PM2.5

According to past researches, most people spend 80%-90% of their time indoors. The ventilation is very important to people’s health and the comfortable surroundings around us. From the viewpoint of energy saving, mechanical ventilation will consume a large amount of additional energy. So variety of ways measuring natural ventilation is worth considering. In fact, in real life, many people tend to have their windows shut rather than open, and the reasons are complex.

The objective of this study is to provide research results of the actual conditions concerning theconcentrations of PM10, PM2.5, PM1 and CO2 among particle and gaseous pollutants in a subwaycarriage. Mean concentrations of PM10, PM2.5 and PM1, and CO2 in a subway carriage wereinvestigated as 215.1101.4 ? m-3, 86.938.6 ? m-3, 27.011.4 ? m-3, and 1,588714 ppm,respectively. These mean concentrations in a subway carriage were higher when it ran on anunderground track than on a ground track.

In this study the question whether or not and to what extend ventilation and air cleaning can contribute to the reduction of exposure to environmental tobacco smoke in the hospitality industry is answered. First a literature review on ventilation and air cleaning technologies has been executed. Unfortunately, only a few papers reporting experimental data from the hospitability industry were available to answer the proposed question. Therefore a model describing the effect of different ventilation systems and building layouts has been set up.

A survey of the particle-size distribution of 17 polycyclic aromatic hydrocarbons (PAHs) in indoor and outdoor air was performed in 20 homes in several Japanese cities. Highest PAH concentrations were found in the fine-particle fraction (smaller than 2.5 μm in diameter). The pro· portion of indoor PAH concentrations in fine particles was found to be higher than that of outdoors.