RESUMO
Lung samples from smokers, nonsmokers, and one stillborn were analyzed by an instrumental neutron activation analysis (INAA) method. Pulmonary tissue and hilum lymph node samples were obtained separately from autopsies, and then submitted to cryogenic homogenization, lyophilization, and sterilization. Short and long irradiations were performed in an IEA-R1 nuclear reactor, and gamma-ray activities were measured using a Ge(Li) or hyperpure Ge detector. Precision of results was evaluated by analyzing one lung tissue in replicates and their accuracy by analyzing reference materials. Comparisons were carried out between results obtained in pulmonary tissues and lymph nodes, as well as those obtained in samples from different groups of individuals.
Assuntos
Pulmão/química , Oligoelementos/análise , Adulto , Idoso , Feminino , Morte Fetal , Germânio/análise , Humanos , Recém-Nascido , Linfonodos/química , Masculino , Pessoa de Meia-Idade , Análise de Ativação de Nêutrons , Padrões de Referência , Fumar/metabolismoRESUMO
In order to assess the adverse effects of urban levels of air pollution, rats were used as biological indicators in a chronic exposure experiment. Animals were housed for 6 months in the center of São Paulo (the largest South American city) and were compared to controls kept for the same period in a clean area. Pollution levels were obtained from a State air pollution monitoring station, 200 m distant from the exposure place, which provided the levels of CO, SO2, particulates, and ozone. The animals were submitted to several tests focusing on the respiratory system, comprising pulmonary function tests, studies on mucociliary clearance and mucus rheology, histochemical evaluation of airways, bronchoalveolar lavage, and ultrastructural studies of the epithelium of the airways. Rats exposed to air pollution developed secretory cell hyperplasia in the airways, ultrastructural ciliary alterations, and a more rigid mucus, changes that caused mucociliary clearance impairment. In addition, nasal resistance and the number of inflammatory cells recovered by bronchoalveolar lavage were increased in air pollution exposed animals. The results obtained in the present investigation suggest that chronic exposure to urban levels of air pollution may cause respiratory lesions in rats.