Strategies To Control Air Pollution

Indoor Environmental/Air Quality

Yesterday we celebrated the longest day of the year - Summer solstice. Now that summer is in full swing, indoor air quality for occupants in and around structures may not be on the top ten list of green building trends as this isn't readily noticeable and tangible as we all try to chill out. But indoor air quality (IAQ) can be affected by mold, bacteria, carbon monoxide, radon and volatile organic compounds (VOC's), and source control is the primary method for improving indoor air quality in most buildings.

With this in mind, welcome to the June edition of the Green Building Journal. Contributing author Stan Gatland offers some insights into IAQ in his article "Achieve High IAQ with Moisture Management Strategies and Innovative, New Building Products." Mr. Gatland's article examines how the average American spends more than 90 percent of their time indoors, yet experiences more pollution and increased asthma rates than those spending more time outdoors.

In the article "Four Facts You Didn't Know About Pests and Indoor Air Quality," Caitlin Seifert looks at how mold, dust and pollen are not the only biological contaminants that negatively affect indoor air quality.

While this is a snapshot of what you will find in this month's journal, dive in and enjoy the articles, blogs, videos, and news. Explore the Green Building Pro social media community, engage with other members, and contribute your expertise to collaborate and communicate with other green building professionals.

We welcome you to join us in our community and attend our webcast series, either as an attendee, sponsor, speaker or all of the above. Feel free to contact me with your input on our community and Journal editions. I look forward to joining you online in the Green Building Pro community.

Jenica Egan

Indoor air quality (IAQ) has increasingly become an integral component of sustainable building and design as more is learned about indoor pollutants and the effect they have on building occupants, many of whom spend a significant amount of their time indoors.

The U.S. Environmental Protection Agency (EPA) reports that the average American spends more than 90 percent of their time indoors, and recent EPA studies have shown that air pollution levels can be up to 100 times higher indoors than those outdoors1.

Clinical Evaluation of Individuals with Suspected Indoor Air Quality

The recognition of indoor air pollution as relevant to the practice of pulmonary medicine reflects the increasing time spent indoors, significant contributions of indoor environments to exposures to pollutants, the sealed environments of modern buildings, and the emergence of new clinical syndromes linked to indoor air pollution. Total personal exposure to pollutants represents a weighted average of the exposures received in indoor and outdoor environments, locations having homogeneous characteristics during the time that exposure is received. For many pollutants, indoor microenvironments make dominant contributions, e.g., radon and volatile organic compounds (VOCs). Even for some pollutants regulated in outdoor air, e.g., particles and nitrogen dioxide, exposures in indoor microenvironments may outweigh exposure received outdoors. The spectrum of adverse respiratory effects of indoor air pollution is broad, ranging from symptoms and exacerbation of preexisting respiratory disease to acute and even fatal conditions that can be readily linked to indoor air pollution. The illnesses directly associated with indoor air pollution can be grouped as specific building-related illnesses and sick-building syndrome. The former includes such well-defined entities as hypersensitivity pneumonitis and Legionnaires' disease. The latter is a nonspecific syndrome, often having both respiratory and nonrespiratory elements. Indoor air is also widely contaminated by respiratory carcinogens: radon, environmental tobacco smoke (the mixture of sidestream smoke and exhaled mainstream smoke), and asbestos. Pulmonary physicians may be consulted concerning the risks posed by these agents and asked for guidance concerning control strategies. Indoor air pollution has myriad sources including the materials from which the space is constructed, its furnishings, processes operating within the environment, biological agents, and even the occupants. Outdoor air pollutants can also penetrate indoors, as can soil gas. The broad source headings are combustion, evaporation, abrasion, biological, and radon. The principal combustion sources are gas cooking stoves, burning cigarettes, fireplaces, wood stoves, and unvented space heaters. Evaporation of volatile organic compounds from materials and products leads to ubiquitous contamination by these agents. Abrasion of friable asbestos is a principal source for this indoor contaminant. The biological agents are heterogeneous, extending from infectious organisms to pets and the occupants themselves. Radon comes primarily from soil gas. The concentration of an indoor contaminant depends on the strength of its source, the rate of removal, the volume of the space, and the rate of exchange of air between the space and outdoors. This “mass-balance” formulation indicates that the concentration of a contaminant might be reduced by limiting source strength, increasing removal rate, or increasing exchange between indoor and outdoor air. In the typical modern building, the exchange of indoor with outdoor air is accomplished by a central heating, ventilating, and air-conditioning (HVAC) system. These systems are diverse, although all have the same purpose: the delivery of air of acceptable quality to building occupants. The volume of air to be delivered follows the recommendation of standards set by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). In the majority of newer buildings, occupants can no longer control the temperature of the work environment, and in most buildings, occupants cannot open windows to increase air exchange. Most residences still rely on natural ventilation. A patient presents to a pulmonary physician with nonspecific complaints, perhaps cough and sore throat. When should indoor air pollution be suspected as a cause? How can the link to indoor air pollution be established? The same questions face the clinician for specific disease entities also caused by indoor air pollution, such as hypersensitivity pneumonitis, Legionnaires' disease, and worsening of asthma. For each, the diagnosis should raise questions about the role of the indoor environment. For the physician evaluating and treating an individual patient, indoor air pollution often presents unusual challenges. First, the physician needs to think beyond diagnosis and management of the individual, to diagnosis and management of the specific environment. Interaction with other health and safety professionals may be needed to deal with problems of indoor environments. Second, because cases involving indoor air pollution often revolve around a workplace, physicians will frequently find themselves dealing with employers, unions, and other organizational entities and with complex nonmedical issues such as return to work, workers' compensation, risk communication and risk management. In some cases these “nonmedical” issues play a substantial role, and physicians should be familiar with the kinds of questions that will be asked (Fig. 1).

Air pollution: its effect on the urban man and his adaptive strategies

Fundamentals of air pollution

Environmental concepts, policies, and strategies

Environment management with Indian experience

Indoor air pollution control