X trends in analytical chemistry, vol. 2, ng. 4, 1983

partially reflecting growing dissatisfac- tion of present faculty members with the conditions of employment. Avail- able faculty positions are not being tilled and this trend, if allowed to continue, could lead to a disastrous situation in several years’.

Logan detailed the supply/demand picture as known at the moment and projected for the future. He also described the activities of an ad hoc organization of academic/industrial people, known as the Allerton Analyti- cal Conferences, which is studying this problem and is suggesting implemen- tations that may bring supply and demand into better balance.

John N. McConnell, Executive Director Emeritus for the National Committee for Clinical Laboratory Standards, Villanova, PA, in a paper entitled $% Billion Annual Workload in Analytical Labs - Th Ones That You Do Not Hear About. Are Clinical Laboratories the Leaders or the Follower? claimed ‘Clinical laboratories constitute a major portion of all laboratory work. These laboratories have exhibited a very steep growth curve during the past decade. This is due to: (1) the increased use of automation, comput- ers and microcomputer technology, (2) the increased importance of the laboratory test in medical diagnoses, (3) the increased demand for patient monitoring during treatment. Analyti- cal chemists have played a key role in the development of today’s modern clinical laboratory. Automation, in- creased instrumental capacity, greater specificity and automated processing of samples to eliminate interferences are key “analytical problems” which have confronted, and will continue to confront the clinical laboratorian. The clinical laboratory, more than any other analytical service, must engage in the constant struggle to establish an accuracy base. Traditionally, analyti- cal chemists have found this to be the single most difficult problem in the clinical field. Recently, the National Committee for Clinical Laboratory Standards (NCCLS) has brought the clinical laboratories together in a unified approach to the many prob- lems of standardization. Through a voluntary consensus process, NCCLS has been able to significantly improve the capabilities of modern clinical

laboratories without the need to impose regulatory controls. The NCCLS approach, while borrowing heavily from traditional processes of intra-laboratory standardization, also points the way with significant new ideas’.

Finally, Tom Lyttle, Session Chairman, Iowa State University, and Chairman of the Analytical Labora- tory Managers’ Association (ALMA) presented a paper outlining the history, goals and objectives of that organization. Lyttle said, ‘Interest in ALMA is increasing due to the need for information on how to maintain and operate a comprehensive analytical instrumentation lab. What was origi- nally envisioned as a regional assembly of university instrumentation lab managers has blossomed into an expanding association of managers from not only university labs, but federal government and industrial labs as well. As a group we are attempting to address the problems faced by analytical laboratories in many differ- ent areas with the objective in mind to improve lab efficiency and productiv- ity. Our first conference, held in

October, 1980, at Northwestern Uni- versity, covered the areas of ‘Labora- tory Organization and Operation’ and ‘Funding Mechanisms’. The second conference held in October, 1981, at Iowa State University, dealt with ‘Service Needs of the Analytical Instrumentation Laboratory’ and further information on ‘Laboratory Operation’. The latest ALMA confer- ence was held 2 1 and 22 October 1982. It was hosted by Dr Tom Farrar at the University of Wisconsin, Madison. The program again stressed topics of current interest to laboratory mana- gers seeking information to improve their labs. The main topic focused on obsolescence in the analytical in- strumentation laboratory. Speakers in- cluded top officials from government funding agencies such as the NSF, NIH and DOD, as well as officials representing the instrument manufac- turers’.

THOMAS LYTTLE

Dr Lyttle is Manager, Research Instrument Services Laboratory, Department of Chemistry, Iowa State University, Ames, Iowa 50011, U.S.A.

Chlorinated dioxins and related compounds

A Report of the 3rd International Symposium on ‘Chlorinated Dioxins and Related Compounds’, held in Salzburg, Austria, 12-l 4 October, 1982

Seveso and Love Canal bear witness to the devastating effects of dioxin pollution and these environmental disasters have underlined the need for a better understanding of the forma- tion, fate and effects of chlorinated dibenzodioxins and dibenzofurans. The different isomers of these com- pounds exhibit markedly different stabilities and toxicities. Mixtures of the hexa-, penta- and octa-chloro- isomers are relatively stable, while the tetra-chloroisomers, tetrachloroben- zodioxin (TCDD) and tetrachlorodi- benzofuran (TCDF), are extremely toxic. Why are there such differences

in toxicity and stability? To answer this question, as well as to

decide upon the best measures to prevent pollution and deal with waste disposal, a multidisciplinary approach is required. Such an approach was discussed at the 3rd International Symposium on ‘Chlorinated Dioxins and Related Compounds’, which focused on more specific topics than had the 1st’ and 2nd’ meetings in this series. Besides review lectures, which summarized the state-of-the-art in the various disciplines, a number of oral presentations and posters dealt with incineration, waste disposal, acciden- tal emissions and epidemiology. This report will concentrate on the topics raised and discussed in the review lectures.

Analytical chemistry It is now possible to detect less than

1 ppt TCDD, according to Crummet

trend in analytical chcmis~, vol. 2, no. 4, 1983 XI

(Midland, MI, U.S.A.). However, there are still limitations in the methodology involved, particularly in sample preparation, which can involve a number of purification steps. Of the techniques available, gas chromato- graphy (GC), high performance liquid chromatography (HPLC), mass spec- trometry (MS) and MS-MS are the most powerful. Extraction procedures, purification steps and column pack- ings have improved since Buser and Rappe first separated 2 3 7 8 -TCDD > > 7 3 from its isomers.

In Crummet’s view, the criteria used for the confirmation of analytical results, the interpretation of data and inter-comparability are crucial. Inter-comparability criteria are par- ticularly important in the analysis of dioxin isomers, since they are found in a variety of matrices (beef, fish, bovine milk, human milk) and in a number of locations. In fact the data now obtained are reliable well below levels necessary for decision-making and show that hexa- hepta- .and octa- chlorodibenzodioxins are more im- portant in environmental samples than TCDD.

The methodology used in dioxin analysis does not appear to have changed significantly since the 1980 Rome meeting’. While improvements have been made in refining, and MS-MS has become more widely available, chromatography-MS is still the method of choice.

Disadvantages, however, remain and current methodology still lacks:

l Valid sample handling procedures.

l Recovery data (extraction efficiency, etc.).

l Analytical standards (too hot to handle?).

l Alternative, low-cost methods suitable for routine monitoring.

l Interlaboratory (validation) studies.

l Methods of analysis for components in human fat.

Nonetheless, Crummet concluded that the quality of analytical data obtained is now much improved and that the ability of the techniques available to distinguish between the various isomers is adequate.

Environmental chemistry Young (Veterans’ Administration,

Washington, DC) identified 5 possible sources of dioxins and furans: ingre- dients in commercial polyhalogenated aromatic compounds; improper chem- ical reaction; byproducts of chemical compounds; low temperature incinera- tion of wastes; and combustion of naturally occurring compounds. Prob- lems remain to be overcome in their analysis and adequate standards, sampling, validation and extraction procedures, have yet to be developed. In addition, information on the toxicological properties, environmen- tal fate and bio-accumulation of these compounds must be established before the results of their analyses can be properly assessed.

Information on the environmental fate of polychlorodibenzodioxins (PCDDs) has been obtained from a number of specific sites of hazardous waste disposal. Studies of their fate in the atmosphere and in the soil, including the role of photolysis, soil-water partioning, volatilization, microbial degradation and the effect of other chemicals, have all been done. In Florida, for example, the uptake of TCDD from the soil by living organisms showed that the hides and livers of rats and beach-mice living in contaminated soil contain as much as several hundred ppt TCDD. Southern meadowlarks contain elevated TCDD residues, but mourning doves and Savannah sparrows do not. These findings indicate that there is a correlation between TCDD levels in a particular species and the way in which that species interacts with the soil. Evidence on the accumulation of TCDD in human fat has been obtained from ex-military personnel, herbicide handlers, defoliant sprayers and others who have come into contact with TCDD. In the discussions on this topic it was agreed that good sampling procedures and good laboratory prac- tice are essential in TCDD analysis, not only to ensure that useful results are obtained, but also that costs are kept under control.

Biochemical effects The common toxic responses to

polychlorinated compounds, such as wasting syndrome, skin disease, lym-

phoid involution, porphyria, etc. were discussed by Safe (Texas A and M University, TX, U.S.A.). Although, qualitatively, the topic responses to the members of this class of compounds are similar, they are quantitatively quite different. Enzyme induction appears to be an important step and messengers induce higher production of certain proteins which change the toxic response.

The large numbers of polychlori- nated compounds found in the en- vironment pose problems both for the analyst and the biochemist. However, there does appear to be a correlation between LD50, enzyme induction and receptor binding. But before the events taking place in cells can be clarified, a better understanding of electronic, hydrophobic and hydrogen-bonding effects is required.

Animal toxicity While the type of toxic effect

produced by PCDDs is similar in all animal species so far studied, the degree of the effect differs markedly from one species to another. In every case, however, an incubation period is necessary before the clinical effects exhibit themselves. These effects range from porphyria, to loss of body heat, liver lesions and anomalies of the lung.

S&latter (Schwertzenbach, Swit- zerland) asserted that the range of symptoms exhibited can be attributed, in part, to the different metabolic rates of the different species. For example, the metabolites of 2,3,7,8-TCDD appear to be less toxic than the parent compound. Thus, animal species metabolizing this isomer at higher rates appear to be less sensitive.

Too few data are currently available to establish the mutagenicity of TCDD. But since unhalogenated dibenzodioxin is not a mutagen, it is unlikely that TCDD or OCDD are mutagens. Even if they are, they will not be mutagens in the classical sense, and probably will be mutagenic only in high concentrations.

Of the studies to date of dioxin carcinogenicity, nonchlorinated and bichlorinated dibenzodioxins show little or no effect, while mixtures of hexachlorinated dibenzodioxin iso- mers show some effect. Other studies have shown that TCDD, in some cases,

XII ken53 in analytical chemistry, vol. 2, no. 4, 1983

inhibits turnover initiation. One fact is clear, if TCDD initiates cancer it is not a simple process.

Observations in man A number of sections of the

population, listed here, risk exposure to dibenzodioxins and dibenzofurans: plant workers, who are at risk from both industrial accidents and from daily occupational exposure; users of herbicides, etc; those living in a continuously contaminated environ- ment; those living near to accidental emissions; and those eating contami- nated foods.

Reggiani (Basle, Switzerland) des- cribed 5 cases of dibenzodioxin-diben- zofuran contamination (Michigan, 1973; Seveso, 1976; Love Canal, 1978; South Japan, 1968; and Taiwan, 1978). In these cases biological sam- ples were not generally examined and the clinical symptoms shown were not consistent - for example, chloracne occurred in some cases, but not in

others. In every one of these 5 cases the

short term pollution effects have subsided and it is the long-term effects which are now of interest. The information available in the South Japan and Taiwan studies is more complete than the others, but a better understanding is still required of potential and actual exposure, which will require better methods ofquantify- ing exposure than are now used.

Analytical and biological measure- ments will have to be adapted to measure absorption of pollutants through the skin, lungs and digestive tract. Clinical reports on individual cases, descriptive epidemiological studies, and analytical epidemiological studies will have to be compared and understood.

Occupational and laboratory safety

Beck (Berlin, F.R.G.) insisted that it is the responsibility of scientists to

decide what should be done in this area, taking precautions on an individual basis. In the F.R.G. the Federal O&e for Health has decreed that standard substances must be produced centrally and that users must adhere to special rules. Guidelines have also been laid down on how to deal with contaminated instruments and particular attention has been given to such matters as decontamina- tion procedures, for which no fured guidelines can be given.

ERNEST MERIAN

References 1 Chlorinated Dioxins and Related Compounds

(1982) Pergamon Series on Environmen- tal Science, Pergamon, Oxford

2 Merian, E. (1982) C~S@TC 11, 5

Dr Ernest Merian is Secretary of the International Association of Entironmental Analytical Chemis- tsy. His address is Im Kirsgarten 22, CH-4106

Therwil, Switzerland.

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