Environmental factors and respiratory hypersensitivity: the Americas.
Toxicol Lett
; 86(2-3): 115-30, 1996 Aug.
Article
em En
| MEDLINE
| ID: mdl-8711764
Diverse environmental exposure profiles exist in the Americas because of widely different climates, ambient pollutants, and bioaerosols in these continents. This paper reviews selected studies from the Americas that support the broad hypothesis that environmental factors contribute to respiratory hypersensitivity. Processes influenced by environmental factors include primary immunologic sensitization, the development and exacerbation of specific immunologic diseases and the activation of nonspecific mechanisms with tissue inflammation, injury and remodeling. Endpoints resulting from these processes include respiratory symptoms, diseases such as asthma, with measures of disease severity including medication use and hospitalization rates, and death due to cardiorespiratory disease. Studies associate sensitization rates to specific allergens with environmental factors such as humidity and indices of allergen exposure. Regional variation occurs with exposure to outdoor source pollutants such as ozone, but varies by household to bioaerosols such as dust mite, cat or cockroach allergen. Indoor allergens are associated with asthma while outdoor allergens are associated with allergic rhinitis. In a national survey, the atopic sensitization rate in the USA increased with urban residence (defined as towns of population > 2500) and varied by region. Controlled human challenge studies show that ozone increases the response of allergic subjects to allergen. Increased ambient photochemical pollution concentrations, of which ozone is an important component, are associated with increased emergency room visits for asthma in cities such as Toronto, New York, Atlanta, and Mexico City. In Sao Paolo, Brazil, mortality due to childhood respiratory disease was influenced by the ambient levels of NO2. Epidemiologic studies including the recent meta-analysis of a large, longitudinal study population associate ambient concentrations of particulate matter < 10 microns and respiratory symptoms, disease severity and increased cardiorespiratory deaths. Toxicology studies show that individual variation in responsiveness is important in nonspecific inflammatory responses to irritant pollutants such as ozone and environmental tobacco smoke. These studies indicate that environmental factors influence primary allergen sensitization, secondary allergic responses, the activation of nonspecific inflammatory responses, and the severity of respiratory diseases, including asthma.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Hipersensibilidade Respiratória
/
Poluição Ambiental
Tipo de estudo:
Etiology_studies
/
Observational_studies
/
Prevalence_studies
/
Risk_factors_studies
Aspecto:
Determinantes_sociais_saude
Limite:
Adolescent
/
Adult
/
Child
/
Humans
País/Região como assunto:
America central
/
America do norte
/
America do sul
Idioma:
En
Revista:
Toxicol Lett
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Estados Unidos
País de publicação:
Holanda