For The IAQ Industry           April, 2007 Vol. 1

HVAC & Sick Buildings

As ventilation is a significant consumer of energy, the rates of ventilation are often minimized in order to reduce equipment and energy costs. Buildings, particularly those in cold climates, have also become more airtight a factor which has reduced ventilation airflow through the building envelope. It has been shown that ventilation rates have adverse effects on communicable respiratory illnesses; on sick building syndrome symptoms; on productivity and perceived air quality. In many studies, the prevalence of sick building syndrome symptoms has also been associated with the characteristics of ventilation systems. Often the prevalence of SBS symptoms is higher in air-conditioned buildings than in naturally ventilated buildings. The evidence suggests that improvements in the hygiene, commissioning, operation and maintenance of air handling systems may be particularly important for reducing the negative effects of air conditioning systems.

Chemical Sensitivities

There are a significant number of people who are sensitive to chemicals. Surveys conducted by the California and New Mexico Departments of Health and by medical researchers in North Carolina found 16 to 33 percent of the people interviewed reported that they are unusually sensitive to chemicals, and in the Calif ornia and New Mexico health departments' surveys 2 percent t o 6 percent reported that they have been diagnosed as having multiple chemical sensitivities.

Burning Incense is a Hazard

Studies have shown that human exposure to fine particulate matter (PM) constitutes a potential health hazard.  It has been found that burning incense is a significant source of PM and has been linked to various illnesses. Studies in the literature have found harmful health effects associated with incense smoke including cancers, asthma, dermatitis, mutagenesis, and  genotoxic effects.  Burning incense emits fine PM in large quantities. An indoor air quality model showed that, under certain conditions, burning incense at home can result in indoor concentrations of PM2.5 that far exceed the outdoor concentrations specified by the NAAQS (National Ambient Air Quality Standards).