Chronic exposure to ambient levels of urban particles affects mouse lung development

Author(s)

Mauad, Thais ^[1] ; Rodriguez Ferreira Rivero, Dolores Helena ^[1] ; de Oliveira, Regiani Carvalho ^[1] ; de Faria Coimbra Lichtenfels, Ana Julia ^[1] ; Guimaraes, Eliane Tigre ^[1] ; de Andre, Paulo Afonso ^[1] ; Kasahara, David Itiro ^[2] ; de Siqueira Bueno, Heloisa Maria ^[1] ; Nascimento Saldiva, Paulo Hilario ^[1]

Affiliation

^[1] Univ Sao Paulo, Sch Med, Dept Pathol, Expt Air Pollut Lab, BR-01246903 Sao Paulo - Brazil

^[2] Univ Vermont, Coll Med, Dept Pathol, Burlington, VT 05405 - USA

• Document type: Journal article
• Source: American Journal of Respiratory and Critical Care Medicine; v. 178, n. 7, p. 721-728, OCT 1 2008.
• Web of Science Citations: 72

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 nonfiltered) placed 20 m from a street with heavy traffic in Sao Paulo, 24 hours/day for 8 months. There was a significant reduction of the levels of PM(2.5) inside the filtered chamber (filtered = 2.9 +/- 3.0 mu g/m(3), nonfiltered = 16.8 +/- 8.3 mu g/m(3); P = 0.001). At this exposure site, vehicular sources are the major components of PM(2.5) (PM <= 2.5 mu m). 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 crossover of mothers and pups occurred within the chambers, resulting in four groups of pups: nonexposed, prenatal, postnatal, and pre+postnatal. Offspring were killed 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 20-ml plethysmograph. Measurements and Main Results: Mice exposed to PM(2.5) pre+postnatally presented a smaller surface to volume ratio when compared with nonexposed 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 nonexposed animals. Conclusions: Our data provide anatomical and functional support to the concept that chronic exposure to urban PM affects lung growth. (AU)

• FAPESP's process: 03/10772-9 - Role of intra-uterine and early post-natal exposure to ambient air pollution and development of deleterious changes in respiratory and reproductive systems in adult life: an experimental study in mice
• Grantee: Paulo Hilário Nascimento Saldiva
• Support Opportunities: Research Projects - Thematic Grants