Abstract |
Although considerable data exist on 24-hour integrated measurements of fine and coarse indoors, much less information is available on moment-to-moment variation for a full range of particle sizes including ultrafine particles. Also, information is limited on the relationships between air change rates, temperature, humidity, indoor-outdoor concentrations ratios, indoor source strengths due to various activities such as cooking and cleaning, penetration factors, and deposition rates under realistic conditions. Therefore EPA and NIST have collaborated on a four-year (October 1, 1996 through Dec. 31, 2000) study of particle concentrations in an occupied house. Target pollutants included ultrafine, fine, and coarse particles from 10 nm to 20 microgram in diameter, black carbon (BC); and particle-bound polyaromatic hydrocarbons (PAH). Ancillary measurements included air change rates, wind velocity, temperature, and relative humidity. Measurements were made continuously and the final database (PMHOME) is on a 5-minute basis. PMHOME is available to researchers in Statistica or SAS format. Types of investigations that can be done using PMHOME include calculation of the relative contribution of outdoor air particles to indoor air concentrations, effects of indoor sources such as cooking and candle burning, and relationships of air change rates to outdoor temperature and wind speed. |