Comparison of indoor air quality on a passenger ship and a chemical ship

Indoor Air 28, 17-22 August 28, Copenhagen, Denmark - Paper ID: 49 Comparison of indoor air quality on a passenger ship and a chemical ship Sun-Sook Kim 1,*, Yoon-Kyung Kang 1, Geun-Young Doe 2 and Yun-Gyu Lee 1 1 Korea Institute of Construction Technology, Korea 2 Korea Maritime University, Korea * Corresponding email: kictkss@kict.re.kr SUMMARY Indoor air quality on ships is important to the passengers comfort and crews habitability. Although the constructors and operators need to be aware of the importance and present status of indoor air quality, sufficient data and information is not available. In this study, we measured the pollutant concentrations on two different kinds of ships, a passenger ship and a chemical ship. Indoor air quality of the chemical ship was worse than that of the passenger ship, and concentrations of some pollutants on the chemical ship surpassed the domestic and international criteria. For a passenger ship, the variation of indoor air quality was also investigated after about one and half year. In order to achieve shipboard air quality, it is necessary to collect more data and to suggest minimum requirements. KEYWORDS Indoor air quality, Ship, Transportation, Volatile organic compound, Formaldehyde INTRODUCTION Recently, there has been a growing public concern over indoor air quality not only in buildings but also in transportations such as vehicles and airplanes. In some countries, indoor air quality measurement and management guidelines for the vehicles have been developed by automobile manufacturers voluntary efforts. The draft international standard that specifies the test method of volatile organic compounds (VOCs) in car interiors is currently under progressing in the ISO technical committee. Recently, the Ministry of Construction & Transportation in Korea also proposed the Standards of indoor air quality in new assembly cars in June, 27. Indoor air quality in airplane cabins has been treated as an important issue and a wide range of research has been conducted for decades. Although ships are not so much common and popular as vehicles and airplanes, indoor air quality on ships is also important to the heath and comfort of passengers and crews. Since the periods on board are relatively longer, poor indoor air quality may have a long-term harmful effect on them by increasing physical and mental fatigue. Furthermore, indoor air quality is likely to be worse on shipboard due to the airtight body and middle corridor-type accommodation layout. Therefore, constructors and operators need to be aware of the importance and present status of indoor air quality. Lloyd s Register assessed indoor air quality onboard a wide range types of vessels and compared it with that of office and residential buildings (Webster and Reynolds, 25). Jang et al. (27) investigated the crews activities and clothing in the cabins of maritime patrol vessels in order to estimate the optimum temperature for PMV/PPD based air conditioning. American Bureau of Shipping (ABS, 21) has developed the guides to meet the needs for passengers comfort and crews habitability on ships. These guides suggest indoor climate requirements and test procedures for air temperature, humidity, vertical and horizontal

gradient, and air velocity. In addition, the international standard on air conditioning and ventilation design in the passenger accommodation of ships makes recommendations with respect to temperature, relative humidity, supply, and exhaust air (ISO, 22 ; Webster and Reynolds, 25). However, these guides and standard do not cover the indoor air quality criteria including pollutant concentrations. Although the constructors and operators need to monitor and manage shipboard air quality, sufficient data and information is not available. Therefore, the purpose of this study is to analyze the characteristics of indoor air quality on ships by measuring the pollutant concentrations in a new passenger ship and a new chemical ship and to investigate the variations after a certain period. METHODS Pollutant concentrations and indoor climate were investigated by field measurements on two different types of ships as shown in Figure 1. The one is a passenger ship for use as a student training ship of the Korea Maritime University, and the other is an oil or chemical tanker. Both of the ships consist of six decks and a series of measurements were accomplished at various locations, including wheelhouse, passenger or crew s cabins, engine rooms, kitchens, and etc. For a passenger ship, the second measurements were conducted after 17 months. Outline of the measurements is shown in Table 1. Concentrations of VOCs, formaldehyde, carbon oxide(co), carbon dioxide(co 2 ), sulfur dioxide(so 2 ), and particulate matter were measured as well as indoor temperatures and relative humidity. Measurement and analysis methods for parameters are shown in Table 2. Figure 1. Features of the investigated ships. a), b). Table 1. Outline of the measurement. Types Size Measuring period Measuring points 6,7 ton 1st : 26 / 2 / 22 ~ 24 2nd : 27 / 7 / 25 ~ 27 14 point 13, ton 27 / 6 / 4 ~ 5 8 point

Table 2. Measurement and analysis methods. Types VOCs Formaldehyde CO, CO 2, SO 2 Particulate matter Temperature and R.H. Instrument / Method 3. liters of air samples with Tenax-TA tubes Thermal desorber / Gas chromatography / Mass Spectrometry 15 liters of air samples with 2,4-DNPH sampler High Performance Liquid Chromatography Multi-gas monitor (3 minutes) Scanning mobility particle sizer (18 minutes) Measuring instrument with multi-probes (3 minutes) The main guidelines concerning indoor air quality were introduced by WHO (2) and ASHARE (26). In Korea, IAQ Management Act was enforced by the Ministry of Environment and came into effect of May, 24. These criteria shown in Table 3 have used for the evaluation of air quality on the ships. ANSI/ASHRAE standard 55-1992 (ASHRAE, 1992) was also referred for evaluating the indoor climate condition. Table 3. Indoor air quality criteria. Parameter WHO/Europe ASHRAE IAQ Act in Korea TVOC Toluene Benzene Ethylbenzene Styrene Xylene Formaldehyde CO CO 2 SO 2 Particulate matter 26 µg/m 3 (1 week) 26 µg/m 3 (1 week) 1 µg/m 3 (3min) 1 ppm(8h) 5 µg/m 3 12 µg/m 3 (3min) 1 µg/m 3 9 ppm(8h) 1 ppm 8 µg/m 3 (1year) 5 µg/m 3 5 µg/m 3 1 µg/m 3 3 µg/m 3 36 µg/m 3 3 µg/m 3 7 µg/m 3 21 µg/m 3 9 ppm 1 ppm.5 ppm 15 µg/m 3 RESULTS Temperature and relative humidity Figure 2 shows the temperature and relative humidity on the ships. The temperatures mainly ranged from 2 C to 26 C in the accommodation, which were acceptable for human comfort. However, temperature reached over 3 C at the engine rooms due to the heat transfer from the operating engines. The average relative humidity on the passenger ship was 24.6% at the 1 st measurement and 34.4% at the 2 nd measurement, which was relatively lower than the relative humidity criteria. The average relative humidity on the chemical ship was 59.9%, and it can be included to the comfort zone for summer. There was not so much variation in the temperature and relative humidity distribution on the passenger ship, but it seemed that the indoor climate on the chemical ship was not controlled fairly well.

8 7 6 8 7 6 1st measurement 2nd measurement R. H.(%) 5 4 3 for winter for summer R. H.(%) 5 4 3 for winter for summer 2 2 1 1 1 2 3 4 Temperature( C) Figure 2. Comparison of temperature and relative humidity. a) The chemical ship and the passenger ship, b) 1 st measurement and 2 nd measurement on the passenger ship Pollutant concentrations on the new ships Figure 3, 4, and 5 shows the comparative data sets of the pollutant concentrations on two different types of ships. TVOC concentrations were higher than the domestic criteria, 5μg/m 3, all over the chemical ship. Especially, the concentration levels in a crew s cabin, the engine control room, and the engine room were so high as to exceed 3, μg/m 3. For the passenger ship, apart from the seminar room and the kitchen, TVOC concentrations were low when compared to the criteria and the chemical ship. As Figure 4 demonstrates, concentrations of most selected VOCs were also higher in the chemical ship than in the passenger ship. Concentrations of VOCs including toluene, ethyl benzene, xylene, and styrene were lower than the recommended standards in most locations, but a relatively larger quantity of toluene was detected in the engine control room of the chemical ship. Besides these four selected VOCs, variety of compounds were also detected including nonane, dodecane, tetradecane, 1,3,5-trimethyl-Benzene, and etc. The average formaldehyde concentration was 18μg/m 3 on the passenger ship and 29μg/m 3 on the chemical ship, which was much lower than the criteria. There was not so much difference in formaldehyde concentration between the ships. 1 2 3 4 Temperature( C) Em'cy Gen. R. IAQ act in Korea Em'cy Gen. R. ASHRAE standard 1 2 3 4 TVOC concentration( μg / m3 ) 3 6 9 12 Formaldehyde concentration( μg / m3 ) Figure 3. TVOC and Formaldehyde concentrations on the ships. a) TVOC, b) Formaldehyde.

6 5 P C Concentration( μg / m3 ) 4 3 2 1 P C P C P C P C Toluene Ethylbenzene Xylene Styrene Figure 4. VOCs concentrations on two ships. CO and CO 2 concentrations on the passenger ship were below the criteria, but all the measurements on the chemical ship exceeded the criteria largely. CO and CO 2 levels were relatively high in the kitchen, engine control room, and engine room on both ships. Especially, in the engine control room of the chemical ship, the largest quantity of CO and CO 2 was observed. Em'cy Gen. R. ASHRAE standard IAQ act in Korea Em'cy Gen. Room ASHRAE standard IAQ act in Korea 5 1 15 2 CO concentration(ppm) Figure 5. CO and CO 2 concentrations on two ships. a) CO, b) CO 2. 5 1 15 2 CO 2 concentration(ppm) Time variation in pollutant concentrations Figure 6 and 7 present variations of pollutant concentrations on the passenger ship at two different measurement periods. The results showed some differences between the selected VOCs levels and other pollutants. VOCs concentrations were decreased after about one and half year, except a few locations. On the other hand, CO, CO 2, SO 2, and PM levels were increased at 2 nd measurement in 27, and CO and CO 2 levels exceeded the criteria at some locations. Average SO 2 concentration is 13.3 ppm at the 1 st measurement and 29 ppm at the 2 nd measurement, and none of the measurements were below the Korean criteria,.5 ppm.

8 4 Toluene Ethylbenzene 2nd concentration( μg / m3 ) 6 4 2 2nd PM concentration( μg / m3 ) 3 2 1 2 4 6 8 1st concentration( μg / m3 ) 1 2 3 4 1st PM concentration( μg / m3 ) Figure 6. Time variations in VOCs and PM concentrations. a) VOCs, b) PM. 3 12 2nd concentration(ppm) 2 1 CO 2nd CO2 concentration(ppm) 9 6 3 SO2 1 2 3 1st concentration(ppm) Figure 7. Time variations in CO, CO 2 and SO 2 concentrations. a) CO and SO 2, b) CO 2. DISCUSSION Generally, the pollutants concentrations on the chemical ship were higher than those on the passenger ship of which overall air quality was acceptable with a few exceptions. TVOC concentrations on the chemical ship exceeded the domestic and international criteria, while the concentrations in the passenger ship were lower than the criteria. The difference in the IAQ of two ships might be influenced various factors, including the air-conditioning systems, finishing materials, furnish, equipments, and etc. The difference in temperature and relative humidity might be resulted from the different seasonal condition and HVAC operations. Relative humidity seemed to be not so adequately controlled as temperature. High TVOC concentrations were shown in the kitchen, the seminar room, and the salon in the passenger ship. The reason for the high concentrations was considered to be related to the emission from the furniture, electronic equipments, and cooking utensils. In the chemical ship, 3 6 9 12 1st CO 2 concentration(ppm)

TVOC concentrations were high at the engine room and engine control room, and this might be attributed to the the new engines, control panels and other equipments and machinery. Since the chemical ship is not intended to carry passengers, it seems that finishing materials and HVAC systems were not so considered very much as the passenger ship. CO, CO 2, and SO 2 concentrations showed similar patterns throughout the measurements. From the high CO, CO 2, and SO 2 concentrations in the kitchen, engine room, and engine control room, high concentrations might be generally attributed to combustion sources. Contrary to other types of transportations, most ships are usually equipped with kitchen, and careful attention should be paid to prevent the spread of pollutants from the kitchens. Although an engine room is not an occupied space, it is also needed to be managed carefully for keeping good indoor air quality of the adjacent engine control room occupied by crews. Even though combustion sources are not so common on the accommodation spaces, it is necessary to investigate measures against pollutants from kitchens and engine rooms. VOCs were initially observed as a major problem on board ships due to the relatively high amount of cleaning, decorating, and furbishing, but these concentrations appeared to decay over a period. While VOCs concentrations in the ships were decreased with the passage of the time, CO, CO 2, SO 2, and PM concentrations were irrelevant to the time variation or increased with the passage of the time, which is similar to most inland buildings. CONCLUSIONS In this study, indoor climate and air quality was measured and compared on two different types of ships to investigate current status of shipboard air quality. Indoor air quality on ships was not considered to be severe when compared with the problems of inland buildings. However, the crews may stay longer, and poor indoor air quality may have a harmful effect on them. Constructors and operators should be aware of the importance and present status of indoor air quality. Since ventilation design is also one of the most important factors to keep good indoor air quality on ships, it is necessary to go on further research. REFERENCES ABS. 22. Guide for habitability on ships. American Bureau of Shipping. ABS. 22. Guide for passenger comfort on ships. American Bureau of Shipping. ASHRAE. 1992. ASHRAE Standard 55-1992, Thermal Environmental Conditions for Human Occupancy. American Society of Heating, Refrigerating, and Air-conditioning Engineers, Inc. ASHRAE. 24. ANSI/ASHRAE Standard 62.1-24, Ventilation for Acceptable Indoor Air Quality. American Society of Heating, Refrigerating, and Air-conditioning Engineers, Inc. ISO. 22. ISO 7547:22, Ships and marine technology - Air-conditioning and ventilation of accommodation spaces - Design conditions and basis of calculations. International Organization for Standards. Jang M.S., Koh C.D., and Moon I.S. 27. Review of thermal comfort design based on PMV/PPD in cabins of Korean maritime patrol vessels. Building and Environment, 42, 55-61. Webster A.D. and Reynolds G.L. 25. Indoor air quality on passenger ships. In: The Handbook of Environmental Chemistry, Vol. 4, pp. 335-349. WHO. 2. Air Quality Guidelines for Europe, 2 nd edn. World Health Organization Regional Publications, European series No. 91.