Community Urbanization and Hospitalization of Adults for Asthma

 

Speaker:                     Rosemarie G Ramos, PhD, MPH

NIH Postdoctoral Fellow, NIEHS

 

Level of Knowledge: Basic

 

Short Abstract:

 

Few studies have assessed the incidence of adult asthma hospitalizations in urban vs. non-urban areas.  Using population size, population density, and traffic-related factors to define urban vs. non-urban environments, six Pennsylvania counties were selected to test the hypothesis that the degree of urbanization influences the asthma hospitalization rate for adults.  To define traffic-related urbanization, daily vehicular traffic count and miles of roads/highways for each of the 6 counties were used.  We found, in some of the counties, a decrease in the adult asthma hospitalization rate as urbanization decreased.  However, for other counties, the rate increased as urbanization decreased.  The counties in which the latter was observed had depressed measures of socio-economic status (SES) and were located "downwind" of industrial facilities in Pennsylvania and neighboring states.  Our findings suggest that other factors may supersede exposure to local traffic-related pollution in those hospitalized for asthma.  

 

Long Abstract:

 

Asthma research has traditionally focused on children and the elderly, two populations considered the most susceptible to complications.  However, the prevalence of asthma in the adult population (19-64 years) is gaining recognition as a formidable clinical and public health problem.  In addition, few studies have assessed the incidence of adult asthma hospitalizations in urban vs. non-urban areas.  Of interest is whether traffic-related and air quality characteristics associated with urban environments increase the risk of respiratory disease morbidity when compared to non-urban environments.  Using population size, population density, and traffic-related factors to define urban vs. non-urban environments, six Pennsylvania counties were selected to test the hypothesis that the degree of urbanization influences the asthma hospitalization rate for adults.  The study group was comprised of adults, 19-64 years, who were hospitalized for asthma (as the primary diagnosis) from 1999-2001. To define urbanization related to traffic, daily vehicular traffic count and miles of roads/highways for each of the 6 counties were used.  We found, in some of the counties, a decrease in the adult asthma hospitalization rate as urbanization decreased.  However, for other counties, the rate increased as urbanization decreased.  The counties in which the latter was observed had depressed measures of socio-economic status (SES).  In addition, these areas appear to be "downwind" of industrial facilities within the state of Pennsylvania and its neighboring states.  Our findings suggest that depressed socioeconomic conditions and regional air quality may supersede exposure to local traffic-related pollution with respect to asthma hospitalizations. 

 

Learning Objectives:

 

  1. Address how designations of urban versus rural are made in the US
  2. Appreciate the multifactorial nature of asthma
  3. Realize the research barriers with respect to assessing the relationship of regional ambient air quality and respiratory health morbidity