Semi-volatile Organic Compounds; Indoor Air; Dust; GC-MS; DEHP

Transcription

1 Phthalates and Polybrominated Diphenyl Ethers in Retail Stores Ying Xu 1, Jorge Urquidi 1, Yirui Liang 1, Jeffery Siegel 1 The University Of Texas At Austin *Corresponding xuying@mail.utexas.edu SUMMARY Retail stores are an environment with a rich diversity of toxic chemicals typically found in consumer products. Among these chemicals, semi-volatile organic compounds (SVOCs) are an important class with great health concerns. They, however, have not been widely studied in retail environments. Phthalates and polybrominated diphenyl ethers (PBDEs) are high production volume SVOC chemicals pervasively used in plastics and other consumer products. Exposure to them may cause serious adverse health effects, including endocrine disruption. In this study, indoor air samples were collected from 15 retail stores in Austin, TX and University Park, PA. Some of these stores were revisited on different temperate seasons to account for weather variability. Indoor concentrations of the most ubiquitous pollutants were correlated with several building characteristics, including retailer type, temperature and humidity, and building materials. Collected data shows a wider variety of phthalates and PBDEs, as well as higher indoor concentrations for large department stores as compared to grocery stores, which typically have fewer sources. KEYWORDS Semi-volatile Organic Compounds; Indoor Air; Dust; GC-MS; DEHP 1 INTRODUCTION Some of the chemicals that have gathered the most attention in recent decades are semivolatile organic compounds (SVOCs; Weschler & Nazaroff, 2010). This group of compounds includes phthalates and brominated flame retardants (BFR), as well as some other compounds that are of interest because of their impact on human health (Oie et al. 1997; Darnerud 2008). Phthalates and BFRs are added to consumer products to alter their physical properties and to reduce material combustibility, respectively (Carlsson et. al, 1997; Wang et. al, 2010), and are often found at mass percentage levels in the order of tenths. For example, polyvinyl chloride (PVC) flooring typically contains 30% to 40% by mass of phthalate plasticizers (Bornehag et al. 2005). When released to the gas phase, these compounds adsorb to settled dust, interior surfaces and suspended particles (Weschler & Nazaroff, 2010). An understudied indoor environment considering the energy, occupant risk and economic implications associated with poor indoor air quality is that of retail stores. Over 15 million people work in the retail sector in the U.S. (NRF, 2010). Retail stores account for approximately 28% of commercial buildings and utilize 22% of commercial floor space (Diamond, 2001). There is evidence that plasticizers and flame-retardants are found in retail

2 environments (Hartman et al, 2004) yet, despite their importance, relatively little is known about SVOC concentrations of retail environments. The goal of this study is to characterize the concentrations of these compounds, and explore some removal mechanisms that might help reduce consumer and worker exposure. 2 MATERIALS/METHODS Indoor air samples were collected in Austin, TX and University Park, PA. Current samples include 2 general merchandise, 2 home improvement and 3 grocery stores. These were chosen to account for different source materials, as well as reflect a wide range of building materials. 2.1 Sampling Methods Air Sampling Method For the sampling of phthalates, two pumps are placed side-by-side simultaneously in all of the stores for Quality Assurance and Quality Control (QA/QC) purposes, with the exception of home improvement store 01 with only one pump deployed, and general merchandise store 01 where four pumps were deployed in two different in-site locations. To consider the samples to be in the breathing zone of building occupants, sampling units were placed one meter above the floor and away from possible obstructions. Tenax TA tubes (1/4 OD x 3-1/2 length, 250mg of sorbent) were used to collect the indoor air samples. Personal air sampling pumps were used. Pumps were calibrated prior to the start of the sampling campaign. Prior to site deployment, background levels of each Tenax TA tube were obtained. Tenax TA tubes were placed in a zip bag and transported in a cooler with temperatures below 4 C before and after sampling. Harvested tubes were stored at temperatures below 18 C. Sampling rates for all stores were of ~75 ml/min, with the exception of general merchandise store 01 and home improvement store 01, with flows of ~110 ml/min; taken for ~48 hr, with the exception of home improvement 01 and 02, with 12 and 24 h of sampling time, respectively. For the sampling of PBDEs, two pumps are placed under the same circumstances as the pumps used for phthalates. Polyurethane foam (PUF) tubes (22 X 100 mm size, 1-section, 76 mm sorbent) were used. The tubes were pre-cleaned with Hexane by Soxhlet extraction. PUF tubes were wrapped in aluminum foil and sealed in a zip bag before and after sampling Dust Sampling Methods Dust samples have been collected from every all retail stores by temporarily replacing one filter used in one of the HVAC systems used in the retail store. After collection, samples were stored at a temperature below 4 C. 2.2 Chemicals and materials Diethyl Phthalate (DEP), Dimethyl Phthalate (DMP), Di-n-butyl Phthalate (DBP), ButylBenzyl Phthalate (BBP), Di(2-ethylhexyl) Phthalate (DEHP) and Di-n-octyl Phthalate

3 (DoP) were purchased from Absolute Standards. 2,2',4,-Tribromodiphenyl ether (BDE-17), 2,4,4'-Tribromodiphenyl ether (BDE-28), 2,2',4,4'-Tetrabromodiphenyl ether (BDE-47), 2,3',4,4'-Tetrabromodiphenyl ether (BDE-66), 2,3',4',6-Tetrabromodiphenyl ether (BDE-71), 2,2',3,4,4'-Pentabromodiphenyl ether (BDE-85), 2,2',4,4',5-Pentabromodiphenyl ether (BDE- 99), 2,2',4,4',6-Pentabromodiphenyl ether (BDE-100), 2,2',3,4,4',5'-Hexabromodiphenyl ether (BDE-138), 2,2',4,4',5,5'-Hexabromodiphenyl ether (BDE-153), 2,2',4,4',5,6'- Hexabromodiphenyl ether (BDE-154), 2,2',3,4,4',5',6-Heptabromodiphenyl ether (BDE-183), 2,3,3',4,4',5,6-Heptabromodiphenyl ether (BDE-190), Decabromodiphenyl ether (BDE-209) were purchased from AccuStandard. Tenax TA tubes (catalog # ) and personal air pumps (catalog# 224-PCXR4) were purchased from SKC. Standard calibration solutions were prepared in methanol. 2.3 Extraction and analysis For the analysis of phthalates, a Thermal Desorption Unit (Turbomatrix 650 ATD) was used preliminary to the GC-MS analysis as for air samples. A GC-MS (Agilent 7890A) system was operated in using a 5:1 split injection, using a 30m DB-5ms column. The oven temperatures were programmed from 80 C for 0.5 min, ramp 20 C/min for 8.5 min, then ramp 30 C for 2 min, hold 9 min. Although no analysis for PBDE compounds or dust particles has been done at this stage of the study, a GC-µECD (Agilent 7890A) system will be used. 3 RESULTS 3.1 Gas-Phase Concentration of Phthalates Most of the phthalates were detected in every store (Table 1). The only exception was DoP which was only found in home improvement stores 01 and 02. Concentrations of the sum of the 6 phthalates ranged from 280 to 2,046 ng m -3 with the highest concentration of phthalates found in a grocery store in State College, PA. The predominant congeners by mass were primarily DEP and DEHP, except in store 4 where BBP was found at higher concentrations as compared to other retail stores sampled. Concentrations of DEHP often show the highest variation between both sample trains. This can be attributed to the different sampling times and flow rates used for the purposes of this study. It is worth noting that for grocery store 03 (Austin, TX), sampling was done in the cosmetics section. This store had the lowest sum concentration of phthalates, and the levels of DEP throughout the whole store might be even lower than those reported in this study. 3.2 Concentration of Polybrominated Diphenyl Ethers Concentrations of PBDEs have not yet analyzed for the purposes of this study. The remaining 16 stores which will be analyzed during the winter, spring and summer seasons of 2012.

4 Table 1. Total Concentrations (ng/m 3 ) on the Gas-Phase of Semi-volatile Phthalates in Air from Retail Stores. First value indicates the average of the two sampling trains. Second value indicates the standard deviation between them (if available). Store Label DMP DEP DBP BBP DEHP DoP H01 a nd H02 a nd ± ± ± ± ± 32 Gm01.a ab 63.2 ± ± ± 18 nd 86.7 ± 77 nd Gm01.b ab 62.9 ± ± ± 16 nd ± 31 nd Gr01 a 27.8 ± ± ± ± ± 4 nd Gr02 a 21.4 ± ± ± ± ± 62 nd Gr03 a 30.6 ± ± ± ± ± 44 nd Gm02 a ± ± ± 0.4 nd 92.8 ± 13 nd a H = Home Improvement Store, Gm = General Merchandise Store, Gr = Grocery Store b a and b denote different sampling trains used in the same store in different locations 4 DISCUSSIONS No other study has characterized phthalates and PBDEs concentration in retail stores. The only study that has characterized another set of flame retardants used in consumer product was done by Hartmann (2004), where 2 furniture stores and 3 electronic stores were sampled for organophosphate flame retardants. Because of the absence of comparable studies, a discussion will be made using residential studies. The values found for phthalate concentration are consistent with those of Rudel et. al (2010), who characterized several SVOC compounds in various residences in Northern California. Of special importance are DEP (Figure 1) and DEHP (Figure 2), which were the phthalates found at higher mass levels in most of the retail stores.

5 Figure 1 - Concentrations of DEP in indoor air samples from retail stores (This study) and median concentrations in residences (Rudel et. al, 2010) Figure 2 - Concentrations of DEHP in indoor air samples from retail stores (This study) and median concentrations in residences (Rudel et. al, 2010) Values found for BDE concentrations have been reported in other studies. Sjodin et. al (2001) reported average concentrations in air of BDE-153 between 14 and 3900 pg/m 3 (the high end being an electronics recycling facility). It is expected that values within this same range will be found in retail stores. 5 CONCLUSIONS The present study is the first to characterize concentrations of selected SVOCs (PBDEs and Phthalates) in American retail stores. Airborne concentrations are comparable to those

6 reported elsewhere for residential studies, except for DEHP which has been found in higher concentrations. Most of the airborne mass of phthalates and PBDEs is expected to be found in the particle and dust phases, which have not yet analyzed for the purposes of this paper. Once the samples are analyzed, an analysis for the relationship between total suspended particles and building materials and characteristics with SVOC concentrations will be done. Following the completion of sampling and analysis of the remaining stores, an occupational exposure analysis to SVOCs via air inhalation and dust ingestion will be done using reference doses estimated by the US EPA. The evidence of this preliminary study suggests that retail stores, with their rich diversity of consumer products may constitute a source of SVOC human exposure. Other tasks that require addressing include: occupational exposure pathways; additional climate factors influencing SVOC concentration in retail environments; influence of higher quality filters used in HVAC systems; and health impacts associated with exposure to SVOCs for both workers and consumers. ACKNOWLEDGEMENTS We thank Shi Shu, Neil Crain, Roxana Darvari for assistance with operation of GC-MS and air sampling. Financial support was provided by the National Science Foundation (NSF) IGERT program (Award DGE ), NSF CBET , and ASHRAE (RP-1596). We also acknowledge gratefully the cooperation from the owners, staffs and workers at the retail stores in Austin, TX and University Park, PA. 6 REFERENCES Darnerud, P. O. (2008) Brominated flame retardants as possible endocrine disrupters. International Journal of Andrology, 31, No. 2, Diamond, Richard C. (2001) An Overview Of The U.S. Building Stock. Tech. no Berkeley, CA: LBNL Hartmann, P., D. Burgi, and W. Giger. "Organophosphate Flame Retardants and Plasticizers in Indoor Air." Chemosphere 57.8 (2004): NRF (2010) National Retail Federation Retail Employees by Occupation, Age, and Education. National Retail Federation. Web. 01 Apr Oie, L., Hersoug, L. G., Madsen, J. O. (1997) Residential exposure to plasticizers and its possible role in the pathogenesis of asthma. Environmental Health Perspectives, 105: Rudel, R., Dodson, R., Perovich, L, Morello-Frosch, R., Camann, D., Zuniga, M., Yau, M., Just, A., Brody, J. (2010) Semivolatile Endocrine-Disrupting Compounds in Paired Indoor-Outdoor Air in Two Northern California Communities. Environmental Science & Technology, 44 (17), Sjodin, A., Carlsson, H., Thuresson, K., Sjolin, S, Bergman, A., Ostman, C., (2001)Flame Retardants in Indoor Air at an Electronics Recycling Plant and at Other Work Environments. Environmental Science & Technology, 35, Weschler, C. J. and Nazaroff, W. W. (2010). SVOC partitioning between the gas phase and settled dust indoors. Atmospheric Environment, 44,