Air pollution, urgent asthma medical visits and the modifying effect of neighborhood asthma prevalence.

BACKGROUND: Social and environmental stressors may modify associations between environmental pollutants and asthma symptoms. We examined if neighborhood asthma prevalence (higher: HAPN vs. lower: LAPN), a surrogate for underlying risk factors for asthma, modified the relationship between pollutants and urgent asthma visits. METHODS: Through zip code, home addresses were linked to New York City Community Air Survey's land use regression model for street-level, annual average nitrogen dioxide (NO2), particulate matter (PM2.5), elemental carbon (EC), summer average ozone (O3), winter average sulfur dioxide (SO2) concentrations. Poisson regression models were fit to estimate the association (prevalence ratio, PR) between pollutant exposures and seeking urgent asthma care. RESULTS: All pollutants, except O3 were higher in HAPN than LAPN (P < 0.01). Neighborhood asthma prevalence modified the relationship between pollutants and urgent asthma (P-interaction < 0.01, for NO2 and SO3). Associations between pollutants and urgent asthma were observed only in LAPN (NO2: PR = 1.38, P = 0.01; SO3: PR = 1.85, P = 0.04). No association was observed between pollutants and urgent asthma among children in HAPN (P > 0.05). CONCLUSIONS: Relationships between modeled street-level pollutants and urgent asthma were stronger in LAPN compared to HAPN. Social stressors that may be more prevalent in HAPN than LAPN, could play a greater role in asthma exacerbations in HAPN vs. pollutant exposure alone.

Infant rhinitis and watery eyes predict school-age exercise-induced wheeze, emergency department visits and respiratory-related hospitalizations.

BACKGROUND: Rhinitis and conjunctivitis are often linked to asthma development through an allergic pathway. However, runny nose and watery eyes can result from nonallergic mechanisms. These mechanisms can also underlie exercise-induced wheeze (EIW), which has been associated with urgent medical visits for asthma, independent of other indicators of asthma severity or control. OBJECTIVE: To test the hypothesis that rhinitis or watery eyes without cold symptoms (RWWC) in infancy predict development of EIW and urgent respiratory-related medical visits at school age, independent of seroatopy. METHODS: Within a prospective birth cohort of low-income, urban children (n = 332), RWWC was queried during the first year of life. Relative risks (RRs) for EIW, emergency department (ED) visits, and hospitalizations for asthma and other breathing difficulties at 5 to 7 years of age were estimated with multivariable models. Seroatopy was determined at 7 years of age. RESULTS: Infant RWWC was common (49% of children) and predicted school-age EIW (RR, 2.8; P < .001), ED visits (RR, 1.8; P = .001), and hospitalizations (RR, 9.8; P = .002). These associations were independent of infant wheeze. They were also independent of birth order, an indicator of increased risk of exposure to viruses in infancy, and infant ear infections, an indicator of sequelae of upper airway infections. The association between infant RWWC and ED visits at 5 to 7 years of age was attenuated (RR, 1.2; P = .23) when EIW at 5 to 7 years of age was included in the model, suggesting EIW mediates the association. Adjustment for seroatopy did not diminish the magnitudes of any of these associations. CONCLUSION: These findings suggest a nonallergic connection between infant nonwheeze symptoms and important consequences of urban respiratory health by school age through EIW.

Allergic sensitization patterns identified through latent class analysis among children with and without asthma.

BACKGROUND: Specific patterns of allergic sensitization to common allergens may provide relevant clinical insight into asthma risk. OBJECTIVE: To identify patterns of allergic sensitization based on multiple individual allergens and link these to current and persistent asthma using baseline and 3-year follow-up data. METHODS: Children 7 to 8 years old with (n = 196) and without (n = 136) asthma from the New York City Neighborhood Asthma and Allergy Study were studied. IgE against a panel of 112 antigens was measured using the ISAC multiplex panel array. Latent class analysis (LCA) was used to identify patterns of allergic sensitization among the 26 most common allergens against which children had measurable IgE. The association between patterns of allergic sensitization and risk of asthma and other allergic diseases was examined. RESULTS: LCA identified 4 patterns of allergic sensitization as follows: low risk of sensitization (prevalence of 53% in children with asthma and 76% in children without asthma), indoor (prevalence of 23% in children with asthma and 15% in children without asthma), pollen and indoor group 1 (prevalence of 16% in children with asthma and 5% in children without asthma), and pollen and indoor group 2 (prevalence of 9% in children with asthma and 4% in children without asthma). Compared with the low risk of sensitization pattern, children belonging to the 3 sensitized patterns had significantly higher risk of asthma at ages 7 to 8 years and 3 years later, with the highest risk for children in the pollen and indoor group 1 pattern. CONCLUSIONS: LCA facilitates the study of sensitization profiles to a large number of common allergens. Analyzing patterns of allergic sensitization from multiple allergens reveals additional relevant associations with asthma than the study of a single allergen or total IgE.

Domestic airborne black carbon levels and 8-isoprostane in exhaled breath condensate among children in New York City.

BACKGROUND: Exposure to airborne black carbon (BC) has been associated with asthma development, respiratory symptoms and decrements in lung function. However, the mechanism through which BC may lead to respiratory symptoms has not been completely elucidated. Oxidative stress has been suggested as a potential mechanism through which BC might lead to adverse health outcomes. Exhaled breath condensate (EBC) allows for the non-invasive collection of airway lining fluid containing biomarkers of oxidative stress like 8-isoprostane, a stable by-product of lipid peroxidation. Therefore, we sought to characterize the association between domestic airborne BC concentrations and 8-isoprostane in EBC. MATERIALS AND METHODS: Seven- and eight-year-old children participated in an asthma case-control study in New York City. During home visits, air samples and EBC were collected. Seven day averages of domestic levels of particulate matter <2.5µm (PM2.5), BC and environmental tobacco smoke (ETS) were measured. Urea and 8-isoprostane were measured by liquid chromatography tandem mass spectrometry (LC/MS/MS) in EBC. RESULTS: In univariate models, PM2.5 and BC, but not ETS, were significantly associated with increases in 8-isoprostane in the EBC (ß=0.006 and ß=0.106 respectively, p<0.05 for both). These associations remained statistically significant for both PM2.5 and BC after adjustment for covariates. In a co-pollutant model including PM2.5, BC and ETS, only BC remained a statistically significant predictor of 8-isoprostane (p<0.05). CONCLUSIONS: Our findings suggest the BC fraction of PM might contain exposure relevant to increased oxidative stress in the airways.

Early-life cockroach allergen and polycyclic aromatic hydrocarbon exposures predict cockroach sensitization among inner-city children.

BACKGROUND: Sensitization to cockroach is one of the strongest identified risk factors for greater asthma morbidity in low-income urban communities; however, the timing of exposures relevant to the development of sensitization has not been elucidated fully. Furthermore, exposure to combustion byproducts, including polycyclic aromatic hydrocarbons (PAHs), can augment the development of allergic sensitization. OBJECTIVE: We sought to test the hypotheses that domestic cockroach allergen measured prenatally would predict cockroach sensitization in early childhood and that this association would be greater for children exposed to higher PAH concentrations. METHODS: Dominican and African American pregnant women living in New York City were enrolled. In the third trimester expectant mothers wore personal air samplers for measurement of 8 nonvolatile PAHs and the semivolatile PAH pyrene, and dust was collected from homes for allergen measurement. Glutathione-S-transferase µ 1 (GSTM1) gene polymorphisms were measured in children. Allergen-specific IgE levels were measured from the children at ages 2, 3, 5, and 7 years. RESULTS: Bla g 2 in prenatal kitchen dust predicted cockroach sensitization at the ages of 5 to 7 years (adjusted relative risk [RR], 1.15; P = .001; n = 349). The association was observed only among children with greater than (RR, 1.22; P = .001) but not less than (RR, 1.07; P = .24) the median sum of 8 nonvolatile PAH levels. The association was most pronounced among children with higher PAH levels and null for the GSTM1 gene (RR, 1.54; P = .001). CONCLUSIONS: Prenatal exposure to cockroach allergen was associated with a greater risk of allergic sensitization. This risk was increased by exposure to nonvolatile PAHs, with children null for the GSTM1 mutation particularly vulnerable.

Children's urinary phthalate metabolites and fractional exhaled nitric oxide in an urban cohort.

RATIONALE: Phthalates are used widely in consumer products. Exposure to several phthalates has been associated with respiratory symptoms and decreased lung function. Associations between children's phthalate exposures and fractional exhaled nitric oxide (Fe(NO)), a biomarker of airway inflammation, have not been examined. OBJECTIVES: We hypothesized that urinary concentrations of four phthalate metabolites would be positively associated with Fe(NO) and that these associations would be stronger among children with seroatopy or wheeze. METHODS: In an urban ongoing birth cohort, 244 children had phthalate metabolites determined in urine collected on the same day as Fe(NO) measurement. Repeated sampling gathered 313 observations between ages 4.9 and 9.1 years. Seroatopy was assessed by specific IgE. Wheeze in the past year was assessed by validated questionnaire. Regression models used generalized estimating equations. MEASUREMENTS AND MAIN RESULTS: Log-unit increases in urinary concentrations of metabolites of diethyl phthalate (DEP) and butylbenzyl phthalate (BBzP) were associated with a 6.6% (95% confidence interval [CI] 0.5-13.1%) and 8.7% (95% CI, 1.9-16.0%) increase in Fe(NO), respectively, adjusting for other phthalate metabolites and potential covariates/confounders. There was no association between concentrations of metabolites of di(2-ethylhexyl) phthalate or di-n-butyl phthalate and Fe(NO). There was no significant interaction by seroatopy. The BBzP metabolite association was significantly stronger among children who wheeze (P = 0.016). CONCLUSIONS: Independent associations between exposures to DEP and BBzP and Fe(NO) in a cohort of inner-city children were observed. These results suggest that these two ubiquitous phthalates, previously shown to have substantial contributions from inhalation, are positively associated with airway inflammation in children.

Using latent class growth analysis to identify childhood wheeze phenotypes in an urban birth cohort.

BACKGROUND: To advance asthma cohort research, we need a method that can use longitudinal data, including when collected at irregular intervals, to model multiple phenotypes of wheeze and identify both time-invariant (eg, sex) and time-varying (eg, environmental exposure) risk factors. OBJECTIVE: To demonstrate the use of latent class growth analysis (LCGA) in defining phenotypes of wheeze and examining the effects of causative factors, using repeated questionnaires in an urban birth cohort study. METHODS: We gathered repeat questionnaire data on wheeze from 689 children ages 3 through 108 months (n = 7,048 questionnaires) and used LCGA to identify wheeze phenotypes and model the effects of time-invariant (maternal asthma, ethnicity, prenatal environmental tobacco smoke, and child sex) and time-varying (cold/influenza [flu] season) risk factors on prevalence of wheeze in each phenotype. RESULTS: LCGA identified four wheezing phenotypes: never/infrequent (47.1%), early-transient (37.5%), early-persistent (7.6%), and late-onset (7.8%). Compared with children in the never/infrequent phenotype, maternal asthma was a risk factor for the other 3 phenotypes; Dominican versus African American ethnicity was a risk factor for the early-transient phenotype; and male sex was a risk factor for the early-persistent phenotype. The prevalence of wheeze was higher during the cold/flu season than otherwise among children in the early-persistent phenotype (P = .08). CONCLUSION: This is the first application of LCGA to identify wheeze phenotypes in asthma research. Unlike other methods, this modeling technique can accommodate questionnaire data collected at irregularly spaced age intervals and can simultaneously identify multiple trajectories of health outcomes and associations with time-invariant and time-varying causative factors.

Neighborhood differences in exposure and sensitization to cockroach, mouse, dust mite, cat, and dog allergens in New York City.

BACKGROUND: Asthma prevalence varies widely among neighborhoods within New York City. Exposure to mouse and cockroach allergens has been suggested as a cause. OBJECTIVE: To test the hypotheses that children living in high asthma prevalence neighborhoods (HAPNs) would have higher concentrations of cockroach and mouse allergens in their homes than children in low asthma prevalence neighborhoods (LAPNs), and that these exposures would be related to sensitization and asthma. METHODS: In the New York City Neighborhood Asthma and Allergy Study, a case-control study of asthma, children 7 to 8 years old from HAPNs (n = 120) and LAPNs (n = 119) were recruited through the same middle-income health insurance plan. Children were classified as asthma cases (n = 128) or controls without asthma (n = 111) on the basis of reported symptoms or medication use. Allergens were measured in bed dust. RESULTS: HAPN homes had higher Bla g 2 (P = .001), Mus m 1 (P = .003), and Fel d 1 (P = .003) and lower Der f 1 (P = .001) than LAPN homes. Sensitization to indoor allergens was associated with asthma, but relevant allergens differed between LAPNs and HAPNs. Sensitization to cockroach was more common among HAPN than LAPN children (23.7% vs 10.8%; P = .011). Increasing allergen exposure was associated with increased probability of sensitization (IgE) to cockroach (P < .001), dust mite (P = .009), and cat (P = .001), but not mouse (P = .58) or dog (P = .85). CONCLUSION: These findings further demonstrate the relevance of exposure and sensitization to cockroach and mouse in an urban community and suggest that cockroach allergen exposure could contribute to the higher asthma prevalence observed in some compared with other New York City neighborhoods.

Prenatal acetaminophen exposure and risk of wheeze at age 5 years in an urban low-income cohort.

BACKGROUND: Acetaminophen has been associated with asthma and is in part metabolised via the glutathione pathway. Inner-city minority children have high asthma morbidity and a relatively high frequency of a minor allele variant in the glutathione S transferase Pi gene (GSTP1). We hypothesised that prenatal acetaminophen exposure would predict wheeze at age 5 years in an inner-city minority cohort and examined whether this association was modified by common polymorphisms in genes related to the glutathione pathway. METHODS: An ongoing population-based birth cohort study of Dominican Republic and African-American children in New York prospectively assessed the use of analgesics during pregnancy and current wheeze at age 5 years in 301 children. Genotyping was conducted for GST polymorphisms. Binomial regression was used to adjust for potential confounders including postnatal acetaminophen use. RESULTS: 34% of mothers reported acetaminophen use during pregnancy and 27% of children had current wheeze at 5 years. Prenatal exposure to acetaminophen predicted current wheeze (multivariate relative risk 1.71; 95% CI 1.20 to 2.42; p=0.003), and the risk increased monotonically with increasing number of days of prenatal acetaminophen exposure (p trend <0.001). 68% of children had at least one copy of the GSTP1 minor allele (Val). The risk of wheeze was modified by GSTP1 (additive interaction p=0.009) and was observed only among children with the GSTP1 minor allele. CONCLUSIONS: Prenatal exposure to acetaminophen predicted wheeze at age 5 years in an inner-city minority cohort. The risk was modified by a functional polymorphism in GSTP1, suggesting a mechanism involving the glutathione pathway.

Exhaled NO among inner-city children in New York City.

BACKGROUND: Fractional exhaled nitric oxide (FeNO) has been proposed as a biomarker of airway inflammation for cohort studies of asthma. OBJECTIVES: To assess the association between FeNO and asthma symptoms among 7-year-old children living in an inner-city community. To test the association between environmental tobacco smoke (ETS) exposure (previous and current) and FeNO among these children. METHODS: As part of a longitudinal study of asthma, children recruited in Head Start centers at age 4 had offline FeNO and lung function testing at age 7. Children with allergen-specific immunoglobulin E (IgE) (≥0.35 IU/mL) at age 7 were considered seroatopic. ETS exposure at ages 4 and 7 was assessed by questionnaire. RESULTS: Of 144 participating children, 89 had complete questionnaire data and achieved valid FeNO and lung function tests. Children with reported wheeze in the previous 12 months (n = 19) had higher FeNO than those without wheeze (n = 70) (geometric means 17.0 vs. 11.0 ppb, p = .005). FeNO remained significantly associated with wheeze (p = .031), after adjusting for seroatopy and forced expiratory volume in 1 second (FEV1) in multivariable regression. FeNO at age 7 was positively associated with domestic ETS exposure at age 4 (29%) (ß = 0.36, p = .015) but inversely associated with ETS exposure at age 7 (16%) (ß = -0.74, p < .001). CONCLUSIONS: Given its association with current wheeze, independent of seroatopy and lung function, FeNO provides a relevant outcome measure for studies in inner-city communities. While compelling, the positive association between ETS exposure at age 4 and a marker of airway inflammation at age 7 should be confirmed in a larger study.

Physical activity and asthma symptoms among New York City Head Start Children.

The coincidence of both an obesity epidemic and an asthma epidemic among children in the United States has suggested that childhood overweight and sedentary lifestyles may be risk factors for asthma development. We therefore conducted a study of those factors among children enrolled in Head Start Centers located in areas of New York City with high asthma hospitalization rates. Data were gathered from 547 children through an intensive home visit, and physical activity was measured on 463 children using the Actiwatch accelerometer. Data on allergy and asthma symptoms and demographic variables were obtained from parents' responses to a questionnaire and complete data were available from 433 children. Overall physical activity was highest in warmer months, among boys, among children whose mothers did not work or attend school, and among children of mothers born in the United States. Activity was also positively associated with the number of rooms in the home. The season in which the activity data were collected modified many of the associations between demographic predictor variables and activity levels. Nearly half the children were above the range considered healthy weight. In cross-sectional analyses, before and after control for demographic correlates of physical activity, asthma symptoms were not associated with physical activity in this age group. Comparing the highest quartile of activity to the lowest, the odds ratio for asthma was 0.91 (95% CI = 0.46, 1.80). However, the novel associations with physical activity that we have observed may be relevant to the obesity epidemic and useful for planning interventions to increase physical activity among preschool children living in cities in the northern United States.

Cockroach allergen levels and associations with cockroach-specific IgE.

BACKGROUND: Among inner-city children with asthma, cockroach allergen exposure has been associated with allergic sensitization. OBJECTIVE: We hypothesized that cockroach allergen levels in homes would be associated with sensitization to cockroach allergens in children. METHODS: From a low-income preschool program, 341 four-year-old children selected on the basis of the willingness of their caregivers to participate in the study were enrolled. Dust from their beds and kitchens were analyzed for cockroach (Bla g 2), mouse (mouse urinary proteins), and cat allergens (Fel d 1). Serum samples were analyzed for allergen-specific IgE antibodies by immunoassay. RESULTS: Bla g 2 levels >1 U/g in children's bed and kitchen dust samples were independently associated with cockroach-specific IgE (odds ratio [OR], 2.7; 95% CI, 1.1-6.4; and OR, 3.4; 95% CI, 1.2-9.4, respectively), adjusting for sex, ethnicity, asthma, pet ownership, mother's allergic sensitization, environmental tobacco smoke, and having lived in other homes. Bla g 2 was associated (OR, 3.6; 95% CI, 1.0-13.1) with cockroach-specific IgE among children with asthma. Among children without asthma, the ORs were similar (OR, 3.0; 95% CI, 0.9-10.3), but the association was not statistically significant. CONCLUSION: Concentrations of the major cockroach allergen, Bla g 2, in settled dust were associated with cockroach-specific IgE independent of other factors in a cohort of 4-year-old inner-city children.

Cat ownership is a risk factor for the development of anti-cat IgE but not current wheeze at age 5 years in an inner-city cohort.

BACKGROUND: Cat ownership is inversely associated with atopy and asthma in some areas of the world, but the relevance of cat ownership to allergic disease in the inner city is less known. OBJECTIVE: We sought to evaluate the relationship between cat ownership and the development of early sensitization and wheeze. METHODS: By using a prospective birth cohort study, Dominican and African American mothers living in New York City underwent repeated questionnaires about their child from birth to age 5 years. Sera collected from children at ages 2 (n = 323), 3 (n = 336), and 5 (n = 242) years were assayed for anti-cat IgE and anti-Fel d 1 IgG antibodies. RESULTS: Cat ownership was a significant risk factor for the development of anti-cat IgE by age 2 years (risk ratio [RR], 6.4; 95% CI, 1.9-22) but not for anti-cat IgE development between the ages of 2 and 5 years (RR, 0.88; 95% CI, 0.24-2.3). Current wheeze was significantly more common among those children with anti-cat IgE at ages 3 (RR, 3.5; 95% CI, 2.1-6.0) and 5 (RR, 3.4; 95% CI, 2.3-4.9) years. Cat ownership was inversely associated with current wheeze at age 5 years among children without anti-cat IgE (RR, 0.26; 95% CI, 0.083-0.81). Among children with anti-cat IgE, a similar trend was observed (RR, 0.57; P = .044, Fisher exact test), although one with borderline statistical significance. CONCLUSIONS: Despite a positive association with sensitization, cat ownership in this inner-city cohort was inversely associated with wheeze, potentially suggesting an IgE-independent protective mechanism in this community.

Total and specific IgE associations between New York City Head Start children and their parents.

BACKGROUND: Allergy and asthma risk share strong inherited components; however, the relative importance of maternal and paternal atopy in predicting child atopy remain unclear. OBJECTIVE: We sought to identify relationships between parents' and children's total and specific IgE levels within family units as predictors of allergic risk in children. METHODS: Total and allergen-specific IgE (to dust mite, cockroach, mouse, and cat) were determined by means of ImmunoCap (Phadia, Inc, Portage, Mich) in a sample of families participating in New York City Head Start programs. Regression models were developed to determine the associations of parents' and children's total IgE levels and sensitization patterns. RESULTS: Blood specimens were collected from 161 family triads of mother, father, and child (83 boys and 78 girls). At a mean age of 4 years, boys had significantly higher total IgE levels than girls. Boys' total IgE levels were highly correlated with both mothers' (P < .002) and fathers' (P = .002) total IgE levels; girls' total IgE levels were not. Unlike total IgE levels, specific IgE levels among both boys and girls were associated with their mothers' specific IgE levels. Dust mite sensitization among mothers was predictive of children's sensitization to each of the 4 aeroallergens. CONCLUSION: The strong associations between parents' and children's IgE levels suggest that assessment of parents' total and locally relevant allergen-specific IgE levels might have value in predicting atopy in children of preschool age.

Early respiratory infections and asthma among New York City Head Start children.

BACKGROUND: Respiratory infections in neonates have been found to predict wheeze among young children. We hypothesized that among preschool children from low-income minority communities in New York City, current asthma would be associated with a history of respiratory infection in the first few months after their birth. METHODS: We asked parents of children in New York City Head Start centers (preschool programs for children of low-income families) to respond to a questionnaire covering demographic factors, lifestyle, home environment, and health history, including a detailed history of respiratory conditions. We used logistic regression to model the association of asthma and asthma severity with history of respiratory infections, controlling for gender, ethnicity, family history of asthma, and other factors. RESULTS: Among 1,022 children (mean age 4+/- 0.6 years) whose parents provided information about their health history, 359 (35%) met our criteria for asthma. Overall, 22% had had a cold by 6 months and 17% an ear infection by 8 months of age. In multivariable models, children with asthma had had more colds (OR = 2.8, 95% confidence interval [CI] 1.4-6.0) and ear infections (OR = 3.4, 95% CI 1.7-6.9) in the past year than other children. Associations of respiratory infections with emergency department use for asthma (as a measure of severity) were similar. In models that did not control for infections in the past year, ages at first cold and first ear infection were associated with asthma and emergency department visits in the past year. CONCLUSIONS: In this sample of preschool children, respiratory infections were common and were associated with asthma and health care utilization for asthma exacerbations. If these findings are confirmed, preventive measures among children who develop such infections at a very early age should be explored to help reduce the burden of asthma in this age group.

Exercise-induced wheeze, urgent medical visits, and neighborhood asthma prevalence.

OBJECTIVE: Exercise-induced wheeze (EIW) may identify a distinct population among asthmatics and give insight into asthma morbidity etiology. The prevalence of pediatric asthma and associated urgent medical visits varies greatly by neighborhood in New York City and is highest in low-income neighborhoods. Although increased asthma severity might contribute to the disparities in urgent medical visits, when controlling for health insurance coverage, we previously observed no differences in clinical measures of severity between asthmatic children living in neighborhoods with lower (3%-9%) versus higher (11%-19%) asthma prevalence. Among these asthmatics, we hypothesized that EIW would be associated with urgent medical visits and a child's neighborhood asthma prevalence. METHODS: Families of 7- to 8-year-old children were recruited into a case-control study of asthma through an employer-based health insurance provider. Among the asthmatics (n = 195), prevalence ratios (PRs) for EIW were estimated. Final models included children with valid measures of lung function, seroatopy, and waist circumference (n = 140). RESULTS: EIW was associated with urgent medical visits for asthma (PR, 2.29; P = .021), independent of frequent wheeze symptoms. In contrast to frequent wheeze, EIW was not associated with seroatopy or exhaled NO, suggesting a distinct mechanism. EIW prevalence among asthmatics increased with increasing neighborhood asthma prevalence (PR, 1.09; P = .012), after adjustment for race, ethnicity, maternal asthma, environmental tobacco smoke, household income, and neighborhood income. CONCLUSIONS: EIW may contribute to the disparities in urgent medical visits for asthma between high- and low-income neighborhoods. Physicians caring for asthmatics should consider EIW an indicator of risk for urgent medical visits.

Prenatal exposure to butylbenzyl phthalate and early eczema in an urban cohort.

BACKGROUND: Recent cross-sectional studies suggest a link between butylbenzyl phthalate (BBzP) in house dust and childhood eczema. OBJECTIVES: We aimed to evaluate whether concentrations of monobenzyl phthalate (MBzP), the main BBzP metabolite in urine, during pregnancy are associated prospectively with eczema in young children, and whether this association varies by the child's sensitization to indoor allergens or serological evidence of any allergies. METHODS: MBzP was measured in spot urine samples during the third trimester of pregnancy from 407 African-American and Dominican women residing in New York City in 1999-2006. Repeated questionnaires asked mothers whether their doctor ever said their child had eczema. Child blood samples at 24, 36, and 60 months of age were analyzed for total, anti-cockroach, dust mite, and mouse IgE. Relative risks (RR) were estimated with multivariable modified Poisson regression. Analyses included a multinomial logistic regression model for early- and late-onset eczema versus no eczema through 60 months of age. RESULTS: MBzP was detected in > 99% of samples (geometric mean = 13.6; interquartile range: 5.7-31.1 ng/mL). By 24 months, 30% of children developed eczema, with the proportion higher among African Americans (48%) than among Dominicans (21%) (p < 0.001). An interquartile range increase in log MBzP concentration was associated positively with early-onset eczema (RR = 1.52 for eczema by 24 months; 95% confidence interval: 1.21, 1.91, p = 0.0003, n = 113 reporting eczema/376 total sample), adjusting for urine specific gravity, sex, and race/ethnicity. MBzP was not associated with allergic sensitization, nor did seroatopy modify consistently the MBzP and eczema association. CONCLUSIONS: Prenatal exposure to BBzP may influence the risk of developing eczema in early childhood.

Domestic airborne black carbon and exhaled nitric oxide in children in NYC.

Differential exposure to combustion by-products and allergens may partially explain the marked disparity in asthma prevalence (3-18%) among New York City neighborhoods. Subclinical changes in airway inflammation can be measured by fractional exhaled nitric oxide (FeNO). FeNO could be used to test independent effects of these environmental exposures on airway inflammation. Seven- and eight-year-old children from neighborhoods with lower (range 3-9%, n=119) and higher (range 11-18%, n=121) asthma prevalence participated in an asthma case-control study. During home visits, FeNO was measured, and samples of bed dust (allergens) and air (black carbon; BC) were collected. Neighborhood built-environment characteristics were assessed for the 500 m surrounding participants' homes. Airborne BC concentrations in homes correlated with neighborhood asthma prevalence (P<0.001) and neighborhood densities of truck routes (P<0.001) and buildings burning residual oil (P<0.001). FeNO concentrations were higher among asthmatics with than in those without frequent wheeze (≥4 times/year) (P=0.002). FeNO concentrations correlated with domestic BC among children without seroatopy (P=0.012) and with dust mite allergen among children with seroatopy (P=0.020). The association between airborne BC in homes and both neighborhood asthma prevalence and FeNO suggest that further public health interventions on truck emissions standards and residual oil use are warranted.

Asthma, allergy, and IgE levels in NYC head start children.

BACKGROUND: Among preschool-age children in New York City neighborhoods with high asthma hospitalization rates, we analyzed the associations of total immunoglobulin E (IgE), specific IgE to common indoor allergens, and allergy symptoms with asthma. METHODS: Parents of children in New York City Head Start programs were asked to complete a questionnaire covering demographic factors, health history (including respiratory conditions), lifestyle, and home environment. Children's serum samples were analyzed for total IgE and specific IgE antibodies to cockroach, dust mite, mouse, and cat allergens by immunoassay. Logistic regression was used to model the association between asthma and IgE, controlling for age, gender, ethnicity/national origin, BMI, parental asthma, smokers in the household, and allergy symptoms (e.g., runny nose, rash). RESULTS: Among 453 participating children (mean age 4.0+/-0.5 years), 150 (33%) met our criteria for asthma. In our multivariable logistic regression models, children with asthma were more likely than other children to be sensitized to each allergen, to be sensitized to any of the four allergens (OR=1.6, 95% CI 1.0-2.6), or to be in the highest quartile of total IgE (OR=3.1, 95% CI 1.5-6.4). Allergy symptoms based on questionnaire responses were independently associated with asthma (OR=3.7, 95% CI 2.3-5.9). CONCLUSIONS: Among preschool-aged urban children, asthma was associated with total IgE and sensitization to cat, mouse, cockroach, and dust mite allergens. However, allergy symptoms were more prevalent and more strongly associated with asthma than was any allergen-specific IgE; such symptoms may precede elevated specific IgE or represent a different pathway to asthma.