Multifaceted Approach to Assess Indoor Environmental Quality
- Of new-onset asthma cases in adults, 15–23% are work-related asthma
[American Thoracic Society 2004] - The highest percentage of work-related asthma occurred among operators, fabricators, and laborers (32.9%)
[Worker Health Chartbook 2004] - Between 35 and 60 million of the 89 million indoor environment workers have building-related symptoms of eye, nose, and throat irritations or headache and fatigue
[Mendell 2002]
The points above very briefly highlight some of the issues related to indoor environmental quality. It has been estimated that indoor environmental quality-related health issues cost businesses in the range of $20–70 billion annually due to lost productivity, decreased performance, and sick absences. Some of these health effects include respiratory issues that could fall under the classification of work-related asthma. Work-related asthma is a subset of occupational lung disease which can be further subdivided into occupational asthma, which can be caused by exposure to a sensitizer or irritant at work, and work-exacerbated asthma, which is when pre-existing asthma becomes worse due to exposures at work.
The indoor environment has changed. Materials emitting high formaldehyde levels are being eliminated from indoor environments. However, many questions remain regarding occupational asthma and work-exacerbated asthma and the indoor environment. What are the irritants/sensitizers that cause these diseases? Can they be controlled? What is the actual physiological mechanism? What are the actual exposures in the workplace? There is probably no single one chemical exposure responsible for these illnesses, but more likely a mixed exposure of chemical classes such as particulate matter and oxygenated organic species (oxidized volatile organic compounds that are likely biologically reactive and potentially cause cell damage and increase susceptibility to disease).
The possible answers to these questions might be found in investigating the chemistry of volatile organic compounds found in the indoor environment, developing new sampling methods, and improving assessments of chemical health effects. Consumer products used in indoor environments for cleaning, surface finishing and deodorizing are typically mixtures of many chemicals. Some of these are volatile organic compounds, meaning they evaporate into the air, and others are non-volatile, meaning they adhere to the surface. There are additional reactants in the indoor environment which can facilitate the oxidation of these consumer products. The recent emphasis on "natural" or "green" cleaning products has led to an increase in the use of terpenes (hydrocarbons produced by plants—particularly conifers) like alpha-pinene, limonene and delta-carene in cleaners and air fresheners. However, natural does not always mean safe. Terpenes can react with components in the indoor environment to form new chemicals that might be the irritants responsible for the observed increases in work-related asthma. Many of these oxidation products are not captured by conventional sampling methods, leading some researchers to suspect that workers who are exposed to oxidized chemicals may not know it.
To address this research question, the National Institute for Occupational Safety and Health (NIOSH) has developed expertise in investigating the fundamental chemistry of several chemicals in consumer products that may be used in an indoor environment. These investigative efforts have produced many important insights into a chemical's fate in the indoor environment, possible new sampling techniques and identification of chemical structures that could lead to health effects.1,2,3,4,5,6
Indoor reactions are initiated mainly by ozone, a pollutant, which is transported from the outdoor environment into the indoor environment by building ventilation. NIOSH research has shown that when combined with ozone, one of the common components of pine oil cleaners, alpha-terpineol, transforms into many oxygenated organic compounds in both the gas-phase and on surface reactions creating new products potentially harmful to those exposed. Similar reactions were observed with many of the terpenes investigated.
Given that these new oxygenated species are not detected by conventional sampling methods, new techniques are needed to assess worker exposure and the potential health risk. These reaction products need to be stabilized to survive the conditions necessary for analysis. NIOSH is working to modify the current stabilization technique so that it can be used by industrial hygienists in the field.
Once we have a better understanding of the exposures created by these products we can work to better understand the health effects caused by indoor pollution. Recent research has shown that products created by these reactions could be sensitizers and irritants contributing to the health effects of those exposed. Additional research is needed to confirm these findings. As we move forward, the following questions continue to motivate this research:
- What are the chemical structures that comprise "missing" or undetected carbon?
- How are the reaction products partitioned in gas phase or particulate phase?
- Does exposure to mixtures of different oxygenated organic compound structures result in disease "greater" than the sum of the parts, i.e., do the reaction products combine to result in a more "toxic" mixture?
—Ray Wells, Ph.D.
Dr. Wells is Team Leader of the Gas and Vapor Team in the Exposure Assessment Branch in the NIOSH Health Effects Laboratory Division.
References
- Anderson, S. E.; Wells, J. R.; Fedorowicz, A.; Butterworth, L. F.; Meade, B. J.; Munson, A. E. Evaluation of the contact and respiratory sensitization potential of volatile organic compounds generated by simulated indoor air chemistry. Toxicological Sciences 2007, 97, 355-363.
- Wells, J. R. Gas-phase chemistry of alpha-terpineol with ozone and OH radical: Rate constants and products. Environmental Science & Technology 2005, 39, 6937-6943.
- Weschler, C. J.; Wells, J. R.; Poppendieck, D.; Hubbard, H.; Pearce, T. A. Workgroup report: Indoor chemistry and health. Environmental Health Perspectives 2006, 114, 442-446.
- Forester, C. D.; Ham, J. E.; Wells, J. R. Geraniol (2,6-dimethyl-2,6-octadien-8-ol) reactions with ozone and OH radical: Rate constants and gas-phase products. Atmospheric Environment 2007, 41, 1188-1199.
- Ham, J. E.; Wells, J. R. Surface chemistry reactions of alpha-terpineol [(R)-2-(4-methyl-3-cyclohexenyl)isopropanol] with ozone and air on a glass and a vinyl tile. Indoor Air 2008, 18, 394-407.
- Pacolay, B. D.; Ham, J. E.; Slaven, J. E.; Wells, J. R. Feasibility of detection and quantification of gas-phase carbonyls in indoor environments using PFBHA derivatization and solid-phase microextraction (SPME). Journal of Environmental Monitoring 2008, 10, 853-860.
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Comments
We have evidence of 5 separate meningiomas occurring in a primary care physician's office over 3 yrs. Any idea besides potential radiation from x-ray unit as possible cause?
Posted 4/9/09 at 2:04 pm
Our research on volatile organic compounds in the indoor environment is not looking at cancer as an endpoint. The development of cancers is complex and currently I am not aware of any research linking the chemistry of the indoor environment to cancer.
Posted 4/9/09 at 3:59 pm
The toxic chemical soup that Americans are breathing at work is excerbated by the fragrance that is contained in almost every personal care product used by individuals. The respiratory and neurological effects of fragrance can be devastating financially and personally to the individual sensitized to these chemicals. The FDA "trade secret" rule provides a loophole for manufacturers using petroleum chemicals in products that allows the word "fragrance" to cover the ingredients used.
I am sensitized to chemicals such as quaternary ammonium, roofing tar, fragrance, second-hand smoke, floor stripping products, air fresheners. My damaged health started with quaternary ammonium that resulted in occupational asthma in 1998, then further sensitization resulted RADS in 2000. I can no longer practice nursing due to the lung damage and am working towards a Ph.D. in nursing with a focus on occupational health. I advocate for organizations to reduce fragrance in the workplace and have developed policy templates for this purpose that I share nationally. Fragrance has a personal cost to the individual and certainly a loss of productivity cost to employers as well as contributing to the toxic chemical soup within buildings. I have many literature resources that I will share with anyone interested in this topic. Fragrance in the workplace is the new "second-hand smoke" resulting in adverse health effects for workers. All Americans have the right to work in a healthy environment that does not compromise their health. A position statement from NIOSH on the adverse health effects of fragrance would be greatly appreciated.
Posted 4/9/09 at 2:21 pm
Thank you for your comment. The chemicals we are investigating are used both in fragrances and solvents. We hope our research will provide insight into the complex indoor environment. The Research Institute for Fragrance Materials (RIFM) may be able to provide additional information.
Posted 4/9/09 at 4:20 pm
I am a patient safety researcher and an MPH student at UM. From reading your article and the comments, I wonder if the materials released during and after construction of our workspace should not be included to the pollutant mentioned above. Furthermore, do you think it is possibile that there is an over-time cumulative effect of free radicals on airborn particles released from the construction materials? To my knowledge, there are studies that show the effect of constructions on nosocomial infections in hospitals. Thank you for your comments.
Posted 4/13/09 at 3:01 pm
The alternate analytical techniques we are developing could be used for sampling during construction. The long-term cumulative effect of radicals on particulate matter is an interesting research area that is challenged by the difficulty in accurately detecting free radicals on particles as well as gaps in the complex toxicology.
Construction work can release significant particulate matter, usually consisting of building materials. During renovation of work spaces, mold could be released into the air from contaminated surfaces and inner building spaces.
Posted 4/15/09 at 8:01 am
I found out that ionic air purifiers have been demonstrated to release potentially unhealthy levels of ozone. I was wondering if any other electrical or electronic appliances we use such as desktop computers also contribute to indoor ozone pollution. Thank you in advance for your valuable input.
Posted 4/14/09 at 8:05 pm
Office equipment emissions have been a research topic due to the increases in the use of computers and printers. There are several publications in the scientific literature on this topic (the first one is a review):
Author(s): Destaillats, H; Maddalena, RL; Singer, BC, et al.
Source: ATMOSPHERIC ENVIRONMENT Volume: 42 Issue: 7 Pages: 1371-1388 Published: 2008
Author(s): Lee, SC; Lam, S; Fai, HK
Source: BUILDING AND ENVIRONMENT Volume: 36 Issue: 7 Pages: 837-842 Published: 2001
Author(s): Tuomi, T; Engstrom, B; Niemela, R, et al.
Source: Appl Occup Environ Hyg Volume: 15 Issue: 8 Pages: 629-34 Published: 2000 Aug
Posted 4/15/09 at 8:01 am
Thank you.
Instead of "chasing the culprit" (i.e., chemicals), would a surveillance system be helpful to identify epidemiologic charachteristics for chemical air contamination? What is your opinion about using lipid peroxidation study of exhaled air (clearly, with appropriate washout period)?
Posted 4/15/09 at 12:27 pm
Over the last couple of years we have been working on connecting chemical structures to toxicology. The aim of this effort is to more easily describe indoor air quality based on concentrations of chemical classes (structures) rather than specific compounds. The surveillance system would still need the connection between exposure and health effect. The lipid peroxidation study would still benefit from knowing which chemical exposures led to the oxidation.
Posted 4/16/09 at 9:56 am
I have been investigating the causes of building-related health effects as an independent consultant for over 18 years. It is my observation that, in most instances, health effects from low-level chemical exposures occur as a result of an acquired hypersensitivity being triggered. I think the focus of future research should be on the causal mechanisms of sensitization. Many workers become sensitized in environments where bacterial endotoxin is present such as in animal research laboratories and where metal working fluids are used. Occupants of water-damaged buildings become sensitized as a result of exposure to bioaerosol contaminants including LPS, B-glucans, fungal digestive enzymes, mycotoxins, etc. It is my opinion that people become sensitized when the innate immune system is potentiated and expression of the genes responsible for creating acquired or adaptive immunity occurs. The non-self chemicals in the blood at the time of innate immune potentiation are typically the volatile organic compounds absorbed in a contaminated indoor environment. An immune memory and sensory mechanism is created by the adaptive immune system to identify the foreign agent in the body in the future. The vanilloid receptor of the trigeminal nerve is often the receptor site where irritant chemicals are sensed (Pall 2004). Neurogenic inflammation results. This can cause virually all of the sick building syndrome symptoms reported (Meggs 1993).
Pharmaceutical researchers have proposed the "danger hypothesis" to describe how cellular damage might potentiate the innate immune system to cause drug hypersensitivity reactions. This may explain how oxidative chemical species are associated with sensitization.
Please make an effort to study the PEOPLE who become sensitized and not just do toxicology studies on the environmental chemicals. It's all about how (and which) people become sensitized and the environmental exposures that determine what non-self substance in the body the adaptive immune system creates a defense against. This substance will become the future trigger of a neurogenic hypersensitivity inflammatory response.
Posted 4/15/09 at 12:27 pm
Thank you for your insight and comments. Risk assessment includes hazard identification, evaluating dose-response, exposure assessment and risk characterization. The research my group is doing is an attempt to better describe the exposure.
Posted 4/16/09 at 11:56 am
I concur with the previous comment about focusing on the "People". In my opinion, a surveillance system that will record the type of workspace/environment will provide the link between the human aspect the the toxicology/immunology aspects. Monitoring concetrations of chemicals is essential for establishing risk factors. However, the potential effect may be identified by linking persons and their medical complaints to the spaces they reside or work. In fact a surveillance system may serve as an intial phase for a prospective cohort study. Your opinion?
Posted 4/17/09 at 2:18 pm
Improved surveillance of indoor work environments would be of great benefit to focus the research direction as there are hundreds of chemicals present. Surveillance data would support or challenge our hypothesis of the importance of the oxidized volatile organic compound reaction products.
Posted 4/20/09 at 7:58 am
In your article you mentioned that NIOSH research has shown that when combined with ozone, one of the common components of pine oil cleaners, alpha-terpineol, transforms into many oxygenated organic compounds in both the gas-phase and on surface reactions creating new products potentially harmful to those exposed. Does the reaction take place on recently applied the pine oil cleaners only? Are there any other free radicals generated in the process, which may continue the reaction?
Posted 4/18/09 at 4:19 pm
Our surface experiments were conducted over a 72 hour time period and we currently do not know the chemistry over longer periods of time. We have not investigated the complete pine oil cleaner formulation. The hydroxyl radical and the Criegee biradical are the most likely radicals produced during the reaction. However, these radicals are fairly reactive and are likely to react with surfaces or other volatile organic compounds present.
Posted 4/20/09 at 7:58 am
Do the ozone free radicals interact with the pine oil cleaners immediately after the later have been applied? For how long does the reaction last, and does it produce other 'nascent' free radicals?
Posted 4/18/09 at 4:57 pm
The rate of ozone reaction is dependent on both the initial ozone concentration and the reaction rate constant. Our work has shown that the ozone/alpha-terpineol reaction is expected to be faster than typical building air exchange. The actual reaction itself (ozone + alpha-terpineol) occurs in a fraction of a second. There are other radicals that can be formed such as the hydroxyl radical and the Criegee biradical. However, these radicals are fairly reactive and are likely to react with surfaces or other volatile organic compounds present.
Posted 4/20/09 at 7:58 am
I am a graduate student at University of Miami in an Environmental Health course. You mention consumer products in your article. Do you have a list of products that are safest for indoor air quality in the home?
Also, is there any practical way for people to assess the air quality in their own homes?
Posted 4/20/09 at 10:46 am
The National Institute for Occupational Safety and Health conducts research and prevention efforts to protect workers in occupational settings. While the results of our research can be applicable for the general public, this is not the focus of our research. You may want to check with the Environmental Protection Agency regarding products for use in the home. I've included a few links below.
Posted 4/20/09 at 3:09 am
Wow this is a great forum. I have an air duct cleaning company in New Jersey. What is your thoughts on air duct cleaning. We are NADCA and IAQA certified. I would like to hear your thoughts on my industry. We use a negative air cleaning system.
Posted 5/6/09 at 7:02 pm
While NIOSH is not conducting research on this aspect of the building environment, it is reasonable to think that chemistry could occur in the air ducts. If oils and other organic substances are removed from the ducts the chance of oxidation chemistry should be reduced.
Posted 5/8/09 at 4:03 pm
I live in an apartment in Phoenix whose management is having some of the apartments remodeled. They are laying laminate on the countertops and using polyurethane or a type of lacquer. The fumes are coming into several of the surrounding apartments. We're not sure if it is coming through the air conditioning, the vents, the walls, kitchen fan, who knows? The management has been told that this is making people sick, there are children in some of these apartments, and yet they are continuing on without ventilating the apartment they are working on. I personally made them open up the patio door of the offending apt. and put a fan in it. I was very sick for a night and a day. Is there a federal, state, county, or municipal department that you know of that would deal with this matter? I have called many departments in the City of Phoenix (fire, neighborhood services, development services), Maricopa County Environmental Services, and they all say they don't deal with issues like this. Any help would be appreciated before we are all asphyxiated. Thank you.
Posted 6/4/09 at 2:02 am
The state agency responsible for indoor air quality in Arizona can be found on the EPA website at http://www.epa.gov/iaq/states/arizona.html.
Posted 6/8/09 at 4:06 pm
I work in a fast food restaurant and the vents over the fryers have not been working properly and I have experienced the worst asthma attacks lately especially when they went completely out and the store filled with smoke. What are the dangers of breathing the smoke for long periods of time besides my asthma getting worse. Three employees work at this business and has been reprimanded for taking time off due to our asthma.
We need help. Thank you so much
Posted 7/20/09 at 1:34 pm
There are many exposures in kitchens that could trigger asthma attacks. Workers in the food service industry are exposed to multiple respiratory hazards including allergens and irritants. Asthma has been linked to exposure to aerosolized food agents such as egg proteins, crab, salmon proteins, enzymes, and organic dusts from tea, coffee, and spices. Baker’s asthma which results from sensitization to wheat, rye, or barley flour is one of the most common causes of occupational asthma worldwide. NOx, an irritant gas, is generated by use of gas cooking appliances. It has been linked to an increase in sensitivity to allergens in asthmatic people and exacerbation of asthma. Additionally, NOx is strongly correlated to the presence of other harmful pollutants, including carbon monoxide, polycyclic aromatic hydrocarbons (PAHs), and soot. Cooking with a wood fire can generate high levels of particulate matter that can be an irritant to the lungs.
You were specifically concerned about fryers. Cooking oil fumes, such as those from Canola oil, lard, and peanut oil, have been shown to have a mutagenic effect on lung tissue. While the oils themselves may contain a small amount of toxic chemicals, heating these oils vaporizes the chemicals, including alkanals, alkenals, and aldehydes. The concentration of volatile emissions appears to be related to cooking temperature, with higher amounts being generated as temperatures increase. A large amount of oil fumes can be emitted during deep frying. The type of food being cooked can also affect the amount of volatile vapors released. Kitchens that cook foods high in fat, or those that produce more fried foods, have been shown to have higher levels of PAHs. Kitchens that have dirty cooking surfaces also have increase risk for exposure to PAHs, since these chemicals are can be concentrated in the scrapings off the grill.
Faulty ventilation causing smoke exposures should be fixed. If the situation has been brought to your employer's attention and has not been corrected, there are some groups that might be able to help. You may want to call the local health department to see if they have any regulatory/inspection authority regarding the ventilation (or lack of) & system performance. If the ventilation inlet may pose a fire hazard, the local fire department may be a resource. You may want to request a Health Hazard Evaluation from NIOSH. Information about the program and instructions for requesting a Health Hazard Evaluation are found on the internet at http://www.cdc.gov/niosh/hhe/Request.html. We may not always be able to conduct a site visit, but could interact with management and provide direct guidance on ventilation systems maintenance as well as asthma risk factors in the workplace & prevention. Finally, the Occupational Safety and Health Administration (OSHA) enforces safe and healthy work conditions. If the situation remains unresolved, you may wish to file a complaint with federal OSHA or state OSHA (if your state has an approved state OSH program). However, OSHA would only be able to issue a citation if it determined that there was a violation of the law.
Posted 7/27/09 at 9:39 pm
How can an individual request to have a building (their workspace) evaluated for indoor air quality? A number of people in my building are complaining of sore throats and increased allergy symptoms, with symptoms disappearing when they are away from the building.
Posted 8/19/09 at 12:54 pm
You can request a Health Hazard Evaluation from NIOSH. Information about the program and instructions for requesting a Health Hazard Evaluation are available on the http://www.cdc.gov/niosh/hhe/Request.html. Information about the program and instructions for requesting a Health Hazard Evaluation are available at http://www.cdc.gov/niosh/hhe/Request.html. We do not always find it necessary to do a field investigation. When this happens, we contact the person(s) who requested our assistance and provide information and guidance. When the request is from employees, we may also contact the employer. The Occupational Safety and Health Administration (OSHA) enforces safe and healthy work conditions. If the situation remains unresolved, you may wish to file a complaint with federal OSHA or state OSHA (if your state has an approved state OSH program). However, OSHA would only be able to issue a citation if it determined that there was a violation of the law. You can also find state and regional contact information for the Environmental Protection Agency.
Posted 11/3/09 at 10:44 am
We need more systems put in place that evaluates air quality and offers pure air quality in the work place.
Posted 9/22/09 at 1:26 am
I work in a school and many workers have several symptoms over several years. Mainly sinus infections and resp. symptoms. In one of the buildings, you can see the mold on the ceiling in the old gym. They have many roof leaks in the main building and when ceiling tiles are down, you can see the mold on the duct work. You can smell it in the carpets, which on certain sides of the school,flood everytime it rains. Not only is staff sickened,but we have over 400 students exposed to this. Where do we complain?
Posted 10/31/09 at 1:38 pm
See the response to comment 14.
Posted 11/3/09 at 10:44 am