Impact of barbecued meat consumed in pregnancy on birth outcomes accounting for personal prenatal exposure to airborne polycyclic aromatic hydrocarbons: Birth cohort study in Poland

Prenatal exposure to polycyclic aromatic hydrocarbons and executive functions at school age: Results from a combined cohort study

BACKGROUND

Executive functions develop rapidly in childhood, enabling problem-solving, focused attention, and planning. Exposures to environmental toxicants in pregnancy may impair healthy executive function development in children. There is increasing concern regarding polycyclic aromatic hydrocarbons (PAHs) given their ability to transfer across the placenta and the fetal blood-brain barrier, yet evidence from epidemiological studies is limited.

METHODS

We examined associations between prenatal PAH exposure and executive functions in 814 children of non-smoking mothers from two U.S. cohorts in the ECHO-PATHWAYS Consortium. Seven mono-hydroxylated PAH metabolites were measured in mid-pregnancy urine and analyzed individually and as mixtures. Three executive function domains were measured at age 8-9: cognitive flexibility, working memory, and inhibitory control. A composite score quantifying overall performance was further calculated. We fitted linear regressions adjusted for socio-demographics, maternal health behaviors, and psychological measures, and examined modification by child sex and stressful life events in pregnancy. Bayesian kernel machine regression was performed to estimate the interactive and overall effects of the PAH mixture.

RESULTS

The results from primary analysis of linear regressions were generally null, and no modification by child sex or maternal stress was indicated. Mixture analyses suggested several pairwise interactions between individual PAH metabolites in varied directions on working memory, particularly interactions between 2/3/9-FLUO and other PAH metabolites, but no overall or individual effects were evident.

CONCLUSION

We conducted a novel exploration of PAH-executive functions association in a large, combined sample from two cohorts. Although findings were predominantly null, the study carries important implications for future research and contributes to evolving science regarding developmental origins of diseases.

Dietary Polycyclic Aromatic Hydrocarbon (PAH) Consumption and Risk of Adverse Birth Outcomes: A Systematic Review and Meta-Analysis

BACKGROUND

There is suggestive epidemiological evidence that maternal dietary polycyclic aromatic hydrocarbons (PAH) may increase the risk of adverse birth outcomes. We sought to summarize the available evidence on the effect of dietary PAH exposure on birth outcomes.

METHODS

PubMed and Scopus databases were systematically searched from inception up to November 2022. Studies were included if they were original articles, were conducted in a human population, assessed dietary PAH consumption, and investigated the relationship between dietary PAH consumption and any adverse birth outcomes. Risk of bias in the included studies was assessed qualitatively and quantitatively. A random effects model was used to compute summary effect estimates in the meta-analysis.

RESULTS

Six observational studies (five prospective cohort studies, and one prevalence case-control study) were included. The included studies assessed dietary PAH exposure using dietary questionnaires. Information on the outcomes of interest was obtained from medical records. Three of the included studies were rated as good quality with the remaining three studies rated as fair quality. One study was considered as having low risk of bias for selection, information and confounding bias. Dietary PAH consumption was associated with 5.65 g [95% confidence interval (CI): - 16.36 , 5.06] and 0.04 cm   (95% CI: - 0.08 , 0.01) reductions in birth weight and birth length, respectively, and an increase in head circumference [effect size  ( ES ) = 0.001 ; 95% CI: - 0.003 , 0.005]. The CI of all the summary effect estimates, however, included the null value. In the sensitivity analysis that included only studies that assessed dietary PAH exposure as the primary exposure of interest, dietary PAH consumption was associated with much higher reductions in birth weight (ES = - 14.61 ; 95% CI: - 21.07 , - 8.15 ) and birth length (ES = - 0.06 ; 95% CI: - 0.1 , - 0.03 ). High statistical heterogeneity was observed in the birth weight and birth length analysis and in the head circumference sensitivity analysis.

DISCUSSION

The body of epidemiological evidence suggests that maternal dietary PAH exposure is associated with reduced fetal growth, measured as birth weight and length. There was considerable heterogeneity in the measurement of PAH exposure among the included studies. Also, nonstandardized and validated dietary questionnaires were employed by a majority of the included studies with potential exposure misclassification. These issues are likely to impact the summary effect estimates computed and underscores the need for high-quality epidemiological studies with improved exposure assessment and adequate confounding control to strengthen the evidence base. https://doi.org/10.1289/EHP12922.

The association between exposure to polycyclic aromatic hydrocarbons and birth outcomes: A systematic review and meta-analysis of observational studies

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been linked to adverse birth outcomes; however, to date, the available studies on such relations, with the exception of birth weight, has not been systematically synthesized. We conducted a systematic review and meta-analysis of the available observational studies on the association of maternal exposure to PAHs and their metabolites during pregnancy with indicators of fetal growth and gestational age at delivery. We searched Web of Science, PubMed and Scopus systematically for all relevant published papers in English until 13 January 2023. Random effects meta-analysis was applied to synthesize the association estimates. Publication bias was assessed using Egger's regression. A total of 31 articles were included in our review (n = 703,080 participants). Our quality assessment of reviewed papers showed that 19 research had excellent, nine had good, and three had fair quality. Most of the reviewed studies on exposure to PAHs and their metabolites with gestational age and preterm birth (seven studies) reported no statistically significant association. Eight studies were eligible for our meta-analysis. Results of the meta-analysis indicated that higher levels of maternal urinary 1-OHP was associated with lower birth weight, birth length and head circumference and a higher risk of low birth weight (LBW). However, these associations were not statistically significant. Similarly, the combined association between maternal urinary 1-OHP and newborn's Ponderal index (PI) and Cephalization index were not statistically significant. Overall, our systematic review and meta-analysis suggested a potential adverse impact of exposure to PAHs on LBW, HC, and CC; however, further studies are required to be able to draw concrete conclusions on such associations.

Prenatal exposure to polycyclic aromatic hydrocarbons is not associated with behavior problems in preschool and early school-aged children: A prospective multi-cohort study

BACKGROUND

Epidemiological study findings are inconsistent regarding associations between prenatal polycyclic aromatic hydrocarbon (PAH) exposures and childhood behavior. This study examined associations of prenatal PAH exposure with behavior at age 4-6 years in a large, diverse, multi-region prospective cohort. Secondary aims included examination of PAH mixtures and effect modification by child sex, breastfeeding, and child neighborhood opportunity.

METHODS

The ECHO PATHWAYS Consortium pooled 1118 mother-child dyads from three prospective pregnancy cohorts in six U.S. cities. Seven PAH metabolites were measured in prenatal urine. Child behavior was assessed at age 4-6 using the Total Problems score from the Child Behavior Checklist (CBCL). Neighborhood opportunity was assessed using the socioeconomic and educational scales of the Child Opportunity Index. Multivariable linear regression was used to estimate associations per 2-fold increase in each PAH metabolite, adjusted for demographic, prenatal, and maternal factors and using interaction terms for effect modifiers. Associations with PAH mixtures were estimated using Weighted Quantile Sum Regression (WQSR).

RESULTS

The sample was racially and sociodemographically diverse (38% Black, 49% White, 7% Other; household-adjusted income range $2651-$221,102). In fully adjusted models, each 2-fold increase in 2-hydroxynaphthalene was associated with a lower Total Problems score, contrary to hypotheses (b = -0.80, 95% CI = -1.51, -0.08). Associations were notable in boys (b = -1.10, 95% CI = -2.11, -0.08) and among children breastfed 6+ months (b = -1.31, 95% CI = -2.25, -0.37), although there was no statistically significant evidence for interaction by child sex, breastfeeding, or neighborhood child opportunity. Associations were null for other PAH metabolites; there was no evidence of associations with PAH mixtures from WQSR.

CONCLUSION

In this large, well-characterized, prospective study of mother-child pairs, prenatal PAH exposure was not associated with child behavior problems. Future studies characterizing the magnitude of prenatal PAH exposure and studies in older childhood are needed.

Association between polycyclic aromatic hydrocarbons (PAH) dietary exposure and mortality risk in the E3N cohort

Most studies have explored the adverse health effects of polycyclic aromatic hydrocarbons (PAH) occupational exposure. However, the general population is also exposed to PAH, mainly through the diet. The goal of the present study is thus to investigate the association between PAH dietary exposure and mortality risk in middle-aged women of the E3N (Étude Épidémiologique auprès de femmes de la mutuelle générale de l'Éducation Nationale) French prospective cohort. The study included 72,513 women, whom completed a validated semi-quantitative food frequency questionnaire on 208 food items in 1993. Food contamination levels were assessed using data provided by the Anses (French Agency for Food, Environmental and Occupational Health & Safety) in the framework of the French second total diet study. PAH dietary exposure was studied as the sum of four PAH (PAH4), namely benzo[a]pyrene (BaP), chrysene (CHR), benzo[a]anthracene (BaA) and benzo[b]fluoranthene (BbF). Cox proportional hazard models were used to estimate hazard ratios (HR) and their 95 % confidence intervals (CI) for the risk of all-cause mortality as well as all-cancer, specific cancer (separately from breast, lung/tracheal, and colorectal cancer), cardiovascular disease (CVD), and specific CVD (including only stroke and coronary heart disease) mortality. During follow-up (1993-2011), 4620 validated deaths were reported, of which 2726 due to cancer and 584 to CVD. The median PAH4 dietary intake was 66.1 ng/day. There was no significant association between PAH4 dietary intake and the risk of all-cause, all-cancer, breast cancer, colorectal cancer, all-CVD and stroke and coronary heart disease mortality. On the contrary, we observed a positive and statistically significant association between PAH4 dietary intake and lung/tracheal cancer mortality risk, with a stronger association among current smokers than among former smokers and never smokers. In this study, we observed an association between PAH dietary exposure and lung/tracheal cancer mortality risk, especially among current smokers.

Association of maternal dietary habits and ADIPOQ gene polymorphisms with the risk of congenital heart defects in offspring: a hospital-based case-control study

OBJECTIVES

To estimate the association of maternal ADIPOQ gene, dietary habits in early pregnancy, and their interactions with the risk of congenital heart defects (CHDs) in offspring.

METHODS

A case-control study of 464 mothers of CHDs children and 504 mothers of healthy children was included. Maternal dietary habits and genetic polymorphisms of ADIPOQ were the main exposure of interest. Their independent effects and interactions in the development of CHDs were analyzed in our study.

RESULTS

The excessive consumption of pickled vegetables (aOR = 1.58, 95%CI: 1.17-2.12), smoked foods (aOR = 1.84, 95%CI:1.34-2.52), barbecued foods (aOR = 1.62, 95%CI: 1.09-2.39), fish and shrimp (aOR = 0.37, 95%CI: 0.27-50), and milk products (aOR = 0.64, 95%CI: 0.51-80) had a significant association with total CHDs risk. The polymorphisms of ADIPOQ gene at rs1501299 (T/T vs G/G: aOR = 0.27, 95%CI: 0.14-50; G/T vs G/G: aOR = 0.67, 95%CI: 0.46-98) and rs2241766 (G/G vs T/T: aOR = 4.35, 95%CI: 2.23-8.51; T/G vs T/T: aOR = 2.23, 95%CI: 1.51-3.28) showed a significant association with total CHDs risk. Likewise, our results found that maternal dietary habits and ADIPOQ genetic variants also were significantly related to the risk of specific CHDs phenotypes. In addition, gene-diet interaction revealed significant associations between the ADIPOQ gene and maternal dietary habits with total CHDs.

CONCLUSIONS

Maternal dietary habits, ADIPOQ gene, and their interactions show a significant association with the risk of CHDs. However, our study has some limitations, thus our findings need to be taken with caution, which highlights that more studies are required to further corroborate our findings.

Contemporary Research Progress on the Detection of Polycyclic Aromatic Hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are a class of the most common and widespread contaminants. The accumulation of PAHs has made a certain impact on the environment and is seriously threatening human health. Numerous general analytical methods suitable for PAHs were developed. With the development of economy, the environmental problems of PAHs in modern society are more extensive and prominent, and attract more attention from environmental scientists and analysts. Deeper understanding of the properties of PAHs depends on the advent of detection methods, which can also be more conducive to promoting the protection of the environment. Till now, more sensitive, more high-speed and more high-throughput analytical tools are being invented and have played important roles in the research of PAHs. In this short review article, we focused mainly on the contemporary analytical methods about PAHs. We started with a brief review on the hazards, migration, distribution and traditional analysis methods of PAHs in recent years, including liquid chromatography, gas chromatography, surface enhanced Raman spectroscopy and so on. We also presented the applications of the modern ambient mass spectrometry, especially microwave plasma torch mass spectrometry, in the detection of PAHs, as well as the far out novel results in our lab by using microwave plasma torch (MPT) mass spectrometry; for example, some new insights about Birch reduction, regular hydrogen addition and the robustness of molecular structure. These studies have demonstrated the versatility of MPT MS as a platform in the research of PAHs.

Prenatal urinary metabolites of polycyclic aromatic hydrocarbons and toddler cognition, language, and behavior

BACKGROUND

Animal and epidemiological studies suggest that prenatal exposure to polycyclic aromatic hydrocarbons (PAHs) may negatively impact toddler neurodevelopment.

METHODS

We investigated this association in 835 mother-child pairs from CANDLE, a diverse pregnancy cohort in the mid-South region of the U.S. PAH metabolite concentrations were measured in mid-pregnancy maternal urine. Cognitive and Language composite scores at ages 2 and 3 years were derived from the Bayley Scales of Infant and Toddler Development, 3rd edition (Bayley-3). Behavior Problem and Competence scores at age 2 were derived from the Brief Infant and Toddler Social Emotional Assessment (BITSEA). We used multivariate linear or Poisson regression to estimate associations with continuous scores and relative risks (RR) of neurodevelopment delay or behavior problems per 2-fold increase in PAH, adjusted for maternal health, nutrition, and socioeconomic status. Secondary analyses investigated associations with PAH mixture using Weighted Quantile Sum Regression (WQS) with a permutation test extension.

RESULTS

1- hydroxypyrene was associated with elevated relative risk for Neurodevelopmental Delay at age 2 (RR = 1.20, 95% CI: 1.03,1.39). Contrary to hypotheses, 1-hydroxynaphthalene was associated with lower risk for Behavior Problems at age 2 (RR = 0.90, 95% CI: 0.83,0.98), and combined 1- and 9-hydroxyphenanthrene was associated with 0.52-point higher (95% CI: 0.11,0.93) Cognitive score at age 3. For PAH mixtures, a quintile increase in hydroxy-PAH mixture was associated with lower Language score at age 2 (βwqs = -1.59; 95% CI: -2.84, -0.34; p_permutation = 0.07) and higher Cognitive score at age 3 (βwqs = 0.96; 95% CI: 0.11, 1.82; p_permutation = 0.05). All other estimates were consistent with null associations.

CONCLUSION

In this large southern U.S. population we observed some support for adverse associations between PAHs and neurodevelopment.

Prenatal exposure to polycyclic aromatic hydrocarbons and effects on neonatal anthropometric indices and thyroid-stimulating hormone in a Middle Eastern population

Prenatal exposure to polycyclic aromatic hydrocarbons (PAHs) evokes extensive concerns regarding public health. Monitoring the pregnant women's exposure can be considered a suitable alternative to assess the fetus's exposure. This study aimed to monitor pregnant women's exposure (n = 126) to PAHs using a biomonitoring approach to evaluate effects on anthropometric indices and neonatal thyroid-stimulating hormone (TSH) in Shiraz, Iran. PAHs priority compounds were measured by gas chromatography-mass spectrometry (GC-MS) after separating blood serum and liquid-liquid extraction (LLE) method. Information on anthropometric indices, neonatal TSH levels, and data from the respondents was obtained from medical records and questionnaires. The mean PAHs concentrations ranged from 0.29 to 327.91 ng/g lipid. There was no significant difference between the measured PAHs in maternal serum at the seventh month and pregnancy termination except for ACY (p-Value<0.05). Regression analysis results showed a significant correlation (p-value<0.05) between exposure to passive smoke and total PAHs concentrations. There was no significant relationship between exposure to PAHs and weight, height, head circumference, and Apgar score of newborns. The results showed TSH decreased by 0.99 units as ACE increased per unit (β = -0.001). This study is the first to evaluate relationships between prenatal exposure to PAHs and effects on newborn health indicators, including TSH levels in a Middle Eastern population. Future studies are suggested to perform detailed assessments of PAHs intake sources, especially in vulnerable populations such as pregnant women and children.

Determination of organic pollutants in meconium and its relationship with fetal growth. Case control study in Northwestern Spain

OBJECTIVES

Antenatal exposure to organic pollutants is a leading public health problem. Meconium is a unique matrix to perform prenatal studies because it enables us to retrospectively evaluate fetal exposure accumulated during the second and third trimester. The aim of the present study was to evaluate associations between organic pollutant levels in meconium and birth weight in NW Spain.

METHODS

In this study, we quantify the concentrations of 50 organic pollutants together with the total values of the most important chemical groups in meconium using gas chromatography coupled to tandem mass spectrometry.

RESULTS

Organochlorine pesticides, polychlorinated biphenyls and polybrominated diphenyl ethers were detected with the highest levels in meconium from small for gestational age newborns. It was estimated that several congeners were statistically significant (p<0.05). However, organophosphorus pesticides attained higher concentrations in newborns with an appropriate weight.

CONCLUSIONS

The occurrence of transplacental transfer can be confirmed. Prenatal exposure to organic pollutants was associated with a decrease in birth weight and, therefore, organic pollutants could have an impact on fetal growth. Nevertheless, these results need validation in larger sample sized studies.

Concentrations of selected monohydroxy polycyclic aromatic hydrocarbons across various stages of glomerular function

The objective of this study was to evaluate the variabilities in the concentrations of selected monohydroxy polycyclic aromatic hydrocarbons (OH-PAH) in urine across various stages of glomerular function. Data from National Health and Nutrition Examination Survey for US adult smokers (N = 3125) and nonsmokers (N = 6793) were selected for analysis to meet the objectives of the study. OH-PAHs selected for analysis were as follows: 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 3-hydroxyfluorene, 9-hydroxyfluorene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, and 1-hydroxypyrene. Stages of glomerular function (GF) considered were as follows: hyperfiltrators (GF-1A, eGFR ≥ 110 mL/min/1.73 m²), normal filtrators (GF-1B, 90 < eGFR < 110 mL/min/1.73 m²), GF-2 (60 ≤ eGFR < 90 mL/min/1.73 m²), GF-3A (45 ≤ eGFR < 60 mL/min/1.73 m²), and GF-3B/4 (15 ≤ eGFR < 45 mL/min/1.73 m²). For the analysis of data for smokers, however, data for GF-3A and GF-3B/4 were merged because of small sample sizes for these GF stages for smokers. Among nonsmokers, (i) there was almost a straight-line decrease in adjusted concentrations of 2-hydroxyfluorene, 3-hydroxyfluorene, 9-hydroxyfluorene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, and 1-hydroxypyrene over GF-1A through GF-3B/4; (ii) concentrations of these OH-PAHs at GF-3B/4 varied from being 37.5% for 1-hydroxypyrene to being 87% for 9-hydroxyfluorene of what they were at GF-1A; and (iii) while concentrations of 1-hydroxynaphthalene were located on an inverted U-shaped curve, concentrations of 2-hydroxynaphthalene were located on a U-shaped curve with pints of inflections at GF-3A. Among smokers, concentrations of all nine OH-PAHs in urine were located on inverted U-shaped curves with points of inflections located at GF-2 and concentrations of these OH-PAHs at GF-3/4 varied from being 48.7% for 1-hydroxypyrene to being 116.1% for 9-hydroxyfluorene of what they were at GF-1A. The kidneys differ in how they process urinary metabolites of PAHs among smokers and nonsmokers.

Association and interaction effect of UCP2 gene polymorphisms and dietary factors with congenital heart diseases in Chinese Han population

Congenital heart diseases (CHDs) are the most common birth defects and the leading cause of non-infectious deaths in infants, with an unknown etiology. We aimed to assess the association of genetic variations in UCP2 gene, dietary factors, and their interactions with the risk of CHDs in offspring. The hospital-based case–control study included 464 mothers of children with CHDs and 504 mothers of healthy children. The exposures of interest were maternal dietary factors in early pregnancy and UCP2 genetic variants. Logistic regression analyses were used to assess the association and interaction of UCP2 gene and dietary factors with CHDs. Our results found that the polymorphisms of UCP2 gene at rs659366 and rs660339, together with maternal dietary factors including excessive intake of pickled vegetables and smoked foods were associated with increased risks of CHDs in offspring. Regular intake of fresh meat, fish and shrimp, and milk products were associated with lower risks of CHDs in offspring. Besides, positive interaction between the dominant model of rs659366 and excessive intake of pickled vegetables was found in the additive interaction model (RERI = 1.19, P = 0.044). These findings provide the theoretical basis for gene screening and a new clue for the prevention of CHDs in offspring.

Methylation of Imprinted Genes in Sperm DNA Correlated to Urinary Polycyclic Aromatic Hydrocarbons (PAHs) Exposure Levels in Reproductive-Aged Men and the Birth Outcomes of the Offspring

Polycyclic aromatic hydrocarbons (PAHs) are known environmental pollutants. Studies are very limited regarding the impacts of paternal PAHs exposure on birth outcomes as well as the underpinning mechanisms in human. In this study, 302 reproductive-aged males (22-46 years old) were enrolled and demographic informatics data were obtained by questionnaires. The levels of urinary hydroxylated PAHs (OH-PAHs) were assessed by ultra-high performance liquid chromatography-tandem mass spectrometry; and methylation levels of the imprinting genes H19, Meg3, and Peg3 of sperm DNA were evaluated via bisulfite pyrosequencing. The analysis of the correlation between OH-PAHs levels and methylation levels of imprinting genes showed that OH-PAHs are correlated with some CpG sites in H19, Peg3, and Meg3. To further investigate an association of urinary OH-PAHs with birth outcomes, follow-up study of wives of these subjects has been performed for 1-3 years. As the result, a total of 157 babies were born. The birth outcomes parameters including birth weight (BW), length (BL), and ponderal index (PI) were recorded. The further analysis of generalized estimating equation indicated a negative correlation between urinary total OH-PAHs levels and newborn BW (β = -0.081, p = 0.020); but this association has not been found for BL and PI. Furthermore, a logistic regression analysis was employed for examining associations of the methylation of imprinting genes with birth outcomes parameters, which indicated a negative correlation between BW and H19, namely, each unit percent (%) elevation in methylation of H19 (but not Peg3 and Meg3) was significantly associated with a 0.135 g reduction of BW (β = -0.135; 95% CI 0.781-0.978). Putting together, these results show that paternal non-occupational environmental exposure to PAHs is associated with newborn BW. And imprinting gene H19 methylation may be involved in the underlying mechanisms. This study in human population adds a support for previous animal study and implies that environmental impact on the offspring through paternal pathway.

Potential role of polycyclic aromatic hydrocarbons in air pollution-induced non-malignant respiratory diseases

Epidemiological studies have found strong associations between air pollution and respiratory effects including development and/or exacerbation of asthma and chronic obstructive pulmonary disease (COPD) as well as increased occurrence of respiratory infections and lung cancer. It has become increasingly clear that also polycyclic aromatic hydrocarbons (PAHs) may affect processes linked to non-malignant diseases in the airways. The aim of the present paper was to review epidemiological studies on associations between gas phase and particle-bound PAHs in ambient air and non-malignant respiratory diseases or closely related physiological processes, to assess whether PAH-exposure may explain some of the effects associated with air pollution. Based on experimental in vivo and in vitro studies, we also explore possible mechanisms for how different PAHs may contribute to such events. Epidemiological studies show strongest evidence for an association between PAHs and asthma development and respiratory function in children. This is supported by studies on prenatal and postnatal exposure. Exposure to PAHs in adults seems to be linked to respiratory functions, exacerbation of asthma and increased morbidity/mortality of obstructive lung diseases. However, available studies are few and weak. Notably, the PAHs measured in plasma/urine also represent other exposure routes than inhalation. Furthermore, the role of PAHs measured in air is difficult to disentangle from that of other air pollution components originating from combustion processes. Experimental studies show that PAHs may trigger various processes linked to non-malignant respiratory diseases. Physiological- and pathological responses include redox imbalance, oxidative stress, inflammation both from the innate and adaptive immune systems, smooth muscle constriction, epithelial- and endothelial dysfunction and dysregulated lung development. Such biological responses may at the molecular level be initiated by PAH-binding to the aryl hydrocarbon receptor (AhR), but possibly also through interactions with beta-adrenergic receptors. In addition, reactive PAH metabolites or reactive oxygen species (ROS) may interfere directly with ion transporters and enzymes involved in signal transduction. Overall, the reviewed literature shows that respiratory effects of PAH-exposure in ambient air may extend beyond lung cancer. The relative importance of the specific PAHs ability to induce disease may differ between the biological endpoint in question.

Cross-validation of biomonitoring methods for polycyclic aromatic hydrocarbon metabolites in human urine: Results from the formative phase of the Household Air Pollution Intervention Network (HAPIN) trial in India

The Household Air Pollution Intervention Network (HAPIN) trial is evaluating health benefits of a liquefied petroleum gas (LPG) stove intervention in biomass cook-fuel using homes (n = 3200) in four low-and middle-income countries (LMICs) that include Peru, Guatemala, Rwanda and India. Longitudinal urine samples (n = 6000) collected from enrolled pregnant women, infants and older women will be analyzed for biomarkers associated with exposure and health outcomes. We report results from cross-validation of a lower cost high-performance liquid chromatography with fluorescence detection (HPLC-FLD) method with a higher resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the measurement of 1-hydroxypyrene (1PYR) and 2-naphthol (2NAP). Twenty-five split urine samples were analyzed by HPLC-FLD method at the India trial site in Chennai, India and by LC-MSMS method at the trial wide Biomarker Coordinating Center, Emory University, USA. The limits of detection (LOD) for the HPLC-FLD method were 0.02 ng/mL and 0.07 ng/mL for 2NAP and 1PYR, respectively. Bland-Altman analysis estimated a bias of 2.98 ng/ml for 2NAP (95% CI: -5.22, -0.75) and 0.09 ng/mL for 1PYR (95% CI: -0.02, 0.21) with HPLC-FLD levels being lower than LC-MSMS levels at higher concentrations. Analyses of additional urine samples (n = 119) collected during the formative phase of the HAPIN trial in India, showed 2NAP and 1PYR levels to be consistently above the limit of quantification (LOQ) and demonstrated the applicability of the method. The HPLC-FLD method can serve as a cost-effective and reliable analytical method to measure 2NAP and 1PYR in human urine in LMICs, within and beyond the HAPIN trial.

Placental levels of polycyclic aromatic hydrocarbons (PAHs) and their association with birth weight of infants

As an alarming group of pollutants, polycyclic aromatic hydrocarbons (PAHs) gather much public health concern not only because of their carcinogenic or co-carcinogenic risk but also by interfering with hormone systems or by causing oxidative damage, henceforth liable to toxic actions on reproduction. Accordingly, the present study was aimed to explore the association between in-utero exposure to PAHs by evaluating their placental levels and infant birth weight among 110 healthy and nonsmoking pregnant women. Placental tissue samples were collected instantly after delivery and were analyzed for the presence of sixteen Environmental Protection Agency (EPA) listed PAHs with the help of Gas chromatography equipped with flame ionization detector (GC-FID). Chrysene and benzo(k)fluoranthene were the predominant PAHs detected in tissue samples. To assess the source of origin of PAHs in placenta tissue samples, the ratio of low molecular weight PAHs to high molecular weight (∑LMW/∑HMW PAHs) was calculated, showing the predominance of pyrogenic sources of PAHs possibly responsible for the exposure of the studied population. Results of regression analysis demonstrated the inverse although not significant association of naphthalene (Nap), acenaphthylene (Acy), anthracene (Anth), pyrene (Pyr), benzo(b)fluoranthene (BbF), benzo(k)Fluoranthene (BkF), benzo(a)pyrene (BaP), indeno (123 cd pyrene (IcdP), dibenzo(ah)anthracene (DahA) and benzo(ghi)Perylene (BghiP) with birth weight of neonates. Additionally, the regression model lay light upon the significant association of fluoranthene (Fla) (coefficient= -1.41 gram, p < 0.05) to the depletion trend of birth weight after adjusting for potential covariates. These findings suggest the possible role of an environmental contaminants like PAHs on impairment of fetal growth.

Review: Polycyclic aromatic hydrocarbons (PAHs)-Action on placental function and health risks in future life of newborns

Polycyclic aromatic hydrocarbons (PAHs) are common environmental pollutants, which are released as products of incomplete combustion processes. Harmful effects of PAHs exposure on human health are observed in increased morbidity of respiratory, cardiovascular and immunological diseases. A particularly sensitive group to PAHs exposure are pregnant women and their developing offspring. PAHs can cross the placental barrier and a lot of published data indicated that prenatal or early postnatal exposure to PAHs can lead to developmental toxicity. Epidemiological data shows increased incidence and prevalence of conditions associated with PAHs exposure, like intrauterine growth retardation. Even more, negative effect of PAHs are observed later in development, low IQ, problems with behavior, allergies or asthma. This review will briefly summarize currently available data on the effects of PAHs on placental function with a specific emphasis on placental differentiation, angiogenesis, hormone signaling and consequences of exposure to PAHs in childhood and adulthood.

Distribution and predictors of urinary polycyclic aromatic hydrocarbon metabolites in two pregnancy cohort studies

Pregnant women and their fetuses represent susceptible populations to environmental contaminants. Exposure to polycyclic aromatic hydrocarbons (PAHs) among pregnant women may contribute to adverse birth outcomes such as preterm birth. Multiple previous studies have assessed airborne sources of PAHs among pregnant women but few have measured urinary PAH metabolites which can capture total exposure through multiple routes. The aim of this study was to bridge this knowledge gap by assessing longitudinal urinary PAH metabolite concentrations over two time points in pregnancy cohorts in Boston (N = 200) and Puerto Rico (N = 50) to better understand exposure distributions throughout pregnancy and how they relate to demographic factors. Urine samples were analyzed for 1-NAP, 2-NAP, 2-FLU, 1-PHE, 2,3-PHE, 4-PHE, 9-PHE, and 1-PYR. Concentrations of 2-NAP, 1-PYR, and 4-PHE were higher in Puerto Rico, while all other metabolites were present in higher concentrations in Boston. In Puerto Rico, intraclass correlation coefficients (ICC) were weak to moderate, ranging from 0.06 to 0.42. PAH metabolite concentrations were significantly higher among younger, heavier (except 1-NAP and 9-PHE), and less educated individuals in Boston only. Consistent significant associations between PAH concentrations and measured covariates were not found in Puerto Rico. Our results suggest that potentially important differences in PAH exposure exist between these two populations. Additionally, our results indicate that multiple urinary measurements are required to accurately assess PAH exposure throughout pregnancy.

Adipose Tissue as a Site of Toxin Accumulation

We examine the role of adipose tissue, typically considered an energy storage site, as a potential site of toxicant accumulation. Although the production of most persistent organic pollutants (POPs) was banned years ago, these toxicants persist in the environment due to their resistance to biodegradation and widespread distribution in various environmental forms (e.g., vapor, sediment, and water). As a result, human exposure to these toxicants is inevitable. Largely due to their lipophilicity, POPs bioaccumulate in adipose tissue, resulting in greater body burdens of these environmental toxicants with obesity. POPs of major concern include polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDDs/PCDFs), and polybrominated biphenyls and diphenyl ethers (PBBs/PBDEs), among other organic compounds. In this review, we (i) highlight the physical characteristics of toxicants that enable them to partition into and remain stored in adipose tissue, (ii) discuss the specific mechanisms of action by which these toxicants act to influence adipocyte function, and (iii) review associations between POP exposures and the development of obesity and diabetes. An area of controversy relates to the relative potential beneficial versus hazardous health effects of toxicant sequestration in adipose tissue. © 2017 American Physiological Society. Compr Physiol 7:1085-1135, 2017.

Impact of prenatal exposure to polycyclic aromatic hydrocarbons from maternal diet on birth outcomes: a birth cohort study in Korea

Objective

Polycyclic aromatic hydrocarbons (PAH) are common dietary exposures that cross the human placenta and are classified as a probable human carcinogen. The aim of the present study was to investigate the potential impact of exposure to PAH-containing meat consumed during pregnancy on birth outcomes.

Design

Prospective birth cohort study. Only non-smoking women with singleton pregnancies, who were free from chronic disease such as diabetes and hypertension, were included in the study. Maternal consumption of PAH-rich meat was estimated through FFQ. Multiple linear regression was used to assess factors related to higher intake and the association between dietary PAH and birth outcomes.

Setting

Republic of Korea, 2006–2011.

Subjects

Pregnant women (n 778) at 12–28 weeks of gestation enrolled in the Mothers and Children’s Environmental Health (MOCEH) study.

Results

The multivariable regression model showed a significant reduction in birth weight associated with higher consumption level of foods rich in PAH, such as grilled or roasted meat, during pregnancy (β=−17·48 g, P<0·05 for every 1 point higher in meat score). Further adjusting for biomarkers of airborne PAH did not alter this association. There was no evidence that higher consumption level of PAH-rich meat shortens the duration of gestation (P=0·561). Regression models performed for birth length and head circumference produced negative effects that were not statistically significant.

Conclusions

Consumption of higher levels of barbecued, fried, roasted and smoked meats during pregnancy was associated with reduced birth weight. Dietary risk of PAH exposure in Korean women is of concern.

Newborns health in the Danube Region: Environment, biomonitoring, interventions and economic benefits in a large prospective birth cohort study

BACKGROUND

The EU strategy for the Danube Region addresses numerous challenges including environment, health and socioeconomic disparities. Many old environmental burdens and heavily polluted areas in Europe are located in the Danube Region, consisting of 14 countries, with over 100 million people. Estimating the burden of environmental exposures on early-life health is a growing research area in Europe which has major public health implications, but the data from the Danube Region are largely missing.

AIM

This review presents an inventory of current environmental challenges, related early-life health risks, and knowledge gaps in the Danube Region, based on publicly available databases, registers, and literature, as a rationale and incentive for a new integrated project. The review also proposes the concept for the project aiming to characterize in utero exposures to multiple environmental factors and estimate their effect on early-life health, evaluate economic impact, as well as identify interventions with a potential to harness social norms to reduce emissions, exposures and health risks in the Danube Region.

METHODS

Experts in environmental epidemiology, human biomonitoring and social science in collaboration with clinicians propose to establish a new large multi-center birth cohort of mother-child pairs from Danube countries, measure biomarkers of exposure and health in biological samples at birth, collect centrally measured climate, air and water pollution data, conduct pre- and postnatal surveys on lifestyle, indoor exposures, noise, occupation, socio-economic status, risk-averting behavior, and preferences; and undertake clinical examinations of children at and after birth. Birth cohort will include at least 2000 newborns per site, and a subset of at least 200 mother-child pairs per site for biomonitoring. Novel biomarkers of exposure, susceptibility, and effect will be applied, to gain better mechanistic insight. Effects of multiple environmental exposures on fetal and child growth, respiratory, allergic, immunologic, and neurodevelopmental health outcomes will be estimated. Parent's willingness to pay for reducing health risks in children will be elicited by survey, while values of cost-of-illness will be gathered from literature and national statistics. Effects of risk reducing interventions will be examined.

CONCLUSIONS

The proposed project would provide novel estimates of the burden of early childhood diseases attributable to environmental exposures and assess health impacts of different intervention scenarios in the Danube Region, in an integrated approach combining human biomonitoring, epidemiological and social science research.

Prenatal polycyclic aromatic hydrocarbon (PAH) exposure, antioxidant levels and behavioral development of children ages 6-9

PURPOSE

Prenatal polycyclic aromatic hydrocarbon (PAH) exposure has been shown to increase DNA adduct levels and to affect neurodevelopment. Micronutrients may modify the adverse effect of PAH on neurodevelopment. Thus, we examined if micronutrient concentrations modified the association between PAH exposure and neurodevelopmental outcomes.

METHODS

151 children from a birth cohort who had micronutrient concentrations measured in cord blood and completed the Child Behavioral Checklist (CBCL), between the ages of 6 and 9 years, were evaluated. Prenatal airborne PAH exposure was measured by personal air monitoring. The betas and 95% CI for the associations of antioxidant concentrations and PAH exposure with each of the outcomes of CBCL raw score and dichotomized standardized T-score (based on clinical cutpoints) were estimated, respectively, by multivariable poisson and logistic models.

RESULTS

Children below the median for alpha-tocopherol and gamma-tocopherol concentrations, compared to those above, were more likely to have thought problems, aggressive behavior and externalizing problems (p<0.05). Lower carotenoid concentration was associated with more thought problems (MVβ=0.60, p<0.001) and externalizing problems (MVβ=0.13, p<0.05) for the same contrast. No statistically significant associations were observed between retinol concentrations and neurodevelopmental symptoms. Overall, no consistent patterns were observed when we examined the interaction between antioxidants (e.g., alpha-tocopherol) and PAH in relation to CBCL symptoms (e.g., internalizing and externalizing problems, p<0.05).

CONCLUSIONS

Lower alpha-tocopherol, gamma-tocopherol and carotenoid levels may adversely affect healthy neurodevelopment, even after accounting for PAH exposure. Future research to confirm these findings are warranted given the importance of identifying modifiable factors for reducing harmful PAH effects.

A review of PAH exposure from the combustion of biomass fuel and their less surveyed effect on the blood parameters

Many epidemiological studies from all over the world have reported that populations of rural and urban environments differ in their health issues due to the differences in the countrywide pollution pattern. In developing countries, various occupational cohorts and subsections of the population in urban and rural areas are routinely exposed to several environmentally widespread contaminants. Polycyclic aromatic hydrocarbons (PAHs) are a group of over hundred different compounds and have ubiquitous presence in rural and urban environments. Smoke from the combustion of biomass fuel contains a high concentration of carcinogenic PAHs, which are related with several human morbidities. The sources and types of biomass fuel are diverse and wide in distribution. Limited numbers of literature reports have focused the significant impact of PAHs on several components of blood, both in human and wildlife. The toxicity of PAHs to rapidly dividing cells (e.g., bone marrow cells) and other tissues is largely attributed to their reactive oxygenated metabolites, potential of causing oxidative stress, and the adducts of their metabolites with DNA. This review aims to encompass the blood-related effects of PAHs and associated human health risks-an aspect that needs further research-on the population of developing countries of the world in particular.

Screening the toxicity and biodegradability of petroleum hydrocarbons by a rapid colorimetric method

Crude oil and petroleum products have a wide variety of hazardous components with high toxicity and low biodegradability. Certain dyes change their colors by intercepting electron transfer reactions during the transformation processes. This study applied resazurin and 2,6-dichlorophenol-indophenol indicators for a rapid screening biodegradation capability and toxicity response to various petroleum products such as motor oil, diesel, gasoline, and phenol. Colorimetry tests were performed in test tubes, and the absorbance values were measured over time. We observed different discoloration profiles after degradation tests using Bacillus subtilis inoculum. Phytotoxicity assays were also performed to compare colorimetric screening assays with a conventional toxicity testing with plants (seed germination). The results indicated that biotransformation of oils can increase its overall toxicity. Intermediate byproducts can be formed through biodegradation and thereby increase the toxicity of oils. The assessment of acute toxicity has shown that phenol is extremely toxic to petroleum-biodegrading microbial communities. Low molecular-weight gasoline was considered biodegradable, but it also exhibited a high acute toxic effect, mainly due to its high solubility and the presence of more volatile compounds that can penetrate cells and potentially damage cellular structures.

Cotinine and polycyclic aromatic hydrocarbons levels in the amniotic fluid and fetal cord at birth and in the urine from pregnant smokers

Cigarette smoking during pregnancy has several impacts on fetal development, including teratogenic effects. The objective of this study was to assess whether the toxic substances (cotinine and polycyclic aromatic hydrocarbons) found in pregnant smokers are transmitted to their fetuses. The outcomes were analyzed measuring cotinine and 1-hydroxypyrene in the amniotic fluid and maternal urine, benzopyrene and cotinine in the umbilical cord blood. Through a controlled cross-sectional design, 125 pregnant women were selected and classified according to their smoking status: 37 current smokers, 25 passive smokers and 63 non-smokers (controls). We performed high-performance liquid chromatography to measure substances’ concentrations. A post-hoc Tukey’s test was used to analyze the differences between the groups. All variables were significantly different between controls and smokers. The mean ratios between the concentration of cotinine in smokers compared to controls were as follows: 5.9 [2.5–13.5], p<0.001 in the urine; 25 [11.9–52.9], p<0.001 in the amniotic fluid; and 2.6 [1.0–6.8], p = 0.044 in the umbilical cord blood. The mean ratios of 1-hydroxypyrene concentration between smokers and controls were 7.3 [1.6–29.6], p = 0.003 in the urine and 1.3 [1.0–1.7], p = 0.012 in the amniotic fluid, and of benzopyrene in umbilical cord blood was 2.9 [1.7–4.7], p<0.001. There were no significant differences between controls and passive smokers. When comparing the three groups together, there were statistical differences between all variables. Thus, the fetuses of pregnant smokers are exposed to toxic and carcinogens substances. To our knowledge, this is the first study to measure 1-hydroxypyrene in the amniotic fluid and benzopyrene in umbilical cord blood by high-performance liquid chromatography when considering pregnant women in relation to smoking exposure only.

Spatiotemporal association between birth outcomes and coke production and steel making facilities in Alabama, USA: a cross-sectional study

BACKGROUND

Previous research has shown exposure to air pollution increases the risk of adverse birth outcomes, although the effects of residential proximity to significant industrial point sources are less defined. The objective of the current study was to determine whether yearly reported releases from major industrial point sources are associated with adverse birth outcomes.

METHODS

Maternal residence from geocoded Alabama birth records between 1991 and 2010 were used to calculate distances from coke and steel production industries reporting emissions to the U.S. Environmental Protection Agency. Logistic regression models were built to determine associations between distance or yearly fugitive emissions (volatile organic compounds, polycyclic aromatic compounds, and metals) from reporting facilities and preterm birth or low birth weight, adjusting for covariates including maternal age, race, payment method, education level, year and parity.

RESULTS

A small but significant association between preterm birth and residential proximity (≤5.0 km) to coke and steel production facilities remained after adjustment for covariates (OR 1.05 95% CI: 1.01,1.09). Above average emissions from these facilities of volatile organic compounds during the year of birth were associated with low birth weight (OR 1.17 95% CI: 1.06, 1.29), whereas metals emissions were associated with preterm birth (OR 1.07 95% CI: 1.01, 1.14).

CONCLUSIONS

The present investigation suggests fugitive emissions from industrial point sources may increase the risk of adverse birth outcomes in surrounding neighborhoods. Further research teasing apart the relationship between exposure to emissions and area-level deprivation in neighborhoods surrounding industrial facilities and their combined effects on birth outcomes is needed.

The determination of polycyclic aromatic hydrocarbons in the urine of non-smoking Polish pregnant women

The aim of this study was to characterize the PAH exposure level among the non-smoking Polish pregnant women and to identify the minimal set of PAH metabolites that specifically reflect environmental PAH exposure. The study population consisted of 210 non-smoking pregnant women. The urine sample was used for analysis of the following PAH metabolites: 1-, 2-, 3-, 4-, 9-hydroxyphenanthrene (1-, 2-, 3-, 4-, 9-OH-PHE), 1-hydroxypyrene (1-OH-PYR), 1,6+1,8-dihydroxypyrene (DI-OH-PYR), phenanthrene trans-1,2-dihydrodiol (PHE-1,2-diol) and phenanthrene trans-9,10-dihydrodiol (PHE-9,10-diol). The analysis of all the biomarkers was performed by gas chromatography-mass spectrometry after their derivatization. The mean PAH metabolite concentrations were in the range of 0.15 (± 0.2) μg/g creatinine for 9-OH-PHE to 5.9 (± 10.6) μg/g creatinine for PHE-9,10-diol. Women living in the city center had higher concentrations of 1-OH-PHE (β=0.6; p=0.04), 3-OH-PHE (β=0.8; p=0.02), 9-OH-PHE (β=0.9; p=0.02), and DI-OH-PYR (β=1.0; p=0.006) than those living outside the city center. The usage of coal for residential heating was a significant predictor of all PAH metabolites except for 9-OH-PHE (p=0.1) and PHE-9,10-diol (p=0.08). With the increasing cotinine levels we observed a significant increase in the concentrations of the following PAH metabolites: 3-OH-PHE (β=0.2; p=0.007), 4-OH-PHE (β=0.3; p=0.002), PHE-1,2-diol (β=0.3; p<0.001), 1-OH-PYR (β=0.2; p=0.01). High-density housing, usage of coal for residential heating, cotinine level in saliva, season of urine collection and distance from the place of residence to the main road explained 26% of the variance of 3-OH-PHE and 21% of the variance of 1-OH-PHE. 2-OH-PHE, 3-OH-PHE, 9-OH-PHE and PHE-9,10-diol are sufficient to predict environmental PAH exposure. The urinary PAH biomarker levels found in this study indicate that non-smoking Polish pregnant women suffer from a higher PAH exposure than those in other western countries. This higher PAH exposure level probably poses a significant health risk for the newborns and young children and will require further attention in the future.

Short-term effects of a perinatal exposure to a 16 polycyclic aromatic hydrocarbon mixture in rats: assessment of early motor and sensorial development and cerebral cytochrome oxidase activity in pups

Humans are exposed to polycyclic aromatic hydrocarbons (PAHs), a family of ubiquitous neurotoxic pollutants, mainly through ingestion of contaminated food. Developing organisms can be exposed also to PAHs due to the ability of these compounds to pass through the placental barrier as well as through the breast milk. Previous animal studies have reported that the exposure of rats to a 16 PAH mixture at environmental doses strictly limited to gestation did not induce any long-lasting consequences, whereas gestational and lactational PAH exposure induced long-term behavioral and cerebral metabolic effects. In the present study, short-term effects of exposures to the same PAH mixture during gestation, or during gestation and lactation, were assessed by evaluating motor and sensory development of rat pups, and by measuring cerebral cytochrome oxidase activity (a marker of energetic metabolism) in different brain areas. Brain levels of PAHs and some monohydroxylated metabolites were also evaluated in pups at birth and at 21 days of postnatal life. No significant short-term modifications of behavioral development and of cerebral metabolism were observed following an early PAH exposure whatever the dose and the period of exposure. Surprisingly, the same brain levels of concentration of PAHs and metabolites were observed in control and exposed pups in both studies. These analytical results raise the difficulty in overcoming environmental contamination of control animals and the choice of such controls in experimental studies which focus on neurotoxicity of exposure to low levels of pollutants.

Longitudinal follow-up of the relationship between dietary intake and growth and development in the Lifeways cross-generation cohort study 2001-2013

In this paper we will review evidence on the early life and familial influences on childhood growth and development, with particular reference to the Lifeways cross-generation cohort study in the Republic of Ireland. The Lifeways cross-generation cohort study was established in 2001-2013 through two maternity hospitals in the Republic of Ireland and was one of many new cohort studies established worldwide in the millennium period. Mothers were recruited at first booking visit, completing a self-administered questionnaire, which included a 147 item semi-quantitative FFQ. Longitudinal follow-up is ongoing in 2013, with linkage data to hospital and general practice records and examination of children when aged 5 and 9 years. The study is one of very few containing data on grandparents of both lineages with at least one grandparent recruited at baseline. There have been consistent associations between parental and grandparental health status characteristics and children's outcomes, including infant birth-weight, BMI when child was aged 5 years and childhood wheeze or asthma when child was aged 3 and aged 5 years. In conclusion, empirical evidence to date shows consistent familial and cross-generational patterns, particularly in the maternal line.

Bulky dna adducts in cord blood, maternal fruit-and-vegetable consumption, and birth weight in a European mother-child study (NewGeneris)

BACKGROUND

Tobacco-smoke, airborne, and dietary exposures to polycyclic aromatic hydrocarbons (PAHs) have been associated with reduced prenatal growth. Evidence from biomarker-based studies of low-exposed populations is limited. Bulky DNA adducts in cord blood reflect the prenatal effective dose to several genotoxic agents including PAHs.

OBJECTIVES

We estimated the association between bulky DNA adduct levels and birth weight in a multicenter study and examined modification of this association by maternal intake of fruits and vegetables during pregnancy.

METHODS

Pregnant women from Denmark, England, Greece, Norway, and Spain were recruited in 2006-2010. Adduct levels were measured by the 32P-postlabeling technique in white blood cells from 229 mothers and 612 newborns. Maternal diet was examined through questionnaires.

RESULTS

Adduct levels in maternal and cord blood samples were similar and positively correlated (median, 12.1 vs. 11.4 adducts in 108 nucleotides; Spearman rank correlation coefficient = 0.66, p < 0.001). Cord blood adduct levels were negatively associated with birth weight, with an estimated difference in mean birth weight of -129 g (95% CI: -233, -25 g) for infants in the highest versus lowest tertile of adducts. The negative association with birth weight was limited to births in Norway, Denmark, and England, the countries with the lowest adduct levels, and was more pronounced in births to mothers with low intake of fruits and vegetables (-248 g; 95% CI: -405, -92 g) compared with those with high intake (-58 g; 95% CI: -206, 90 g).

CONCLUSIONS

Maternal exposure to genotoxic agents that induce the formation of bulky DNA adducts may affect intrauterine growth. Maternal fruit and vegetable consumption may be protective.

Dietary benzo(a)pyrene intake during pregnancy and birth weight: associations modified by vitamin C intakes in the Norwegian Mother and Child Cohort Study (MoBa)

BACKGROUND

Maternal exposure to polycyclic aromatic hydrocarbons (PAH) during pregnancy has been associated with reduced fetal growth. However, the role of diet, the main source of PAH exposure among non-smokers, remains uncertain.

OBJECTIVE

To assess associations between maternal exposure to dietary intake of the genotoxic PAH benzo(a)pyrene [B(a)P] during pregnancy and birth weight, exploring potential effect modification by dietary intakes of vitamins C, E and A, hypothesized to influence PAH metabolism.

METHODS

This study included 50,651 women in the Norwegian Mother and Child Cohort Study (MoBa). Dietary B(a)P and nutrient intakes were estimated based on total consumption obtained from a food frequency questionnaire (FFQ) and estimated based on food composition data. Data on infant birth weight were obtained from the Medical Birth Registry of Norway (MBRN). Multivariate regression was used to assess associations between dietary B(a)P and birth weight, evaluating potential interactions with candidate nutrients.

RESULTS

The multivariate-adjusted coefficient (95%CI) for birth weight associated with maternal energy-adjusted B(a)P intake was -20.5g (-31.1, -10.0) in women in the third compared with the first tertile of B(a)P intake. Results were similar after excluding smokers. Significant interactions were found between elevated intakes of vitamin C (>85mg/day) and dietary B(a)P during pregnancy for birth weight (P<0.05), but no interactions were found with other vitamins. The multivariate-adjusted coefficients (95%CI) for birth weight in women in the third compared with the first tertile of B(a)P intake were -44.4g (-76.5, -12.3) in the group with low vitamin C intakes vs. -17.6g (-29.0, -6.1) in the high vitamin C intake group.

CONCLUSION

The results suggest that higher prenatal exposure to dietary B(a)P may reduce birth weight. Lowering maternal intake of B(a)P and increasing dietary vitamin C intake during pregnancy may help to reduce any adverse effects of B(a)P on birth weight.

Polycyclic aromatic hydrocarbons (PAHs) as determinants of various anthropometric measures of birth outcome

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants that are known to induce oxidative stress. There have been several reports about the link between PAH exposure and complications in pregnancy. This cross-sectional study was conducted to: (1) measure the levels of benzo(a)anthracene (BaA), chrysene (Ch), benzo(b)fluoranthene (BbF), benzo(a)pyrene (BaP), and dibenzo(a,h)anthracene (DBahA) in placentas and maternal and -umbilical cord blood obtained at delivery from 1578 women between June 2005 and 2006 in the area of Al-Kharj, Saudi Arabia; (2) assess their influence on various anthropometric measures of birth outcome taking into consideration the carcinogenic properties of these PAHs; and (3) determine the degree of PAH-related oxidative DNA damage and birth outcome. Among the five tested PAHs, only BaP was carcinogenic; therefore, the levels of the other four probable or possible carcinogenic PAHs (BaA, Ch, BaF, and DBahA) were summed as ∑4-PAHs. Levels of 1-hydroxypyrene (1-HP) were determined in maternal urine samples as a biomarker of PAH internal dose. Urinary cotinine (COT) was measured as an index of smoking. The following markers of oxidative stress were selected: malondialdehyde (MDA) in cord (C-MDA) and maternal (M-MDA) serum and 8-hydroxy-2-deoxyguanosine (8-OHdG) in maternal urine. None of the tested PAHs was found in maternal or cord blood. However, all five PAH compounds were detected in placentas; Ch was the highest (6.582 μg/kg dry wt.), and BaA was the lowest (0.236 μg/kg dry wt.). The mean concentration of urinary 1-HP found in this study was 0.216 ± 0.856 μg/g Cr. After adjusting for gestational age and other confounding variables, regression models revealed an inverse relationship between placental weight, cord length and placental BaP. A similar trend was observed between cord length and ∑4-PAHs in placental tissues. Urinary 1-HP, though, cannot be used as an unequivocal biomarker of PAH exposure, but it can be an appropriate indicator of exposure to environmental tobacco smoke (ETS). The data demonstrate that ETS exposure (as measured by urinary COT) may adversely affect birth outcome as shown by reduced head circumference, birth weight, and birth length, as well as increased cephalization index. The positive relationship between 8-OHdG levels and 1-HP in urine provides evidence of an oxidative stress mechanism. Although this study provides no direct evidence of an association between PAH exposure and DNA damage, increased oxidative stress in the form of lipid peroxidation significantly affected various birth measures. Therefore, there is a need for studies regarding PAH exposure and its associated biological effects to determine the extent of potential fetal damage as well as possible long-term effects, such as cancer.

Health impact of air pollution to children

Health impact of air pollution to children was studied over the last twenty years in heavily polluted parts of the Czech Republic during. The research program (Teplice Program) analyzed these effects in the polluted district Teplice (North Bohemia) and control district Prachatice (Southern Bohemia). Study of pregnancy outcomes for newborns delivered between 1994 and 1998 demonstrated that increase in intrauterine growth retardation (IUGR) was associated with PM10 and c-PAHs exposure (carcinogenic polycyclic aromatic hydrocarbons) in the first month of gestation. Morbidity was followed in the cohort of newborns (N=1492) up to the age of 10years. Coal combustion in homes was associated with increased incidence of lower respiratory track illness and impaired early childhood skeletal growth up to the age of 3years. In preschool children, we observed the effect of increased concentrations of PM2.5 and PAHs on development of bronchitis. The Northern Moravia Region (Silesia) is characterized by high concentrations of c-PAHs due to industrial air pollution. Exposure to B[a]P (benzo[a]pyrene) in Ostrava-Radvanice is the highest in the EU. Children from this part of the city of Ostrava suffered higher incidence of acute respiratory diseases in the first year of life. Gene expression profiles in leukocytes of asthmatic children compared to children without asthma were evaluated in groups from Ostrava-Radvanice and Prachatice. The results suggest the distinct molecular phenotype of asthma bronchiale in children living in polluted Ostrava region compared to children living in Prachatice. The effect of exposure to air pollution to biomarkers in newborns was analyzed in Prague vs. Ceske Budejovice, two locations with different levels of pollution in winter season. B[a]P concentrations were higher in Ceske Budejovice. DNA adducts and micronuclei were also elevated in cord blood in Ceske Budejovice in comparison to Prague. Study of gene expression profiles in the cord blood showed differential expression of 104 genes. Specifically, biological processes related to immune and defense response were down-regulated in Ceske Budejovice. Our studies demonstrate that air pollution significantly affect child health. Especially noticeable is the increase of respiratory morbidity. With the development of molecular epidemiology, we can further evaluate the health risk of air pollution using biomarkers.

Dietary benzo(a)pyrene and fetal growth: effect modification by vitamin C intake and glutathione S-transferase P1 polymorphism

BACKGROUND

Previous studies have reported maternal exposure to airborne polycyclic aromatic hydrocarbons (PAH), as well as DNA adducts reflecting total PAH exposure, to be associated with reduced fetal growth. The role of diet, the main source of PAH exposure among non-smokers, remains uncertain.

OBJECTIVE

To assess associations between birth weight, length and small size for gestational age (SGA) with maternal intakes of the genotoxic PAH benzo(a)pyrene [B(a)P] during pregnancy, exploring potential effect modification by dietary intakes of vitamin C, vitamin E, alpha- and beta-carotene, as well as glutathione S-transferase P1 (GSTP1) polymorphisms, hypothesized to influence PAH metabolism.

METHODS

657 women in the INMA (Environment and Childhood) Project from Sabadell (Barcelona) were recruited during the first trimester of pregnancy. Dietary B(a)P and nutrient intakes were estimated from food consumption data. Genotyping was conducted for the Ile105Val variant of GSTP1. Multivariable models were used to assess associations between size at birth and dietary B(a)P, evaluating potential interactions with candidate nutrients and GSTP1 variants.

RESULTS

There were significant interactions between elevated intakes of vitamin C (above the mean of 189.41 mg/day) and dietary B(a)P during the first trimester of pregnancy in models for birth weight and length (P<0.05), but no interactions were found with other nutrients. B(a)P intakes were associated with significant reductions in birth weight and length (coefficient±SE for a 1-SD increase in B(a)P: -101.63±34.62 g and -0.38±0.16 cm, respectively) among women with low, but not high, vitamin C intakes. Elevated dietary B(a)P was also associated with increased risk of SGA births among women with low dietary vitamin C. Among these women, associations were strongest in those carrying the GSTP1 Val allele, associated with lower contaminant detoxification activity.

CONCLUSION

Results suggest that dietary B(a)P exposure may impair fetal growth, particularly in genetically susceptible populations, and that increasing maternal intakes of vitamin C may help to reduce any adverse effects.