Effect of housewife's activity pattern on indoor particulate matter concentration: Ko-CHENS Mom study

Abstract

Background/Aim Most housewives spend a lot of time at home and do housework such as cleaning and cooking. Low-cost sensors have advantage of being able to measure indoor particulate matter concentration in real time. Activities such as cooking, eating and cleaning can affect exposure patterns of indoor particulate matter. The purpose of this study was to identify changes in indoor particulate matter concentration according to the time-activity patterns of housewives. Methods We enrolled 306 participants in the study for the housewives located in Seoul and Ulsan, Korea. Housewives were measured their indoor exposures by low-cost sensor and completed time-activity diaries for a 7-days monitoring period. PM data is obtained every 5 minutes via Wi-Fi and cloud system connection. Participants self-reported their major activities every hour in their time-activity diary. The time activity diary provides hourly information on participants' activities and locations. Indoor PM concentrations over time were compared with participants' behavior patterns. We also performed the stratified analysis based on weekdays/weekends and seasons. The accuracy of the sensor measurment was evaluated by examining the correlation between the indoor PM measured by the sensor and the indoor PM measured by the GRIMM. Results During the study, the indoor occupancy rate of the participants was about 82%. The average age of the participants was 34 years. The time having highest average of indoor PM concentration was 10 am (PM2.5: 21.8 μg/m3, PM10: 26.3 μg/m3). Activity patterns related to cooking/eating, and cleaning influenced changes in indoor particulate matter concentrations. There was no difference in indoor PM concentration during weekdays/weekends. The correlation coefficients between concentrations measured by sensor and GRIMM were 0.9. Conclusion This study provides a comprehensive assessment of the variation in indoor particulate matter concentration associated with housewives’ time-activities. Our results found that indoor PM concentrations increased with indoor cooking /cleaning behavior.