TIPOS DE TRABAJO INFANTIL Y LOGROS DE APRENDIZAJE

The discussion on monitoring location consist of three topics; monitoring area (Section 5.6.2.1), monitoring location within monitoring area (Section 5.6.2 2), and monitoring height (Section 5.6.2.3).

5.6.2.1 Monitoring Area

Since the objective of monitoring the airborne pollutants is to determine their health hazards to office workers, occupied areas, workstations, and problem and non problem areas are included as the monitoring areas. The criteria for determining the problem are the symptoms of building sickness and the presence of excessive airborne pollutants. Another criterion which is used to select the monitoring areas is representative. Some literature dcS%ot specify the monitoring areas in the study building. The preceding paragraphs 5aborate the monitoring areas used by the previous researchers.

Shaw et al (1991) monitored the concentration of carbon dioxide and carbon monoxide at the occupied areas within each of the seven upper floors of an eight storey building. Goyer (1990) reports a thorough measurement of chemical pollutants in seventeen office towers. The measurement was conducted in workstations.

Some literature stat^that the monitoring areas included problem and non-problem

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or in which the airborne pollutants are suspected to be generated excessively. Therefore, non-problem area means an area which neither have the symptoms nor excessive airborne pollutants. The non-problem area is also known as the control area (Quinlan et al, 1989) and the area of least potential problem (Yocom and McCarthy, 1991).

According to Yocom and McCarthy (1991), the problem areas which should be monitored include the areas of lowest ventilation efficiency, highest potential source, and occupied by the most susceptible office workers. The problem areas which were monitored by Goyer (1990) included smoking areas, print shops, workshops using solvents, and wet-process photocopier rooms. In a study on VOCs in a building with health and comfort complaints, the elevator shaft and the elevator machine rooms were found as the problem areas (Weshler et al, 1990).

This paragraph describes the building, area, and location which are used for monitoring control of airborne pollutants. Quinlan et al (1989) recommend another part of the building or similar building in which the occupants do not complain as the control building or area. The control locations for monitoring outdoor air are at the roof and street levels. Outdoor air was sampled by Grot et al (1991) at both roof and street levels. However, in a study on office-library building, Shaw et al (1991) sampled carbon monoxide, carbon dioxide, and TVOC at roof level only but under different heating, ventilating, and air- conditioning mode. The control locations for monitoring air in the heating, ventilating, and air-conditioning systems are reported at downstream and upstream of the intake fan and at the return fan. Air in the heating, ventilating, and air- conditioning systems was sampled by Grot at al (1991) at downstream and upstream of the intake fan and at the return fan. In a study on an office-library building, Shaw et al (1991) sampled carbon monoxide, carbon dioxide, and TVOC at the return duct only but under different heating, ventilating, and air-conditioning mode.

Some literature state^that the monitoring areas are or should be based on building ^ sickness sym ptom^or representative. Representative is based on the physical

characteristics of the building and the activity of the office workers. Quinlan et al (1989) recommend the monitoring location to be in the area where the office workers, who are experiencing the symptoms of building sickness, work. In a study on fourteen buildings, Skov et al (1990) selected one representative office in each of the buildings. The criteria of representative are building material, equipment, size, and activity. The exact monitoring location within the representative office is not stated.

Some literature do not specify the monitoring areas in the study building. Weschler et al X (1990) report a comprehensive investigation of VOCs in buildings. But in the report, the determination of monitoring areas is not stated. Grot et al (1991) monitored airborne

pollutants at more than 100 monitoring locations in an office building including interior spaces. However, the exact monitoring areas in the interior spaces is not stated.

S.6.2.2 Monitoring Location within Monitoring Area

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Some literature report that the middle of the monitoring area is selected or recommended as the monitoring location. Shaw et al (1991) monitored the concentration of carbon dioxide and carbon monoxide at the centre of the occupied area. In discussing the monitoring for enforcement of regulation, Kagawa (1993) states that indoor monitoring should be conducted in the centre of the room. But some literature, for example Goyer (1990), do not specify the exact location of the monitoring location in the monitoring area.

5.6.2.3 Monitoring Height

A monitoring height of between 1.1 to 1.5 metre from floor is used in the monitoring of airborne pollutants. However, a monitoring height at a lower level is also possible. ASHRAE Standard 62-1989 defines the occupied zone as the space 75 to 1,800 millimetres above the floor and not closer than 600 millimetres from walls or air- conditioning units. In discussing the monitoring for enforcement of building regulation, Kagawa (1993) states that a monitoring height between 0.75 to 1.2 metre is used. However, past researchers of airborne pollutants used a monitoring height between 1.1 to 1.5 metre from the floor. Skov et al (1990) sampled airborne pollutants at a monitoring height 1.1 metre from the floor. Rohbock et al (1988) sampled air at a working place or a desk in the middle of the room, 1.5 metre above the floor.