WNYLaborToday.com Editor’s Note: The Center for Occupational & Environmental Medicine (COEM), located at Buffalo’s Erie County Medical Center (ECMC), is available to Workers both Union and non, providing care to those who are injured, impaired or who develop an illness as a result of workplace factors – which may include exposure issues, physical injuries, or any other job hazard.  The COEM is also a New York State Department of Health-funded Clinic for the diagnosis and treatment of occupational injuries and illnesses for Workers living in the five counties of Western New York.  The COEM also offers services for any Worker with other job-related medical needs, such as physicals required for employment or licensure - and they assist with completion of paper work for Worker Compensation Claims. With state-of-the-art diagnostic equipment and a highly-skilled and caring Staff, the COEM’s Health Care Services meet U.S. Occupational Safety & Health Administration (OSHA), U.S. Environmental Protection Agency (EPA) and Department of Health Safety Standards.  The COEM takes a different approach to the treatment of injured Workers through prevention, early diagnosis and treatment.  Opened in 2015, the COEM was developed with great support from Western New York Labor Unions and their Leadership.  The COEM, which is open Monday through Friday - 9 a.m. through 5 p.m., can be reached at 716-898-5858.

The author of this article is Nellie Brown (pictured below), who serves as the Director of the Workplace Health and Safety Program, a Statewide Program of the Worker Institute at Cornell University’s School of Industrial and Labor Relations.  Nellie provides Industrial Hygiene Services for the COEM.

Dennis has been experiencing asthma flare-ups which allergy testing indicates is triggered by fragrances and dust.  Recently, it has become so serious at work that he has been working from home.  His employer wants to find out if the indoor environment in the office building is a problem and what could be done to help Dennis.

Indoor Air Quality or IAQ is what we experience as the temperature, humidity, ventilation, and chemical or biological contaminants of the air inside a non-industrial building, such as schools, offices, hotels or banks - environments typically considered pristine when compared with industrial settings.

In today’s world, we spend about 90% of our day indoors and the pollution indoors is two to five times - and occasionally more than 100 times - higher than outdoor levels.  After all, we humans exhale (and otherwise produce) the end-products of metabolism.  We shed hair and dander.  We have in our buildings all kinds of textiles, equipment, paper, cleaning products, and maintenance activities - so the air can be very different from “fresh outside air.”

We notice this difference – sometimes simply as odors and sometimes as symptoms such as: Irritation of eyes, nose, or throat; Dry mucous membranes and skin: as Erythema, the reddening or flushing of the face or skin; Mental fatigue, headache, sleepiness; Airway infections, cough hoarseness, wheezing, nausea, dizziness and hyper-sensitivity reactions.

Studies of buildings have indicated that poor IAQ can cause health problems, affect occupants’ productivity and reduce learning, as well as have liability issues and cause poor public relations - a building gets a bad reputation affecting leasing and purchasing.

Overall, there appears to be higher costs to fix problems than to prevent them.  So, if we suspect an IAQ problem, how might we investigate it? Because, without a comprehensive building investigation, sampling results alone are only of limited value.

So, let’s look at some typical causes and solutions of IAQ problems.  In a nutshell, a basic Indoor Air Investigation consists of: Collecting information from building occupants concerning the nature of the complaints; Checking for patterns of symptoms and times at which they occur. (Medical expertise may be needed to investigate serious health problems.); Investigating building ventilation for the nature of its operation, its adequacy, and maintenance; Verifying with carbon dioxide or other measurements, as appropriate; Seeking out sources of contaminants (sometimes with sampling or monitoring) which may originate from inside the building or out; Biological contamination (such as fungi, “mold,”, “mildew” and other) of the building; Building construction materials; and Reporting and discussing findings and recommendations.

Dennis and his Co-Workers were asked to fill out indoor air quality questionnaires and 28 of 33 people responded.  Their complaints included: Temperature in the offices feels too cold; The air is stuffy and stale; There seems like a lack of air circulation; Sneezing and coughing occurs more when at work; Allergies also act up more at work; and the appearance of fruit flies.

The U.S. Environmental Protection Agency (EPA) recommends that building occupants should be kept informed during the entire process of an Indoor Air Quality (IAQ) investigation and mitigation - I’ve learned these items the hard way, so I am in complete agreement - including: 

How the investigation is progressing, the types of information being gathered and the ways that they can help the process along; The nature of the health problems being reported (this enables occupants to put their symptoms into perspective); How long the investigation is expected to last; Any attempts that are made to improve Indoor Air Quality; and Any remaining work which needs to be done and the schedule for its completion.

There are also other questions to ask, including what is the basic information on the building and its history: How is the building constructed?  And is there any remodeling/redecorating, storm events, sewer backups, flooding, or other problems?  Dennis’s building was constructed back in 1987, with remodeling occurring in 2005 and 2006.  It’s constructed of concrete block and brick and its interior walls are drywall on steel studs.  The foundation is a concrete slab on grade, the roof is a rubber membrane covered with stone and the ceiling consists of ceiling tiles (cellulosic). Almost all rooms are carpeted and the kitchen and restrooms have floor tiles.

You can also ask about ventilation inadequacy as a source of any indoor air problems: Ventilation can be “inadequate” for one or more of several reasons.  There may simply be insufficient fresh outdoor air being brought into the building, usually to lower heating/cooling costs, or the ventilation system doesn’t match occupancy – it starts too late in the morning or shuts down too early in the afternoon.  Sometimes there’s poor air distribution and mixing - even an open-plan work area can have partitions down to the floor restricting airflow; and Maintenance of the Heating/Ventilating/Air-Conditioning (HVAC) system can be improper, inadequate or completely absent - the accumulation of dirt and particulates (pollen, fibers, debris, bird nests and feces, leaves, etc.) in air intakes, on filters or in ductwork can lead to many health complaints, as well as provide habitats for micro-organisms to flourish.  A damaged bird screen on an air intake can allow all kinds of critters to enter, nest and defecate in the ventilation system and, bring diseases with them.

One way to determine if there is sufficient fresh air supplied in a building to meet the needs of the occupants is to consult ASHRAE Standard 62.1 - Ventilation for Acceptable Indoor Air Quality (ASHRAE is the American Society of Heating, Refrigerating, and Air-Conditioning Engineers).  This standard attempts to maintain good Indoor Air Quality by recommending sufficient fresh air to keep the concentrations of carbon dioxide in the occupied spaces at no more than 700 ppm higher than the outside air concentration (typically about 400 ppm).  Carbon dioxide is exhaled by people, so the CO2 level inside the building is usually higher than that outside the building anyway.  At these levels, CO2 itself is not causing problems, but it is a useful surrogate - especially as inadequate ventilation can cause other air contaminants to build up to concentrations at which they can cause symptoms.

The offices in Dennis’s building are served by eight rooftop central Air Handling Units (AHUs) with more than sufficient capacity for fresh and recirculated air for the building’s occupancy. Each AHU has a rooftop air intake from which air is supplied to the rooms through ducts.  From each office or zone, the return air is ducted back to its rooftop AHU.  The building’s exhaust air exits from powered exhausts in the restrooms, but these have manual switches – a restroom occupant could turn off the exhaust, as was observed in one restroom during the site visit. Measurements of the air concentration of carbon dioxide in the offices ranged from 700 to 1,000 ppm - thus all office areas appeared to have a sufficient fresh air supply for the building occupancy present during the site visit.  However, on other occasions when more Field Staff are in the office, all the exhausts will need to be running to enable sufficient fresh air supply and exhaust - so these should be part of the automatic HVAC and not under manual control.

For evaluating temperature and humidity in a building, the ASHRAE Standard 55 on Thermal Environmental Conditions For Human Occupancy is useful.  This standard has charts recommending acceptable ranges of temperature and humidity for people in typical Summer and Winter clothing doing light, primarily sedentary, activity and aims for 80% of the occupants to be satisfied/comfortable.  No minimum humidity limit is recommended for thermal comfort.  However, very low humidity could produce skin drying, irritation of mucus membranes, dryness of the eyes, and static electricity generation.  Similarly, the maximum recommended humidity addresses human comfort only, not the potential for high humidity levels resulting in condensation on building surfaces which in turn could lead to microbial growth.  

Room air temperature and humidity measurements were also made in Dennis’s building and the results indicated office temperatures ranged from 70.9 to 77.0 F.  These met the recommendations of ASHRAE Standard 55.  The humidity ranged from 16.8% to 26.8%, which is fairly dry.  While the air temperatures would not usually be considered cold at all, very dry air can make us feel that temperatures are cooler.

Exploring the inside sources of air contaminants involves evaluating the processes and products which are used indoors - many can produce irritants or particulates in the air.  Exposure to these items can be aggravated where there is a lack of sufficient ventilation as these contaminants cannot be diluted and flushed from the building (where this is possible for the contaminant in question).  Here are some possibilities: Paints, varnishes, glues; often made with solvents; Pesticides, due to active ingredients and/or the solvent carriers; Off-gassing from new carpets, floor tiles, wall coverings, furniture, partitions - especially plywood, particleboard and strand board, or from new equipment, such as computers; Custodial products used for cleaning, disinfecting or polishing; Fibers from textiles, insulation, paper products, ceiling tiles and air filters; Ozone and nitrogen dioxide from xerography (photocopying), these gases plus ultra-fine particulates from printers (especially laser printers); Nitrogen oxides, sulfur oxides, formaldehyde and miscellaneous other contaminants from smoking, cooking, pilot lights, heaters and boilers; and Formaldehyde and dusts from carbonless copy paper.

A review of cleaning and other chemical products used in Dennis’s building indicated a number of products with perfumes and fragrances.  The restrooms had liquid fragrance dispenser/heater units plugged into wall outlets.  The women’s restroom had a wall-mounted fragrance dispenser unit and the men’s restroom had a deodorant product dispensed in the urinal.  Dennis shares his office with two other staff who had brought an aromatherapy diffuser into the office.  Due to the trend of adult-onset asthma, it is prudent to consider removing from the indoor environment potential triggers of allergy, such as fragrances.  It is also important to convey to building occupants that they need to have any products they bring into the workplace screened by the employer so that the employer can determine if such items are necessary and to obtain their safety data sheets (as per OSHA regulations).

Note that custodial work and the use of cleaning products often occurs at night when ventilation in the building may be reduced (or even off).  This means potential chemical exposure for Housekeeping Staff, plus air contaminants remain in the building for the next day’s occupants to breathe.  Solutions for inside sources may involve: Choosing alternative products or processes for doing the task; Scheduling the task to avoid exposure by building occupants; or Using local exhaust ventilation (such as venting a high-use copier to the outside when more frequent replacement of the carbon filter on its exhaust is not sufficient).

The “dust” in a building can include grit, plastic dusts, fibers from carpets and clothing, human dander, pet dander (which people bring to work on clothing), pollen, mold spores, and dust mites (and their excrement).  For Dennis’s dust allergy, it could be helpful to upgrade the vacuum cleaner to one with a High-Efficiency Particulate Air (HEPA) Filter.  While removing carpet can also help with dust mite problems, it is not always an option – especially if the workplace needs the carpet to control noise.  Smoking, even when restricted to the outdoors, should be kept at a distance from air intakes or entrances.  An alternative would be to move the smoking area further out into the parking area, provide a small shelter for it, or ban it from the property altogether.

Exploring potential outside sources of indoor air contaminants involves looking at building exhausts, as well as products and processes which happen adjacent or nearby to the building - these could be brought into the building through air intakes or infiltration (leakage around windows and doors).  Some examples would be exhaust gases from traffic (including idling delivery trucks) or exhaust air from the building (including boiler stacks and sanitary stacks) which is brought back in the air intakes.  A building operated under negative pressure may result in the pressure differences causing the air flow where unwanted, such as backwards down the sanitary stacks.  Solutions could include: Raising stacks to allow better dispersal of exhausts or separating intakes and exhausts through height or distance or relocating air intakes.  As the New York State Department of Environmental Conservation (NYSDEC) has a regulation which limits the idling of vehicles, it could be helpful to put up signage forbidding idling and enforcing it for delivery trucks.  For Dennis’s building, air intakes, exhausts, and sanitary stacks were identified on the roof.  Observations were made for the air intake minimum separation distance from contaminant sources as per ASHRAE 62.1 and the observed exhausts appeared well separated from the air intakes.

The investigation of biological sources tends to reveal that they are commonly related to a current or past history of building water damage from leaks or condensation, standing water in ducting or other parts of an HVAC system, bio-films on HVAC components (such as coils), or high building humidity levels.  Sometimes they’re related to a very tight building causing the recirculation of aerosols from occupants coughing or sneezing.  Other sources may include infestations of insects or rodents due to the availability of food sources, inadequate bird screens or mites in paper storage or archival areas.  Some contaminants may be allergens such as cockroaches, rodents, or pet dander (as noted above).  It can be helpful to inquire whether a building has an integrated pest management program so that critters can be controlled using methods of lowest risk to occupants.  For Dennis’s building, one AHU had a damaged and loose bird screen.  This should be repaired to prevent birds, insects or vermin from entering the HVAC System and their droppings providing a habitat for fungal growth.  A removable, cleanable rug is located at the front door - this is very useful to stop dirt and moisture being tracked into the building where they can provide habitat for bacterial or fungal growth in carpets.  Similar rugs should be placed at all doorways that lead into carpeted areas.  No water stains were observed on the ceilings or walls.  A moisture meter was used to evaluate carpets, as well as cabinets in the restrooms and kitchen - the results indicated levels that would not be expected to support microbial growth.  A survey respondent noted the presence of fruit flies.  Typically, fruit flies may be associated with cans and bottles collected for recycling which contain residues that attract and support flies.  Besides better rinsing of these containers, they could be placed in sealed plastic trash bags or sealed containers soon after rinsing.  Investigating sources of air contaminants which arise from the construction materials of the building could involve the off-gassing of new materials (such as plywood or particle board), dusts from installation of drywall, or fibers from insulation.  Another example of this category would be exposure to formaldehyde from urea-formaldehyde foam insulation.  Typically, off-gassing from new materials tends to be most troublesome in the first few months after installation.

In the end, for Dennis’s building, the most recent remodeling was reported as taking place in 2006, when Dennis’s employer moved into this building, and thus the project work is most likely too old to currently constitute a problem.