Agata Sowa

Intrauterine exposure to polycyclic aromatic hydrocarbons, fine particulate matter and early wheeze. Prospective birth cohort study in 4‐year olds

Jedrychowski WA, Perera FP, Maugeri U, Mrozek‐Budzyn D, Mroz E, Klimaszewska‐Rembiasz M, Flak E, Edwards S, Spengler J, Jacek R, Sowa A. Intrauterine exposure to polycyclic aromatic hydrocarbons, fine particulate matter and early wheeze. Prospective birth cohort study in 4‐year olds.
Pediatr Allergy Immunol 2010: 21: e723–e732.
© 2010 John Wiley & Sons A/S

Case-control study on beneficial effect of regular consumption of apples on colorectal cancer risk in a population with relatively low intake of fruits and vegetables.

Laboratory in-vitro studies and animal experiments showing the potential health benefits from apples raises the question to what extent the regular consumption of apples in humans may have a beneficial effect on colorectal cancer risk. A total of 592 incident cases of colorectal cancer have been enrolled in a hospital-based case–control study. The comparison group included 765 controls chosen from the patients of the same hospital without history of cancer and admitted for treatment of nonneoplastic conditions. Interviews of both cases and controls were conducted in the hospital setting by trained interviewers. The median intake of fruits among cases was lower than in controls (9.5 vs. 11 servings/week) and the difference was statistically significant. Apples were the most frequent fruit consumed by the study participants and about 80% of variability in the total fruit consumption resulted from the intake of apples. We did not observe any significant statistical differences in consumption of berries, citrus, or stone fruits and other kinds of fruits across cases and controls. The adjusted estimates of colorectal cancer risk related to the daily consumption of apples (in quintiles) were based on the unconditional multivariate logistic model, which considered the set of potential confounding variables such as demographic characteristics of participants (age, gender, place of residency, marital status, tobacco smoking), total energy intake, intake of vegetables and fruits without apples. The results of the logistic analysis showed that the adjusted risk of colorectal cancer inversely correlated with daily number of apple servings. The reduced risk of colorectal cancer of border significance level was already observed at the consumption of at least one apple a day (odds ratio=0.65, 95% CI: 0.39–1.09), but at the intake of more than one apple a day the risk was reduced by about 50% (odds ratio=0.53, 95% CI: 0.35–0.79). Neither the consumption of vegetables nor other fruits have shown beneficial effects on the risk of colorectal cancer. The observed protective effect of apple consumption on colorectal risk may result from their rich content of flavonoid and other polyphenols, which can inhibit cancer onset and cell proliferation.

Early wheezing phenotypes and severity of respiratory illness in very early childhood: study on intrauterine exposure to fine particle matter.

The main goal of the paper was to assess the pattern of risk factors having an impact on the onset of early wheezing phenotypes in the birth cohort of 468 two-year olds and to investigate the severity of respiratory illness in the two-year olds in relation to both wheezing phenotypes, environmental tobacco smoke (ETS) and personal PM(2.5) exposure over pregnancy period (fine particulate matter). The secondary goal of the paper was to assess possible association of early persistent wheezing with the length of the baby at birth. Pregnant women were recruited from ambulatory prenatal clinics in the first and second trimester of pregnancy. Only women 18-35 years of age, who claimed to be non-smokers, with singleton pregnancies, without illicit drug use and HIV infection, free from chronic diseases were eligible for the study. In the statistical analysis of respiratory health of children multinomial logistic regression and zero-inflated Poisson regression models were used. Approximately one third of the children in the study sample experienced wheezing in the first 2 years of life and in about two third of cases (67%) the symptom developed already in the first year of life. The early wheezing was easily reversible and in about 70% of infants with wheezing the symptom receded in the second year of life. The adjusted relative risk ratio (RRR) of persistent wheezing increased with maternal atopy (RRR=3.05; 95%CI: 1.30-7.15), older siblings (RRR=3.05; 95%CI: 1.67-5.58) and prenatal ETS exposure (RRR=1.13; 95%CI: 1.04-1.23), but was inversely associated with the length of baby at birth (RRR=0.88; 95%CI: 0.76-1.01). The adjusted incidence risk ratios (IRR) of coughing, difficult breathing, runny/stuffy nose and pharyngitis/tonsillitis in wheezers were much higher than that observed among non-wheezers and significantly depended on prenatal PM(2.5) exposure, older siblings and maternal atopy. The study shows a clear inverse association between maternal age or maternal education and respiratory illnesses and calls for more research efforts aiming at the explanation of factors hidden behind proxy measures of quality of maternal care of babies. The data support the hypothesis that burden of respiratory symptoms in early childhood and possibly in later life may be programmed already in prenatal period when the respiratory system is completing its growth and maturation.

COGNITIVE FUNCTION OF 6-YEAR OLD CHILDREN EXPOSED TO MOLD-CONTAMINATED HOMES IN EARLY POSTNATAL PERIOD. PROSPECTIVE BIRTH COHORT STUDY IN POLAND

In the last decade, the neurologic effects of various air pollutants have been the focus of increasing attention. The main purpose of this study was to assess the potential impact of early childhood exposure to indoor molds on the subsequent cognitive function of 6-year old children. The results of this study are based on the six-year follow-up of 277 babies born at term to mothers participating in a prospective cohort study in Krakow, Poland. The study participants are all non-smoking pregnant women who were free of chronic diseases such as diabetes and hypertension. The presence of visible mold patches on indoor walls was monitored at regular time intervals over gestation and after birth up to the age of five. The Wechsler Intelligence Scale for Children (WISC-R) was administered to children at age 6. The exposure effect of living in mold-contaminated homes on the IQ scores of children was adjusted for major confounders, known to be important for the cognitive development of children such as maternal education, the childs gender, breastfeeding practices in infancy, the presence of older siblings and the prenatal exposure to lead and environmental tobacco smoke (ETS). The adjusted IQ deficit attributed to longer exposures to indoor molds (>2 years) was significantly lower on the IQ scale (beta coeff.=-9.16, 95%CI: -15.21, -3.10) and tripled the risk of low IQ scoring (OR=3.53; 95%CI: 1.11-11.27) compared with references. While maternal education (beta coeff.=0.61, 95%CI: 0.05, 1.17) and breastfeeding (beta coeff.=4.0; 95%CI: 0.84, 7.17) showed a significant positive impact on cognitive function, prenatal ETS exposure (beta coeff.=-0.41; 95%CI: -0.79, -0.03) and the presence of older siblings (beta coefficient=-3.43; 95%CI: -5.67, -1.20) were associated with poorer cognitive function in children. In conclusion, the results of this study draw attention to the harmful effect of early postnatal exposure to indoor molds on childrens cognitive development and provide additional evidence on the role of environmental determinants in human cognitive development.

Long term effects of prenatal and postnatal airborne PAH exposures on ventilatory lung function of non-asthmatic preadolescent children. Prospective birth cohort study in Krakow.

The main goal of the study was to test the hypothesis that prenatal and postnatal exposures to polycyclic aromatic hydrocarbons (PAH) are associated with depressed lung function in non-asthmatic children. The study sample comprises 195 non-asthmatic children of non-smoking mothers, among whom the prenatal PAH exposure was assessed by personal air monitoring in pregnancy. At the age of 3, residential air monitoring was carried out to evaluate the residential PAH exposure indoors and outdoors. At the age of 5 to 8, children were given allergic skin tests for indoor allergens; and between 5 and 9 years lung function testing (FVC, FEV05, FEV1 and FEF25-75) was performed. The effects of prenatal PAH exposure on lung function tests repeated over the follow-up were adjusted in the General Estimated Equation (GEE) model for the relevant covariates. No association between FVC with prenatal PAH exposure was found; however for the FEV1 deficit associated with higher prenatal PAH exposure (above 37 ng/m(3)) amounted to 53 mL (p=0.050) and the deficit of FEF25-75 reached 164 mL (p=0.013). The corresponding deficits related to postnatal residential indoor PAH level (above 42 ng/m(3)) were 59 mL of FEV1 (p=0.028) and 140 mL of FEF25-75 (p=0.031). At the higher residential outdoor PAH level (above 90 ng/m(3)) slightly greater deficit of FEV1 (71 mL, p=0.009) was observed. The results of the study suggest that transplacental exposure to PAH compromises the normal developmental process of respiratory airways and that this effect is compounded by postnatal PAH exposure.

Depressed height gain of children associated with intrauterine exposure to polycyclic aromatic hydrocarbons (PAH) and heavy metals: The cohort prospective study

Fetal exposure to environmental toxicants may program the development of children and have long-lasting health impacts. The study tested the hypothesis that depressed height gain in childhood is associated with prenatal exposure to airborne polycyclic aromatic hydrocarbons (PAH) and heavy metals (lead and mercury). The study sample comprised 379 children born to non-smoking mothers among whom a total of 2011 height measurements were carried out over the 9-year follow-up period. Prenatal airborne PAH exposure was assessed by personal air monitoring of the mother in the second trimester of pregnancy and heavy metals were measured in cord blood. At the age of 3 residential air monitoring was done to evaluate the level of airborne PAH, and at the age 5 the levels of heavy metals were measured in capillary blood. The effect estimates of prenatal PAH exposure on height growth over the follow-up were adjusted in the General Estimated Equation (GEE) models for a wide set of relevant covariates. Prenatal exposure to airborne PAH showed a significant negative association with height growth, which was significantly decreased by 1.1cm at PAH level above 34.7 ng/m(3) (coeff.=-1.07, p=0.040). While prenatal lead exposure was not significantly associated with height restriction, the effect of mercury was inversely related to cord blood mercury concentration above 1.2 μg/L (coeff.=-1.21, p=0.020), The observed negative impact of prenatal PAH exposure on height gain in childhood was mainly mediated by shorter birth length related to maternal PAH exposure during pregnancy. The height gain deficit associated with prenatal mercury exposure was not seen at birth, but the height growth was significantly slower at later age.

Early wheeze as reported by mothers and lung function in 4-year-olds. Prospective cohort study in Krakow

The purpose of the study was to check the hypothesis that early wheezing as reported by mothers would be associated with reduced lung function in 4‐year olds. Study participants were recruited prenatally, as part of a prospective cohort study on the respiratory health of young children exposed to various ambient air pollutants. After delivery, infants were followed over 4 years and the interviewers visited participants at their home to record respiratory symptoms every 3 months in the childs first 2 years of life and every 6 months in the 3rd and 4th years. In the 4th year of follow‐up, children were invited for standard lung function testing by spirometry quantified by forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), and forced expiratory volume in 0.5 sec (FEV0.5) levels. Out of 258 children attending spirometry testing 139 performed at least two acceptable exhalation efforts. Cohort children with acceptable spirometric measurements did not differ with respect to wheezing experience and exposure characteristics from those without. The study shows that episodic wheeze was reported in 28.1% of 4‐year olds, 6.5% had transient wheeze, and 4.3% had recurrent wheeze. There was an increased frequency of wheezing symptoms and their duration in transient and recurrent wheezers. Adjusted multivariable regression models for gender and height showed that children who reported more than two episodes of wheezing at any point over the follow‐up had FVC values lower by 120.5 ml (P = 0.016) and FEV1 values lower by 98.3 ml (P = 0.034) compared to those who did not report any wheezing; children experiencing more than 10 wheezing days by age 4 showed FVC deficit of 87.4 ml (P = 0.034) and FEV1 values of 65.7 ml (P = 0.066). The ratios of FEV1/FVC%, and FEV0.5/FVC% were neither associated with wheezing episodes nor wheezing days. In recurrent wheezers, lung function decrement amounted to 207 ml of FVC, 175 ml of FEV1, and 104 ml of FEV0.5. In conclusion, our findings show that wheezing experience during early postnatal life may be associated with lung function deficit of restrictive character in preschool children and detailed history of wheeze in early postnatal life, even though not physician‐confirmed, may help define the high risk group of children for poor lung function testing. Pediatr. Pulmonol. 2010; 45:919–926.

Fractional exhaled nitric oxide in healthy non‐asthmatic 7‐year olds and prenatal exposure to polycyclic aromatic hydrocarbons: Nested regression analysis

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 childrens specific atopy to common domestic allergens.

Occurrence of respiratory symptoms resulting from exposure to house dust mites in early childhood

The aim of the study was to describe the distribution of house dust mite (HDM) allergens within homes of three‐year‐old children, to identify factors responsible for its variation and to test the hypothesis whether the content of HDM allergens exceeding 2 µg/g dust may be regarded as a risk level of sensitization possibly affecting respiratory health in early childhood. House dust samples were collected in 279 dwellings from the mattresses, children’s bedroom and kitchen floors. In the laboratory, dust samples were analyzed for Der f 1 and Der p 1 using monoclonal antibody enzyme‐linked immunosorbent assays. At the time of the house dust collection, interviews with mothers on the household characteristics and child’s respiratory health were performed. Respiratory outcome variables included running or stuffed nose, cough, barking cough, difficult (puffed) breathing and wheezing or whistling in the chest irrespective of respiratory infection. For each of the symptoms the number of the episodes and duration in days over the past six months were recorded in the questionnaire. In the multivariate Poisson regression analysis, a set of potential confounders has been taken into account such as gender of child, season, maternal education, maternal atopy, older siblings and environmental tobacco smoke. The adjusted rate ratio for episodes of running nose among those exposed to higher HDM exposure was 1.09 (95% confidence interval (CI): 0.98–1.20), for episodes of cough 1.11 (95% CI: 0.99–1.24), barking cough 1.44 (95% CI: 0.99–2.09) difficult breathing 1.31 (95% CI: 0.91–1.92) and for wheezing 1.42 (95% CI: 1.00–2.02). In contrast, rate ratios for the duration of all respiratory symptoms were significantly higher in children exposed to higher HDM level. The corresponding rate ratios for duration of symptoms (in days) were 1.10 (95% CI: 1.06–1.14), 1.06 (95% CI: 1.02–1.11), 1.64 (95% CI; 1.42–1.90), 2.05 (95% CI: 1.79–2.35) and 1.40 (95% CI: 1.21–1.62). The children with positive history of maternal atopy showed a higher risk of wheezing than those without the maternal atopy. The rate ratios for number of wheezing episodes in children of mothers without atopy was insignificant 1.11 (95% CI: 0.94–1.30) while in the group with maternal atopy the risk ratio amounted to 1.47 (95% CI: 1.09–1.96); the corresponding rate ratio estimates for the duration of wheezing were 1.12 (95% CI: 1.04–1.20) and 1.46 (95% CI: 1.29–1.66). The data support the view that exposure to higher level of HDM allergens may affect susceptibility of the bronchi to environmental factors and increase the burden of respiratory diseases in early childhood.

Dose-dependent relationship between prenatal exposure to fine particulates and exhaled carbon monoxide in non-asthmatic children. A population-based birth cohort study

ObjectivesThe main goal of the study was to assess possible association between fetal exposure to fine particulate matter (PM2.5) and exhaled carbon monoxide (eCO) measured in non-asthmatic children.Material and MethodsThe subjects include 118 children taking part in an ongoing population-based birth cohort study in Kraków. Personal samplers of PM2.5 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 PM2.5 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.ResultsThe 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 PM2.5 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 PM2.5 and cough severity recorded in the follow-up were related to eCO level. The prenatal PM2.5 exposure represented 5.1%, while children’s cough represented only 2.6% of the eCO variability.ConclusionOur 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.