Wieslaw Jedrychowski

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants produced by combustion of fossil fuel and other organic materials. Both experimental animal and human studies have reported the harmful impacts of PAH compounds on fetal growth and neurodevelopment, including verbal IQ of children. Here, we have assessed the association between cognitive function of children and prenatal PAH exposures. The study is part of an ongoing, longitudinal investigation of the health effects of prenatal exposure to air pollution on infants and children in Krakow, Poland. The subjects in this report included 170 children whose mothers were enrolled to the study in the first or second trimester of pregnancy whose cord blood were tested for PAH–DNA adducts and who were assessed at age 7 using the Wechsler Intelligence Scale for Children-Revised (WISC-R). The outcome of a priori interest was depressed verbal IQ index (DepVIQ), which is the difference between WISC-R performance and verbal IQ scores. Prenatal PAH exposure was measured by cord blood PAH–DNA adducts, an individual dosimeter, integrating exposure from various sources of exposure over the gestational period. The estimated effect of prenatal PAH exposure on cognitive function was adjusted in multivariable regression for a set of potential confounders (child’s gender, parity, maternal education, breastfeeding practice, environmental tobacco smoke (ETS), and postnatal PAH exposure). The prevalence of DepVIQ was significantly higher in children with detectable PAH–DNA adducts compared to those with undetectable adducts (13.7 vs. 4.4 %,). Binary multivariable regression documented that the relative risk of DepVIQ increased threefold with a ln-unit increase in cord blood adducts (relative risk (RR) = 3.0, 95 % confidence interval (CI) 1.3–6.8). Postnatal PAH exposure also increased the risk of DepVIQ (RR = 1.6, 95 % CI 1.1–2.5). Long-term exclusive breastfeeding (at least 6 months) showed a protective effect (RR = 0.3, 95 % CI 0.1–0.9). In conclusion, these results provide further evidence that PAHs are harmful to the developing fetal brain with effects extending through childhood, with implications for the academic success of the children.

The main purpose of the present study was to test the hypothesis that the depressed lung growth attributable to prenatal exposure to polycyclic aromatic hydrocarbons (PAH) may be modified by the intake of antihistamine medications. Individual prenatal PAH exposure was assessed by personal air monitoring in 176 children who were followed over nine years, in the course of which outdoor residential air monitoring, allergic skin tests for indoor allergens, lung function tests (FVC, FEV₁, FEV₀₅, and FEF_25‐75) were performed. The analysis with the General Estimated Equation (GEE) showed no association between prenatal PAH exposure and lung function in the group of children who were reported to be antihistamine users. However, in the group of antihistamine non‐users all lung function tests except for FEF_25‐75 were significantly and inversely associated with prenatal airborne PAH exposure. The results of the study suggest that the intake of antihistamine medications in early childhood may inhibit the negative effect of fetal PAH exposure on lung growth and provides additional indirect evidence for the hypothesis that lung alterations in young children resulting from PAH exposure may be caused by the allergic inflammation within lung. Pediatr Pulmonol. 2015; 50:469–478.

The goal of this epidemiologic investigation was to analyze the associations between prenatal and postnatal exposure to airborne polycyclic aromatic hydrocarbons (PAH) and severity of wheeze and recurrent wheeze. The 257 children included in this analysis had a complete set of prenatal and postnatal PAH measurements and attended regular health checkups over a 4‐year follow‐up period since birth. Transplacental PAH exposure was measured by personal air monitoring of the mothers during the second trimester of pregnancy; postnatal exposure was estimated using the same instruments indoors at the children's residences at age 3. Chemical analysis tests were performed to determine airborne concentrations of nine PAH compounds. The results show that both prenatal and postnatal exposure were associated positively with the severity of wheezing days and recurrent wheezing reported in the follow‐up. While the incidence rate ratio (IRR) for severity of wheeze and prenatal PAH exposure was 1.53 (95%CI: 1.43–1.64) that for postnatal PAH exposure was 1.13 (95%CI: 1.08–1.19). However, recurrent wheezing was more strongly associated with airborne PAH levels measured at age 3 (OR = 2.31, 95%CI: 1.26–4.22) than transplacental PAH exposure (OR = 1.40, 95% CI: 0.85–2.09), but the difference was statistically insignificant. In conclusion, it appears that prenatal PAH exposure may precipitate and intensify early onset of wheezing symptoms in childhood, resulting from the postnatal exposure and suggest that success in reducing the incidence of respiratory diseases in children would depend on reducing both fetal and childhood exposure to air pollution. Pediatr Pulmonol. 2014; 49:162–172.

In a birth cohort study, we have assessed the dose-response relationship between individual measurements of prenatal airborne polycyclic aromatic hydrocarbon (PAH) exposure and specific PAH–DNA adducts in cord blood adjusted for maternal blood adducts and season of birth. The study uses data from an earlier established birth cohort of children in Krakow. The final analysis included 362 pregnant women who gave birth to term babies and had complete data on personal exposure in the second trimester of pregnancy to eight airborne PAHs including benzo[a]pyrene (B[a]P), as well as DNA adducts, both in maternal and cord blood. The relation between cord blood PAH–DNA adducts and airborne prenatal PAH exposure was non-linear. Although cord blood PAH–DNA adducts were significantly associated with the B[a]P exposure categorized by tertiles (non-parametric trend z=3.50, Pz=1.63, P=0.103). Based on the multivariable linear regression model, we estimated the effect of the prenatal airborne B[a]P on the level of cord blood adducts. In total, 14.8% of cord blood adducts variance was attributed to the level of maternal adducts and 3% to a higher prenatal B[a] exposure above 5.70 ng/m³. The calculated fetal/maternal blood adduct ratio (FMR) linearly increased with B[a]P exposure (z=1.99, P=0.047) and was highest at B[a]P concentrations exceeding 5.70 ng/m³. In conclusion, the results support other findings that transplacental exposure to B[a]P from maternal inhalation produces DNA damage in the developing fetus. It also confirms the heightened fetal susceptibility to prenatal PAH exposure that should be a matter of public health concern, particularly in the highly polluted areas, because DNA adducts represent a pro-carcinogenic alteration in DNA. The continuation of this birth cohort study will assess the possible health effects of fetal DNA damage on the health of children and help in establishing new protective guidelines for newborns.

The main goal of the study was to assess possible association between fetal exposure to fine particulate matter (PM_2.5) and exhaled carbon monoxide (eCO) measured in non-asthmatic children. The subjects include 118 children taking part in an ongoing population-based birth cohort study in Kraków. Personal samplers of PM_2.5 were used to measure fine particle mass in the fetal period and carbon monoxide (CO) in exhaled breath from a single exhalation effort at the age of 7. In the statistical analysis of the effect of prenatal PM_2.5 exposure on eCO, a set of potential confounders, such as environmental tobacco smoke (ETS), city residence area, sensitization to house dust allergens and the occurrence of respiratory symptoms monitored over the seven-year follow-up was considered. The level of eCO did not correlate with the self-reported ETS exposure recorded over the follow-up, however, there was a positive significant relationship with the prenatal PM_2.5 exposure (non-parametric trend p = 0.042). The eCO mean level was higher in atopic children (geometric mean = 2.06 ppm, 95% CI: 1.58–2.66 ppm) than in non-atopic ones (geometric mean = 1.57 ppm, 95% CI: 1.47–1.73 ppm) and the difference was statistically significant (p = 0.036). As for the respiratory symptoms, eCO values were associated positively only with the cough severity score recorded in the follow-up (nonparametric trend p = 0.057). In the nested multivariable linear regression model, only the effects of prenatal PM_2.5 and cough severity recorded in the follow-up were related to eCO level. The prenatal PM_2.5 exposure represented 5.1%, while children’s cough represented only 2.6% of the eCO variability. Our study suggests that elevated eCO in non-asthmatic children may result from oxidative stress experienced in the fetal period and that heme oxygenase (HO) activity in body tissues may be programmed in the fetal period by the exposure to fine particulate matter.

The goal of the study is to evaluate the importance of maternal atopy as a potential biological source of variability of exhaled FeNO values in healthy children who were non-asthmatic and non-sensitized to common domestic allergens. The study sample consisted of 61 seven-year old children. Fractional exhaled nitric oxide (FeNO) has been measured by NObreath (Bedfont portable device). Children with reported maternal atopy had significantly higher mean FeNO values (geometric mean =10.7 ppb; 95%CI: 6.7-17.1 ppb) than those who denied it (geometric mean =5.2 ppb 95%CI: 3.9-6.9 ppb) (p=0.010). Neither the correlation between FeNO values and gender, respiratory and eczema symptoms, nor ETS exposure in the prenatal and postnatal period or body mass of children were significant. We also found no significant association of FeNO values with the amount of common domestic allergens measured in the households. The results of the ROC analysis suggested 11 ppb as the cut-off point for FeNO to distinguish groups of healthy children with and without maternal atopy. In conclusion, our study provided some evidence suggesting that maternal atopy may affect FeNO level in children independently of asthma and sensitization status to common domestic allergens. The data should be considered in the interpretation of FeNO levels in clinical practice and setting up FeNO screening criteria for identification of eosinophilic airway inflammation.

The main goal of the study was to assess possible association between transplacental exposure to genotoxic PAH compounds assessed by the cord blood PAH–DNA adducts and fractional exhaled nitric oxide (FeNO) measured in healthy non‐asthmatic children at the age of 7 years. The subjects included the subsample of 89 children who took part in the ongoing population based birth cohort study in Krakow and attended FeNO testing. The effect of transplacental PAH exposure was adjusted for potential confounders, such as maternal allergy and children's specific atopy to common domestic allergens.Results: FeNO values were significantly elevated in children with higher prenatal PAH exposure (gmean = 7.7 ppb; 95% CI: 5.8–10.2 ppb) compared with those at low exposure level (gmean = 3.8 ppb; 95% CI: 2.3–6.3) (P = 0.011). Children with maternal allergy had also significantly higher mean FeNO values (gmean = 13.7 ppb, 95% CI: 8.8–21.4 ppb) compared with the subjects whose mothers denied allergy (gmean = 5.6 ppb, 95% CI: 4.3–7.3 ppb) (P = 0.012). Similarly, FeNO values in atopic children were higher (gmean = 11.2 ppb; 95% CI: 3.8–32.8 ppb) than in non‐atopic individuals (gmean = 6.0 ppb; 95% CI: 4.7–7.7 ppb, P = 0.079). The results of the nested multivariable linear regression analysis showed that both maternal allergy and sensitization of children to domestic aeroallergens jointly explained 10.4% of FeNO variance, however, the additional 10.9% was determined by prenatal PAH exposure.Conclusion: FeNO is more than a marker useful for screening atopy or symptomatic bronchial inflammation and may also be a proxy for cytokine deregulation and “allergic response” phenotype possibly established in fetal period due to transplacental PAH exposure. Preliminary results of our study should encourage more studies on intrauterine PAH exposure and later respiratory symptoms. Pediatr Pulmonol. 2012. 47:1131–1139.