Air pollution and its relationship to lung function among adolescents from Taubate, São Paulo, Brazil

Background: This paper sought to evaluate individual exposure to air pollution by quantifying the carbon in alveolar macrophages (AMs) and its relationship to lung function. We also examined the proximity of participants' residences to the Presidente Dutra highway (PDH) in adolescents with asthma from Taubaté, São Paulo, Brazil. Methods: This descriptive study examined fifty 13- to 14-year-old adolescents with asthma identified by the International Study of Asthma and Allergies in Childhood (ISAAC) in Taubaté. These adolescents underwent spirometry and sputum induction via the inhalation of 3% hypertonic saline (HSS). Sputum was collected after each nebulisation, and forced expiratory flow in one second (FEV1) was measured. The collected sputum was stored and transported to the laboratory; it was then processed and analysed for ultrafine particles (≤100 nm). This analysis was correlated with the residence location and FEV1 of each adolescent. Results: A total of 39 adolescents completed the study. The comparison of the carbon fraction within macrophages (CA/MA) showed no differences according to residence in relation to the PDH (p=0.758). After adjustment, a mixed linear model with FEV1 as the dependent variable and CA/MA, location, and evaluation condition as the predictors found that the interactions among the variables were not significant. Conclusions:T he amount of carbon present within the AMs of adolescents with asthma was not correlated with either lung function or residence location. Evaluations of the topograghy and local climatic conditions in Taubaté should be considered in future studies (AU)

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Diesel emissions significantly influence composition and mutagenicity of ambient particles: a case study in São Paulo, Brazil.

In 2003, a bus strike paralyzed the fleet of buses in Sao Paulo, Brazil during 3 days, from 6 to 8 of April, the complete interruption of services being achieved on the 7th. We evaluated the effect of the absence of this source of pollution on the composition, mutagenicity, and toxicity of the fine particulate material collected during this period. Particles were sampled in glass fiber filters on days 7 and 15 of April of 2003 (strike and nonstrike days, respectively), using a high-volume sampler. Trace element determinations (As, Br, Co, Cl, Fe, La, Mn, Sb, Sc, and Th) of particulate material samples were carried out by neutron activation analysis. Sulfur determination was done by X-ray fluorescence analysis. The ratio between nonstrike/strike concentrations of hydrocarbons associated with automotive emissions (benzene, toluene, ethyl-benzene, and xylenes; BTEX) was determined by gas chromatography/mass spectrometry. Mutagenesis of testing solutions was determined by means of the Tradescantia micronucleus assay in early tetrads of Tradescantia pallida. The inhibition of mitosis of the cells of the primary meristema of the root tips of Allium cepa was used as an index of the toxicity. Fine particle trace element contents were lower during the strike. The concentrations of sulfur and BTEX were 50% and 39.3% lower, respectively, on the strike day. A significant (P=0.038) reduction of micronuclei induced by fine particles sampled during the strike was observed. No effect of the strike on toxicity was detected. These results indicate that a program aiming to reduce emissions of the bus fleet in our town may impact positively the air quality by reducing the mutagenic potential of ambient particles.