Predictors of pesticide levels in carpet dust collected from child care centers in Northern California, USA

BACKGROUND

Young children may be exposed to pesticides in child care centers, but little is known about determinants of pesticide contamination in these environments.

OBJECTIVE

Characterize pesticide contamination in early care and education (ECE) centers and identify predictors of pesticide concentrations and loading in dust collected from classroom carpets.

METHODS

Carpet dust samples were collected from 51 licensed child care centers in Northern California and analyzed for 14 structural and agricultural pesticides. Program characteristics were collected through administration of director interviews and observational surveys, including an integrated pest management (IPM) inspection. Pesticide use information for the prior year was obtained from the California Department of Pesticide Regulation to characterize structural applications and nearby agricultural pesticide use.

RESULTS

The most frequently detected pesticides were cis-permethrin (98%), trans-permethrin (98%), bifenthrin (94%), fipronil (94%), and chlorpyrifos (88%). Higher bifenthrin levels were correlated with agricultural applications within 3 kilometers, and higher fipronil levels were correlated with professional pesticide applications in the prior year. In multivariable models, higher IPM Checklist scores were associated with lower loading of chlorpyrifos and permethrin. Placement of the sampled area carpet was also a predictor of chlorpyrifos loading. The strongest predictor of higher pesticide loading for the most frequently detected pesticides was location in California's San Joaquin Valley.

SIGNIFICANCE

Our findings contribute to the growing understanding that pesticides are ubiquitous in children's environments. Pesticide levels in carpet dust were associated with some factors that ECE directors may have control over, such as IPM practices, and others that are beyond their control, such as geographic location. IPM is an important tool that has the potential to reduce pesticide exposures in ECE environments, even for pesticides no longer in use.

IMPACT

One million children in California under six years old attend child care programs where they may spend up to 40 h per week. Children are uniquely vulnerable to environmental contaminants; however early care settings are under researched in environmental health studies. Little is known about predictors of pesticide levels found in environmental samples from child care facilities. This study aims to identify behavioral and environmental determinants of pesticide contamination in California child care centers. Findings can empower child care providers and consumers and inform decision makers to reduce children's exposures to pesticides and promote lifelong health.

Lung function growth trajectories in non-asthmatic children aged 4-9 in relation to prenatal exposure to airborne particulate matter and polycyclic aromatic hydrocarbons - Krakow birth cohort study

BACKGROUND

Patterns of lung function development during childhood can be helpful in understanding the pathogenesis of respiratory diseases. A variety of environmental and lifestyle factors, present from the prenatal period to adulthood, may affect or modulate lung function growth. The aim of this study was to investigate, the associations between individual growth trajectories of children's lung function during childhood and prenatal exposure to airborne fine particulate matter (PM_2.5) and polycyclic aromatic hydrocarbons (PAH), which were hypothesized to adversely affect spirometry parameters.

MATERIAL AND METHODS

The study group comprised 294 non-asthmatic, full term children from the Krakow birth cohort, who underwent annual spirometry testing at the ages of 4-9 years. Individual personal air monitoring of PM_2.5 and PAH were performed over 48 h in the second trimester of pregnancy. Possible confounders or modifiers such as child's gender, height, atopic status and exposure to environmental tobacco smoke (ETS) were considered. Polynomial multilevel mixed models were used to assess the growth rates of children's lung functions.

RESULTS

Lung function trajectories differed significantly for boys and girls for FVC, FEV1 and FEF25-75. Girls had lower rates of increase than boys: - 20.5 (95%CI: - 32.4; - 8.6) ml/year (FVC); - 19.9 (95%CI: -30.7;-9.0) ml/year (FEV1); and - 32.5 (95%CI: - 56.9; - 8.2) ml/year (FEF25-75). Spirometry functions increased with age; however the growth rate decelerated over time. Significant lung function impairment (lower FVC and FEV1 levels) was observed from 4 to 9 years among subjects prenatally exposed to higher levels of PM_2.5 as well as PAH, but not in the case of FEF25-75. No significant differences were observed in the rates of increase over time in relation to prenatal PM_2.5 and PAH exposure.

CONCLUSION

Our results indicate that in non-asthmatic children high prenatal exposure to airborne PM_2.5 and PAH is associated with lower trajectories of FVC and FEV1, but not the rate of increase over time, suggesting that the initial effect is not diminishing in time.

Urinary polycyclic aromatic hydrocarbon metabolites among 3-year-old children from Krakow, Poland

Polycyclic aromatic hydrocarbons (PAHs) are widespread in the environment and can adversely affect human health. The aim of the present study is to describe the level of PAHs exposure in children living in Kraków, one of the most polluted cities in Poland, and to determine the relationship of urinary biomarkers with environmental PAHsexposure. Urinary monohydroxy metabolites (OH-PAHs) of 20 PAHs were assessed in 218 three-year old children, of which only 10 were present in nearly all the samples: monohydroxy metabolites of naphthalene, fluorene, phenantrene and pyrene. Of the metabolites analyzed, hydroxynaphthalenes were predominant and constituted almost 73% of total excreted OH-PAHs, while 1-OH-PYRene was the least abundant (2.3% of total OH-PAHs). All measured urinary OH-PAHs were statistically significantly correlated with each other (R = 0.165-0.880) but the highest correlation coefficients with other individual OH-PAHs and with total OH-PAHs were observed for 2-OH-FLUOR. Children exposed at home to environmental tobacco smoke (ETS) had higher concentrations of fluorene and pyrene urinary metabolites compared to those without ETS exposure; and those exposed to gas-based appliances used for cooking or heating water had higher levels of fluorene and phenanthrene metabolites than children not exposed. The use of coal, wood or oil for heating was associated with elevated levels of 1-OH-PYRene. Urinary PAHs metabolites only modestly reflect high molecular weight carcinogenic PAHs exposures such as those monitored in air in the present study. None of the measured PAHs metabolites was correlated with airborne PM_2.5 and only two were slightly correlated with measured higher molecular mass airborne PAHs. The average concentrations of these specific metabolites in Polish children were much higher than observed in other pediatric populations living in developed countries. Our findings suggest that to capture various sources of PAHs, in addition to 1-OH-PYRene, biomonitoring of PAHs exposure should include 2-OH-NAP and 2-OH-FLUOR.

A novel method for source-specific hemoglobin adducts of nitro-polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAH) are ubiquitous air pollutants associated with negative impacts on growth, development and behavior in children. Source-specific biological markers of PAH exposure are needed for targeting interventions to protect children. Nitro-derivatives of PAH can act as markers of exposure to diesel exhaust, gasoline exhaust, or general combustion sources. Using a novel HPLC-APCI-MS/MS detection method, we examined four hemoglobin (Hb) adducts of nitro-PAH metabolites and the Hb adduct of a benzo[a]pyrene (BaP) metabolite in 22 umbilical cord blood samples. The samples were collected from a birth cohort with comprehensive data on prenatal PAH exposure, including prenatal personal air monitoring and DNA adducts in maternal and umbilical cord blood. Using non-parametric analyses, heat maps, and principal component analysis (PCA), we analyzed the relationship between the five Hb adducts and previous PAH measurements, with each measurement representing a different duration of exposure. We found that Hb adducts derived from several diesel-related nitro-PAHs (2-nitrofluorene and 1-nitropyrene) were significantly correlated (r = 0.77, p ≤ 0.0001) and grouped together in PCA. Nitro-PAH derived Hb adducts were largely unrelated to previously collected measures of exposure to a number of PAH parent compounds. These measures need to be validated in a larger sample.

Prenatal exposure to fine particles and polycyclic aromatic hydrocarbons and birth outcomes: a two-pollutant approach

BACKGROUND

Previous epidemiologic studies have considered the effects of individual air pollutants on birth outcomes, whereas a multiple-pollutant approach is more relevant to public health policy.

OBJECTIVES

The present study compared the observed effect sizes of prenatal fine particulate matter (PM_2.5) and polycyclic aromatic hydrocarbons (PAH) (a component of PM_2.5) exposures on birth outcome deficits, assessed by the single vs. two-pollutant approaches.

METHODS

The study sample included 455 term infants born in Krakow to non-smoking mothers, among whom personal exposures to PM_2.5 and PAH were monitored in the second trimester of pregnancy. The exposure effect estimates (unstandardized and standardized regression coefficients) on birth outcomes were determined using multivariable linear regression models, accounting for relevant covariates.

RESULTS

In the single-pollutant approach, each pollutant was inversely associated with all birth outcomes. The effect size of prenatal PAH exposure on birth weight and length was twice that of PM_2.5, in terms of standardized coefficients. In the two-pollutant approach, the negative effect of PM_2.5 on birth weight and length, adjusted for PAH exposure, lost its significance. The standardized effect of PAH on birth weight was 10-fold stronger (β = -0.20, p = 0.004) than that estimated for PM_2.5 (β = -0.02, p = 0.757).

CONCLUSION

The results provide evidence that PAH had a greater impact on several measures of fetal development, especially birth weight, than PM_2.5. Though in the single-pollutant models PM_2.5 had a significant impact on birth outcomes, this effect appears to be mediated by PAH.

Differences in Ambient Polycyclic Aromatic Hydrocarbon Concentrations between Streets and Alleys in New York City: Open Space vs. Semi-Closed Space

Background: Outdoor ambient polycyclic aromatic hydrocarbon (PAH) concentrations are variable throughout an urban environment. However, little is known about how variation in semivolatile and nonvolatile PAHs related to the built environment (open space vs. semi-closed space) contributes to differences in concentrations. Methods: We simultaneously collected 14, two-week samples of PAHs from the outside of windows facing the front (adjacent to the street) open side of a New York City apartment building and the alley, semi-closed side of the same apartment unit between 2007 and 2012. We also analyzed samples of PAHs measured from 35 homes across Northern Manhattan and the Bronx, 17 from street facing windows with a median floor level of 4 (range 2–26) and 18 from alley-facing windows with a median floor level of 4 (range 1–15). Results: Levels of nonvolatile ambient PAHs were significantly higher when measured from a window adjacent to a street (an open space), compared to a window 30 feet away, adjacent to an alley (a semi-closed space) (street geometric mean (GM) 1.32 ng/m³, arithmetic mean ± standard deviation (AM ± SD) 1.61 ± 1.04 ng/m³; alley GM 1.10 ng/m³, AM ± SD 1.37 ± 0.94 ng/m³). In the neighborhood-wide comparison, nonvolatile PAHs were also significantly higher when measured adjacent to streets compared with adjacent to alley sides of apartment buildings (street GM 1.10 ng/m³, AM ± SD 1.46 ± 1.24 ng/m³; alley GM 0.61 ng/m³, AM ± SD 0.81 ± 0.80 ng/m³), but not semivolatile PAHs. Conclusions: Ambient PAHs, nonvolatile PAHs in particular, are significantly higher when measured from a window adjacent to a street compared to a window adjacent to an alley, despite both locations being relatively close to street traffic. This study highlights small-scale spatial variations in ambient PAH concentrations that may be related to the built environment (open space vs. semi-closed space) from which the samples are measured, as well as the relative distance from street traffic, that could impact accurate personal exposure assessments.

Prenatal exposure to polycyclic aromatic hydrocarbons and cognitive dysfunction in children

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.

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.

Time trends of polycyclic aromatic hydrocarbon exposure in New York City from 2001 to 2012: assessed by repeat air and urine samples

BACKGROUND

Exposure to air pollutants including polycyclic aromatic hydrocarbons (PAH), and specifically pyrene from combustion of fuel oil, coal, traffic and indoor sources, has been associated with adverse respiratory health outcomes. However, time trends of airborne PAH and metabolite levels detected via repeat measures over time have not yet been characterized. We hypothesized that PAH levels, measured repeatedly from residential indoor and outdoor monitors, and children׳s urinary concentrations of PAH metabolites, would decrease following policy interventions to reduce traffic-related air pollution.

METHODS

Indoor PAH (particle- and gas-phase) were collected for two weeks prenatally (n=98), at age 5/6 years (n=397) and age 9/10 years (n=198) since 2001 and at all three age-points (n=27). Other traffic-related air pollutants (black carbon and PM2.5) were monitored indoors simultaneous with PAH monitoring at ages 5/6 (n=403) and 9/10 (n=257) between 2005 and 2012. One third of the homes were selected across seasons for outdoor PAH, BC and PM2.5 sampling. Using the same sampling method, ambient PAH, BC and PM2.5 also were monitored every two weeks at a central site between 2007 and 2012. PAH were analyzed as semivolatile PAH (e.g., pyrene; MW 178-206) (∑8PAH(semivolatile): Including pyrene (PYR), phenanthrene (PHEN), 1-methylphenanthrene (1-MEPH), 2-methylphenanthrene (2-MEPH), 3-methylphenanthrene (3-MEPH), 9-methylphenanthrene (9-MEPH), 1,7-dimethylphenanthrene (1,7-DMEPH), and 3,6-dimethylphenanthrene (3,6-DMEPH)) and the sum of eight nonvolatile PAH (∑8PAH(nonvolatile): Including benzo[a]anthracene (BaA), chrysene/iso-chrysene (Chry), benzo[b]fluoranthene (BbFA), benzo[k]fluoranthene (BkFA), benzo[a]pyrene (BaP), indeno[1,2,3-c,d]pyrene (IP), dibenzo[a,h]anthracene (DahA), and benzo[g,h,i]perylene (BghiP); MW 228-278). A spot urine sample was collected from children at child ages 3, 5, 7 and 9 between 2001 and 2012 and analyzed for 10 PAH metabolites.

RESULTS

Modest declines were detected in indoor BC and PM2.5 levels between 2005 and 2012 (Annual percent change [APC]=-2.08% [p=0.010] and -2.18% [p=0.059] for BC and PM2.5, respectively), while a trend of increasing pyrene levels was observed in indoor and outdoor samples, and at the central site during the comparable time periods (APC=4.81%, 3.77% and 7.90%, respectively; p<0.05 for all). No significant time trend was observed in indoor ∑8PAH(nonvolatile) levels between 2005 and 2012; however, significant opposite trends were detected when analyzed seasonally (APC=-8.06% [p<0.01], 3.87% [p<0.05] for nonheating and heating season, respectively). Similarly, heating season also affected the annual trends (2005-2012) of other air pollutants: the decreasing BC trend (in indoor/outdoor air) was observed only in the nonheating season, consistent with dominating traffic sources that decreased with time; the increasing pyrene trend was more apparent in the heating season. Outdoor PM2.5 levels persistently decreased over time across the seasons. With the analyses of data collected over a longer period of time (2001-2012), a decreasing trend was observed in pyrene (APC=-2.76%; p<0.01), mostly driven by measures from the nonheating season (APC=-3.54%; p<0.01). In contrast, levels of pyrene and naphthalene metabolites, 1-hydroxypyrene and 2-naphthol, increased from 2001 to 2012 (APC=6.29% and 7.90% for 1-hydroxypyrene and 2-naphthol, respectively; p<0.01 for both).

CONCLUSIONS

Multiple NYC legislative regulations targeting traffic-related air pollution may have led to decreases in ∑8PAH(nonvolatile) and BC, especially in the nonheating season. Despite the overall decrease in pyrene over the 2001-2012 periods, a rise in pyrene levels in recent years (2005-2012), that was particularly evident for measures collected during the heating season, and 2-naphthol, indicates the contribution of heating oil combustion and other indoor sources to airborne pyrene and urinary 2-naphthol.

Polycyclic aromatic hydrocarbon exposure, obesity and childhood asthma in an urban cohort

BACKGROUND

Exposure to traffic-related air pollutants, including polycyclic aromatic hydrocarbons (PAHs) from traffic emissions and other combustion sources, and childhood obesity, have been implicated as risk factors for developing asthma. However, the interaction between these two on asthma among young urban children has not been studied previously.

METHODS

Exposure to early childhood PAHs was measured by two week residential indoor monitoring at age 5-6 years in the Columbia Center for Children's Environmental Health birth cohort (n=311). Semivolatile [e.g., methylphenanthrenes] and nonvolatile [e.g., benzo(a)pyrene] PAHs were monitored. Obesity at age 5 was defined as a body mass index (BMI) greater than or equal to the 95th percentile of the year 2000 age- and sex-specific growth charts (Center for Disease Control). Current asthma and recent wheeze at ages 5 and 7 were determined by validated questionnaires. Data were analyzed using a modified Poisson regression in generalized estimating equations (GEE) to estimate relative risks (RR), after adjusting for potential covariates.

RESULTS

Neither PAH concentrations or obesity had a main effect on asthma or recent wheeze. In models stratified by presence/absence of obesity, a significant positive association was observed between an interquartile range (IQR) increase in natural log-transformed 1-methylphenanthrene (RR [95% CI]: 2.62 [1.17-5.88] with IQRln=0.76), and 9-methylphenanthrene (2.92 [1.09-7.82] with IQRln=0.73) concentrations and asthma in obese children (n=63). No association in non-obese (n=248) children was observed at age 5 (Pinteraction<0.03). Similar associations were observed for 3-methylphenanthrene, 9-methylphenanthrene, and 3,6-dimethylphenanthrene at age 7.

CONCLUSIONS

Obese young children may be more likely to develop asthma in association with greater exposure to PAHs, and methylphenanthrenes in particular, than non-obese children.

Prenatal exposure to air pollution, maternal psychological distress, and child behavior

BACKGROUND

Airborne polycyclic aromatic hydrocarbons (PAHs) are pollutants generated by combustion of fossil fuel and other organic material. Both prenatal PAH exposure and maternal psychological distress during pregnancy have each been associated with neurodevelopmental problems in children. The goal was to evaluate potential interactions between prenatal exposure to airborne PAHs and maternal psychological distress during pregnancy on subsequent behavioral problems in children.

METHODS

In a longitudinal birth cohort study, 248 children of nonsmoking white women in the coal-burning region of Krakow, Poland, were followed from in utero until age 9. Prenatal PAH exposure was measured by personal air monitoring during pregnancy, maternal demoralization during pregnancy by the Psychiatric Epidemiology Research Instrument-Demoralization, and child behavior by the Child Behavior Checklist.

RESULTS

Significant interactions between maternal demoralization and PAH exposure (high versus low) were identified for symptoms of anxious/depressed, withdrawn/depressed, social problems, aggressive behavior, internalizing problems, and externalizing problems. The effects of demoralization on syndromes of anxious/depressed, withdrawn/depressed, rule-breaking, aggressive behavior, and the composite internalizing and externalizing scores were seen only in conjunction with high PAH exposure. Fewer significant effects with weaker effect sizes were observed in the low-PAH-exposure group.

CONCLUSIONS

Maternal demoralization during pregnancy appears to have a greater effect on child neurobehavioral development among children who experienced high prenatal PAH exposure. The results provide the first evidence of an interaction between prenatal exposure to maternal demoralization and air pollution on child neurobehavioral development, indicating the need for a multifaceted approach to the prevention of developmental problems in children.

The relationship between prenatal exposure to airborne polycyclic aromatic hydrocarbons (PAHs) and PAH-DNA adducts in cord blood

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, P<0.001), the relationship between B[a]P and maternal blood adducts was insignificant (z=1.63, P=0.103). Based on the multivariable linear regression model, we estimated the effect of the prenatal airborne B[a]P on the level of cord blood adducts. In total, 14.8% of cord blood adducts variance was attributed to the level of maternal adducts and 3% to a higher prenatal B[a] exposure above 5.70 ng/m(3). 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/m(3). 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.

Repeated exposure to polycyclic aromatic hydrocarbons and asthma: effect of seroatopy

BACKGROUND

Exposure to traffic-related air pollutants, including polycyclic aromatic hydrocarbons (PAHs), can induce asthma. However, the effects of early repeated PAH exposure over time on different asthma phenotypes have not been examined.

OBJECTIVE

To assess associations between repeated PAH exposure, measured from prenatal personal and residential indoor monitors in children's homes, and asthma in an inner-city cohort.

METHODS

Prenatal exposure was assessed by personal air monitoring during 48 hours and exposure at 5 to 6 years of age by 2-week residential monitoring in the Columbia Center for Children's Environmental Health cohort. PAH was dichotomized into pyrene (representative semivolatile PAH) and the sum of 8 nonvolatile PAHs. High exposure to each was defined as measures above the median at both repeated time points. Asthma and wheeze were determined by validated questionnaires at ages 5 to 6 years. Children with specific IgE levels greater than 0.35 IU/mL to any of 5 indoor allergens were considered seroatopic.

RESULTS

Among all 354 children, repeated high exposure to pyrene was associated with asthma (odds ratio [OR], 1.90; 95% confidence interval [CI], 1.13-3.20). Among 242 nonatopic children, but not those sensitized to indoor allergens (n = 87) or with elevated total IgE levels (n = 171), high pyrene levels were associated positively with asthma (OR, 2.89; 95% CI, 1.77-5.69), asthma medication use (OR, 2.28; 95% CI, 1.13-4.59), and emergency department visits for asthma (OR, 2.43; 95% CI, 1.20-4.91). Associations between the levels of the 8 nonvolatile PAHs and asthma were not observed, even when stratifying by seroatopy.

CONCLUSION

Nonatopic children may be more susceptible to the respiratory consequences of early pyrene exposures.

Association of childhood obesity with maternal exposure to ambient air polycyclic aromatic hydrocarbons during pregnancy

There are concerns that prenatal exposure to endocrine-disrupting chemicals increases children's risk of obesity. African-American and Hispanic children born in the Bronx or Northern Manhattan, New York (1998-2006), whose mothers underwent personal air monitoring for polycyclic aromatic hydrocarbon (PAH) exposure during pregnancy, were followed up to ages 5 (n = 422) and 7 (n = 341) years. At age 5 years, 21% of the children were obese, as were 25% of those followed to age 7 years. After adjustment for child's sex, age at measurement, ethnicity, and birth weight and maternal receipt of public assistance and prepregnancy obesity, higher prenatal PAH exposures were significantly associated with higher childhood body size. In adjusted analyses, compared with children of mothers in the lowest tertile of PAH exposure, children of mothers in the highest exposure tertile had a 0.39-unit higher body mass index z score (95% confidence interval (CI): 0.08, 0.70) and a relative risk of 1.79 (95% CI: 1.09, 2.96) for obesity at age 5 years, and they had a 0.30-unit higher body mass index z score (95% CI: 0.01, 0.59), a 1.93-unit higher percentage of body fat (95% CI: 0.33, 3.54), and a relative risk of 2.26 (95% CI: 1.28, 4.00) for obesity at age 7 years. The data indicate that prenatal exposure to PAHs is associated with obesity in childhood.

Prenatal polycyclic aromatic hydrocarbon (PAH) exposure and child behavior at age 6-7 years

BACKGROUND

Airborne polycyclic aromatic hydrocarbons (PAH) are widespread urban air pollutants from fossil fuel burning and other combustion sources. We previously reported that a broad spectrum of combustion-related DNA adducts in cord blood was associated with attention problems at 6-7 years of age in the Columbia Center for Children's Environmental Health (CCCEH) longitudinal cohort study.

OBJECTIVES

We evaluated the relationship between behavioral problems and two different measures of prenatal exposure--both specific to PAH--in the same cohort.

METHODS

Children of nonsmoking African-American and Dominican women in New York City (NYC) were followed from in utero to 6-7 years. Prenatal PAH exposure was estimated by personal air monitoring of the mothers during pregnancy as well as by the measurement of DNA adducts specific to benzo[a]pyrene (BaP), a representative PAH, in maternal and cord blood. At 6-7 years of age, child behavior was assessed using the Child Behavior Checklist (CBCL) (n = 253). Generalized linear models were used to test the association between prenatal PAH exposure and behavioral outcomes.

RESULTS

In multivariate analyses, high prenatal PAH exposure, whether characterized by personal air monitoring (greater than the median of 2.27 ng/m³) or maternal and cord adducts (detectable or higher), was positively associated with symptoms of Anxious/Depressed and Attention Problems (p ≤ 0.05).

CONCLUSION

These results provide additional evidence that environmental levels of PAH encountered in NYC air can adversely affect child behavior.

Prenatal exposure to polycyclic aromatic hydrocarbons, benzo[a]pyrene-DNA adducts, and genomic DNA methylation in cord blood

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic environmental pollutants generated during incomplete combustion. After exposure and during metabolism, PAHs can form reactive epoxides that can covalently bind to DNA. These PAH-DNA adducts are established markers of cancer risk. PAH exposure has been associated with epigenetic alterations, including genomic cytosine methylation. Both global hypomethylation and hypermethylation of specific genes have been associated with cancer and other diseases in humans. Experimental evidence suggests that PAH-DNA adduct formation may preferentially target methylated genomic regions. Early embryonic development may be a particularly susceptible period for PAH exposure, resulting in both increased PAH-DNA adducts and altered DNA methylation.

OBJECTIVE

We explored whether prenatal exposure to PAHs is associated with genomic DNA methylation in cord blood and whether methylation levels are associated with the presence of detectable PAH-DNA adducts.

METHODS

In a longitudinal cohort study of nonsmoking women in New York City, we measured PAH exposure during pregnancy using personal air monitors, assessed PAH internal dose using prenatal urinary metabolites (in a subset), and quantified benzo[a]pyrene-DNA adducts and genomic DNA methylation in cord blood DNA among 164 participants.

RESULTS

Prenatal PAH exposure was associated with lower global methylation in umbilical cord white blood cells (p = 0.05), but global methylation levels were positively associated with the presence of detectable adducts in cord blood (p = 0.01).

CONCLUSIONS

These observations suggest that PAH exposure was adequate to alter global methylation in our study population. Additional epidemiologic studies that can measure site-specific cytosine methylation and adduct formation will improve our ability to understand this complex molecular pathway in vivo.

Effects of Floor Level and Building Type on Residential Levels of Outdoor and Indoor Polycyclic Aromatic Hydrocarbons, Black Carbon, and Particulate Matter in New York City

Consideration of the relationship between residential floor level and concentration of traffic-related airborne pollutants may predict individual residential exposure among inner city dwellers more accurately. Our objective was to characterize the vertical gradient of residential levels of polycyclic aromatic hydrocarbons (PAH; dichotomized into Σ(8)PAH(semivolatile) (MW 178-206), and Σ(8)PAH(nonvolatile) (MW 228-278), black carbon (BC), PM(2.5) (particulate matter) by floor level (FL), season and building type. We hypothesize that PAH, BC and PM(2.5) concentrations may decrease with higher FL and the vertical gradients of these compounds would be affected by heating season and building type. PAH, BC and PM(2.5) were measured over a two-week period outdoor and indoor of the residences of a cohort of 5-6 year old children (n = 339) living in New York City's Northern Manhattan and the Bronx. Airborne-pollutant levels were analyzed by three categorized FL groups (0-2nd, 3rd-5th, and 6th-32nd FL) and two building types (low-rise versus high-rise apartment building). Indoor Σ(8)PAH(nonvolatile) and BC levels declined with increasing FL. During the nonheating season, the median outdoor Σ(8)PAH(nonvolatile,) but not Σ(8)PAH(semivolatile), level at 6th-2nd FL was 1.5-2 times lower than levels measured at lower FL. Similarly, outdoor and indoor BC concentrations at 6th-32nd FL were significantly lower than those at lower FL only during the nonheating season (p < 0.05). In addition, living in a low-rise building was associated significantly with higher levels of Σ(8)PAH(nonvolatile) and BC. These results suggest that young inner city children may be exposed to varying levels of air pollutants depending on their FL, season, and building type.

Effects of Heating Season on Residential Indoor and Outdoor Polycyclic Aromatic Hydrocarbons, Black Carbon, and Particulate Matter in an Urban Birth Cohort

Exposure to air pollutants has been associated with adverse health effects. However, analyses of the effects of season and ambient parameters such as ozone have not been fully conducted. Residential indoor and outdoor air levels of polycyclic aromatic hydrocarbons (PAH), black carbon (measured as absorption coefficient [Abs]), and fine particulate matter <2.5 μm (PM)(2.5) were measured over two-weeks in a cohort of 5-6 year old children (n=334) living in New York City's Northern Manhattan and the Bronx between October 2005 and April 2010. The objectives were to: 1) characterize seasonal changes in indoor and outdoor levels and indoor/outdoor (I/O) ratios of PAH (gas + particulate phase; dichotomized into Σ(8)PAH(semivolatile) (MW 178-206), and Σ(8)PAH(nonvolatile) (MW 228-278)), Abs, and PM(2.5); and 2) assess the relationship between PAH and ozone. Results showed that heating compared to nonheating season was associated with greater Σ(8)PAH(nonvolatile) (p<0.001) and Abs (p<0.05), and lower levels of Σ(8)PAH(semivolatile) (p<0.001). In addition, the heating season was associated with lower I/O ratios of Σ(8)PAH(nonvolatile) and higher I/O ratios of Σ(8)PAH(semivolatile) (p<0.001) compared to the nonheating season. In outdoor air, Σ(8)PAH(nonvolatile) was correlated negatively with community-wide ozone concentration (p<0.001). Seasonal changes in emission sources, air exchanges, meteorological conditions and photochemical/chemical degradation reactions are discussed in relationship to the observed seasonal trends.

Prenatal exposure to airborne polycyclic aromatic hydrocarbons and children's intelligence at 5 years of age in a prospective cohort study in Poland

BACKGROUND

In this prospective cohort study of Caucasian mothers and children in Krakow, Poland, we evaluated the role of prenatal exposure to urban air pollutants in the pathogenesis of neurobehavioral disorders.

OBJECTIVES

The objective of this study was to investigate the relationship between prenatal polycyclic aromatic hydrocarbon (PAH) exposure and child intelligence at 5 years of age, controlling for potential confounders suspected to play a role in neurodevelopment.

METHODS

A cohort of pregnant, healthy, nonsmoking women was enrolled in Krakow, Poland, between 2001 and 2006. During pregnancy, participants were invited to complete a questionnaire and undergo 48-hr personal air monitoring to estimate their babies' exposure, and to provide a blood sample and/or a cord blood sample at the time of delivery. Two hundred fourteen children were followed through 5 years of age, when their nonverbal reasoning ability was assessed using the Raven Coloured Progressive Matrices (RCPM).

RESULTS

We found that higher (above the median of 17.96 ng/m3) prenatal exposure to airborne PAHs (range, 1.8-272.2 ng/m3) was associated with decreased RCPM scores at 5 years of age, after adjusting for potential confounding variables (n = 214). Further adjusting for maternal intelligence, lead, or dietary PAHs did not alter this association. The reduction in RCPM score associated with high airborne PAH exposure corresponded to an estimated average decrease of 3.8 IQ points.

CONCLUSIONS

These results suggest that prenatal exposure to airborne PAHs adversely affects children's cognitive development by 5 years of age, with potential implications for school performance. They are consistent with a recent finding in a parallel cohort in New York City.

Assessment of benzo(a)pyrene-equivalent carcinogenicity and mutagenicity of residential indoor versus outdoor polycyclic aromatic hydrocarbons exposing young children in New York City

The application of benzo(a)pyrene (BaP)-toxic equivalent factor to polycyclic aromatic hydrocarbons (PAH) concentrations can provide a more accurate risk assessment from environmental exposure to PAH. We hypothesized that BaP-equivalent toxicity determined following residential air monitoring among young urban children may vary by season. Residential indoor and outdoor air levels of PAH measured over two-weeks in a cohort of 5-6 year old children (n = 260) in New York City were normalized to the cancer and mutagen potency equivalent factor of BaP (BaP = 1). Data are presented as carcinogenic equivalents (BaP-TEQ) and mutagenic equivalents (BaP-MEQ) for the sum of 8 PAH (Sigma(8)PAH; MW >or= 228) and individual PAH and compared across heating versus nonheating seasons. Results show that heating compared to nonheating season was associated significantly with higher (BaP-TEQ)(Sigma8PAH) and (BaP-MEQ)(Sigma8PAH) both indoors and outdoors (p < 0.001). Outdoor (BaP-TEQ)(Sigma8)(PAH) and (BaP-MEQ)(Sigma8PAH) were significantly higher than the corresponding indoor measures during the heating season (p < 0.01). These findings suggest that at levels encountered in New York City air, especially during the heating season, residential exposure to PAH may pose an increased risk of cancer and mutation.

Modulation of the effect of prenatal PAH exposure on PAH-DNA adducts in cord blood by plasma antioxidants

The fetus is more susceptible than the adult to the effects of certain carcinogens, such as polycyclic aromatic hydrocarbons (PAH). Nutritional factors, including antioxidants, have been shown to have a protective effect on carcinogen-DNA adducts and cancer risk in adults. We investigated whether the effect of prenatal airborne PAH exposure, measured by personal air monitoring during pregnancy, on the level of PAH-DNA adducts in a baby's cord blood is modified by the concentration of micronutrients in maternal and cord blood. The micronutrients examined were: retinol (vitamin A), alpha-tocopherol and gamma-tocopherol (vitamin E), and carotenoids. With the use of multiple linear regression, we found a significant interaction between prenatal PAH exposure and cord blood concentration of alpha-tocopherol and carotenoids in predicting the concentration of PAH adducts in cord blood. The association between PAH exposure and PAH adducts was much stronger among those with low alpha-tocopherol (beta = 0.15; P = 0.001) and among those with low carotenoids (beta = 0.16; P < 0.001) compared with babies with high levels of these micronutrients (among those with high alpha-tocopherol: beta = 0.05; P = 0.165; among those with high carotenoids: beta = 0.06; P = 0.111). These results suggest a protective effect of micronutrients on the DNA damage and potential cancer risk associated with prenatal PAH exposure.

Prenatal airborne polycyclic aromatic hydrocarbon exposure and child IQ at age 5 years

OBJECTIVE

This study evaluated the relationship between prenatal exposure to airborne polycyclic aromatic hydrocarbons (PAHs) and child intelligence.

METHODS

Children of nonsmoking black or Dominican-American women residing in New York City were monitored from in utero to 5 years of age, with determination of prenatal PAH exposure through personal air monitoring for the mothers during pregnancy. At 5 years of age, intelligence was assessed for 249 children by using the Wechsler Preschool and Primary Scale of Intelligence-Revised. Multivariate linear regression models were used to estimate and to test the associations between prenatal PAH exposure and IQ.

RESULTS

After adjustment for maternal intelligence, quality of the home caretaking environment, environmental tobacco smoke exposure, and other potentially confounding factors, high PAH levels (above the median of 2.26 ng/m(3)) were inversely associated with full-scale IQ (P = .007) and verbal IQ (P = .003) scores. Children in the high-exposure group had full-scale and verbal IQ scores that were 4.31 and 4.67 points lower, respectively, than those of less-exposed children (<or=2.26 ng/m(3)). The associations between logarithmically transformed, continuous, PAH levels and these IQ measures also were significant (full-scale IQ: beta = -3.00; P = .009; verbal IQ: beta = -3.53; P = .002).

CONCLUSION

These results provide evidence that environmental PAHs at levels encountered in New York City air can affect children's IQ adversely.

Prenatal airborne polycyclic aromatic hydrocarbon exposure and child IQ at age 5 years

OBJECTIVE

This study evaluated the relationship between prenatal exposure to airborne polycyclic aromatic hydrocarbons (PAHs) and child intelligence.

METHODS

Children of nonsmoking black or Dominican-American women residing in New York City were monitored from in utero to 5 years of age, with determination of prenatal PAH exposure through personal air monitoring for the mothers during pregnancy. At 5 years of age, intelligence was assessed for 249 children by using the Wechsler Preschool and Primary Scale of Intelligence-Revised. Multivariate linear regression models were used to estimate and to test the associations between prenatal PAH exposure and IQ.

RESULTS

After adjustment for maternal intelligence, quality of the home caretaking environment, environmental tobacco smoke exposure, and other potentially confounding factors, high PAH levels (above the median of 2.26 ng/m(3)) were inversely associated with full-scale IQ (P = .007) and verbal IQ (P = .003) scores. Children in the high-exposure group had full-scale and verbal IQ scores that were 4.31 and 4.67 points lower, respectively, than those of less-exposed children (<or=2.26 ng/m(3)). The associations between logarithmically transformed, continuous, PAH levels and these IQ measures also were significant (full-scale IQ: beta = -3.00; P = .009; verbal IQ: beta = -3.53; P = .002).

CONCLUSION

These results provide evidence that environmental PAHs at levels encountered in New York City air can affect children's IQ adversely.

Polybrominated diphenyl ether (PBDE) concentrations in house dust are related to hormone levels in men

Despite documented widespread human exposure to polybrominated diphenyl ethers (PBDEs) through dietary intake and contact with or inhalation of indoor dust, along with growing laboratory evidence for altered endocrine function following exposure, human studies of PBDE exposure and endocrine effects remain limited. We conducted a preliminary study within an ongoing study on the impact of environmental exposures on male reproductive health. We measured serum hormone levels and PBDE concentrations (BDE 47, 99 and 100) in house dust from 24 men recruited through a US infertility clinic. BDE 47 and 99 were detected in 100% of dust samples, and BDE 100 was detected in 67% of dust samples, at concentrations similar to those reported in previous US studies. In multivariable regression models adjusted for age and BMI, there was a statistically significant inverse relationship between dust PBDE concentrations and free androgen index. Dust PBDE concentrations were also strongly and inversely associated with luteinizing hormone (LH) and follicle stimulating hormone (FSH), and positively associated with inhibin B and sex hormone binding globulin (SHBG). Finally, consistent with limited recent human studies of adults, PBDEs were positively associated with free T4. In conclusion, the present study provides compelling evidence of altered hormone levels in relation to PBDE exposures estimated as concentrations in house dust, and that house dust is an important source of human PBDE exposure, but more research is urgently needed.

Estimating individual-level exposure to airborne polycyclic aromatic hydrocarbons throughout the gestational period based on personal, indoor, and outdoor monitoring

OBJECTIVES

Current understanding on health effects of long-term polycyclic aromatic hydrocarbon (PAH) exposure is limited by lack of data on time-varying nature of the pollutants at an individual level. In a cohort of pregnant women in Krakow, Poland, we examined the contribution of temporal, spatial, and behavioral factors to prenatal exposure to airborne PAHs within each trimester and developed a predictive model of PAH exposure over the entire gestational period.

METHODS

We monitored nonsmoking pregnant women (n = 341) for their personal exposure to pyrene and eight carcinogenic PAHs-benz[a]anthracene, chrysene/isochrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene [B(a)P], indeno[1,2,3-c,d]pyrene, dibenz[a,h]anthracene, and benzo[g,h,i]perylene-during their second trimester for a consecutive 48-hr period. In a subset (n = 78), we monitored indoor and outdoor levels simultaneously with the personal monitoring during the second trimester with an identical monitor. The subset of women was also monitored for personal exposure for a 48-hr period during each trimester. We repeatedly administered a questionnaire on health history, lifestyle, and home environment.

RESULTS

The observed personal, indoor, and outdoor B(a)P levels we observed in Krakow far exceed the recommended Swedish guideline value for B(a)P of 0.1 ng/m(3). Based on simultaneously monitored levels, the outdoor PAH level alone accounts for 93% of total variability in personal exposure during the heating season. Living near the Krakow bus depot, a crossroad, and the city center and time spent outdoors or commuting were not associated with higher personal exposure. During the nonheating season only, a 1-hr increase in environmental tobacco smoke (ETS) exposure was associated with a 10-16% increase in personal exposure to the nine measured PAHs. A 1 degrees C decrease in ambient temperature was associated with a 3-5% increase in exposure to benz[a]anthracene, benzo[k]fluoranthene, and dibenz[a,h]anthracene, after accounting for the outdoor concentration. A random effects model demonstrated that mean personal exposure at a given gestational period depends on the season, residence location, and ETS.

CONCLUSION

Considering that most women reported spending < 3 hr/day outdoors, most women in the study were exposed to outdoor-originating PAHs within the indoor setting. Cross-sectional, longitudinal monitoring supplemented with questionnaire data allowed development of a gestation-length model of individual-level exposure with high precision and validity. These results are generalizable to other nonsmoking pregnant women in similar exposure settings and support reduction of exposure to protect the developing fetus.

Characterization of phthalate exposure among pregnant women assessed by repeat air and urine samples

BACKGROUND

Although urinary concentrations of phthalate metabolites are frequently used as biomarkers in epidemiologic studies, variability during pregnancy has not been characterized.

METHODS

We measured phthalate metabolite concentrations in spot urine samples collected from 246 pregnant Dominican and African-American women. Twenty-eight women had repeat urine samples collected over a 6-week period. We also analyzed 48-hr personal air samples (n = 96 women) and repeated indoor air samples (n = 32 homes) for five phthalate diesters. Mixed-effects models were fit to evaluate reproducibility via intraclass correlation coefficients (ICC). We evaluated the sensitivity and specificity of using a single specimen versus repeat samples to classify a woman's exposure in the low or high category.

RESULTS

Phthalates were detected in 85-100% of air and urine samples. ICCs for the unadjusted urinary metabolite concentrations ranged from 0.30 for mono-ethyl phthalate to 0.66 for monobenzyl phthalate. For indoor air, ICCs ranged from 0.48 [di-2-ethylhexyl phthalate (DEHP)] to 0.83 [butylbenzyl phthalate (BBzP)]. Air levels of phthalate diesters correlated with their respective urinary metabolite concentrations for BBzP (r = 0.71), di-isobutyl phthalate (r = 0.44), and diethyl phthalate (DEP; r = 0.39). In women sampled late in pregnancy, specific gravity appeared to be more effective than creatinine in adjusting for urine dilution.

CONCLUSIONS

Urinary concentrations of DEP and DEHP metabolites in pregnant women showed lower reproducibility than metabolites for di-n-butyl phthalate and BBzP. A single indoor air sample may be sufficient to characterize phthalate exposure in the home, whereas urinary phthalate biomarkers should be sampled longitudinally during pregnancy to minimize exposure misclassification.

Relation between prenatal lipid-soluble micronutrient status, environmental pollutant exposure, and birth outcomes

BACKGROUND

Adverse postnatal health effects have been associated with compromised fetal growth, which makes it essential to understand its determinants. Significant effects of environmental pollutants on birth outcomes have been observed in our study population, and nutritional status may be an additional factor influencing fetal development and effects of environmental toxins.

OBJECTIVE

The objective of the study was to examine the relations between birth outcomes and lipid-soluble plasma micronutrient concentrations and to explore interactions between micronutrients and environmental pollutant exposure in newborns in Krakow, Poland.

DESIGN

In this prospective cohort study, retinol, alpha-tocopherol, and carotenoids were measured in maternal and cord blood samples obtained at delivery (251 maternal-newborn pairs), and birth weight, birth length, head circumference (HC), and gestational age were evaluated. Linear regression analysis was used to estimate the effects of micronutrients while covariates were controlled for. Interaction terms assessed whether the effects of polycyclic aromatic hydrocarbons (PAHs), common environmental pollutants, varied by nutrient status.

RESULTS

Infants whose mothers had low plasma alpha-tocopherol concentrations (below the median) weighed 92.9 g less and had 0.41-cm smaller HCs than did infants whose mothers had high alpha-tocopherol concentrations. Infants with low plasma retinol (below the median) weighed 125.9 g less and had 0.31-cm smaller HCs. There was no evidence of an interaction between PAHs and micronutrients, although power was limited.

CONCLUSION

Maternal alpha-tocopherol and cord retinol concentrations were significantly and positively associated with BW and HC. These micronutrients may have direct effects or may be markers for other underlying determinants of these pregnancy outcomes.

Effect of prenatal exposure to airborne polycyclic aromatic hydrocarbons on neurodevelopment in the first 3 years of life among inner-city children

Our prospective cohort study of nonsmoking African-American and Dominican mothers and children in New York City is evaluating the role of prenatal exposure to urban pollutants, including polycyclic aromatic hydrocarbons (PAHs) , environmental tobacco smoke (ETS) , and pesticides, in the pathogenesis of neurobehavioral disorders. We used the Bayley Scales of Infant Development to evaluate the effects on child mental and psychomotor development of prenatal exposure to airborne PAHs monitored during pregnancy by personal air sampling. Behavioral development was assessed by the Child Behavior Checklist. We adjusted for potential confounders including sociodemographic factors and prenatal exposure to ETS and chlorpyrifos. Prenatal exposure to PAHs was not associated with psychomotor development index or behavioral problems. However, high prenatal exposure to PAHs (upper quartile) was associated with lower mental development index at age 3 [beta=-5.69; 95% confidence interval (CI), -9.05 to -2.33; p<0.01]. The odds of cognitive developmental delay were also significantly greater for children with high prenatal exposure (odds ratio=2.89; 95% CI, 1.33 to 6.25; p=0.01). General estimated equation analysis showed a significant age times PAH effect on mental development (p=0.01), confirming the age-specific regression findings. Further adjustment for lead did not alter the relationships. There were no differences in effect sizes by ethnicity. The results require confirmation but suggest that environmental PAHs at levels recently encountered in New York City air may adversely affect children's cognitive development at 3 years of age, with implications for school performance.

Validation and calibration of a model used to reconstruct historical exposure to polycyclic aromatic hydrocarbons for use in epidemiologic studies

OBJECTIVES

We previously developed a historical reconstruction model to estimate exposure to airborne polycyclic aromatic hydrocarbons (PAHs) from traffic back to 1960 for use in case-control studies of breast cancer risk. Here we report the results of four exercises to validate and calibrate the model.

METHODS

Model predictions of benzo[a]pyrene (BaP) concentration in soil and carpet dust were tested against measurements collected at subjects' homes at interview. In addition, predictions of air intake of BaP were compared with blood PAH-DNA adducts. These same soil, carpet, and blood measurements were used for model optimization. In a separate test of the meteorological dispersion part of the model, predictions of hourly concentrations of carbon monoxide from traffic were compared with data collected at a U.S. Environmental Protection Agency monitoring station.

RESULTS

The data for soil, PAH-DNA adducts, and carbon monoxide concentrations were all consistent with model predictions. The carpet dust data were inconsistent, suggesting possible spatial confounding with PAH-containing contamination tracked in from outdoors or unmodeled cooking sources. BaP was found proportional to other PAHs in our soil and dust data, making it reasonable to use BaP historical data as a surrogate for other PAHs. Road intersections contributed 40-80% of both total emissions and average exposures, suggesting that the repertoire of simple markers of exposure, such as traffic counts and/or distance to nearest road, needs to be expanded to include distance to nearest intersection.

Proximity to crops and residential exposure to agricultural herbicides in iowa

Rural residents can be exposed to agricultural pesticides through the proximity of their homes to crop fields. Previously, we developed a method to create historical crop maps using a geographic information system. The aim of the present study was to determine whether crop maps are useful for predicting levels of crop herbicides in carpet dust samples from residences. From homes of participants in a case-control study of non-Hodgkin lymphoma in Iowa (1998-2000), we collected vacuum cleaner dust and measured 14 herbicides with high use on corn and soybeans in Iowa. Of 112 homes, 58% of residences had crops within 500 m of their home, an intermediate distance for primary drift from aerial and ground applications. Detection rates for herbicides ranged from 0% for metribuzin and cyanazine to 95% for 2,4-dichlorophenoxyacetic acid. Six herbicides used almost exclusively in agriculture were detected in 28% of homes. Detections and concentrations were highest in homes with an active farmer. Increasing acreage of corn and soybean fields within 750 m of homes was associated with significantly elevated odds of detecting agricultural herbicides compared with homes with no crops within 750 m (adjusted odds ratio per 10 acres = 1.06; 95% confidence interval, 1.02-1.11). Herbicide concentrations also increased significantly with increasing acreage within 750 m. We evaluated the distance of crop fields from the home at < 100, 101-250, 251-500, and 501-750 m. Including the crop buffer distance parameters in the model did not significantly improve the fit compared with a model with total acres within 750 m. Our results indicate that crop maps may be a useful method for estimating levels of herbicides in homes from nearby crop fields.

Residential Insecticide Use and Risk of Non-Hodgkin's Lymphoma

Previous studies have linked non-Hodgkin's lymphoma (NHL) with occupational exposure to insecticides, but residential use is largely unexplored. In this population-based case-control study, we examined NHL risk and use of insecticides in the home and garden. We identified NHL cases, uninfected with HIV, diagnosed between 1998 and 2000 among women and men ages 20 to 74 years in Iowa and the metropolitan areas of Los Angeles, Detroit, and Seattle. Controls were selected using random digit dialing or Medicare files. Computer-assisted personal interviews (1,321 cases and 1,057 controls) elicited data on insecticide use at each home occupied since 1970. Insecticide levels were measured in dust taken from used vacuum cleaner bags (682 cases and 513 controls). We previously reported a positive association with dichlorodiphenyldichloroethylene levels in carpet dust residues. Here, we focus on insecticides that were commonly used after 1970, the time period covered by our questionnaire. People whose homes were treated for termites had elevated NHL risk (odds ratio, 1.3; 95% confidence interval, 1.0-1.6). Risk was modestly, although not significantly, elevated in all but one study center and in all sexes and races. The elevation in risk was restricted to people whose homes were treated before the 1988 chlordane ban. There was a significant trend of increasing risk with increasing levels of alpha-chlordane residues in dust (P(trend) = 0.04) and a marginally significant trend for gamma-chlordane (P(trend) = 0.06). We found no evidence of associations for insects overall, for specific types of insects other than termites, or for elevated residues of other insecticides. We concluded that chlordane treatment of homes for termites may increase residents' NHL risk.

Residential environmental exposures and other characteristics associated with detectable PAH-DNA adducts in peripheral mononuclear cells in a population-based sample of adult females

The detection of polycyclic aromatic hydrocarbon (PAH)-DNA adducts in human lymphocytes may be useful as a surrogate end point for individual cancer risk prediction. In this study, we examined the relationship between environmental sources of residential PAH, as well as other potential factors that may confound their association with cancer risk, and the detection of PAH-DNA adducts in a large population-based sample of adult women. Adult female residents of Long Island, New York, aged at least 20 years were identified from the general population between August 1996 and July 1997. Among 1556 women who completed a structured questionnaire, 941 donated sufficient blood (25+ ml) to allow use of a competitive ELISA for measurement of PAH-DNA adducts in peripheral blood mononuclear cells. Ambient PAH exposure at the current residence was estimated using geographic modeling (n=796). Environmental home samples of dust (n=356) and soil (n=360) were collected on a random subset of long-term residents (15+ years). Multivariable regression was conducted to obtain the best-fitting predictive models. Three separate models were constructed based on data from : (A) the questionnaire, including a dietary history; (B) environmental home samples; and (C) geographic modeling. Women who donated blood in summer and fall had increased odds of detectable PAH-DNA adducts (OR=2.65, 95% confidence interval (CI)=1.69, 4.17; OR=1.59, 95% CI=1.08, 2.32, respectively), as did current and past smokers (OR=1.50, 95% CI=1.00, 2.24; OR=1.46, 95% CI=1.05, 2.02, respectively). There were inconsistent associations between detectable PAH-DNA adducts and other known sources of residential PAH, such as grilled and smoked foods, or a summary measure of total dietary benzo-[a]-pyrene (BaP) intake during the year prior to the interview. Detectable PAH-DNA adducts were inversely associated with increased BaP levels in dust in the home, but positively associated with BaP levels in soil outside of the home, although CIs were wide. Ambient BaP estimates from the geographic model were not associated with detectable PAH-DNA adducts. These data suggest that PAH-DNA adducts detected in a population-based sample of adult women with ambient exposure levels reflect some key residential PAH exposure sources assessed in this study, such as cigarette smoking.

Biomarkers in assessing residential insecticide exposures during pregnancy and effects on fetal growth

The Columbia Center for Children's Environmental Health is using a combination of environmental and biologic measures to evaluate the effects of prenatal insecticide exposures among urban minorities in New York City. Of the 571 women enrolled, 85% report using some form of pest control during pregnancy and 46% report using exterminators, can sprays, and/or pest bombs. Chlorpyrifos, diazinon, and propoxur were detected in 99.7-100% of 48-h personal air samples collected from the mothers during pregnancy (n = 394) and in 39-70% of blood samples collected from the mothers (n = 326) and/or newborns (n = 341) at delivery. Maternal and newborn blood levels are similar and highly correlated (r = 0.4-08, P < 0.001). Levels of insecticides in blood samples and/or personal air samples decreased significantly following the 2000-2001 U.S. Environmental Protection Agency's regulatory actions to phase out residential use of chlorpyrifos and diazinon. Among infants born prior to 1/1/01, birth weight decreased by 67.3 g (95% confidence interval (CI) -116.6 to -17.8, P = 0.008) and birth length decreased by 0.43 centimeters (95% CI, -0.73 to -0.14, P = 0.004) for each unit increase in log-transformed cord plasma chlorpyrifos levels. Combined measures of (ln)cord plasma chlorpyrifos and diazinon (adjusted for relative potency) were also inversely associated with birth weight and length (P </= 0.007). Birth weight averaged 215.1 g less (95% CI -384.7 to -45.5) among those with the highest exposures compared to those without detectable levels. No association was seen between birth weight and length and cord plasma chlorpyrifos or diazinon among newborns born after 1/1/01 (P > 0.8). Results support recent regulatory action to phase out residential uses of these insecticides.

Organochlorines in Carpet Dust and Non-Hodgkin Lymphoma

BACKGROUND

The incidence of non-Hodgkin lymphoma (NHL) has risen over the past several decades. Reasons for this increase are largely unexplained.

METHODS

In this population-based case-control study, we examined NHL risk and exposure to organochlorine compounds using concentrations in carpet dust as an exposure indicator. We identified NHL cases, uninfected with HIV, diagnosed between 1998 and 2000 among women and men ages 20-74 years in Iowa, Los Angeles County, and the Detroit and Seattle metropolitan areas. Controls were selected using random-digit-dialing or Medicare files. Organochlorine concentrations were measured in vacuum bag dust from 603 white cases and 443 white controls who had owned most of their carpets for at least 5 years.

RESULTS

NHL risk was elevated if any of the polychlorinated biphenyl (PCB) congeners (PCBs 105, 138, 153, 170, or 180) was detected (odds ratio = 1.5; 95% confidence interval = 1.2-2.0). Risk was elevated in the top tertile of PCB 180 (1.7; 1.1-2.6) and in the top 2 tertiles of total PCBs (middle tertile, 1.6 [1.1-2.4]; top tertile 1.5 [1.0-2.2]). There was a positive trend in risk with increasing PCB 180 levels (P trend = 0.03). NHL risk was elevated if dichlorodiphenyldichloroethylene (DDE) was detected (1.3; 1.0-1.7), but only among men. A positive, but not monotonic, dose-response relationship was observed for DDE (P trend = 0.02).

CONCLUSIONS

Our findings suggest an increased risk of NHL associated with exposure to PCBs, with evidence of greater effects for PCB 180. There is also some evidence of an association with DDE.

Residential Herbicide Use and Risk of Non-Hodgkin Lymphoma

CONTEXT

Environmental exposure to herbicides has been hypothesized to contribute to the long-term increase in non-Hodgkin lymphoma (NHL).

OBJECTIVE

To estimate the effects of residential herbicide exposure on NHL risk.

DESIGN

Population-based case-control study.

SETTING

Iowa and metropolitan Detroit, Los Angeles, and Seattle, 1998 to 2000.

PARTICIPANTS

NHL patients ages 20 to 74 years and unaffected residents identified by random digit dialing and Medicare eligibility files.

MAIN OUTCOME MEASURES

Computer-assisted personal interviews (1,321 cases, 1,057 controls) elicited data on herbicide use at each home occupied since 1970. Levels of 2,4-dichlorophenoxy-acetic acid and dicamba were measured in dust taken from used vacuum cleaner bags in the current home (679 cases, 510 controls who had owned at least half of their carpets for > or = 5 years).

RESULTS

Herbicide use on the lawn or garden was similar among cases and controls (adjusted relative risk, 1.02; 95% confidence interval, 0.84-1.23). Estimated risk did not increase with greater duration, frequency, or total number of applications of herbicides to the lawn, the garden, or to both combined. Risk was not elevated for respondents who applied the herbicides themselves and not for those exposed during the 1970s, 1980s, or 1990s. We detected 2,4-dichlorophenoxy-acetic acid equally often in homes of cases and controls (78%). We found dicamba in homes of 15% of cases and 20% of controls. We also found no elevation in risk among the respondents who had the highest dust levels and highest self-reported exposures. We found no consistent patterns for specific histologies.

CONCLUSIONS

We found no detectable excess associated with residential exposures. Residential herbicide exposures are unlikely to explain the long-term increase in NHL.

Polycyclic aromatic hydrocarbons, environmental tobacco smoke, and respiratory symptoms in an inner-city birth cohort

STUDY OBJECTIVES

Several studies have found associations between diesel exposure, respiratory symptoms, and/or impaired pulmonary function. We hypothesized that prenatal exposure to airborne polycyclic aromatic hydrocarbons (PAH), important components of diesel exhaust and other combustion sources, may be associated with respiratory symptoms in young children. We also hypothesized that exposure to environmental tobacco smoke (ETS) may worsen symptoms beyond that observed to be associated with PAH alone.

DESIGN/PARTICIPANTS

To test our hypotheses, we recruited 303 pregnant women from northern Manhattan believed to be at high risk for exposure to both PAH and ETS, collected 48-h personal PAH exposure measurements, and monitored their children prospectively.

RESULTS

By 12 months of age, more cough and wheeze were reported in children exposed to prenatal PAH in concert with ETS postnatally (PAH x ETS interaction odds ratios [ORs], 1.41 [p < 0.01] and 1.29 [p < 0.05], respectively). By 24 months, difficulty breathing and probable asthma were reported more frequently among children exposed to prenatal PAH and ETS postnatally (PAH x ETS ORs, 1.54 and 1.64, respectively [p < 0.05]).

CONCLUSIONS

Our results suggest that early exposure to airborne PAH and ETS can lead to increased respiratory symptoms and probable asthma by age 12 to 24 months. Interventions to lower the risk of respiratory disease in young children living in the inner city may need to address the importance of multiple environmental exposures.

Epidemiologic evaluation of measurement data in the presence of detection limits

Quantitative measurements of environmental factors greatly improve the quality of epidemiologic studies but can pose challenges because of the presence of upper or lower detection limits or interfering compounds, which do not allow for precise measured values. We consider the regression of an environmental measurement (dependent variable) on several covariates (independent variables). Various strategies are commonly employed to impute values for interval-measured data, including assignment of one-half the detection limit to nondetected values or of "fill-in" values randomly selected from an appropriate distribution. On the basis of a limited simulation study, we found that the former approach can be biased unless the percentage of measurements below detection limits is small (5-10%). The fill-in approach generally produces unbiased parameter estimates but may produce biased variance estimates and thereby distort inference when 30% or more of the data are below detection limits. Truncated data methods (e.g., Tobit regression) and multiple imputation offer two unbiased approaches for analyzing measurement data with detection limits. If interest resides solely on regression parameters, then Tobit regression can be used. If individualized values for measurements below detection limits are needed for additional analysis, such as relative risk regression or graphical display, then multiple imputation produces unbiased estimates and nominal confidence intervals unless the proportion of missing data is extreme. We illustrate various approaches using measurements of pesticide residues in carpet dust in control subjects from a case-control study of non-Hodgkin lymphoma.

Estimated risk for altered fetal growth resulting from exposure to fine particles during pregnancy: an epidemiologic prospective cohort study in Poland

The purpose of this study was to estimate exposure of pregnant women in Poland to fine particulate matter [less than or equal to 2.5 microm in diameter (PM 2.5)] and to assess its effect on the birth outcomes. The cohort consisted of 362 pregnant women who gave birth between 34 and 43 weeks of gestation. The enrollment included only nonsmoking women with singleton pregnancies, 18-35 years of age, who were free from chronic diseases such as diabetes and hypertension. PM 2.5 was measured by personal air monitoring over 48 hr during the second trimester of pregnancy. All assessed birth effects were adjusted in multiple linear regression models for potential confounding factors such as the size of mother (maternal height, prepregnancy weight), parity, sex of child, gestational age, season of birth, and self-reported environmental tobacco smoke (ETS). The regression model explained 35% of the variability in birth weight (beta = -200.8, p = 0.03), and both regression coefficients for PM 2.5 and birth length (beta = -1.44, p = 0.01) and head circumference (HC; beta = -0.73, p = 0.02) were significant as well. In all regression models, the effect of ETS was insignificant. Predicted reduction in birth weight at an increase of exposure from 10 to 50 microg/m3 was 140.3 g. The corresponding predicted reduction of birth length would be 1.0 cm, and of HC, 0.5 cm. The study provides new and convincing epidemiologic evidence that high personal exposure to fine particles is associated with adverse effects on the developing fetus. These results indicate the need to reduce ambient fine particulate concentrations. However, further research should establish possible biologic mechanisms explaining the observed relationship.

Developmental effects of exposure to environmental tobacco smoke and material hardship among inner-city children

Because of the growing concern that exposures to airborne pollutants have adverse effects on fetal growth and early childhood neurodevelopment, and the knowledge that such exposures are more prevalent in disadvantaged populations, we assessed the joint impact of prenatal exposure to environmental tobacco smoke (ETS) and material hardship on the 2-year cognitive development of inner-city children, adjusted for other sociodemographic risks and chemical exposures. The purpose was to evaluate the neurotoxicant effects of ETS among children experiencing different degrees of socioeconomic disadvantage, within a minority population. The sample did not include children exposed to active maternal smoking in the prenatal period. Results showed significant adverse effects of prenatal residential ETS exposure and the level of material hardship on 2-year cognitive development, as well as a significant interaction between material hardship and ETS, such that children with both ETS exposure and material hardship exhibited the greatest cognitive deficit. In addition, children with prenatal ETS exposure were twice as likely to be classified as significantly delayed, as compared with nonexposed children. Postnatal ETS exposure in the first 2 years of life did not contribute independently to the risk of developmental delay, over and above the risk posed by prenatal ETS exposure. The study concluded that prenatal exposure to ETS in the home has a negative impact on 2-year cognitive development, and this effect is exacerbated under conditions of material hardship in this urban minority sample.

Comparison of pesticide levels in carpet dust and self-reported pest treatment practices in four US sites

Epidemiologic studies have used both questionnaires and carpet dust sampling to assess residential exposure to pesticides. The consistency of the information provided by these two approaches has not been explored. In a population-based case-control study of non-Hodgkin's lymphoma, carpet dust samples were collected from the homes of 513 control subjects in Detroit, Iowa, Los Angeles, and Seattle. The samples were taken from used vacuum cleaner bags and analyzed for 30 pesticides. Interviewers queried subjects about the types of pests treated in their home using a detailed questionnaire accompanied by visual aids. Geographic variations in pesticide levels were generally consistent with geographic differences in pest treatment practices. Los Angeles residents reported the most treatment for crawling insects, fleas/ticks, and termites, and Los Angeles dust samples had the highest levels of propoxur, chlorpyrifos, diazinon, permethrin, and chlordane. Iowa had the most treatment for lawn/garden weeds, and also the highest levels of 2,4-dichlorophenoxyacetic acid and dicamba. Although Seattle had the highest proportion of subjects treating for lawn/garden insects, the lawn/garden insecticides were higher in other sites. Multivariate linear regression revealed several significant associations between the type of pest treated and dust levels of specific pesticides. The strongest associations were between termite treatment and chlordane, and flea/tick treatment and permethrin. Most of the significant associations were consistent with known uses of the pesticides; few expected associations were absent. The consistency between the questionnaire data and pesticide residues measured in dust lends credibility to both methods for assessing residential exposure to pesticides. The combined techniques appear promising for epidemiologic studies. Interviewing is the only way to assess pesticide exposures before current carpets were in place. Dust sampling provides an objective measure of specific compounds to which a person may have been exposed through personal use of a pesticide or by drift-in or track-in from outside, and avoids recall bias.

Effects of transplacental exposure to environmental pollutants on birth outcomes in a multiethnic population

Inner-city, minority populations are high-risk groups for adverse birth outcomes and also are more likely to be exposed to environmental contaminants, including environmental tobacco smoke (ETS), polycyclic aromatic hydrocarbons (PAHs), and pesticides. In a sample of 263 nonsmoking African-American and Dominican women, we evaluated the effects on birth outcomes of prenatal exposure to airborne PAHs monitored during pregnancy by personal air sampling, along with ETS estimated by plasma cotinine, and an organophosphate pesticide (OP) estimated by plasma chlorpyrifos (CPF). Plasma CPF was used as a covariate because it was the most often detected in plasma and was highly correlated with other pesticides frequently detected in plasma. Among African Americans, high prenatal exposure to PAHs was associated with lower birth weight (p = 0.003) and smaller head circumference (p = 0.01) after adjusting for potential confounders. CPF was associated with decreased birth weight and birth length overall (p = 0.01 and p = 0.003, respectively) and with lower birth weight among African Americans (p = 0.04) and reduced birth length in Dominicans (p < 0.001), and was therefore included as a covariate in the model with PAH. After controlling for CPF, relationships between PAHs and birth outcomes were essentially unchanged. In this analysis, PAHs and CPF appear to be significant independent determinants of birth outcomes. Further analyses of pesticides will be carried out. Possible explanations of the failure to find a significant effect of PAHs in the Hispanic subsample are discussed. This study provides evidence that environmental pollutants at levels currently encountered in New York City adversely affect fetal development.

The Long Island Breast Cancer Study Project: description of a multi-institutional collaboration to identify environmental risk factors for breast cancer

The Long Island Breast Cancer Study Project is a federally mandated, population-based case-control study to determine whether breast cancer risk among women in the counties of Nassau and Suffolk, NY, is associated with selected environmental exposures, assessed by blood samples, self-reports, and environmental home samples. This report describes the collaborative project's background, rationale, methods, participation rates, and distributions of known risk factors for breast cancer by case-control status, by blood donation, and by availability of environmental home samples. Interview response rates among eligible cases and controls were 82.1% (n = 1,508) and 62.8% (n = 1,556), respectively. Among case and control respondents who completed the interviewer-administered questionnaire, 98.2 and 97.6% self-completed the food frequency questionnaire; 73.0 and 73.3% donated a blood sample; and 93.0 and 83.3% donated a urine sample. Among a random sample of case and control respondents who are long-term residents, samples of dust (83.6 and 83.0%); soil (93.5 and 89.7%); and water (94.3 and 93.9%) were collected. Established risk factors for breast cancer that were found to increase risk among Long Island women include lower parity, late age at first birth, little or no breast feeding, and family history of breast cancer. Factors that were found to be associated with a decreased likelihood that a respondent would donate blood include increasing age and past smoking; factors associated with an increased probability include white or other race, alcohol use, ever breastfed, ever use of hormone replacement therapy, ever use of oral contraceptives, and ever had a mammogram. Long-term residents (defined as 15+ years in the interview home) with environmental home samples did not differ from other long-term residents, although there were a number of differences in risk factor distributions between long-term residents and other participants, as anticipated.

Proposed PCB congener groupings for epidemiological studies

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A current study of mottled enamel in Texas

Enamel mottling is strongly associated with the water fluoride level of the community water supply. About 32% of the variation in the mottled enamel scores of subjects aged 7 to 12 was attributable to their community's water fluoride level. Objectionable mottling (moderate mottling) occurred at 2.3 times the currently accepted optimum water fluoride level. Subjects with incomes less than $10,000 have slightly more mottling (mostly moderate mottling) than subjects from higher income families. It should be emphasized that the effect of gender, ethnic group, or family income on enamel mottling is small compared with the effect of water fluoride level. Although many other personal and water supply characteristics were evaluated, virtually none of the remaining variation in mottled enamel scores could be attributed to any of these characteristics.