INDOOR AIR QUALITY

Indoor Air Quality (IAQ) problems can arise from a number of sources such as contaminated air being pulled into the building; emissions from office equipment such as copiers or blue print machines; improperly maintained HVAC systems; human activities such as smoking, housekeeping activities, and maintenance activities; and emissions from building components and furnishings. The use of IAQ services in a building will protect against owner liability; reduce employee sickness and absenteeism; and improve overall building maintenance and production.

AM H&S has trained teams to perform IAQ investigations with a combination of multi-disciplined services and the use of state-of-the-art equipment to ensure that indoor air quality problems will be evaluated and solved in a comprehensive, efficient, and cost-effective manner.

To identify and eliminate existing and/or potential air quality problems, the IAQ team at AM H&S reviews all records and mechanical drawings relevant to indoor air quality; interviews employees; inspects the facility; conducts long- and short-term air sampling for airborne contaminants such as dust, relevant volatile organic compounds, formaldehyde, and bioaerosols; examines and evaluates building HVAC systems; and performs basic IAQ testing for comfort levels. Basic IAQ testing consists of the collection of carbon monoxide (CO), carbon dioxide (CO2), relative humidity, and temperature utilizing a hand-held direct reading instrument to log results.

Upon completion of these steps, the team compiles and analyzes lab data and building information, creating a report of administrative and engineering recommendations to promote safe and healthy indoor air quality. In addition, the IAQ team recommendations meet guidelines for interpreting ventilation data established by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) Standard 62-1989 “Ventilation for Acceptable Indoor Air Quality.”

In order to efficiently investigate IAQ problems, the causes must be understood. The National Institute of Occupational Safety and Health (NIOSH) performed a study of 500 federal buildings. Of all the known causes of IAQ problems, 52 percent were inadequate ventilation, 16 percent were pollution sources inside the building, and 10 percent were sources outside the building. For this reason, airborne contaminant sampling may not always be the primary step. Due to the complexity of indoor air quality and the diversity in each case, the following IAQ investigation strategies are utilized as guidelines that are modified to each specific building.

Preliminary IAQ Investigation

A Preliminary IAQ Investigation may involve:

• Discussions with property/building management;

• Evaluation of concern;

• Walkthrough investigation of building and surrounding areas by an industrial hygienist;

• Discussions with HVAC maintenance—drawings, review of maintenance schedule, preventative

maintenance program;

• Preliminary observation/review of the HVAC system;

• Direct readings of carbon monoxide, carbon dioxide, relative humidity, and temperature for a general

review of the indoor comfort levels, ventilation system efficiency, and possible causes of building occupant

health complaints;

• Determining potential indoor and outdoor sources of indoor air pollution;

• Obtaining relevant material safety data sheets (MSDS); and

• Presenting report of findings with Phase I IAQ survey strategy, if necessary.

Phase I IAQ Survey

In addition to the actions taken in a Preliminary IAQ, a Phase I IAQ Survey may involve:

• A continuous data log of carbon monoxide, carbon dioxide, temperature, and relative humidity for approximately one week in each problem area and in one non-complaint area as a control;

• A detailed review of HVAC system to include:

Fresh air supply rate

HVAC efficiency

Exhaust system efficiency;

• The distribution of building occupant questionnaire forms/reviews;

• Once the pollutant source is suspected, conducting one or two days of full shift airborne area concentration monitoring of potential indoor air contaminants;

• Conducting surface wipe or water microbial testing and outdoor bioaerosol monitoring to compare with bioaerosol results to find sources of possible airborne occupant exposures; and

• Presenting a report of findings with recommendations of HVAC preventative maintenance, and Phase II IAQ survey strategy, if necessary.

Phase II IAQ Survey

In addition to the services of a Phase I IAQ Survey, a Phase II IAQ Survey may involve:

• A definitive review of HVAC system and drawings by a mechanical engineer;

• Follow-up occupant questionnaires with detailed occupant interviews;

• CADD quality drawings of HVAC systems and other indoor pollutant sources as necessary to illustrate indoor source pollution;

• An industrial hygienist on site for three to four full shifts to observe work practices of people working inside and in the vicinity of the building;

• A report with findings and recommendations;

• A client meeting with management to discuss report; and

• An IAQ survey follow-up meeting with building occupants and building management to explain the purpose for the investigation, findings, and proposed solutions.