Birth order, atopy, and symptoms of allergy and asthma among inner-city children attending Head Start in New York City.

BACKGROUND: In past research, children with older siblings were more likely than others to wheeze at age 2 years, but less likely by age 6 years. Higher infection transmission and a down-regulated allergic immune response as a result of these infections, respectively, were suggested as the causes. However, in a study of children aged 0-3 years in a low-income urban community in New York City, USA, with high asthma prevalence, we observed no birth-order effect. OBJECTIVE: To evaluate the association between birth order and atopy and respiratory symptoms in 4-year-old children attending Head Start programs in NYC. METHODS: Respiratory symptoms were assessed by questionnaire for 1005 children (mean age 4.0 years) living in high asthma prevalence neighbourhoods. Serum was collected from a subgroup of the children (n=494) and specific IgE responses to dust mite, cockroach, mouse, and cat allergens were measured. RESULTS: Prevalence of specific IgE (> or =0.35 IU/mL) did not differ significantly among first (35%), second (35%), and later-born children (28%) (P=0.23). Increasing birth order was associated with increasing prevalence of respiratory symptoms in the prior year, including wheeze (first 20%, second 27%, third or later 35%; P<0.001), being awakened at night by cough (28%, 33%, 38%; P=0.005), emergency department visits (14%, 17%, 21%; P=0.02) and hospitalizations for difficulty breathing (6.1%, 6.6%, 10%; P=0.04). The associations of birth order with respiratory symptoms were statistically significant only for the non-seroatopic children and those without an asthmatic parent. CONCLUSIONS: Non-seroatopic children with older siblings were more likely than those without older siblings to have respiratory symptoms at age 4 years. Although the stability of these associations over time remains to be determined, the differences in findings between this study and our previous NYC birth cohort study suggest that patterns of asthma development may vary even among low-income populations within the same city.

Asthma, body mass, gender, and Hispanic national origin among 517 preschool children in New York City.

BACKGROUND: Striking differences in asthma prevalence have been reported among Hispanic adults and children living in different cities of the USA. Prevalence is highest among those of Puerto Rican and lowest among those of Mexican origin. We hypothesized that body size would mediate this association. METHODS: Parents of children in New York City Head Start programs completed a questionnaire including demographic factors, health history, a detailed history of respiratory conditions, lifestyle, and home environment. Children's height and weight were measured in home visits. Logistic regression was used to model the association of asthma with body mass index percentile (<85th percentile, gender/age specific vs>or=85th percentile, gender/age specific), national origin, and other factors. RESULTS: Of 517 children at mean age of 4.0 +/- 0.6 years, 34% met the study criteria for asthma, and 43% were above the 85th percentile. Asthma was strongly associated with non-Mexican national origin, male gender, allergy symptoms, and maternal asthma, and marginally with body size. The odds of asthma among boys of non-Mexican origin was 5.9 times that among boys of Mexican origin [95% confidence interval (CI): 2.9-12.2]; the comparable odds ratio (OR) among girls was 1.8 (95% CI: 0.9-3.6). Body mass was associated with asthma among girls [OR = 2.0 (95% CI: 1.1-3.7)], but not boys [OR = 1.4 (95% CI: 0.8-2.6)]. CONCLUSIONS: The association of asthma with both body mass and national origin was gender-specific among the children in our study. Ours is one of the first studies to report on pediatric asthma in different Hispanic populations in the same city, by gender.

Atopy in children and parental social class.

OBJECTIVES: This analysis was conducted to determine whether atopic disorders were related to social class in a pediatric population of a former socialist country. METHODS: A cross-sectional study of 2471 schoolchildren was carried out in 1992 and 1993 in 3 towns in the former East Germany. Parents completed a standardized questionnaire regarding health events and lifestyle factors. In addition, skin-prick tests were performed and total serum immunoglobulin (IgE) was determined. RESULTS: Lifetime prevalence rates for atopic disease and rates of allergic sensitization were highest in children from social class III (in which parents had more than 10 years of formal education) and lowest in social class I (less than 10 years of parental education), while rates in social class II (10 years of parental education) were constant at an intermediate level. CONCLUSIONS: The data confirmed the assumption that in formerly socialist countries social inequalities existed under the socialist system, which were reflected by a social gradient in health outcomes. The findings support the hypothesis that increased access to modern lifestyle could be one reason for the increasing rates of atopic disorders during the last 3 decades.

Reexamination of epidemic asthma in New Orleans, Louisiana, in relation to the presence of soy at the harbor.

Epidemic asthma occurred in New Orleans, Louisiana, in the 1950s and 1960s, but its causes were never fully understood. Subsequently, similar outbreaks of epidemic asthma in Barcelona, Spain, were shown to be caused by the release of soy dust at the harbor. To investigate whether airborne soy dust may have contributed to epidemic asthma in New Orleans, the authors examined historical data on vessel cargo from the New Orleans harbor together with data on emergency department visits for asthma, for the period from 1957 through 1968. Days on which there were 64 or more visits for asthma were twice as likely to have occurred on days when a vessel carrying soy was at the harbor (odds ratio (OR) = 2.3, 95% confidence interval (CI) 1.5-3.3). The association was stronger when the maximum wind speed was less than 12 miles/hour (19.3 km/hour) (OR = 4.0, 95% CI 2.1-7.7) and strongest when wind speeds were low and the prevailing winds were from the south or southwest, the direction of two grain elevators from the hospital (OR = 6.7, 95% CI 1.5-46.7). Various temporal and climatic factors that had been associated with the occurrence of asthma outbreaks did not appear to be important confounding factors. The association was specific to soy cargo; no association was observed between asthma-epidemic days and the presence of either wheat or corn in vessels at the harbor. The results of this analysis provide further evidence that ambient soy dust is very asthmogenic and that asthma morbidity in a community can be influenced by exposures in the ambient atmosphere.

Acute health effects of exposure to high levels of air pollution in eastern Europe.

Acute effects of winter-type air pollution characterized by high levels of SO2, moderate levels of particles, and low acidity were studied. A panel of 155 asthmatic children and 102 adults with a history of asthma from the former German Democratic Republic cities of Erfurt and Welmar and from the Czech Republic city of Sokolov participated from September 1990 through June 1992. The panelists recorded daily symptoms, medication intake, and peak expiratory flow (PEF). Statistical analysis was based on linear regression of population-averaged time series controlling for trend, meteorology, and autocorrelation. A temporospatial time series approach was also applied to the data to eliminate possible confounding by some known or unknown variables that occurred simultaneously in two of the study areas. Weak same-day effects and a stronger cumulative effect of air pollution on children was observed both for PEF and for symptoms. PEF decreased -0.90% (-1.35 to -0.46%), and a symptom score increased 14.7% (0.8-28.6%) in association with an average increase of 128 micrograms/m3 SO2 over the previous 5 days. Effects on adults were smaller and less consistent. Morbidity of children was best predicted by SO2 and sulfate concentrations. The authors conclude that prolonged, high exposure to winter-type pollution was associated with small adverse health effects in asthmatics.

Acute respiratory effects of short-term exposures to nitrogen dioxide.

Eleven study subjects with asthma and 12 normal controls were monitored for 5 days with a portable continuous nitrogen dioxide (NO2) monitoring instrument held at breathing level before, during, and after cooking dinner on a gas cooking range. Forced expiratory volume in 1 sec (FEV1.0), forced expiratory volume (FEV25-75), peak expiratory flow, and a tracing of the entire flow curve was monitored before the gas stove was turned on, during a break in cooking, immediately after, and 1 hr after cooking was completed. Study design for detection of health effects of the acute exposures to NO2 described above and a method of validating findings in an exposure chamber are discussed in this paper.

Air pollution and asthma: effects of exposures to short-term sulfur dioxide peaks.

Recent laboratory studies have shown exposures to SO2 at levels as low as 0.1 ppm and lasting as little as 10 min to lead to changes in respiratory functions as well as symptoms in asthmatic individuals exposed during exercise. The present study was conducted to determine whether similar responses to short-term SO2 peaks in the ambient air can be detected in a free-living population. Tests were made for an association between days with SO2 peaks above various levels, as identified from hourly measurements obtained by the New York City Aerometric Network, and days with high numbers of emergency room visits for asthma at three inner-city municipal hospitals in New York City. No association was found.

Seasonal patterns of asthma: a clue to etiology.

An extensive data set of daily hospital emergency room visits for asthma for two geographic areas (1953-77 in New Orleans and 1969-77 in New York City) was examined for seasonality. Previous studies using smaller data bases have reported an autumn increase (principally during October and November) in the number of emergency room visits for asthma in many locations in this country (including New Orleans and New York City). The results of this study indicated that for every hospital and every year of observation in New York City the number of asthma emergency room visits increased in September, reached a peak in October and November and declined in December. In contrast, in New Orleans an autumn increase in the number of asthma emergency room visits was not consistently observed, being absent or reduced during many years. The distribution of asthma epidemic days (days on which the number of asthma emergency room visits was greatly elevated) by month was also examined. In New York City, there was a tendency for these days to occur during September, October, and November while in New Orleans there was an equal likelihood of epidemic days occurring in April, May, and June as well as during September, October, and November. The observations tend to suggest different etiologies for asthma attacks in the two geographic areas.

Daily patterns of asthma in New York City and New Orleans: an epidemiologic investigation.

Examination of records of daily visits to emergency rooms for asthma covering 25 years from New Orleans and 9 years from New York City reveals a distinct day-of-the-week pattern in New York City whereas no such pattern is discernible in New Orleans. The difference in daily patterns of asthma attacks in the populations from the two cities strongly suggests a different environmental etiologic agent acting on these two populations. It is proposed herein that in New York susceptible individuals are exposed to some agents or factors triggering attacks which are present in the home environment where most of their time is spent on weekends, while in New Orleans, homes are not as sealed off from the outside air, because of the warmer climate, so that the agent triggering attacks is as common outdoors as indoors, and thus there is little difference between weekend and weekday exposure.

Analysis of air pollution patterns in New York City distribution of air pollutants over the city.

Distribution of daily levels of sulfur dioxide and smokeshade over the five boroughs of New York City are described in terms of a coordinate grid covering the area of the City and heights above ground level and above sea level. Implications for the design of epidemiologic studies of the health effects of air pollution are discussed.

Distribution of seasonal mean levels of air pollutants over New York City.

Distributions of seasonal average levels of sulfur dioxide and smoke-shade over the five boroughs of New York City are described in terms of the distance between stations and the heights of the stations above ground level and sea level. An assessment of the suitability of the data for epidemiologic studies of acute and chronic health effects of air pollution is made.

Application of a time-space clustering methodology to the assessment of acute environmental effects on respiratory illnesses.

A new methodology is proposed for the identification of environmental events of health significance. Health indices measured on a daily basis at various location in a single geographical area are collected over time. First, the daily variations are examined to determine whether they reflect purely random variations or whether there are days on which there are extreme variations not plausibly explicable as random events. After such days are identified, the question of whether they occur only at a single location within the larger geographical area at one time, or whether the occur simultaneously at more than one location is investigated. Tests of statistical significance for both temporal and spatial clustering are propose. The methodology is applied to daily hospital emergency room visits for various respiratory complaints to several New York City hospitals situated in two geographically separated districts which however have population of similar socio-economic and ethnic composition.

Methodological problems arising from the choice of an independent variable in linear regression, with application to an air pollution epidemiological study.

In epidemiological studies using linear regression, it is often necessary for reasons of economy or unavailability of data to use as the independent variable not the variable ideally demanded by the hypothesis under study but some convenient practical approximation to it. We show that if the correlation coefficient between the "practical" and "ideal" variables can be obtained, then a range of uncertainty can be obtained within which the desired regression coefficient of dependent on "ideal" variable may lie. This range can be quite wide, even if the practical and ideal variables are fairly well correlated. These points are illustrated with data on observed regression coefficients from an air pollution epidemiological study, in which pollution measured at one station in a large metropolitan area (containing 40 aerometric stations) was used as the practical approximation to the city-wide average pollution. The uncertainties in the regression coefficients were found to exceed the regression coefficients themselves by large factors. The problem is one that may afflict application of linear regression in general, and suggests caution when selecting independent variables for regression analysis on the basis of convenience, rather than relevance to the hypotheses tested.

Exposure data for the study of acute health effects of air pollution.

The use of aerometric network data has been criticized before on the grounds that it might give an unreliable picture of population exposure. However, the extensive data obtained from networks is still being used for studies of health effects of air pollution. This study uses a rigorous approach in analyzing these data to test their suitability for studies of acute health effects of air pollution. New York City, with one of the most extensive aerometric networks, consisting of 40 air pollution monitoring stations, is taken as an example. Three years of hourly SO2 readings and bi-hourly readings of smokeshade have been analyzed. The use of one aerometric station to represent the daily exposure of the population of New York City as has been done in previous studies is shown to be invalid. The use of individual monitoring stations of the New York City aerometric network to represent the day-to-day exposure to SO2 and smokeshade of the populations surrounding these monitoring stations is examined, with results showing that further work will be necessary before such an approach is justified.