Comparison of Diffusion Characteristics of Aerosol Particles in Different Ventilated Rooms by Numerical Method

Particle diffusion with gravitational sedimentation in displacement and mixing ventilated rooms is investigated numerically. The drift flux model, which considers the settling of particles under the effect of gravitational sedimentation, is adopted to simulate particle diffusion, while the simplified
model for solving the continuous fluid flow is combined. Since the PM 2.5 and PM 10 particles are mostly concerned in indoor environment, passive contaminant and 2.5-20 micron particles are investigated in this paper. The numerical results show that in a mixing ventilated room, the

Indoor chemistry and health: where are we going?

Indoor chemistry is receiving attention due to the possible health effects of products ofreactions between indoor pollutants, and the potential for such products to contribute to indoorparticulate matter (PM). Much of the focus with respect to indoor chemistry has been onterpene/ozone reaction products, since terpenes are ubiquitous indoors, ozone readilyinfiltrates from outdoors, and the reaction rates are comparable to typical air exchange rates inmany indoor settings. Several studies have documented particle formation from reactionsbetween ozone and a-pinene or d-limonene.

Distributions of indoor and outdoor air pollutants in downtown Rio de Janeiro city, Brazil

Indoor air quality (IAQ) has been a matter of public concern in Brazil. An IAQ survey wasconducted in an office building and in a commercial bank in Rio de Janeiro, Brazil. Indoorand outdoor air of offices was analysed due to the possibility of causing adverse effect on thehealth of the occupants. Measurements were made in a day during working hours. Sampleswere collected for volatile organic compounds (VOCs), total volatile organic compounds(TVOCs), aldehydes, total particulate matter (TPM) and microbiological analysis.

Indoor particles and symptoms among office workers : results from a double-blind cross-over study

The aim of the article is to study the effect of removing small airborne particles in an office building.The standard particle filters were replaced with highly efficient filters. Occupants answered questionnaire weekly and multiple environment measurements were done.The enhanced filtration reduced the concentration of smallest particles, symptoms were not reduced, but performance-related mental states improved.

Modeling exposure to particulate matter

Scientific tools are used to get insights into the processes that affect the exposure assessment : these are the exposure models. This paper aims at reviewing the process and methodology of estimating inhalation exposure to particulate matter (PM) using various types of models.Indirect type, direct type and stochastical models are discussed in this paper.

How do the indoor size distributions of airborne submicron and ultrafine particles in the absence of significant indoor sources depend on outdoor distributions ?

The inhabitants of Central Europe spend more of their time indoors. And indoor pollutants often affect human health more than the outdoor pollutants. This study aims at analysing how the indoor size distributions of submicron and ultrafine particles depends on outdoor distributions.
In the absence of indoor sources, concentrations of particulates are lower than in outdoor concentrations.

Air flow and particle control with different ventilation system in a classroom

Istis normally assumed by designers that all pollutants in a displacement ventilation system follow the buoyant air flow into an upper zone, where they are evacuated. But studies have shown that it is not always true and that concentrations of pollutant particles can be found in the breathing zone. This study aims at designing a ventilation system that will minimize the respirable airborne particle in that breathing zone.

Fine PM measurements : personal and indoor air monitoring

This paper is a review of the techniques and equipment used during the last 20 years, to monitor Particulate Matter personal exposures, microenvironment concentrations and the constituants of sampled particulate matter.

"Europart" Airborne particles in the indoor environment. European interdisciplinary review of scientific evidence on associations between exposure to particles in buildings and health effects.

The European interdisciplinary group of researchers have reviewed 70 papers and selected 8 studies for their final review. From most studies, no definite conclusions could have been drawn concerning the association between particles matter concentration and health outcomes.
So giving limit values or guidelines for particulate mass or number concentrations in non-industrial indoor environment is not an adequate scientific evidence.

An overview of particulate matter in indoor environments : sources and effects

This paper gives an overview of sources of indoor particulate matter (PM) and its effects on occupants. Studies indicate that outdoor PM contributes to indoor PM, yet a large fractionof indoor PM is generated indoors. The ratio of indoor to outdoor PM concentrations (I/O ratio) varies substantially due to different indoor conditions and PM spatial distributions.Real-time investigation using multiple point sampling technique is needed for better understanding of PM spatial distribution.