Jay Peters Gina M. Plantz Richard J. Rago Implications of indoor air background concentrations on health risks in buildings Jay Peters Gina M. Plantz Richard J. Rago

Major sources of VOCs in indoor air (IA): homes, offices, and schools Consumer products Cleaners; personal, hobby, and auto care products; furniture and furnishings Building materials Flooring, construction adhesives, paint, stain Heating systems Fossil fuel burning Outdoor air Industrial and vehicular emissions Environmental contamination Vapor intrusion

Major sources of VOCs in indoor air: homes, offices, and schools Consumer products Cleaners; personal, hobby, and auto care products; furniture and furnishings Building materials Flooring, construction adhesives, paint, stain Heating systems Fossil fuel burning Outdoor air Industrial and vehicular emissions Environmental contamination Vapor intrusion Indoor air background Is there a way we can get this red box to animate around the previous slide?

Indoor air background Recognized in environmental regulations “Indoor air concentrations resulting from sources other than vapor intrusion (i.e., ambient air and indoor sources) are commonly referred to as “background.” (EPA, 2011) “Background IA sources can be broken down into several categories … household activities, consumer products, building materials and furnishings, ambient air pollution.” (NJDEP, VITG 2013) EPA provides guidance on addressing background conditions in Superfund cleanups (Role of Background in the CERCLA Cleanup Program, OSWER Directive No. 9285.607P, April 26, 2002) But … health risk associated with indoor air background and implications on risk management for environmental contamination not well established

Identified background indoor air concentrations of VOCs Approach Identified studies that examined indoor air quality from background sources Identified background indoor air concentrations of VOCs . Characterized health risks associated with background indoor air quality Evaluated health risks in the context of common environmental risk management guidelines

Residential indoor air background studies Considered three major studies: 2,898 samples; compiles data from 15 studies (1990-2005) “Background Indoor Air Concentrations of Volatile Organic Compounds in North American Residences (1990–2005): A Compilation of Statistics for Assessing Vapor Intrusion, EPA 530-R-10-001, June 2011” 200 indoor air background samples in Los Angeles, CA, and Houston, TX “Relationships of Indoor, Outdoor, and Personal Air (RIOPA),” Weisel et al, The Health Effects Institute, November 2005 100 indoor air background samples in Montana “Typical Indoor Air Concentrations of Volatile Organic Compounds in Non-Smoking Montana Residences Not Impacted by Vapor Intrusion,” Montana Department of Environmental Quality, August 2012

Non-residential indoor air background studies Offices EPA Building Assessment Survey and Evaluation (BASE) Study (1999) California Health Buildings Study (Daisey et al, 1994) Haley & Aldrich: Rago et al (2013-2015); manuscript in preparation Jay to add sample numbers to these slides Schools Adgate et al (2004) Haley & Aldrich: Rago et al (2013-2015); manuscript in preparation

Background concentrations Focused on: VOCs commonly analyzed and detected among IAQ studies VOCs of potential concern for environmental contamination Three main groups of VOCs: Benzene, ethylbenzene, toluene, xylene (BTEX) Chlorinated VOCs: tetrachloroethylene (PCE), trichloroethylene (TCE), 1,2-dichloroethane (DCA), vinyl chloride (VC), chloroform, carbon tetrachloride Petroleum-related: naphthalene, aliphatic and aromatic hydrocarbons Background defined as a range of concentrations: 50th and 90th percentile values of background data set .

Characterizing health risks Risk is a function of Air concentration Exposure time (hours/day) and frequency (days/year) Toxicity Toxicity values derived by USEPA Cancer unit risk factor (URF) – non-threshold effects; used to derive incremental lifetime cancer risk (ILCR) Reference concentration (RfC) – threshold effects; used to derive hazard index

Risk management levels Risk management: cancer risk Probability of carcinogenic response in excess of background cancer risk 1 in 1,000,000 (1x10-6) x 1 in 10,000 (1x10-4) Many states: 1x10-6 to 1x10-5 Risk management: non-cancer hazard No increased risk of adverse health effects Hazard index (HI): 1 Screening levels are set at the lowest risk management thresholds, to gauge whether a chemical requires further evaluation Risks are managed as cumulative risk among all chemicals

Inset box “Hazard rank = background / screening level’

INSERT GRAPHIC HERE: COMPARE RES, OFFICE, SCHOOL BACKGROUND FOR THE 7 COCs Cancer Risks Cumulative Cancer Risk: 2x10-4 (90th PCTL) 7x10-5 (50th PCTL) Edit figure to state ‘cancer risk’ (not ‘risk rank ranges’). Add inset box with cumulative risks and add lines to show risk management ranges

HI = 1

Summary of indoor air background risks ILCR and maximum hazard index (HI) for 50th and 90th percentile background indoor air Residences: ELCR = 7x10-5 to 2x10-4 and HI = 1 to 4 Schools: ELCR = 2x10-6 to 3x10-6 and HI = 0.2 to 0.3 Offices: ELCR = 2x10-6 to 5x10-6 and HI = 0.1 to 0.4 Background risk estimates for residences 1-2 order of magnitudes higher than for schools and offices

Conclusions Residential background indoor air is associated with cumulative risks well above the threshold risk management levels used by most regulatory agencies Screening levels for indoor air are below or within the ranges for normal residential indoor air background Decisions about managing environmental contamination from vapor intrusion focus on levels well within or below background

Thank You! Jay Peters Haley & Aldrich, Inc. Gina Plantz Richard Rago jpeters@haleyaldrich.com T. 603.391.3312 C. 603.702.0533 Gina Plantz Haley & Aldrich, Inc. gplantz@haleyaldrich.com T. 603.391.3319 C. 603.748.3770 Richard Rago Haley & Aldrich, Inc. rrago@haleyaldrich.com T. 860.290.3115 C. 617.719.6128