| Title | Chronic Exposure to Ambient Levels of Urban Particles Affects Mouse Lung Development. | | Author(s) | Mauad T, Rivero DH, Carvalho de Oliveira R, Lichtenfels AJ, Guimaraes ET, de Andre PA, Kasahara DI, Bueno HM, Saldiva PH | | Institution | Department of Pathology, Experimental Air Pollution Laboratory, Sao Paulo University Medical School, Sao Paulo, Brazil. | | Source | Am J Respir Crit Care Med 2008 Jul 2. | | Abstract | RATIONALE: Chronic exposure to air pollution has been associated with adverse effects on children's lung growth.
OBJECTIVES: We analyzed the effects of chronic exposure to urban levels of particulate matter (PM) on selected phases of mouse lung development.
METHODS: The exposure occurred in two open-top chambers (filtered and non-filtered) placed 20m from a street with heavy traffic in Sao Paulo, 24 hours/day for eight months. There was a significant reduction of the levels of PM2.5 inside the filtered chamber (filtered=2.9+/-3.0 microg/m(3), non-filtered=16.8+/-8.3 microg/m(3); p=0.001). At this exposure site, vehicular sources are the major components of PM2.5 (PM</=2.5Km). Exposure of the parental generation in the two chambers occurred from the 10th to the 120th days of life. After mating and birth of offspring, a cross-over of mothers and pups occurred within the chambers, resulting in four groups of pups: non-exposed, prenatal, postnatal and pre+postnatal. Offspring were euthanized at the age of 15 (n=42) and 90 (n=35) days; lungs were analyzed by morphometry for surface to volume ratio (as an estimator of alveolization). Pressure-volume curves were performed in the older groups, using a 20ml plethysmograph.
RESULTS: Mice exposed to PM2.5 pre+postnatally presented a smaller surface to volume ratio when compared to non-exposed animals (p=0.036). The pre+postnatal group presented reduced inspiratory and expiratory volumes at higher levels of transpulmonary pressure (p=0.001). There were no differences among prenatal and postnatal exposure and non-exposed animals.
CONCLUSIONS: Our data provide anatomical and functional support to the concept that chronic exposure to urban PM affects lung growth. | | Language | ENG | | Pub Type(s) | JOURNAL ARTICLE
| | PubMed ID | 18596224 |
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