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Indoor air quality 101: Investigating the air you breathe

By Timothy Bryant
| www.cos-mag.com

A component of workplace health that is often overlooked is the one component that cannot be avoided: the air we breathe.

The air quality inside a workplace is often the cause of myriad health problems, ranging from a mundane dry throat or headache to more serious bouts of nausea and dizziness.

A clue that workplace IAQ may be causing these problems is if the symptoms subside outside the workplace, only to flare up upon returning to work.

Poor indoor air quality can have a negative effect on productivity and morale, as employees have to cope with their environment while trying to do their jobs. In prolonged cases, it can also lead to problems with employee retention and recruitment.

Signs of poor IAQ:

•    dryness and irritation of the eyes, nose, throat and skin
•    headache
•    fatigue
•    shortness of breath
•    hypersensitivity and allergies
•    sinus congestion
•    coughing and sneezing
•    dizziness
•    nausea

But assessing the cause of poor IAQ is far from a simple process. To perform a proper assessment requires being aware of poor IAQ’s many causes, which can include (but are not limited to) an inefficient HVAC system, mould from water damage and volatile organic compounds from cleaning chemicals or new furniture.

It is this variety of causes that prompts industrial hygienist John Oudyk to say, “investigating IAQ problems can be one of the most complex things that hygienists do.”

Conducting IAQ assessments

There are two ways an IAQ assessment can be conducted: internally or by hiring an outside consultant. In both cases the same steps are usually taken.

The majority of IAQ assessments conducted in Canadian workplaces are reactive, in that they are performed as part of an investigation into an employee’s complaint.

“It’s an investigation of indoor environmental conditions related to health and comfort complaints reported by occupants,” says Chris Collett from Christopher Collett and Associates Ltd., a Vancouver-based IAQ services consulting company. He added the majority of complaints he investigates are comfort complaints.

In many cases the first step is to talk to the people who are complaining about IAQ, in order to fully understand what the problem is. This gives the assessor the opportunity to determine how best to go about his or her investigation.

“What we want to do is we want to take the pattern of complaints that happen and to look for stressors and to see what might need to be improved,” says Bruce Stewart, vice president with Pinchin Environmental Ltd.

Since most complaints are comfort-based, which consists of such elements as temperature and relative humidity, the usual course of action is to examine the building’s HVAC system.

“If it’s a general ventilation issue, we always ask to inspect the air-handling units,” says Stewart. “We are looking for issues of cleanliness, recent calibration, the fresh-air intake, where it’s located, the condition of the filters and the minimum amount of fresh air that is being provided by the system.”

This HVAC system check will often yield problems which, when corrected, will alleviate the problems that caused the complaints. If this doesn’t happen, it is often in the company’s best interests to call in an investigator or consultant.

Common indoor air contaminants and their main sources:

•    Carbon dioxide (CO2), tobacco smoke, perfume, body odours -- from building occupants.

•    Dust, fibreglass, asbestos, gases, including formaldehyde -- from building materials.

•    Toxic vapours, volatile organic compounds (VOCs) -- from workplace cleansers, solvents, pesticides, disinfectants, glues.

•    Gases, vapours, odours -- off-gas emissions from furniture, carpets, and paints.

•    Dust mites -- from carpets, fabric, foam chair cushions.

•    Microbial contaminants, fungi, moulds, bacteria, -- from damp areas, stagnant water and condensate pans.

•    Ozone -- from photocopiers, electric motors, electrostatic air cleaners.

The next step in an assessment is a walkthrough of the building, and can be done in conjunction with the HVAC examination. The general point of the walkthrough is to compare the layout of the building with a plan of the ventilation system, which helps the investigator spot any problems with the system that could contribute to reduced IAQ.

The walkthrough can also be used to identify any other contributing factors, such as photocopiers, cleaning agents or water damage, all of which can affect IAQ and have their own remediation procedures.

Also included in the walkthrough, although often a separate part of an assessment, is performing general IAQ measurements. This is done using different instruments to measure the temperature, relative humidity, carbon dioxide and carbon monoxide levels in the building being tested.

These readings are used to determine the effectiveness of the HVAC system. The carbon dioxide levels are a measure of how well the system circulates air into and out of the building, whereas the temperature and humidity levels demonstrate how consistent the system is. The carbon monoxide levels are often indicative of the location of the HVAC intake manifold.

IAQ reporting

How these levels are assessed differs depending on the consultant performing the investigation. In many cases, the consultant will walk through the building, taking spot readings in various locations. This is often accompanied by leaving a measurement station in a specific location for upwards of a week. This is done to assess any changes in the environment, such as fluctuations in temperature or humidity that can’t be assessed through simple spot checks.

Upon completion of the investigation, a report is drawn up outlining the findings. Again, what the report contains is dependant on the consultant and what he or she found. Some reports will simply list the findings, while others will list the findings and provide recommendations.

In extreme cases further tests will be suggested, often in the case of mould findings. But rarely will a mould test be performed without an indication that it may be present. “I do not advocate routine mould measurements,” says Collett, citing such inspections are expensive.

It is necessary to note that despite the best work to improve IAQ in a workplace, it may be impossible to eliminate complaints completely. Failure to please everyone in the workplace may be disappointing, but is accounted for in many IAQ regulations.

“The gold standard for determining whether you have adequate air quality and acceptable thermal conditions is to keep 80 per cent of your people happy, and the only way to assess that is to ask them,” says Oudyk.

A companion to a typical, reactive IAQ assessment is a proactive IAQ audit. These audits are usually performed in order to stay on top of any IAQ issues that may arise. Collett views them as preventative measures that often comprise part of a building’s routine maintenance process.

“There really isn’t any immediate need for proactive IAQ investigations,” says Stewart. “Some people will find them of value, but most are complaint driven.”

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