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(2) Anderson, J. W.; Neff, J. M.; Cox, B. A.; Tatem, H. E.; Hightower, G. M. Mar. Biol. 1974, 27, 75. (3) Mironov, 0. G.; Shchekaturina, T. L.; Tsimbal, I. M. Mar. Ecol. Prog. Ser. 1981,5, 303. (4) Maher, W. A. Bull. Environm. Contam. Toxicol. 1982,29, 268. (5) Bastian, hl.V.; Toetz, D. W. Bull. Enuironm. Contam. Toxicol. 1982, 29, 531. (6) Widdows, J.; Bakke, T.; Bayne, B. L.; Donkin, P.; Livingstone, D. R.; Lowe, D. M.; More, M. N.; Evans,S. V.; More, S. L. Mar. Biol. 1982, 67, 15. (7) Kauss, P.; Hutchinson, T. C.; Soto, C.; Hellebust, J.; Griffiths. M. Proc. J. Conf. Prev. Control Oil S d l s 1973, 703. (8) Pulich, W. M., Jr.; Winters, K.; Van Baalen, C. Mar. Biol. 1974, 28, 87. (9) Mahoney, B. M.; Haskin, H. H. Enuironm. Pollut., Ser. A 1980, 22, 123. (10) Prouse, N. J.; Gordon, D. C., Jr.; Keizer, P. D. J. Fish. Res. Board Can. 1976, 33, 810. (11) Soto, C.; Hellebust, J.; Hutchinson, T. C.; Sawa, T. Can. J . Bot. 1976, 53, 109. (12) Kusk, K. 0. Bot. Mar. 1980,23, 587. (13) Shaw, D. G.; Reidy, S. K. Environ. Sei. Technol. 1979,13, 1259. (14) Petrakis, L., Weiss, F. T., Eds. “Petroleum in the Marine Environment”; papers from a symposium, Miami Beach, FL, Sept 1978; American Chemical Society: Washington DC, 1980. (15) Guillard, R. R. L.; Ryther, J. H. Can. J. Microbiol. 1962, 8, 229. (16) Ostgaard, K.; Jensen, A. Int. J. Environ. Anal. Chem. 1982, 14, 55.
(17) Berg, N.; Gustavsen, K.; Gjcls, N.; Lichtenthaler, R. G.; Oreld, F.; Vadum, K.; Ofsti, T. “ChemicalAnalysis of Water Soluble Petroleum Fractions and Studies of Their Aceumulation in Flounders”; SI Report 780702-1: Oslo, 1980. (18) Samuelsson, G.; Oquist, G. Physiol. Plant. 1977, 40, 315. (19) Giddings, J. M.; Washington, J. N. Enuiron. Sei. Technol. 1981, 15, 106. (20) Price, L. C. Am. Assoc. Pet. Geol. Bull. 1976, 60, 213. (21) Ostgaard, K.; Eide, I.; Jensen, A. Mar. Environ. Res., in press. (22) Winters, K.; ODonell, R.; Batterton, J. C.; Van Baalen, C. Mar. Biol. 1976, 36, 269. (23) Steeman Nielsen, E.; Wium-Andersen, S. Mar. Biol. 1970, 6, 93. (24) Migita, S. Bull. Jpn. SOC.Sei. Fish. 1967, 33, 392. (25) Lacaze, J. C.; Villedon de Naide, 0. Mar. Pollut. Bull. 1976, 7,73. (26) Larson, R. A.; Bott, T. L.; Hunt, L. L.; Rogenmuser, K. Environ. Sci. Technol. 1979, 13, 965. (27) Kauss, P. B.; Hutchinson, T. C. Environ. Pollut. 1975,9, 158. (28) Soto, C.; Hellebust, J. A.; Hutchinson, T. C. Can. J. Bot. 1979,24, 2717. (29) Hutchinson, T. C.; Hellebust, J. A,; Mackay, D.; Tam, D.; Kauss, P. In “Proceedings-1979 Oil Spill Conference”; American Petroleum Institute: Washington DC, 1979; p 541.
Received for review July 29,1982. Revised manuscript received March 22,1983. Accepted April 6, 1983. This work is part of the Norwegian Marine Pollution Research and Monitoring Program.
On the Formation of Mutagens in the Chlorination of Humic Acid Knut P. Kringstad, Pierre 0. Ljungqulst, Filipe de Sousa, and Lars M. Stromberg” Swedish Forest Products Research Laboratory, Box 5604, S-114 86 Stockholm, Sweden
The present investigation shows that the strong direct-acting mutagens 1,3-dichloroacetone and 2-chloropropenal are formed at low levels in the chlorination of humic acid. These results therefore suggest that these two compounds may also possibly contribute to the mutagenic activity of chlorinated drinking water. Introduction A large number of organic compounds have been identified as constituents of chlorinated drinking and wastewater (1-4). Several of these compounds were found to be mutagens and/or carcinogens (5-7). The compounds may be present in the raw water itself but also may be produced in the water chlorination process by reactions between chlorine and organic matter such as humic and fulvic acids (1, 8-11). The presence of mutagens and carcinogens in drinking water has caused concern and led to considerable efforts to identify and characterize as many as possible of the organic compounds present. Recently, we described the identification and mutagenic properties of some chlorinated aliphatic compounds present in the spent liquor from the chlorination of softwood kraft pulp (12,13). Several mutagenic compounds were found, and some belong to those previously identified in chlorinated drinking water. This is not surprising, since the chemical structures of humic and fulvic acids on one hand and of residual lignin in kraft pulp on the other are related (14). However, two of the mutagens in the spent chlorination liquor have so far not been identified in 0013-936X/83/09 17-0553$0 1.5010
drinking water. These direct-acting mutagens, which appeared to be particularly strong, were 1,3-dichloroacetone and 2-chloropropenal. The latter very likely carries a major responsibility for the total mutagenic activity (Ames test, Salmonella typhimurium TA 1535) of the spent chlorination liquor (13). This paper describes studies carried out with the primary objective of determining to what degree, if any, 1,3-dichloroacetoneand/or 2-chloropropenal are formed in the chlorination of humic acid and of determining its consequent potential contribution to drinking water mutagenicity. Experimental Section
Humic Acid Materials. Four humic acid materials were studied. Two of these were isolated from aquatic sources, and two were commercially available samples. Isolation procedures and characteristics for the various materials were as follows: Aquatic Sample I: Surface water (1300 L) was collected from a lake in the southern part of Sweden. The permanganate number of the water was 67 mg of KMn04/L. Humic acid was isolated from the water by acidification with HCl to pH 2.1, following a lengthy previously described procedure (15). Elemental analysis of the material revealed a C:H:O:N:S ratio of 1.00:1.20:0.48:0.05:0.005. The ash content was found to be 13%. The IR absorption spectrum showed absorption bands at -3400 (br), 2920, -1710,1620 (slightly broadened), 1525 (w), 1450-1350 (w), and 1080-1030 cm-’ (weak)
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Table I. Quantitative Determination of Various Mutagens in the Reaction Mixture from the Chlorination of Humic Acida C1,:C ratio humic material aquatic sample I
quantified compd 0.1:l 0.5:l 1:l 2: 1 4:l 2-chloropropenal b b 13.5 44.6 110.8 I ,3-dichloroacetone 1.9 2.7 5.7 27.2 59.2 1,1,3,3-tetrachloroacetone 2.1 30.4 416.0 444.0 541.6 pentachloroacetone 26.7 352.0 6.4 856.0 1730.0 hexachloroacetone b b 9.9 28.2 66.4 aquatic sample I1 2-chloropropenal c b C 43.0 C 1,3-dichloroace to ne 10.5 82.6 1,1,3,3-tetrachloroacetone 96.6 64.2 pentachloroacetone 548.6 4816.0 hexachloroacetone 3.2 152.6 commercial sample I 2-chloropropenal C b C C 39.4 1,3-dichloroacetone 39.8 160.0 1,1,3,3-tetrachloroacetone 8.5 108.0 pentachloroacetone 64.2 372.0 hexachloroacetone b 52.4 commercial sample I1 2-chloropropenal C 0.3 C 32.8 87.2 1,3-dichloroacetone 1.1 1.8 4.7 1,1,3,3-tetrachloroacetone 33.0 152.0 396.0 pentachloroacetone 76.2 1790.0 2060.0 hexachloroacetone b 5.9 241.0 a The values are given as nanograms per milligram organic carbon chlorinated and are mean values of at least four GC-MS (MID) determinations. Not detectable. Not determined.
'
(1 mg of sample/280 mg of KBr). These bands are characteristic for humic acid materials (16). The IR absorption spectrum was run on a Perkin-Elmer infrared spectrometer 421. Aquatic Sample 11: This sample was obtained by acidifying (15)a reverse osmosis concentrate of water from a lake in the central part of Norway (17). Elemental analysis of the sample revealed a C:H:O:N ratio of 1.00:0.92:0.46:0.03. The ash content was found to be 25%. Commercial Sample I (Fluka AG, Buchs SG, practical): According to the manufacturer this humic acid material is produced by extraction of peat. Elemental analysis of the sample revealed a C:H:O:N ratio of 1.00:0.940.39:0.01. The ash content was found to be 9%. Commercial Sample I1 (Ega Chemie, technical, sodium salt): According to the manufacturer this humic acid material is produced by extraction of peat. Elemental analysis of the sample revealed a C:H:O:N ratio of 1.00:1.04:0.51:0.01. The ash content was found to be 30.1%. Chlorination Procedure. Humic acid was dissolved in 2400 mL of dilute NaOH (pH 12). After this mixture was stirred for 1h at room temperature, the humic acid had dissolved. Traces of undissolved material were removed by filtration. Thereafter, the pH of the solution was lowered to 7.0 by adding 2 M HC1. Phosphate buffer (600 mL) of pH 7.0 was added. The amount of humic acid used was selected in all cases to give a final concentration of organic carbon of 73.5 mg/L. To the buffered solution, chlorine-containingwater that had been neutralized to pH 7.0 was added. The amount of chlorine added was varied corresponding to a C1,:C ratio of O.l:l, 0.51,1:1,2:1, or 4 1 (w/w). Immediately after the addition of the chlorine, the total volume of the reaction mixture was adjusted to 3400 mL by adding additional phosphate buffer. All chlorinations were carried out at room temperature by using a reaction time of 2 h. The reaction mixture was then filtered and the pH lowered to 2.4 by the addition of 2 M HC1. Any residual chlorine was removed by purging with N2. Workup Procedure and Analytical Procedure. To isolate reaction products, the acidified reaction mixture was extracted with 800 mL of ether [(pro analysis) May and Baker Ltd. Dagenham, England] in a percolator for 554
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48 h. After being dried with anhydrous Na2S04,the ether extract was concentrated to a final volume of approximately 3 mL by using a rotary evaporator at a temperature of approximately 25 "C. Thereafter the extract was analyzed by the GC-MS (MID) technique described previously (13). Mutagenicity Tests. The obtained reaction mixtures and ether extracts of some of these were tested according to the Ames test as described previously (12,18). As test organism, Salmonella typhimurium TA 1535 was used without metabolic activation.
Results and Discussion An introductory attempt to identify 1,3-dichloroacetone and/or 2-chloropropenal in drinking water from one Swedish water-treatment plant failed. To determine if this was due to the fact that these compounds do not form in the drinking water chlorination process, solutions of humic acid were chlorinated in the laboratory. In these experiments, higher concentrations of humic acid and chlorine were used than what is normally used in the water treatment process (73.5 mg/L TOC vs. 0-20 mg/L TOC). This was done to facilitate the detectability of reaction products. The C12:C ratio was varied within the interval 0.1-4.0 mg of C12/mg of total organic carbon. Table I shows the results obtained in the quantitative determinations of 1,3-dichloroacetone, 2-chloropropenal, and some additional mutagens that had been identified in kraft pulp spent chlorination liquor (12) as well as in chlorinated drinking water ( I ) . It may be seen that 1,3dichloroacetone as well as 2-chloropropenal are indeed formed in the chlorination of humic acid under these conditions. However, the quantity of both compounds decreases with the decreasing C12:C ratio used. Thus, at a ratio of about 0.51 only 1,3-dichloroacetoneis detectable. In separate experiments it was found that when chlorinating at pH 8.0,the quantities of 1,3-dichloroacetoneand 2-chloropropenal formed were considerably lower than at pH 7.0. It was recently shown that both compounds are rather unstable under alkaline conditions (19). Table I also shows the quantities found of three other chlorinated acetones. Compared to the quantities of chloroform found upon the chlorination of humic and fulvic acids under similar conditions (8, 9),the quantities found of these
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Loper, J. C. Mutat. Res. 1980, 76, 241. Cheh, A. M.; Skochdopole,J.; Heilig, C.; Koski, P. M.; Cole, L., In “Water Chlorination: Environmental Impact and Health Effects“,Jolley, R. L., Brungs, W. A., Cumming, R. B., Eds.; Ann Arbor Science: Ann Arbor, MI, 1980;Vol. 3,p 803. Rook, J. J. Environ. Sci. Technol. 1977, 11, 478. Babcock, D.B.; Singer, P. C. J . Am. Water Works Assoc. 1979, 71, 149. Christman, R. F.; Johnson, J. D.; Pfaender, F. K.; Norwood, D. L.; Webb, M. R.; Haas, J. R.; Bobenrieth, M. J. In “Water Chlorination: Environmental Impact and Health Effects”; Jolley, R. L., Brungs, W. A., Cumming, R. B., Eds.; Ann Arbor Science: Ann Arbor, MI, 1980;Vol. 3, p 75. Christman, R. F.; Liao, W. T.; Millington, D. S.; Johnson, J. D.; In “Advances in the Identification and Analysis of Organic Pollutants in Water”; Keith, L. H., Ed.; Ann Arbor Science: Ann Arbor, MI, 1981;Vol. 2,p 979. Kringstad, K. P.; Ljungquist, P. 0.;de Sousa, F.; Stromberg, L. M. Enuiron. Sci. Technol. 1981, 15, 562. Kringstad, K. P.; Ljungquist, P. 0.;de Sousa, F.; Stromberg, L. M. In ”Water Chlorination: Environmental Impact and Health Effeds”; Jolley, R. L., et al., Eds.; Ann Arbor Science: Ann Arbor, MI, 1983;Vol. 4,Book 2,p 1311. Christman, R. F.;Oglesby, R. T. In “Lignins: Occurrence, Formation, Structure and Reactions”; Sarkanen, K. V., Ludwig, C. H., Eds.; Wiley-Interscience: New York, 1971. Christman, R. F.; Johnson, J. D.; Hass, J. R.; Pfaender, F. K.; Liao, W. T.; Norwood, D. L.; Alexander, H. J. In “Water Chlorination: Environmental Impact and Health Effects”; Jolley, R. L., et al., Eds.; Ann Arbor Science: Ann Arbor, MI, 1978;VoI. 2, p 15. Hergert, H. L. In “Lignins: Occurrence, Formation, Structure and Reactions”;Sarkanen, K. V., Ludwig, C. H., Eds.; Wiley-Interscience: New York, 1971. Thorsen, T. “Vanndagene 1982”;Trondheim, Norway, Aug 1982;proceedings, p 117. Ander, P.; Eriksson, K.-E.; Kolar, M.-C.; Kringstad, K.; Rannug, U.; Ramel, C. Suen. Papperstidn. 1977,80,454. Kringstad, K. P.; Ljungquist, P.0.; de Sousa, F.; Stromberg, L. M. Environ. Sci. Technol., in press.
compounds as well as of 1,3-dichloroacetone and 2chloropropenal are very low. The mutagenicity of the chlorinated humic acid solutions and of ether extracts from some of these were determined according to the Ames test. The results obtained in testing the aqueous solutions were difficult to interpret due to low survival rates of the bacteria. However, the ether extracts of the 2:l and 4:l C12:C ratio chlorination liquors showed significant mutagenic activities. A comparison of the number of revertants found with the Ames test mutagenicity of 1,3-dichloroacetone and 2-chloropropenal (13) suggests that in particular the latter compound may be responsible for a significant part of the mutagenic activity of the humic acid chlorination solutions.
Acknowledgments We thank H. Flagstad, SINTEF, Trondheim, Norway, for a gift of reverse osmosis humic acid concentrate. Registry No. 2-Chloropropenal,683-51-2; 1,3-dichloroacetone, 53407-6;1,1,3,3-tetrachloroacetone, 632-21-3; pentachloroacetone, 1768-31-6; hexachloroacetone, 116-16-5.
Literature Cited Rook, J. J. In ”Water Chlorination: Environmental Impact and Health Effects”;Jolley, R. L., Brungs, W. A., Cumming, R. B., Eds.; Ann Arbor Science: Ann Arbor, MI, 1980;Vol. 3. D 85. Glaze, W. H.; Henderson, E. J . Water Pollut. Control. Fed. 1975.47.2511. Lin, D. C. K.; Melton, R. G.; Kopfler, F. C.; Lucas, S. V. Water, Air, Soil Pollut. 1983,19, 351-359. In “Advances in the Identification and Analysis of Organic Pollutants in Water”; Keith, L. H., Ed.; Ann Arbor Science: Ann Arbor, MI, 1981;Vol. 2,p 861. Bull. R. J. In “Application of Short-term Bioassays in the Analysis of Complex Environmental Mixtures”; Sandhu, S. S., Ed.; Plenum Press: New York, 1981;Vol. 2. Simmon, V. F.; Kauhanen, K.; Tardiff, R. G. In “Progress in Genetic Toxicology”;Scott, D., Bridges, B. A., Sobels, F. H., Eds.; ElsevierlNorth-Holland Biomedical Press: Amsterdam, 1977;p 249.
Received for review August 2,1982. Revised manuscript received March 10, 1983. Accepted April 25, 1983.
A Gaseous Tracer Model for Air Pollution from Residential Wood Burning M. A. K. Khalll,” S. A. Edgerton, and R. A. Rasmussen Department of Environmental Science, Oregon Graduate Center, Beaverton, Oregon 97006
A novel method is proposed whereby one may determine the contributions of wood burning, and other anthropogenic sources, to urban air pollution. This gaseous tracer model (GTM) relates the concentrations of methyl chloride (CH3C1) in polluted environments to the mass of fine particles emitted from wood burning. As a distinct advantage over existing methods this model can provide almost real-time assessment of the contribution of anthropogenic sources to urban pollution. When the model was applied to data obtained over the winter of 1981 at various suburban locations near Portland, OR, it showed that during peak wood-burning periods of the evening when wood smoke is evident, about 130 pg/m3 of fine particles may be contributed by this source. The effect of wood burning is reduced when averaged over 24 h, and the results agree with past studies that used different analytical methods. Introduction For centuries inhabitants of cities have been subjected to air pollution in the form of smoke and in recent years 0013-936X/83/0917-0555$01.50/0
emissions of exotic man-made gases, leading to the formation of a fine-particle haze. This smoke and haze not only obscure the view but upon long-term exposure may be extremely harmful to human health. Nowadays many diverse classes of sources contribute to urban air pollution, including industrial processes, cars, mass transportation, and in many cities, burning of wood to heat homes. A difficult problem in atmospheric chemistry and physics has been to construct theoretical and experimental methods for determining the amount of fine particles contributed by each source category so as to design optimal control strategies whereby pollution can be nipped at the source with least cost and greatest benefit. In this paper a new model will be derived to determine the contribution of various source categories to urban air pollution. The general method will be applied to the burning of wood for heating homes, which may be a significant source of air pollution during winter in many American cities and in cities all over the world (1,2). There are at present many different independent methods for estimating the contribution of various sources
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