Environ. Sci. Technol. lQ83, 17, 504-504
(12) Ryan, D. K.; Weber, J. H. Environ. Sci. Technol. 1982,16, 866-872. (13) Parker, C. A. “Photoluminescence of Solutions”; Elsevier: New York, 1968. (14) Miller, J. N., Ed. “Standards in Fluorescence Spectrometry”; Chapman and Hall: New York, 1981. (15) Velapoldi, R. A.; Mielenz, K. D. “A Fluorescence Standard Reference Material: Quinine Sulfate Dihydrate”; U S .
Department of Commerce: Washington, DC, 1980. Received for review November 24,1982. Accepted April 11,1983. This research was partially supported by CNRS A T P “Oc6anographie Chimique” 1980-1980 (M.E.), by National Science Foundation Grant OCE 79-10571 (J.H.W.), and by N A T O Grant RG 056.82 (M.E. and J.H. W.).
CORRESPONDENCE Comment on “Chlorobenzenes in Sediments, Water, and Selected Fish from Lakes Superior, Huron, Erie, and Ontario” SIR: The survey of chlorobenzenes (CBs) in the Great Lakes by Oliver and Nicol(1) provides a valuable picture of their present distribution. However, I disagree with their perpetuation of the myth that all CBs are resistant to microbiological oxidation. The lower CBs containing 1-3 chlorines have been shown to be biodegradable under aerobic conditions by many researchers using a variety of laboratory systems. Laboratory tests show biodegradation for monochlorobenzene (MCB) (2-6), 1,2-dichlorobenzene (1,2-DCB), 1,4-dichlorobenzene (1,4-DCB) (2b,4), and 1,2,4-trichlorobenzene (1,2,4-TCB) (2, 6-9). Their biodegradation is also demonstrated in the dilution bottle biochemical oxygen demand (BOD) test (Table I). Those studies that found the lower CBs to be toxic or not biodegraded generally employed environmentally unrealistic concentrations of the CBs, 5 mg/L or more (2b, 11,12). The toxicity of the CBs at these high concentrations to microorganisms may have led to their apparent recalcitrance (13). One of the most interesting pieces of data in this paper is the distribution of the different CB congeners in the sediment core (Table IV, ref 1). In the older layers, the ratio of DCBs and TCBs to hexachlorobenzene (HCB) and pentachlorobenzene (QCB) increases dramatically. For Table I BOD, % of theor
504
compound
5 days
1 0 days
20 days
MCB ( I 0 ) 1,2-DCB ( 1 0 ) 1,4-DCB( 1 0 ) 1,2,4-TCB( 9 )
26
29
0
41 71
45 51 77 76
65 11
52
Environ. Scl. Technol., Vol. 17,No. 8, 1983
example, the ratios of 1,4-DCB to HCB in the core slices are 0.41, 0.26, 0.40, 1.44, 1.16, 1.81, and 20 as the depth increases from 0-1 to 6-7. This is consistent with a slow dehalogenation process of HCB in the anaerobic sediment or a much different release pattern in the past. This change in CB congener distribution does not appear for 30-40 years, a long time to wait for laboratory experiments. Study of additional sediment cores might reveal more precisely the rate of change in distribution and those conditions that cause this change. >
Literature Cited (1) Oliver, Barry G.; Nicol, Karen D. Environ. Sci. Technol. 1982, 16, 532. (2) (a) Pfaender, F. K.; Bartholomew, G. W. Appl. Environ. Microbiol. 1982,44,159-164. (b) Tabak, H. H.; Quave, S. A.; Masbi, C. I.; Barth, E. F. J. Water Pollut. Control. Fed. 1981,553, 1503. (3) Lee, R. F.; Ryan, C. U.S. Environmental Protection Agency, Report EPA-600/9-79-012, 1979; pp 443-450. (4) Rittman, B. E.; Bouwer, E. J.; Schreiner, J. E.; McCarty, P. L. Technical Report 255, Department of Civil Engineering, Stanford University, 1980. (5) Ilisescu, A. Stud. R o t . Epurarea Apelor 1971,15,249-266. (6) Haider, K.; Jagnow, G.; Kohnen, R.; Lim, S. U.; Arch. Microbiol. 1974, 96, 183-200. (7) Marinucci, L.; Bartha, R. Appl. Enuiron. Microbiol. 1979, 38, 811-817. (8) Porter, J. J.; Snider, E. H. Book Pap., Natl. Tech. Conf. -AATCC 1975,427-436. (9) Simmons, P. B.; Branson, D. R.; Moolenaar, R. J.; Bailey, R. E. Am. Dyest. Rep. 1977, 66, No. 8, 21-24. (10) The Dow Chemical Co. (11) Haas, J. M.; Earhart, H. W.; Todd, A. S. Book Pap., Natl. Tech. Conf.-AATCC 1974,442-447. (12) Garrison, A. W.; Hill, D. W. Am. Dyest. Rep. 1972,61, No. 2, 21, 24-25. (13) Bringmann, G.; Kuhn, R. Water Res. 1980, 14, 231-241.
Robert E. Balley
Environmental Sciences Research The Dow Chemical Cqmpany Midland, Michigan 48&0 0013-936X/83/0917-0504$01.50/0
0 1983 American Chemical Society
