GCI Summary of The Fifth International Congress on Toxic Combustion Byproducts held at the University of Dayton in Dayton Ohio June 22nd thru June 25th 1997


Jim Woodford

The Congress was co-sponsored by several groups, the National Institute of Environmental Health Science, USEPA, United States Air Force - Wright Laboratory, the University of Dayton, Sandia National Laboratory, Coalition for Responsible Waste Incineration and the Cement Kiln Recycling Coalition. The keynote address was by David Christiani of the Harvard School of Public Health. He spoke about Genetic susceptibility to lung cancer. The next speaker was Colin Park of Dow Chemical. Colin started things off by mentioning that his oldest daughter has worked for Greenpeace for the past two years and that they have had some very interesting family discussions. Colin’s topic was the role of risk assessment in the permitting process.

The next talk was by Henning Bockhorn from the University of Karsruhe in Germany. He spoke about toxic byproducts from combustion sources. No sooner had he finished about one fourth of the hands in the room went up and there was question after question after question until Barry Dellinger finally called and end to things and we went to lunch approximately an hour late.

There were three concurrent sessions. Session 1 was entitled Mechanistic Studies of the Formation of Toxic Organics, Session 2 was entitled Physical and Chemical Modeling Studies and Session 3 was entitled Advanced Diagnostic and Measurement/Monitoring Techniques. This synopsis incorporates Session 3. R. Zimmerman of the Universitat Munchen talked about the application of resonance-ionization mass spectrometry (REMPI-TOFMS) for monitoring of combustion byproducts. This was interesting but was not in use in a full scale industrial application.

D.L. Monts of Mississippi State then spoke about the development of a laser-based continuous emission monitor system for RCRA metals in off-gases. The potentially big positive here was that there was only need of a viewing window and no need to pull a sample. It did not appear sensitive enough to be reliable for As, Cd, Hg, Pb, & Sb. His experiments were also not industrial scale.

Don Lucas of the University of California (Berkley) talked about detection of toxic metals in aerosol particles using ELFFS, Excimer laser fragmentation-fluoresence spectroscopy. While definitely interesting and may be applicable down the road, all the work was lab/bench scale.

The next talk, by C.R. Shaddix of Sandia National Laboratories was on TDL measurements of transient emissions from a rotary kiln, the EPA’s pilot-scale rotary kiln incineration simulator in Research Triangle Park. This work was designed to detect “puffs” in an incinerator.

Gerry Meyer of Thermo Jarrell Ash talked about an argon plasma based continuous emissions monitor for hazardous air-pollutant metals. While units are planned for incinerator and cement kiln application, none appear to be currently in operation.

The final presentation of this session was by L.O. Mays of the University of Alabama in Huntsville who spoke about a laser diagnostic technique to measure chemical time delay in hypergolic combustion.

The first Plenary Lecture was delivered by David Carpenter of the University of Albany, School of Public Health who spoke about adverse human health effects of metals as combustion byproducts. He spoke mostly about lead because that was what he knew from his research, even though he pointed out that lead was not a hazardous waste combustion problem. The lead culprit was of course, leaded paints and leaded gasoline. Other metals that are related to combustion were very lightly addressed.

The next speaker was the crowning event of the Congress for me. Dr. Ron Hites of Indiana University School of Public and Environmental Affairs and Department of Chemistry. He spoke about the environmental fate of dioxins and related compounds and initial estimates of trying to mass balance the dioxins going into the environment with the dioxins coming out of the air and was off by a factor of 45ish, 2000 kg/yr going into the air, but 94,000 kg/yr getting deposited. This made him reassess his position and they focused on soil data. Over the next several years his students gathered soil samples from all over the world, literally. They used this data to rework their estimates. That got them up to 3000 kg/yr. Close but no cigar. In the end, he began to look at what happens to dioxins once they are emitted into the atmosphere. The homologue profiles of typical incinerators (we saw them in the dioxin reassessment) did not match very well with the environmental sinks homologue profiles and he designed experiments to find out why. One experiment essentially determined that when dioxins are entrained on particles, they are very stable and cannot be degraded. However, his other experiments(s) demonstrated that dioxins in the gaseous phase do degrade. Unfortunately, it was a monumental pain in the ass to do the one homologue that he did do but fortunately someone else had estimated degredation rates and it just so happened that the degradation experiment confirmed the estimated degradation rate for the one homologue so they used the rest of the estimates to calculate a new environmental sink(s) homologue profile. While not exact, it came very close to the actual environmental sink(s) homologue profile.

The were three concurrent sessions before lunch on Thursday, June 26th . Session 4 was entitled Metals Characterization and Speciation, Session 5 was entitled Mechanistic Studies of PCDD/F Formation and Session 6 was entitled Pollution Prevention/Industrial Operation. There were also three concurrent sessions following lunch. Session 7 was entitled Advanced Diagnostic and Measurement/Monitoring Techniques, Session 8 was entitled Integrated Bench/Pilot-Scale Research and Session 9 was entitled Mechanistic Studies of PPCD/F Formation.

The Friday general session was kicked off by the former director of OSW, Marcia Williams. Her Plenary address was entitled environmental decision making - an industrial perspective. However she really gave her perspective starting when she was with the environmental agency in 1970/71 which was transformed into the EPA. She talked about when incineration was a preferred option because it took waste out of the ground a burned it up forever and how between 1972 & 1982 the EPA began to realize that maybe they weren’t regulating things enough. She was the director of OSW from 1985 - 1988 and she talked about the Reagan assault on the agency, decimation of the ranks and aggressive efforts to hold up regulations. It was during this time that the Democratic Congress began passing legislation that required actions no matter what the agency was politically coerced into doing. She also believes that from the beginning days of EPA, when most people were technical and understood the technical issues, that now the agency is more populated by policy people and they need to get back to the technical issues. She even mentioned that people do not believe the science anymore. Both sides of an issue have always got a technical expert and who are the people suppose to believe? She thought that this aspect plus the Reagan attempts to gut the agency, which caused people to lose their faith in government regulators actually trying to protect them, has led to the wellspring of grass roots environmental groups who feel they have to take things into their own hands. The basic message was that EPA has regained their “protective” credibility and it is time for them to stand up and not only take responsibility but take back the technical high ground.

The Congress had hoped to get Bill Farland of USEPA to speak to the group but instead we heard from Dorothy Canter, the science advisor for OSW. She was probably a more fitting speaker since she was so technical. She spoke primarily of risk assessment and used the recent WTI risk assessment information generously throughout her talk. She was apparently integrally involved with that assessment. She showed initial data which was very high in dioxins and then subsequent tests, following modifications, which brought the dioxins down into the respectable range. She referred to Marcia’s talk several times during her own talk and while some things she agreed with and others she did not, she did think it was time for EPA to take back the technical high ground and take responsibility for making decisions. She used the WTI risk assessment as an example of a very detailed, comprehensive and expensive risk assessment. This was unfortunate on the one hand but now that it exists, the data from this assessment should be used whenever possible to help avoid expensive risk assessments in the future.

Three concurrent sessions were also held on Friday, June 27th. Session 10 was entitled Mechanistic Studies of the Formation of Toxic Organics. Session 11 was entitled Chemical Analysis and Health Effects of Sub-Micron Particulate Matter and Session 12 was entitled Large Scale Characterization/Evaluation for Emission Control. This synopsis addresses Session 12. The first presentation dealt with chlorine behavior in fluidized bed incineration of refuse derived fuels, presented by Masayiki Horio from Tokyo University. The next presentation was by Peter Maly of EER who spoke about evaluation of air toxics emissions from RDF slurry combustion.. Jerry Cole was the next presenter and he spoke about the application of acoustic and design enhancement to onboard naval waste thermal treatment facilities. This talk was the most interesting from a unique standpoint. He dealt primarily with “blackwater” and for non-military types, that means all the sewage. Briefly, important papers used to be written on paper that would quickly dissolve at sea but during the Pueblo incident they didn’t get the stuff in the water fast enough. This led to on board incinerators which of course ended up being misused. Eventually one caught on fire and caused big problems. This led to a reassessment and ultimately to the Navy deciding that their fleets were going to comply with land based regulations. This is where EER came in. Getting started was tough because no-one in the Navy seemed to know how the damn thing was built. They did finally figure it out and his report was on the experiments conducted. CO and HC are big time problems that have to be dealt with. Before these experiments of course, no one knew.

The next presentation was by Jim Woodford of Gossman Consulting, Inc. who spoke about the carcinogenicity of PIC emissions from a hazardous waste burning cement kiln with “high” hydrocarbon emissions versus a “low” hydrocarbon emitting commercial incinerator. Even though the total hydrocarbons were 20 times higher from the cement kiln than from the incinerator, when the risk factor of carcinogenic PAH compounds of concern were determined by using Appendix V of 40CFR 266, the “lower” total hydrocarbon emissions from the incinerator produced greater risk factors. (During review of the paper, in preparation for publication, it was learned that Appendix V of 40CFR 266 contained incorrect values which significantly affected the premise of the paper. It was pulled from publication by the authors.)

The next presentation was by F. Hasselriis who talked about an assessment of realistic emissions from municipal, medical, and hazardous waste combustors. His talk was interesting because he had a lot of historical data on municipal waste incinerators and what they were capable of doing from a dioxin emissions standpoint. He chastised the EPA for trying to implement a one-size-fits-all regulatory approach. An approach that he felt was closing down businesses that were doing a good job but couldn’t meet the letter of a poorly written regulation. The final talk of the session, day and Congress was by Steve Buckley of Sandia National Laboratories who spoke on combustion properties of energetic materials. This was also an interesting talk. He talked about bomb incineration which is done by OB/OD, open burn/open detonation. The one that he watched was observed from six miles away.

Additional information on the conference can be found at the University of Dayton Research Institute web page address: http://www.udayton.edu/news/nr/062097a.html

If this address does not work for some reason then try http://www.udayton.edu/ then click on the /research / hot button.