IAQ 2016 Defining Indoor Air Quality: Policy, Standards and Best Practices Co-Organized by ASHRAE and AIVC

The health effects of outdoor exposure to particulate matter (PM) are well-established and are used to set health-based National Ambient Air Quality Standards (NAAQS). Although much less studied to date, indoor exposure to PM is gaining attention as a potential source of adverse health effects. PM found indoors can be particles of outdoor origin that migrate indoors, or from indoor sources. Indoor PM sources include combustion—cooking, appliances, and like—and occupant activities, notably secondhand smoke. Indoor PM levels have the potential to exceed outdoor levels and NAAQS. In response to a request from the US Environmental Protection Agency, the Institute of Medicine of the National Academies of Sciences, Engineering, and Medicine is conducting a workshop that will address the potential health risks of indoor exposure to particulate matter and the state of scientific understanding regarding them, focusing on PM2.5 and smaller exposures. The workshop will feature invited presentations and discussions regarding the health conditions that are most affected by PM, the attributes of the exposures that are of greatest concern, exposure modifiers, vulnerable populations, exposure assessment, risk management, and gaps in the science. It will take place in February 2016. An Academies report summarizing the workshop will be released in Summer 2016. This presentation summarizes the results of the workshop, reviewing the issues regarding indoor PM exposure and health, and discussing the major unknowns and research needs identified.

Organizations set minimum ventilation standards in order to maintain acceptable indoor air quality (IAQ) in indoor environments. For example, the American Society of Heating, Refrigeration, and Air Conditioning Engineering (ASHRAE) calls for a minimum ventilation rate (VR) of 8.5 l/s-occ at standard occupant density (5 occupants per 100m²) in offices. However, new studies have shown that higher VRs in offices can have positive effects on occupants’ wellbeing, including increased productivity and fewer incidences of absenteeism and sick building syndrome. These positive effects come at a cost associated with increased energy consumption due to additional outdoor air that needs to be conditioned, as well as greater introduction of outdoor-originating to the indoors, namely particulate matter (PM), which can degrade the health of the occupants. This study used a detailed outcome simulation of a typical office environment using EnergyPlus in conjunction with outdoor pollutant data collected by the U.S. Environmental Protection Agency (USEPA) to model the energy consumption and exposure to pollutants with outdoors sources (CO, O₃, NO₂, and PM_2.5) in the indoor environment under various constant VRs (0, 8,5, 17, and 25.5 l/s-occ). The simulation also considered seven filters of different minimum efficiency reporting values (MERVs) to assess their effects on occupant exposure to indoor PM concentrations. The intake-incidence-DALY (IND) method was used to estimate the disability-adjusted life years (DALYs) lost due to the occupants’ exposure to these outdoor originating pollutants. The energy consumption and DALYs lost due to exposure were monetized and their trends were assessed to create a unique empirical function that can predict the likely total cost associated with increased ventilation. This function can be used to estimate a building’s performance under any combination of constant ventilation and filtration within our studied range, so the cost associated with ventilating at high VRs may be easily compared with its many benefits on occupant wellbeing.

We describe and demonstrate a graphical approach that can be used to illustrate the performance of buildings with respect to indoor air quality (IAQ). In the absence of an adequate or agreed-upon IAQ metric(s), we describe a graphical approach to presenting IAQ performance. This approach displays measured or predicted levels of indoor pollutants relative to health-based guidelines or other appropriate reference values. The development of this graphical approach leads to several challenging questions regarding how to characterize building IAQ performance, including the determination of relevant contaminant concentration limits and the impacts of contaminant mixtures. This paper discusses those questions with the intent of promoting future dialog on how to characterize IAQ performance using this graphical or any other approach. Lastly, we briefly describe how the approach can be extended to illustrate the performance of buildings with respect to IAQ and other building parameters (e.g., energy and water consumption).

The prevalence and morbidity of allergic disease and asthma in the industrialized world has increased significantly in recent decades. Exposure to indoor allergens produced by dust mites, furry pets, rodents, cockroaches, foods and molds is a major driver of asthma morbidity and allergic sensitization. In recent years, multiple research studies have highlighted the role of exposures to allergens as well as other factors in determining health outcomes of allergic individuals, and indicate that the causal relationship between exposure and health effect may be far more complicated than previously assumed. This presentation provides a summary of relevant findings of the newest peer-reviewed studies of allergen and endotoxin exposures, health effects of allergen exposure itself, as well as co-exposures with environmental pollutants and endocrine disruptors. Topics addressed will include latest results of the CDC’s National Health and Nutrition Examination Survey (NHANES), and other epidemiologic surveys conducted in schools and homes, occupational exposures in laboratory animal facilities and other work environments. The second part of the presentation focuses on effective allergen avoidance and remediation measures, to provide better tools and knowledge to the IEQ practitioner.