Transmission electron microscopy findings in the respiratory epithelium of guinea pigs exposed to the polluted air of southwest Mexico City.
J Environ Pathol Toxicol Oncol
; 18(4): 323-34, 1999.
Article
em En
| MEDLINE
| ID: mdl-15281245
We evaluated the nature and the extent of the damage to the respiratory epithelium of guinea pigs after a 4-month exposure to the mixture of air pollutants in southwest Mexico City. Guinea pigs were placed outdoors on the roof of our facility, 8 hours daily, from February to May 1995. At the same time, control guinea pigs were kept indoors breathing filtered air. Air pollutants, temperature, and humidity data were obtained from the nearest station of the Environmental Monitoring Net. The airways and lung parenchyma were analyzed after 120 days using transmission electron microscopy (TEM). During the 4-month exposure period, ozone (O3) exceeded the norm during 511 hours, and suspended particles less than 10 microm in diameter (PM10) during 52 hours. Both pollutants reached peak levels of more than twice the norm. TEM revealed no important abnormalities in the control group. In the exposed group, there was loss of cilia, detachment of epithelial cells, and eosinophil and macrophage migration toward alveolar spaces through type I pneumocytes with destruction of their basal membranes. In six guinea pigs in the exposed group, we noted bacteria along the airways, with associated inflammatory response. We explain the colonization of the respiratory epithelium by bacteria as the result of the impairment on the defense mechanism caused by the exposure to environmental O3 and PM10.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Microscopia Eletrônica
/
Monitoramento Ambiental
/
Exposição por Inalação
/
Mucosa Respiratória
/
Poluentes Atmosféricos
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
País/Região como assunto:
Mexico
Idioma:
En
Revista:
J Environ Pathol Toxicol Oncol
Assunto da revista:
NEOPLASIAS
/
PATOLOGIA
/
SAUDE AMBIENTAL
/
TOXICOLOGIA
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
México
País de publicação:
Estados Unidos