Respiratory effects caused by exposure to diesel exhaust particles during moderate exercise: a murine model.

Aerobic exercise is an increasing trend worldwide. However, people are increasingly exercising outdoors, alongside roadways where heavy vehicles release diesel exhaust. We analyzed respiratory effects caused by inhaled diesel particulate emitted by vehicles adhering to Brazilian legislation, PROCONVE Phase P7 (equivalent to EURO 5), as well the effects of exposure during moderate-intensity aerobic exercise. Male C57BL/6 mice were divided into four groups for a 4-wk treadmill protocol: CE (n = 8) received intranasal sterile physiological saline and then performed moderate-intensity exercise (control), CS (n = 10) received saline and then remained stationary on the treadmill (control), DS (n = 9) received intranasal diesel exhaust particles and then remained stationary, and DE (n = 10) was exposed to diesel exhaust and then exercised at moderate intensity. Mice were subsequently connected to a mechanical ventilator (SCIREQ flexiVent, Canada) to analyze the following respiratory mechanics parameters: tissue resistance, elastance, inspiratory capacity, static compliance, Newtonian resistance, and pressure-volume loop area. After euthanasia, peripheral pulmonary tissue strips were extracted and subjected to force-length tests to evaluate parenchymal elastic and mechanical properties, using oscillations applied by a computer-controlled force transducer system; parameters obtained were tissue resistance, elastance, and hysteresivity. DS displayed impaired respiratory mechanics for all parameters, in comparison with CS. DE exhibited significantly reduced inspiratory capacity and static compliance, and increased Newtonian resistance when compared with CE. Exposure to diesel exhaust, both during exercise and rest, still exerts harmful pulmonary effects, even at current legislation limits. These results justify further changes in environmental standards, to reduce the health risks caused by traffic-related pollution.NEW & NOTEWORTHY Exercise, while beneficial, is often performed in areas of greater inhaled particulates. Here we show this effect using mice exposed to controlled diesel particle inhalation and moderate aerobic exercise. Diesel particle inhalation, without or with exercise, worsened both respiratory mechanical properties associated with changes in lung tissue mechanics and morphometry.

Lung injury caused by exposure to the gaseous fraction of exhaust from biomass combustion (cashew nut shells): a mice model.

Currently, to reduce the use of nonrenewable energy sources in energy matrices, some industries have already incorporated biomass as a source of energy for their processes. Additionally, filters are used in an attempt to retain the particulate matter present in exhaust gases. In this work, the emission gases of a cashew nut shell (CNS) combustion reactor and the deleterious effects on the respiratory system of mice exposed to gaseous fraction present in CNS emissions (GF-CNS) are analyzed. The system for CNS combustion is composed of a cylindrical stainless steel burner, and exhaust gases generated by CNS combustion were directed through a chimney to a system containing two glass fiber filters to retain all the PM present in the CNS exhaust and, posteriorly, were directed to a mice exposure chamber. The results show changes in the variables of respiratory system mechanics (G, H, CST, IC, and PV loop area) in oxidative stress (SOD, CAT, and NO2-), as well as in the histopathological analysis and lung morphometry (alveolar collapse, PMN cells, mean alveolar diameter, and BCI). Through our results, it has been demonstrated that even with the use of filters by industries for particulate material retention, special attention should still be given to the gaseous fraction that is released into the environment.