Indoor Air Quality- What You Need to Know

Transcription

1 Indoor Air Quality- What You Need to Know Overview Indoor air quality (IAQ) concerns present ever-mounting problems to facility managers and health and safety personnel. From toxic mold to carbon dioxide levels, the adverse health effects from poor IAQ are flooding the news and resulting in the loss of millions of dollars and countless workdays to businesses and institutions everywhere. Federal regulations and guidance exist to help combat IAQ-related problems, but most dilemmas are easily alleviated through the use of some common-sense approaches. Good IAQ includes the introduction and distribution of adequate air ventilation, control of airborne contaminants, and maintenance of acceptable temperature and relative humidity. A basic rule for ventilation and replacement of air is that for every cubic foot or meter of air exhausted, a cubic foot or meter of air must enter the building. The consequences of poor IAQ are numerous and include the following: 1 Health problems such as cough, eye irritation, headache, and allergic reactions. In some cases, life- threatening conditions such as Legionnaire's Disease and carbon monoxide poisoning are created. Reduced productivity resulting from discomfort and absenteeism. Accelerated deterioration of furnishings and equipment. Strained relationships between property owners,employers, and facility managers and property occupants or tenants, employees, and facility users. Negative publicity. Legal liability (pollution-related claims are often excluded in insurance policies). The following are some common workplace contaminants and possible sources that may cause adverse health effects: Contaminant Health Effects Example of Sources Carbon Monoxide Nausea, headaches, visual disturbances, brain damage, angina Automobile exhaust; improperly vented stoves, hot water heaters, and furnaces Formaldehyde Mucous membrane irritation, fatigue, skin rash, and cancer from high exposures. Particle board; plywood; adhesives in office furnishings and carpets; and tobacco smoke Ozone Upper respiratory irritation; dry eyes Copiers; laser printers; air Organic Vapors Upper respiratory irritation; fatigue and nausea; long term exposures result in liver and kidney damage ionizers Paints, solvents, disinfectants and plastics

2 Asbestos Asbestosis (lung tissue damage); mesothelioma (cancer of peritoneal lining); lung cancer [Pipe] insulation; ceiling and floor tiles Dusts Upper respiratory irritation; dry throat; Various rhinitis Biological Agents - fungi, Hypersensitivity pneumonitis, chronic Various bacteria, viruses, protozoa rhinitis, common respiratory ailments Carbon Dioxide Fatigue and malaise; shortness of breath Bioeffluents; poor HVAC operation. ASHRAE The American Society for Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) periodically publishes standards and guidelines for improving IAQ. Acceptable air quality is a factor of the given quantity and quality of outdoor air coupled with occupant density and space use. Standards have also been developed that cover such environmental parameters as thermal comfort, radiation, humidity, and air movement. ASHRAE standards and guidelines plus other governmental regulations and codes guide health and safety personnel (particularly Industrial Hygienists) through IAQ investigations and resolutions for building occupants. ASHRAE Ventilation for Acceptable Air Quality This standard is meant to guide in the proper design of ventilation systems for buildings and presents two procedures for ventilation design: 2 1. Ventilation rate procedure: Acceptable air quality is achieved by specifying a given quantity and quality of outdoor air on the basis of occupant density and space usage. 2. Air quality procedure: This less common method determines a performance specification that allows acceptable air quality to be achieved within a space by controlling for known and specifiable contaminants. ASHRAE also includes a definition of acceptable air, discussion of ventilation effectiveness, recommendation of source control through isolation and local exhaust and for the use of heat recovery ventilation, guidelines for allowable carbon dioxide levels, and appendices listing suggested guidelines for common indoor pollutants. ASHRAE Thermal Environment Conditions for Human Occupancy This standard covers several environmental parameters, such as temperature, radiation, humidity, and air movement. It specifies thermal conditions for comfort in the winter and summer and introduces limits on temperature variations within a given space. It also specifies ranges for humidity, air movement, temperature cycling and drift, radiant asymmetry, and floor temperatures. ASHRAE provides a definition of acceptable thermal comfort, discussion of the additional environmental parameters that should be considered, recommendations for summer and winter comfort zones for temperature and humidity, and guidelines for making adjustments for activity levels and taking measurements. If workplace complaints are made that an area is too hot/cold and/or damp/dry, an industrial hygienist generally uses the following comfort zone ranges as a guide to

3 thermal comfort during air quality monitoring: Examples of acceptable operative temperature ranges based on comfort zone diagrams in ASHRAE Standard Conditions Acceptable operative temperatures C F Summer (clothing insulation = 0.5 clo) Relative humidity 30% Relative humidity 60% Winter (clothing insulation = 1.0 clo) Relative humidity 30% Relative humidity 60% Other Standards/Guides Some of the other important ASHRAE standards to keep in mind include the following: ASHRAE Method of Testing Air-Cleaning Devices Used in General Ventilation for Removing Particulate Matter (this standard is intended to assist professionals in the evaluation of air-cleaning systems for particle removal). ASHRAE Guideline for the Commissioning of HVAC Systems (this guideline suggests methods for documenting and verifying the performance of HVAC systems so that they operate in conformity with the design intent). Toxic Mold The key to mold control is moisture control. Here are some preventive tips on how you can reduce the risk of toxic mold growth and exposure. 1. Fix leaky plumbing and leaks in the building envelope as soon as possible. Watch for condensation and wet spots. 2. Prevent moisture from condensation by increasing surface temperatures or reducing the moisture level (humidity) in the air. 3. Keep HVAC drip pans clean, flowing properly, and unobstructed. 4. Vent moisture-generating appliances to the outside where possible. 5. Maintain low indoor humidity, below 60 percent relative humidity (ideally 30 percent to 50 percent). 6. Perform regular building/hvac inspections and maintenance as scheduled. 7. Clean and dry wet or damp spots within 48 hours. 3

4 What to Do Facility Supervisors: Should complaints come pouring in over a particular IAQ issue, there are a few steps you can take to clarify the concern. If you've been keeping good records, you should have helpful building history available (including former employee complaints) from which you can work to narrow down a problem. Here's a basic step-by-step method for resolvingiaq problems: Perform an initial walkthrough. Collect information about the history of the building and complaints. Identify HVAC zones and areas of particular concern. Notify environmental, health & safety personnel of your investigative plans (6-7411). Identify key individuals needed for access and information. Create an incident log. Your incident log should track individual cases, including the date of the incident, location of the problem, and a checklist that covers whether the following have been conducted or determined: Filing of complaint form Occupant interview Log of activities Zone/room record HVAC checklist Pollutant pathway Source inventory Formation of hypothesis Continue to keep a log, reviewing it and interviewing occupants to aid in determining the cause of the specific symptoms affecting your co-workers. Soon, a pattern will emerge. Symptom patterns include thermal discomfort, which can be solved with alterations in HVAC design, rectification of excessive heat loss or gain, and the elimination of drafts or stagnant areas; headaches or dizziness, which often point to uncontrolled emissions or spillage, outdoor air intake problems, or pollutant sources; allergy-like symptoms, which may stem from microbial contamination or chemical leakage; and severe medical symptoms, which requires immediate consultation with a physician and/or occupational health clinic. IAQ problems can be easily fixed using good recordkeeping practices, paying attention to what your coworkers are talking about, and staying on top of all the equipment, chemicals, and aspects of your building. Building Occupants: The following steps can prevent IAQ problems from occurring: Place office furniture, partitions, and equipment with air circulation, temperature control, and pollutant removal functions of the HVAC system in mind. Make sure air supply vents and return grilles are not blocked by furniture or equipment. Computers and other heat-producing equipment placed near or under an HVAC sensor device system can trigger cooling, even if the actual temperature for occupants is cool. Place such equipment away from HVAC sensors to avoid this kind of situation. Comply with the office and building smoking policy. Smoke in designated areas only. 4

5 Clean up all water spills promptly, water and maintain office plants properly and report water leaks right away. Water creates a hospitable environment for the growth of micro-organisms such as molds or fungi. Some of these microbes, if they become airborne, can cause health problems. Dispose of garbage promptly and properly. Dispose of garbage in appropriate containers that are emptied daily to prevent odors and biological contamination. Store food properly. Food attracts pests. Some foods, if left unrefrigerated, can spoil and generate unpleasant odors. Never store perishable food products in your desk or on shelves. Refrigerators should be cleaned on a regular basis to prevent odors. Keep kitchens and dining areas clean and sanitize as necessary to prevent pests and maintain hygiene. Avoid procedures and products that can cause problems. Many common products used in offices, like solvents, adhesives, cleaners, and pesticides can give off pollutants and odors, as can office equipment such as copiers, printers, and fax machines. If any of these items are used in the office environment, adequate and sometimes separate ventilation should be provided. If your organization engages in activities that may generate pollutants, such as photographic or printing processes, exhaust ventilation will be especially important. Pollutants and odors (which may or may not indicate a health concern) generated in your space may not only bother those in the immediate area, but may enter the building ventilation system and cause problems for other tenants in other parts of the building. Think The following questions can help you determine patterns of symptoms and/or timing that might provide insight in alleviating or providing guidance to a given IAQ problem: What kind of symptoms or discomfort are you experiencing? Are you aware of other people with similar symptoms or concerns? If so, what are their names and locations? Do you have any health conditions that may make you particularly susceptible to environmental problems? When and where did your symptoms start/stop? If the process of elimination cannot help you self-diagnose and resolve simpler IAQ problems (i.e., annoyances vs. those causing adverse health effects), please submit an Indoor Air Quality- Preliminary Occupant Questionnaire to the UIC Environmental, Health, & Safety Office (EHSO), An industrial hygienist will contact you for further questioning and arrange for a site investigation. Important- If an acute (immediate) adverse, serious symptom occurs (e.g., problems breathing, faintness, etc.), please advise your supervisor and seek medical attention at UIH emergency room or UIC Health Services (M-F, 7a-3p). Supervisors shall report to EHSO (6-SAFE [6-7233]) and request for an on-call safety officer to immediately investigate and monitor the workplace of concern, 5