Buildings complaints from occupants

There have been numerous reports of a spectrum of nonspecific health complaints from occupants of various buildings, including schools, hospitals, and, most often, modern offices. Complaints include respiratory tract infection, irritation of the eyes, nose,... 

Overcrowding issues should be noted. Future occupant density is estimated when the ventilation system for a building is designed. When the actual number of occupants approaches or exceeds this occupant design capacity, managers may find that lAQ complaints increase. At that point, the outdoor air ventilation rate will have to be increased. However, the ventilation and cooling systems may not have sufficient capacity to handle the increased loads from the current use of the space. 

Evaluate airflow patterns into and within the complaint area. Because of the complexity and variability of airflow patterns, investigators cannot be expected to understand how air moves within the building under all potential operating conditions. However, data on pathways and driving forces can help to locate potential pollutant sources and to understand how contaminants are transported to building occupants. The discovery of unexpected pollutant pathways can show a need to study areas of the building that may be distant from the original complaint area. 

It has been estimated that hundreds of billions of dollars per year is lost due to decreased workplace productivity and increased health costs that can be saved by maintaining good indoor air quality in commercial buildings. The financial benefits of improving lAQ can accrue from reducing costs for health care and sick leave, as well as the costs of performance decrements at work caused by illness or adverse health symptoms and of responding to occupant complaints and costs of LAQ investigations. 

The current professional ventilation standard (ASHRAE 62-89) suggests two approaches to ventilation a ventilation rate procedure and an air quality procedure. The former provides a tabular approach to ventilation requirements office buildings require 20 ft of outside air per occupant per minute to maintain occupant complaint rates of environmental discomfort at below 20%. This assumes relatively weak pollution sources. When stronger sources are present, the same rate will provide less satisfaction. For example, when smoking is permitted at usual rates (according to data from the early 1980s), 30% of occupants will complain of environmental discomfort. The second approach requires the selection of a target concentration in air (e.g., particulates, VOCs, and formaldehyde), information on emission rates (pollutant per time per mass or surface), and... 

Viaene MK, Pauwels W, Veulemans H, et al Neurobehavioural changes and persistence of complaints in workers exposed to styrene in a polyester boat building plant influence of exposure characteristics and microsomal epoxide hydrolase phenotype. Occup Environ Med 58 103-112, 2001 Welp E, Kogevinas M, Andersen A, et al Exposure to styrene and mortality from nervous system diseases and mental disorders. Am J Epidemiol 144 623-633,1996 White DM, Daniell WE, Maxwell JK, et al Psychosis following styrene exposure a case report of neuropsychological sequelae. J Clin Exp Neuropsychol 12 798-806, 1990... 

At present an old review (Mplhave, 1986, 1991) is the only available attempt to draw conclusions on dose-response relations. Mplhave clearly states the inadequacy of the data used for the estimates and that these values must be seen in the context that very little health data is available, that the most recent study referred to is from the mid 80 s, and that the researchers are using different definitions of TVOC. It appears that at TVOC concentrations of ca. 3 mg/m complaints are evident in all investigated buildings, occupants having symptoms and odors being perceived in experimental studies. Physiological effects are seen at 5 mg/m, and exposures up to 8 mg/m lead to significant mucosal irritation in eyes, nose and throat. Whereas headaches are reported to occur at levels around 3 mg/m in field studies, chamber studies indicate no such effect at levels below 25 mg/m. At TVOC levels between 0.2 and 3 mg/m, irritation and discomfort may occur if other types of exposures interact. 

While any of these factors can play an important part in the overall lAQ complaint, all four must be present for a complaint to occur. Consider, for example, that a source such as an odor is present in a building, but away from any occupied spaces. The building s occupants are located at the other end of the building. In this instance, even with the odor occurring and the building occupied, if there is no transport mechanism present (HVAC system) an lAQ complaint is not likely to occur. Consider a second example in a building that clearly has a contaminant source and a fully functional HVAC system, but no building occupants. In this instance the chance of an lAQ complaint is also limited. However, in any instance where an... 

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