[Inside and outside particulate pollution of a locality]

Area of Science:

• Environmental Science
• Indoor Air Quality
• Aerosol Science

Background:

• Suspended matter concentration is a key indicator of indoor air quality.
• Understanding indoor vs. outdoor particulate matter dynamics is crucial for public health.
• Previous studies have not fully quantified the impact of human occupancy on indoor particulate matter.

Purpose of the Study:

• To investigate the concentration and characteristics of suspended matter inside and outside occupied premises.
• To determine the relationship between human occupancy and indoor particulate matter levels.
• To analyze the chemical composition and grain size of indoor particles.

Main Methods:

• Comparative monitoring of suspended matter concentration inside and outside buildings.
• Development of an "occupation index" based on the number of occupants.
• Chemical analysis and grain size spectrum analysis of collected particulate matter.

Main Results:

• Indoor suspended matter concentration is lower than outdoor during non-occupation periods due to wall filtration.
• Indoor concentration significantly exceeds outdoor levels during occupancy.
• An "occupation index" correlates with the increase in indoor particulate matter.
• Particulate matter inside shows altered chemical composition (more ammonia/nitrates, less SO4/Ca/Fe/Pb) and grain size.

Conclusions:

• Human occupancy dramatically increases indoor suspended matter concentration.
• Changes in particle composition suggest indoor sources like condensation and recent abrasion.
• The "occupation index" provides a quantifiable measure of occupancy impact on indoor air quality.