Air Quality Makes a Difference in Offices.

Office air quality can be a major contributor in lost time and increased sick days. Indoor air affects the body in several ways:

the nose detects odors; mucus membranes are affected by changes in humidity; airborne pollen can aggravate allergies. Air pollutants can cause colds, allergy attacks, sinus problems and headaches.

The Sick Building Syndrome occurs when the concentration of pollutants and/or the interaction between pollutants causes temporary illness among occupants. Common complaints of Sick Building Syndrome are headaches, fatigue and membrane irritation. These symptoms are relieved when the person leaves the building.

Building-Related Illness (BRI) concerns infections or diseasescaused by bio-aerosols that find favorable growth conditions in the building environment. The bio-aerosols are fungi, bacteria, and viruses that flourish in car peting, furnishings, and air-handling systems. Unlike Sick Building Syndrome-related illness, BRI's usually require medical treatment.

These problems are not a result of the age of the building but more so of the ventilation, air changeover; pollution-causing equipment (such as blueprint machines, some copiers), and the people themselves.

The two basic standards used to specify, control, and evaluateindoor air quality are:

* Prescriptive criteria, describing acceptable system throughout, such as ventilation rates, is used primarily during building design stage to determine system capacity needs.

* Performance criteria, describing acceptable conditions within occupied spaces, such as temperature and humidity conditions based on scientific findings, are used for system evaluation and control after construction.

In 1989 the American Society of Heating, Refrigerating, and Air- Conditioning Engineers (ASHRAE) published a revised "Ventilation Standard for Acceptable Indoor Air Quality". (ASHRAE 62-1989) as a prescriptive standard for office buildings based on the air-flow rate per occupant. The previous rating of 15 cubic feet per minute (CFM) per person was revised to 20 cfm to meet the need of a typical office.

Careful maintenance programs on your air-handling system can prevent many of the problems outlined here.

Robert McNamera is a Office Standards Consultant based in San Jose.