reach 20 s looking at the stimuli, measure of attention) were assessed. During test trials, novelty preference (proportion of time looking at the novel face, measure of recognition memory) was assessed. Multivariable generalized linear models were used to assess associations of monoethyl phthalate (MEP), sum of di(2-ethylhexyl) phthalate metabolites (ΣDEHP), sum of di(isononyl) phthalate metabolites (ΣDINP), and sum of anti-androgenic phthalate metabolites (ΣAA) with each outcome. RESULTS: Mothers were mostly white and college educated, and urine phthalate concentrations were similar to those in reproductive age women in the U.S. POPULATION: All phthalate exposure biomarkers, except MEP, were associated with increases in average run duration. However, depending on the phthalate, associations were only in males or infants who saw the set 2 stimuli as familiar. Unexpectedly, ΣAA was associated with a shorter time to reach familiarization. Phthalate biomarkers also were associated with modest decrements in novelty preference, but these associations were nonsignificant. CONCLUSION: Prenatal exposure to phthalates may be related to slower information processing and poorer recognition memory in infants.

Measuring prenatal secondhand smoke exposure in mother-baby couplets.

INTRODUCTION: Pregnant women often underreport their smoking status and extent of secondhand smoke (SHS) exposure. Biomarker confirmation is the recommended method to assess smoking behaviors and SHS exposure in both mothers and infants. OBJECTIVES: The primary aims are to (a) examine the relationship between smoking behaviors and SHS exposure in mother-baby couplets using maternal and infant hair nicotine and maternal urine cotinine analyses and (b) determine whether there is an association between maternal and infant hair nicotine samples obtained shortly after birth. DISCUSSION: A cross-sectional study with a multiethnic sample of 210 mother-baby couplets assessing SHS exposure. RESULTS: The level of maternal hair nicotine (MHN) was significantly different among three groups: nonsmoking, nonsmoking/passive exposed, and smoking (p < .0001), with nonsmoking and nonexposed women having the lowest level. Urine cotinine was strongly associated with self-reported smoking status (rho = .88; p < .0001). Maternal and infant hair nicotine were correlated, although MHN correlated more strongly with smoking status (rho = .46, p < .0001) than infant hair nicotine (rho = .39, p < .0001). CONCLUSIONS: MHN was a more precise biomarker of prenatal SHS exposure than infant hair nicotine; mothers' urine cotinine was strongly correlated with self-reported smoking status.

Gestational and childhood urinary triclosan concentrations and academic achievement among 8-year-old children.

BACKGROUND: Early life exposure to triclosan, an antimicrobial chemical and suspected endocrine disruptor, may adversely affect neurodevelopment. No studies have examined gestational and early childhood exposure to triclosan and children's academic achievement. METHODS: Using data from 193 mother-child pairs from the HOME Study, we quantified triclosan in maternal and child urine samples up to nine times between the second trimester of gestation (16-weeks) and age 8 years. At age 8 years, we administered the reading and math components of the Wide Range Achievement Test-4 (WRAT-4) to children. Using multiple informants models, we estimated covariate-adjusted associations of triclosan concentrations during each time period with WRAT-4 scores. We also tested whether associations differed by exposure period and child sex. RESULTS: There was evidence that timing of exposure modified the associations between triclosan and reading composite scores (triclosan-exposure period interaction p-value = 0.20), but not math scores (interaction p-value = 0.72). Each 10-fold increase in triclosan concentrations at delivery was associated with lower reading composite scores (ß:-2.6; 95 % CI:-5.0, -0.1). Additionally, we observed weaker and less precise inverse association of math scores with triclosan concentrations at delivery (ß:-1.9; 95 % CI:-4.6, 0.8) and at age 1 year (ß:-2.0; 95 % CI:-6.0, 2.1). There was not strong evidence that child sex modified the pattern of associations between repeated triclosan measures and WRAT-4 reading composite or math scores (sex-triclosan-exposure period interaction p-values>0.20). CONCLUSION: Urinary triclosan concentrations at delivery and at age 1 year, but not other times during gestation or childhood, were associated with lower reading composite and to a lesser extent math test scores at age 8 years in this cohort of U.S. children.

Sex-Specific Differences in Cognitive Abilities Associated with Childhood Cadmium and Manganese Exposures in School-Age Children: a Prospective Cohort Study.

To examine sex-specific associations of neonatal and childhood exposure to eight trace elements with cognitive abilities of school-age children. The association between exposure and effects was assessed among 296 school-age children from a population-based birth cohort study, who had manganese (Mn), cadmium (Cd), and lead (Pb) exposure measured in cord blood and chromium (Cr), manganese, cobalt (Co), copper (Cu), arsenic (As), selenium (Se), cadmium, and lead exposure quantified in spot urine. Cognitive abilities were assessed using the Wechsler Intelligence Scale for Children-Chinese Revised (WISC-CR). Generalized linear models were performed to analyze associations of intelligence quotient (IQ) with trace element concentrations in cord blood and urinary trace element levels. General linear models were used to evaluate association between exposure fluctuation and children's IQ. Urinary Cd concentrations were negatively associated with full-scale IQ (ß = - 3.469, 95% confidence interval (CI) - 6.291, - 0.647; p = 0.016) and performance IQ (ß = - 4.012, 95% CI - 7.088, - 0.936; p = 0.011) in girls; however, neonatal Cd exposure expressed as Cd concentrations in cord blood was in inverse associations with verbal IQ (ß = - 2.590, 95% CI - 4.570, - 0.609; p = 0.010) only in boys. Positive association between urinary Mn concentrations and performance IQ (ß = 1.305, 95% CI 0.035, 2.575; p = 0.044) of children was observed, especially in girls. In addition, inverse association of urinary Cu concentrations with verbal IQ (ß = - 2.200, 95% CI - 4.360, - 0.039; p = 0.046) was only found in boys. Childhood Cd exposure may adversely affect cognitive abilities, while Mn exposure may beneficially modify cognitive abilities of school-age children, particularly in girls.

Infant exposure to environmental tobacco smoke: Jordan University hospital-based study.

To study exposure to environmental tobacco smoke during the first year of life, 220 infants attending the outpatient paediatric clinic of the University of Jordan for routine visits with their mothers were recruited to the study. Mothers completed a questionnaire about smoking habits of household members, and urine samples were obtained from infants for analysis of cotinine levels. A total of 60.0% of infants were reported to be exposed to passive smoking at home and 36.4% had detectable levels of urine cotinine (mean 7.1 ng/mL, range 0.27-41 ng/mL). Detectable saliva cotinine levels in 8/20 mothers of neonates (1-2 days old) suggested in utero exposure. Recommendations are made to protect this vulnerable population from tobacco smoke exposure.