Letters to the Editor Letters are welcomed and will be published, if found suitable, as space permits. The editors reserve the right to edit and abridge letters, to publish replies, and to solicit responses from authors and others. Letters should be submitted in duplicate, double-spaced (including references), and generally should not exceed 400 words.

On the Hazards of Smoking: Statement from 1836 The ill effects of smoking are widely acknowledged. There are over 30,000 articles in the world literature regarding the relationship between health and tobacco use. ' The recent updated Report of the U.S. Surgeon General on Smoking and Health strengthens earlier impressions from the 1964 report concerning the relationship of smoking to various cancers, and illustrates the reduced life expectancy of smokers as well as their greater prevalence of acute and chronic illnesses with attendant excess morbidity, hospitalization, and lost work time.' Difficulty in eliminating this serious health problem persists, however. Evidence obtained by the National Clearinghouse for Smoking and Health, Center for Disease Control, in cooperation with the National Cancer Institute indicates that the battle is far from won. For adults over age 20, cigarette smoking has decreased over the decade 1965-75, from 49.7 to 46.9 million adult smokers, a decrease from 42 per cent to 34 per cent. This decrease is apparent among both sexes, with 39 per cent men and 29 per cent women reportedly smoking cigarettes in 1975.2 Teenagers from age 13 to 19 years, however, show an increase in cigarette smoking in the same time period, from a total of 3.5 to 6.0 million-an increase from 14 per cent to 20 per cent of teenagers smok-

ing.3 AJPH April 1979, Vol. 69, No. 4

Health professionals smoke less than the adult population at large, with physicians, dentists, and pharmacists showing less cigarette smoking, and nurses showing slightly more. Percentage changes include: physicians 30 per cent to 21 per cent (1%7-75), dentists 34 per cent to 23 per cent (1967-75), pharmacists 35 per cent to 28 per cent (1968-75), and nurses 37 per cent to 39 per cent (1969-75).4 Most health professionals believe they have an obligation to inform the public of the hazards of smoking, feel they should set an example by not smoking, and are optimistic concerning their ability to effect changes in the smoking behavior of others.3 Although there have been some encouraging results in the campaign to reduce smoking, the habit is still with us. Young people especially seem to require warning against this self-destructive activity. Despite the passage of 142 years, the opinion of Samuel Green in the New England Almanack and Farmers' Friend, 1836, on the hazards of smoking differs little from present day thinking on these matters. "Smoking-That tobacco may kill insects on shrubs and that one stench may overpower another, is possible enough; but that thousands and tens of thousands die of diseases of the lungs generally brought on by tobacco smoking, is a fact as well known in the whole history of disease. How is it possible to be otherwise? Tobacco is a poison. A man will die of an infusion of tobacco as of a shot through the head. Can inhaling this powerful narcotic be good for man? Its operation is to produce a sensation of giddiness and drowsiness-is it good to be within the next step to perpetual drunkenness? It inflames the mouth and requires a perpetual flow of saliva, a fluid known to be among the most important to the

whole economy of digestion; it irritates the eyes, corrupts the breath and causes thirst. No doubt the human frame may become so far accustomed to this drain, that the smoker may go on from year to year making himself a nuisance to society, yet there can be no doubt whatever, that the custom is as deleterious in general as it is filthy."5

One wonders why any intelligent person continues to ignore these admonitions. James S. Powers, MD Martha Wetteman, MPA 3558 Strathavon Road Cleveland, OH 44120

REFERENCES 1. Center for Disease Control, Highlights of the Surgeon General's Report on Smoking and Health. MMWR 28:1, 1979. 2. Center for Disease Control, Cigarette Smoking in the United States. MMWR 25:237, 1976. 3. Center for Disease Control, Adult and Teenage Smoking Patterns-United States. MMWR 26:160, 1977. 4. Center for Disease Control, Smoking Behavior and Attitudes of Physicians, Dentists, Nurses, and Pharmacists, 1975. MMWR 26:185, 1977. 5. Green S: Smoking. New England Almanack and Farmers' Friend, 1836, New London, CT, pp. 25-26.

Detection of Enteric Viruses in Solid Waste Landfill Leachates The article entitled "Field Survey of Enteric Viruses in Solid Waste Landfill Leachates" by Sobsey' brings up several interesting questions. First, according to the results in Table 4, less than three coliforms per 100 ml were found in the leachate samples in which the enteric viruses were isolated. This indicates that fecal contamination was unlikely, so what was the source of the 389

LETTERS TO THE EDITOR

virus? Was the virus tested to determine if it was virulent or attenuated? Attenuated live, Type 3 poliovirus is presently being used in oral immunization. If, in fact, the isolate was an attenuated form, then the primary source was probably due to human fecal contamination. However, it should be pointed out that attenuated Type 3 poliovirus may be genetically unstable and change in virulence.2 Another question that came to mind, was the leachate checked for inactivated viruses by serological methods such as ELISA or Direct FA? ELISA, for example, has been successfully used to detect viruses in other situations.3 If used in this type sampling one may be able to determine the efficiency of such landfills by sampling at varied times for active viruses as described by Sobsey' and determining inactivated forms serologically. Sobsey reported significant findings from a public health standpoint and his work appeared to have been a monumental task. However, methods as described should be investigated in order to insure adequate landfill operations which in turn would ensure the prevention of public health hazard due to enteric viruses. David L. Smalley, MS, MT(ASCP) Department of Biology Memphis State University Memphis, TN 38152

REFERENCES 1. Sobsey MD: Field survey of enteric viruses in solid waste landfill leachates. Am J Public Health 68:858-864, 1978. 2. Davis BD et al: Microbiology, 2nd Ed. Hagerstown, MD: Harper and Row, pp. 1295-12%, 1973. 3. Voller A, Bidwell D and Bartlett A: Manual of Clinical Immunology, Rose NR and Friedman H, (eds.), Washington: American Society for Microbiology, pp. 506-512, 1976.

Dr. Sobsey Responds Noting that virus-positive samples contained less than 3 coliforms per 100 ml, Mr. Smalley concludes that fecal contamination was an unlikely source for the viruses isolated. Although this is a possible explanation, there are other possible interpretations for finding low coliform levels in virus-positive samples. It is possible that the leachate 390

actually contained higher coiform levels but leachate toxicity either prevented their growth or caused them to die off. Both toxicity and die-off of coliforms due to leachates have been reported previously.'-3 If the coliform die-off rate was faster than that for enteric viruses, then the initial concentration differential between them could be reduced. Such conditions have been reported for both natural waters and treated sewage effluents.4 In response to the question about the virulence of attenuation of the isolated poliovirus, this has not been unequivocally determined. Finally, immunochemical methods were not used to search for viruses in leachates because they are not nearly as sensitive as infectivity assays for detecting infectious viruses. In the reported study, only infectious viruses were being sought because they are the only ones posing a potential public health hazard. Mark D. Sobsey, PhD Dept. of Environmental Sciences and Engineering School of Public Health University of North Carolina Chapel Hill, NC 27514

REFERENCES 1. Cameron RD and McDonald EC: Coliforms and municipal landfill leachate, Jour Water Poll Control Fed, 49:25042506, 1977. 2. Glotzbecker RA and Novello AL: Poliovirus and bacterial indicators of fecal pollution in landfill leachates, News of Environmental Research in Cincinnati, U.S. EPA, Cincinnati, OH, Jan. 31, 1975. 3. Engelbrecht, RS, Weber MJ, Amirhor P, et al: Biological properties of sanitary landfill leachate, pp. 201-216 In Virus Survival in Water and Wastewater Systems, JF Malina, Jr. and BP Sagik, (eds.), Water Resources Symposium No. 7, Center for Research in Water Resources, University of Texas, Austin, 1974. 4. Berg G and Metcalf TG: Indicators of viruses in waters, Chapter 11, pp. 267-2%, In Indicators of Viruses in Water and Food, G Berg (ed), Ann Arbor Science, Ann Arbor, MI, 1978.

Comments on Restaurant Inspections I read Dr. Kaplan's paper, published in the July 1978 issue of the Journal' which refers to our article pub-

lished in an earlier issue of the Journal.2 In it we concluded that the frequency of inspections could be adjusted according to the previous performance of the food establishment. This was not a matter of belief as alluded to by Dr. Kaplan but was based on the finding that 217 (or 78 per cent) of the 279 food establishments rated as satisfactory in September of 1974 were still so rated six months later while of the 171 establishments rated as unsatisfactory on the original inspection, only 83 (or 48 per cent) were found satisfactory six months later. Mathematical models and statistical methods such as expansion of binomials and regression and correlation analyses have often been used to estimate probabilities, predict progression of epidemics or incidence of disease, and test degrees of association. Although these models and probabilities may appear to be sophisticated and interesting to the casual observer or to a novice, they have very little value in practical life. In these years of austerity and fiscal constraints, public health administrators have to depend on professional judgment and years of experience to improve productivity and to cope with increasing demands. Among the variables which may have an impact on the findings of sanitary inspections are intermittent shortterm illness of food handlers, quality and operation of equipment, type of food served, training of food handlers, inter- and intra-individual variation among inspectors, time of day, day of week, season, and a few others. Should one take all of these variables into consideration and try to decide on an "optimum'" number of inspections per year, the proposed frequency would not only be fiscally prohibitive but, to say the least, absurd. In fact, the only way to uncover all unsanitary conditions which could lead to foodborne infection is to be present on the premises at all times. As was stated by Dr. Kaplan, "Even 30 inspections will fail to detect an unsafe condition in 4 per cent of the restaurants in which such condition exists 10 percent of the year." Assuming that available resources were unlimited, which is not the case, it would be totally wasteful to increase the number of AJPH

April 1979, Vol. 69, No. 4