by Kim Krisberg
It really is a chemical world, which is bad news for people with asthma.
According to a recent report released in August, at this very moment from where I write, I'm fairly surrounded by objects and materials that contain chemicals that are known or suspected asthmagens — substances that can act as asthma triggers if inhaled. There's formaldehyde (it's in office furniture, wood flooring, curtains and drapes); maleic anhydride (it's in interior paint and tile flooring); hexamethylene diisocyanate (it's in metal storage shelving and decorative metal); and diisodecyl phthalate (it's in horizontal blinds). In just two items found in practically all indoor environments — paints and adhesives — there are 75 substances linked to the chronic respiratory disease. It is not a stretch to say that we are all swimming in a world built with the help of chemicals about whose long-term human health effects we know too little.
The new report, compiled by the architecture and design firm Perkins+Will on behalf of the National Institutes of Health, lists nearly 400 substances typical to our built environments — the places we live, work and play — that are known or suspected asthmagens. One section of the report addresses asthmagens that are common in building design and construction, while another describes asthmagens found in a variety of environments and products (e.g., baking ingredients, agricultural inputs and personal care products). The purpose of the report is "raising awareness of the connection between health and buildings while identifying existing sources of information so that healthy buildings will result," states a news release. However, a quick glance through the report's long lists of hard-to-pronounce chemicals and the ubiquitous and prolific items they're used in made me wonder: How can this list be put into action to actually make a difference?
Ken Rosenman, professor and chief of the Division of Occupational and Environmental Medicine at Michigan State University, says it seems mostly beneficial for workers — "to me, it's most useful for (workers) more so than for us sitting in our offices or at home."
"For example right now, I'm sitting on a chair that contains diisocyanates," Rosenman told me. "But there's no real risk to me of developing asthma from it. The risk is to the guys manufacturing it."
According to the American Academy of Allergy, Asthma & Immunology, occupational asthma is the most common work-related lung disease in developed nations, with up to 15 percent of U.S. asthma cases related to a person's job. OSHA estimates that about 11 million workers in a variety of job settings and occupations are exposed to substances known to be linked with occupational asthma. However, the real rate of occupational asthma is likely way undercounted — "you wouldn't find anybody who'd say that's an accurate estimate," said Katherine Kirkland, executive director of the Association of Occupational and Environmental Clinics. Right now, only five states officially track work-related asthma. Both Kirkland and Rosenman said the report could be a useful and educational resource for physicians, many of whom are simply unfamiliar with occupational-related asthma and its contributors.
"The average clinician never asks what people are exposed to at work," Kirkland told me. "This would be routine at occupational health clinics...but it's not something the average physician would even know to ask about."
Occupational exposures to asthmagens truly run along the spectrum. The Perkins+Will report notes that an average carpenter comes in contact with at least 13 substances linked to asthma on a daily basis; agricultural workers with six substances; dentists with 14 substances; pharmaceutical or chemical industry workers with 34 substances; and health care workers with five substances. These numbers are in addition to the 75 asthma-related substances common to most indoor environments, the report states. The report's complete list of 374 substances and the occupations most exposed ranges from ammonium persulphate (common among factory workers and hairdressers) to soy flour (common among bakers) to triplochiton scleroxylon, otherwise known as African Maple (common among carpenters).
Specifically, Rosenman said there may be some healthier substitutes that builders and manufacturers could use instead. However, a more practical way to reduce the impact is to reduce workers' exposure through better safety practices and controls, such as providing appropriate ventilation and, if that isn’t sufficiently effective, respiratory equipment.
"Just because it's an asthmagen doesn't mean it'll cause asthma in everyone exposed," said Kirkland. "On the other hand, if you know something is an asthmagen, you can take preventive measures to reduce harm. We're not saying ban everything that's an asthmagen...but be aware and try to mediate the risk as best as possible."
Rosenman noted that the report is a reminder of the enormous complexity of our built environments and the items we come in contact with on a daily basis. We use about 80,000 chemicals regularly in our society, he said, a large number of which have never been subjected to toxicology tests or studies to determine their health impacts.
"People think that if I can buy it in my local hardware store then it must be safe, there must be somebody who's looked at it," he said. "But that's not the case."
Asthma at home
Asthma may be the quintessential public health problem. Its severity and progression ebbs and flows with our environments, and its management requires both a clinical and public health-based approach to be truly effective. According to the Centers for Disease Control and Prevention, the numbers of people with asthma have grown by the millions in the last decade: In 2009, about 25 million U.S. residents had asthma, compared to about 20 million in 2001, with the greatest rise among black children. Health care costs related to asthma totaled about $56 billion in 2007.
About 40 percent of asthma cases can be linked to housing conditions, says Rebecca Morley, executive director of the National Center for Healthy Housing, though often the factors are related to pests, mold and indoor exposure to secondhand tobacco smoke. (These are often the contributors in which public health workers can make a critical difference — providing education and empowering people with the tools to manage asthma on their own and prevent serious respiratory complications through changes in their environments.) Still, Morley said, building materials present risks as well.
"History tells us that with building materials, oftentimes we don't recognize the full extent of problems until much later on," she said, pointing to asbestos, lead, arsenic and formaldehyde. "All of these things were put in building materials for durability and maintenance but they were never really tested for health effects, so it stands to reason that we have a whole body of chemicals that have a whole set of health effects that have never been explored."
(For more on the benefits of reforming the nation's out-of-date chemical safety laws, read this 2011 article from the Pump Handle.)
Morley said that builders and contractors in markets where there's demand for healthier materials might be sensitive to the Perkins+Will report; but otherwise, it might not make much of a difference unless new regulations come down from policy-makers.
"We really want to drive health considerations into the decision-making process when manufacturers and builders are selecting their materials," she said. "In the past, that's never really been a factor — health and environmental concerns have been distance concerns for most builders unless their part of a market that positions itself as green and healthy.
"Builders are mostly driven by consumer demand, so the important thing for families and people to understand is the contribution of their homes to their health and demand better, healthier products."
To download the full Perkins+Will report, "Healthy Environments: A Compilation of Substances Linked to Asthma," click here.
Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for the last decade.