Environ. Sci. Technol. 1991, 25, 857-862
Zafonte, L.; Lyons, J. M. Benzene/aromatics measurements and exhaust emissions from gasoline vehicles. Air Waste Management Association Meeting, Anaheim, C A June 1989; Paper 89-34B.4. Marshall, W. F. Study to determine the fate of benzene precursors in gasoline. Final Report to California Air Resources Board, December 1988. Haskew, H. M.; Gumbleton,J. J. SOC. Automot. Eng. [Proc.] 1988, P-881682. Haskew, H. M.; Garrett, D. P.; Gumbleton, J. J. SOC.Automot. Eng. [Proc.] 1989, P-890185. Grizzle. P. L.: Coleman. H. J. Anal. Chem. 1979. 51. 602. Gray, C. L. Mobile source benzene emissions and a preliminary estimate of their health impacts. Memorandum to Richard D. Wilson; May 15, 1986. Zweidinger, R. B.; Sigsby, J. E.; Tejada, S. B.; Stump, F. D.; Dropkin, D. L.; Ray, W. D.; Duncan, J. W. Enoiron. Sci. Technol. 1988, 22, 956. Ingalls, M. N. Southwest Research Institute, personal communication, 1989.
Volkswagen AG. Unregulated Motor Vehicle Exhaust Gas Components;Volkswagen AG Research and Development; 1989; p 54. Black, F. M.; High, L. E.; Lang, J. M. J. Air Pollut. Control Assoc. 1980, 30, 1216. Williams, R. L.; Lipari, F.; Potter, R. A. Formaldehyde, methanol, and hydrocarbon emissions from methanol-fueled vehicles. General Motors Laboratories Research Publication, GMR-6728; June 22, 1989. Bogdonoff, A. C.; McGill, P. D.; Jenckes, C. H.; Chiolo, J. F. Exhaust benzene emissions from late model vehicles. American F’etroleum Institute Report No. 841-44700; October 1988. Lyons, J. M. Presented at the Air Pollution Control Association Meeting, New York; June 1987; Paper 87-1.3. Seizinger, 1). E.; Marshall, W. F.; Cox, F. W.; Boyd, M. W. Vehicle evaporative and exhaust emissions as influenced by benzene content of gasoline. Final report to Coordinating Research Council. Inc.: Ami1 1986. Stump, F.; Tehada, S.; Ray, W.; Dropkin, D.; Black, F.; Crews, W.; Snow, R.; Siudak, P.; Davis, C. 0.;Baker, L.; Perry, N. Atrnos. Environ. 1989, 23, 307. Nebel, G. 300 50 f 20 218 f 20 121 f 10
110 f 10
90
loo f 10
* *
33 71 f 158 f 67 f 100 f
>loo
,.
Group Group 9 z a Flgure 2. Indoortoutdoor ratios lor peroxyacetyl nitrate in museums. Group 1. no H V A C group 2. HVAC; group 3, HVAC and chemical fiiiration. Location code, from kfl to right AVILA (El Pueblo), OLIVAS (Olivas Adobe), SOUTHWEST (Southwest Museum), PAGE (Page Museum), NAT. HIS. (Natural History Museum), UCLA (UCLA Libraries), SCOTT (Huntington'sScott Gallery). JPGM (J. Paul Gelty Museum). and I
median
C*CI,
SCUTHWEST NAT HI5 SCOTT LACnA CLIVAS PAGE "CLA JPGM
Group
range
CH,CCI,
'*Ofl
AVILA
median
PAN
LACMA (Los Angeles County Museum 01 Art).
group 3, air conditioning with chemical filtration system, low 110 air exchange. Thus, 110 concentration ratios for PAN and NO2,which have no indoor sources, and for the chlorinated hydrocarbons when no indoor sources are present, were found to be high in group 1 settings (e.g., El Pueblo's Avila Adobe, Olivas Adobe, Southwest Museum tower), high in group 2 buildings (e.g., Page, Natural History, UCLA), and low in only one of the three group 3 museums, namely, Huntington's Virginia Steele Scott Gallery. 110 ratios at LACMA's Pavilion for Japanese Art, a new building equipped with HVAC and chemical filtration, were much higher than expected for a group 3 structure, perhaps pointing to a malfunction of the filtration equipment. Elevated 1 / 0 ratios at the J. Paul Getty Museum may reflect a substantial influx of outdoor air. While 110 ratios for PAN and NOp were consistent with penetration of outdoor air at all locations, much larger ratios were observed for chlorinated hydrocarbons at six of the nine museums surveyed. Possible indoor sources of chlorinated hydrocarbons at these six museums have been discussed in the preceding section. A brief comparison of this work with an earlier and more limited study of indoor Ozone in some of the same museums (7) reveals differences in 110 ratios. At the only institution equipped with a carbon filtration system in
range
10
10 10 20 20
working condition (Huntington's Virginia Steele Scott Gallery), low indoor levels of photochemical pollutants were indeed observed, with 110 ratios of 2% for NOp,8% for PAN, and less than 1%for ozone. However, PAN and NOz were not removed as efficiently as Ozone by the carbon filtration system. In group 2 buildings with air conditioning and no chemical filtration, 1 / 0 ratios for PAN (65-100%) and NOz (75-100%) were substantially higher than those of 24-40% measured earlier for ozone (7). Thus, air conditioning appears to remove ozone substantially but to offer much less protection against penetration of outdoor PAN, NOz. and perhaps other pollutants as well. Other Survey Findings. Outdoor concentrations were generally lower on weekends than on weekdays (lower emissions), thus resulting in lower indoor levels for pollutants that have no indoor sources. The somewhat lower 110 PAN ratios at the Southwest Museum may reflect thermal decomposition indoors (daytime indoor temperatures exceeded outdoor ones by 2-3 "C, a significant difference in terms of PAN thermal stability; see ref 22), perhaps offset to some extent by in situ formation (by reaction of hydrocarbons and oxides of nitrogen in sunlight in the tower's pottery storage room, which has large windows on all sides). PAN decomposes rapidly on alkaline surfaces and may therefore be removed on clay pottery. Examination of diurnal variations in 110 ratios for chlorinated hydrocarbons did not reveal specific patterns in indoor use (e.g., janitorial activities before or after museum hours, or solvent use during staff working hours). For example, CH,CCl, levels a t the Virginia Steele Scott Gallery increased markedly during the third day of our survey and remained high thereafter. Indoor levels of NO2 and nitric acid varied substantially from one sublocation to the next, i.e., from levels comparable to outdoor levels a t locations with high 1/0 air exchange to low levels in more confined settings such as storage rooms, where deposition to walls and collections, as well as lower 110 air-exchange rate, may be consistent with our findings. Concluding Comments The air pollutants NOz, PAN, nitric acid, and chlorinated hydrocarbons were measured at nine southern California museums and were ubiquitous in indoor air a t all locations. At six of the nine museums surveyed, indoor concentrations of chlorinated hydrocarbons (but not PAN, NO?, or nitric acid) exceeded outdoor levels, thus indicating ind;or sources for these compounds. In the absence of indoor sauces, indoor concentrations of all pollutants were comparable to outdoor levels and exhibited the same spatial (from coastal to inland) and diurnal variations. Actual 1/0 ratios reflected building air-exchange characteristics. For buildings without air conditioning (HVAC), indoor levels were essentially identical with outdoor conEnviron. Sci. Technol..
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1991 861
centrations. Buildings with HVAC still exhibited high 1/0 ratios, as did two of the three buildings equipped with HVAC and chemical filtration systems. While damage due to ozone has received some attention (71, little is known regarding possible adverse effects of other air pollutants on museum collections. Nitrogen dioxide damage to textile dyes and other materials has been documented (23, 2 4 ) . Nitric acid may be involved in corrosion damage and may adversely affect organic colorants as well. PAN is an oxidant and can cause damage to biological systems (251, but the adverse impact of PAN on museum collections remains to be assessed. The role of chlorinated hydrocarbons is simply unknown, as is that of several other airborne pollutants whose levels in museum air remain to be characterized. A c k nou:1edg me n t s We thank Dr. Frank Preusser and Mr. James R. Druzik of the Getty Conservation Institute for their technical input during the course of this project. The following individuals provided critically important assistance during field measurements at their institution: Mr. John Coghlan, Mr. Skip Robinson, Mr. John Twilley, Ms. Carol Verheyen, Mr. Christopher Coleman, Ms. Kathryn Sibley, Ms. Cheri Doyle, and Ms. Lisbet Thoresen. Mr. Eric Grosjean had major responsibility in carrying out the field operations. Mr. Edwin Williams and Dr. Sucha Parmar assisted in instrument calibration and samples preparation. Ms. Jennifer Felix and Ms. Denise Yanez prepared the draft and final versions of this manuscript. Registry No. PAN, 2278-22-0; NOz, 10102-44-0; methylchloroform, 71-55-6; tetrachloroethylene, 127-18-4; nitric acid, 7697-37-2.
Literature Cited (1) Fassina, V. Atmos. Enuiron. 1978, 12, 2205. (2) Gauri, K. L.; Holdren, G. C., Jr. Enuiron. Sei. Technol. 1981, l C 5 ,386. (3) Reddy. M. M. Enuiron. Sei. Technol. 1989, 23, 264-265. (4) Thompson, G. The Museum Environment; Butterworths: London, 1978.
(5) Baer, N. S.; Banks, P. N. f n t . J . Museum Manage. Curatorship 1985, 4, 9-20. (6) Davis, T. D.; Ramer, B.; Kaspyzok, G.; Delany, A. C. J . Air Pollut. Control Assoc. 1984, 34, 135-137.
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(7) Cass, G. R.; Druzik, J. R.; Grosjean, D.; Nazaroff, W. W.;
Whitmore, P. M.; Wittman, C. L. Protection of works of art from photochemical smog. Environmental Quality Laboratory, California Institute of Technology, Pasadena, CA 1988. (8) Shaver, C. L.; Cass, G. R.; Druzik, J. Enuiron. Sei. Technol. 1983, 17, 748-752. (9) Grosjean, D.; Whitmore, P. M.; DeMoor, C. P.; Cass, G. R.; Druzik, J. R. Enuiron. Sei. Technol. 1987, 21, 635-642. (10) Whitmore, P. M.; Cass, G. R.; Druzik, J. R. J . Am. fnst. Conseru. 1987, 26, 45-58. (11) Grosjean, D.; Whitmore, P. M.; Cass, G. R.; Druzik, J. R. Enuiron. Sci. Technol. 1988, 22, 292-298. (12) Grosjean, D.; Whitmore, P. M.; DeMoor, C. P.; Cass, G. R.; Druzik, J. R. Enuiron. Sei. Technol. 1988, 22, 1357-1361. (13) Hackney, S. Stud. Conseru. 1984, 29, 105-116. (14) Druzik, C.; et al. A survey of aldehydes and organic acids
in museum air. The Getty Conservation Institute, Marina del Rey, CA, 1989. (15) Hisham, M. W. M.; Grosjean, D. Southern California Air Quality Study: Toxic Air Contaminants, Task 1. Final report to State of California Air Resources Board, Agreement A832-152, DGA, Inc., Ventura, CA, 1990. (16) Williams, E. L.; Grosjean, D. Southern California Air Quality Study: Peroxyacetyl Nitrate (PAN) Measurements. Final report to State of California Air Resources Board, Agreement A6-099-32, DGA, Inc., Ventura, CA, 1989. National Technical Information Service PB-89-187322, Springfield, VA. (17) Williams, E. L.; Grosjean, D. Atmos. Enuiron. 1990,24A, 2369-2377. (18) Grosjean, D. Atmos. Enuiron. 1990, 24A, 2695-2698. (19) Grosjean, D.; Parmar, S. S.; Van Neste, A. J . Liq. Chromatogr. 1989, 12, 3007-3017. (20) Grosjean, D. Atmos. Enuiron. 1988, 22, 1637-1648. (21) Grosjean, D. Enuiron. Sci. Technol. 1990, 24, 77-81. (22) Grosjean, D., Ed. Nitrogenous Air Pollutants: Chemical
and Biological Implications; Ann Arbor Science Publishers: Ann Arbor, MI, 1979. (23) Beloin, N. J. Text. Chem. Color. 1973, 5 , 128-133. (24) Graedel, T. E.; McGill, R. Enuiron. Sei. Technol. 1986,20, 1093-1100. (25) Ozone and Other Photochemical Oxidants; Committee on
Medical and Biological Effects of Environmental Pollutants; National Research Council: Washington, DC, 1977.
Received for review June 14,1990. Accepted December 26, 2990. This work has been sponsored by the Getty Conservation Institute.
