2005 Fiscal Year Final Research Report Summary
Development of a simple method for monitoring air-borne fungi in houses
| Project/Area Number |
15560517
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Architectural environment/equipment
|
|---|
| Research Institution | Tokai University |
|---|
Principal Investigator |
IWATA Toshie Tokai University, School of Engineering 2, Professor, 第二工学部, 教授 (80270627)
|
|---|
| Project Period (FY) |
2003 – 2005
|
| Keywords | indoor air / air-borne fungi / simplified measurement / passive sampler / long-term exposure / culture / accuracy of measurement |
|---|
| Research Abstract |
Air-borne fungi cause health problems e.g. allergic asthma. Since there are various methods to measure the concentration of air-borne fungi, it is difficult to compare the results measured by different measurement methods. In this study, a simple monitoring method which is cheap and easy to handle has been developed
Using existing air samplers the reproducibility, the effects of sampling volume and airflow on the sampling efficiency were examined and the relationships between the samplers were identified. The accuracy which was required for measurement of air-borne fungi was also identified. The basic concept of the method was determined in which Air-borne fungi spores adhering on the vertical sampling faces are collected on agar plate. It was found that the number of CFU with PET was the highest and the coefficient of variance of the number of CFU with PET was the lowest. The difference between the conductors was not significant.
The sampling efficiency of the simple method was defined. From the results of the measurements, the suitable exposure time was expected from one week to two weeks. The effects of air velocity against the sampler could be disregarded in case the air velocity was lower than 0.5m/s. the effects of electrical charged amount on the sampler surface on sampling efficiency could be disregarded in case the relative humidity was higher than 35%.
In order to reduce invalid samplings which are caused by inadequate sterilization of samplers before exposure and individual difference in pressure, the method was modified by using a sample case filled with ethanol vapor and weight for 25 g/cm^2 of pressure.
This modification reduces percentage of invalid samples to 20%.
|
