In this study, we measured the concentration of total volatile organic compounds (TVOCs) in four different seasons from 2016 to 2017 in order to determine seasonal variation of indoor air quality in relation to public transportation modes (subways, trains, and express buses). The measurement was carried out both during rush hour when traffic was congested as well as during non-rush hour when traffic was not congested. Effects by season, degree of congestion, and characteristics of public transportation were analyzed on the basis of 295 items of data during the periods of congestion and 295 items of data during the periods of non-congestion. The average TVOCs concentration in winter was the highest with 226.4 μg/m 3 . The average TVOCs concentration on an express bus was the highest with a seasonal average of 142.3 μg/m 3 . The TVOCs concentration in the period of congested traffic was higher than in the period of non-congested traffic for all public transportation modes. For the average TVOCs concentration by season and transportation, there was no data that exceeded the guidelines regarding maintaining indoor air quality. However, 2.5% of all sample measured data (TVOCs) exceeded the guidelines regarding maintaining indoor air quality. Therefore, the continuous monitoring of public transport vehicles is required.
In this study, the condition of the hazardous materials in the bus was monitored according to the ventilation mode of the air conditioning system during bus service. The bus was surveyed using the indoor air quality measurement method of public transportation vehicles within one year of delivery. We evaluate the CO2 and PM10, which are the controlled parameters in buses by the Ministry of Environment, and VOCs and HCHO, the non-controlled parameters. The PM10 concentration increased due to outdoor air intake; however the CO2 concentration was found to decrease. In addition, the concentration of VOCs and HCHO was found to decrease due to the forced ventilation system and the outdoor air intake. These results show that the concentration of the other materials except PM10 can be changed due to the outside air concentration and forced ventilation system. Therefore, through indoor air quality characteristics of the bus according to air condition system are intended to be used as the basis of an operation manual.
This study investigates the indoor air quality conditions of the total of 52 buses depend on seasons, time and others. We evaluated the CO₂and PM10, the controlled parameters in express buses by Ministry of Environment and VOCs and HCHO, the non-controlled parameters. The CO₂concentration during peak commute times was 38.5% in summer and 15.4% in autumn, which are higher than the normal. But, PM10 concentration was influenced by the outside air not number of passengers. The concentration of VOCs were not related with other parameters such as number of passengers, seasons, and driving time. And then, the formaldehyde concentration was not related with seasons as it showed little difference between summer and autumn.
형태학적으로 구분이 어려운 황정과 위유의 범위를 구분하기 위해 황정에 속하는 층층갈고리둥굴레, 다화황정, 진황정 등 3종과 위유에 속하는 8종의 둥굴레 동속 식물 등 11종 23 개체 시료로 RAMP분석한 결과를 요약하면 다음과 같다. 1. 황정그룹과 위유그룹은 NTSYS를 통한 유연관계 분석에서 55%의 유연관계를 나타냈으며, 층층갈고리둥굴레와 층층둥굴레는 81.75%로 분석에 사용된 둥글레 동속 식물 중 가장 높은 유연관계를 나타냈다. 2. 둥굴레 동속식물에 해당하는 층층둥글레는 황정의 약재인 층층갈고리둥굴레와 외부형태학적으로, 그리고 다형성패턴결과가 매우 유사하므로 황정의 약재에 속하는 것으로 사료된다. 3. 진황정은 위유와 외부형태적으로 유사하며, 유연관계분석에서도 위유의 그룹에 속하므로 위유의 약재에 대한 구분을 새롭게 할 필요성이 있다.