LETTERS TO THE EDITOR 2. Stern AC: Air pollution standards: an overview and discussion. JOM 18:297303, 1976 3. Luria SM, McKay CL: Effects of low levels of carbon monoxide on vision of smokers and non-smokers. Arch Environ Health 34:38-43, Jan/Feb 1979. 4. Shimmel H, Murawski TJ: The relation of air pollution to mortality. JOM 18:316333, 1976. 5. Goldstein IF, et al: Critique of "The relation of air pollution to mortality." JOM 19:375-376, 1977. 6. Kuller LH, et al: Carbon monoxide and heart attacks. Arch Environ Health 30:477-482, 1975. 7. Spivey GH: Inner-city housing and respiratory disease in children: A pilot study. Arch Environ Health 34:23-29, Jan/Feb. 1979.
Author's Explanation of Ambient CO Study The critique by Bader is commendable in its interest, but each assumption falls short. While asking for clarification of items, he is not clear himself in describing carbon monoxide standards, nor does he reference a scientific report substantiating his alleged billion dollar cost. While our investigation did not bring up cost/effectiveness, the implications are appropriate to pursue. We found a 23 per cent excess of chest pain and shortness of breath as presenting complaints on high carbon monoxide days compared to low days. If one calculated the health care costs for these patients, the excesses for our hospital's catchment area alone would be considerable. A recent tobacco study reported American smokers spent $15.7 for tobacco in 1975, while tobacco-related health care costs in the same year totaled $41.5 billion.' Bader's comments further ignore the clinical studies by Aronow and others2' 3 which clearly show that exacerbations of symptoms can occur at low levels of carbon monoxide; Stewart's blood bank study4 confirmed that Denver and Los Angeles nationally are the two "best" locations for a study of this nature. During our study, we reviewed the ambient air pollution data in the Denver basin fromfive CAMP (Continuous Air Monitoring Program) stations in which parallel trends were demonstrated. The station we specifically mention in the report was less than 822
1,000 meters from the hospital's emergency entrance. Shortness of breath did not represent minor respiratory infections, because our Adult Walk-In Clinic for such problems was separated then; instead, it represented manifestations of underlying cardiopulmonary disease; only adults were involved since pediatric emergency services were provided separately. The Baltimore post-mortem study Bader cites can be considered faulted because "sudden death was defined as occurring within 24 hours of onset" and "blood samples were taken postmortem."5 Therefore, oxygen administered in emergency rooms, coronary care units, and during cardiopulmonary resuscitation may have lowered carboxyhemoglobin levels at the significant time, i.e., onset of symptoms. The half life of carboxyhemoglobin while breathing room air at rest is four to six hours, and mask oxygen can lower this to 45 minutes.6 Support from the letter by Goldstein, et al., collapses if one reads the rebuttal by Schimmel and Murawski which follows.7 The external review draft of the new carbon monoxide criteria document covers all these implications more substantially.8 We had intended to ask all the biographic data that Bader suggests in a proposal which had participation from all four major hospitals in Denver's ambulance system. Delays and severe fiscal constraints foiled us,
however. Thomas L. Kurt, MD, MPH Associate Professor University of Colorado Medical Center B-130 Denver, CO 80262
REFERENCES 1. Luce BR, Schweitzer SO: The economic costs of smoking-induced illness. In: Research on Smoking Behavior, Jarvik ME, et al., (eds.) NIDA Research Monograph 17, Dec 1977, pp. 221-229. 2. Aronow WS, Isbell MW: Carbon monoxide effect on exercise-induced angina pectoris. Ann Intern Med 79:392-395, 1973. 3. Aronow WS, Ferlinz J, Glauser F: Effect of carbon monoxide on exercise performance in chronic obstructive pulmonary disease. Am J Med 63:904-908, 1977. 4. Stewart RD, Baretta ED, Platte LR, et al: Carboxyhemoglobin levels in American blood donors. JAMA 229:1187-1191, 1974.
5. Kuller LH, Radford ED, Seift D, et al: Carbon monoxide and heart attacks. Arch Environ Health 30:477-482, 1975 6. Stewart RD, Peterson MR: Experimental human exposure to carbon monoxide. Arch Environ Health 21:154-164, 1970 7. Goldstein IF, Goldstein M, Landovitz L: A critique of "The relation of air pollution to mortality" and Schimmel H, Murawski TJ: Response to Drs. Goldstein and Landowitz. J Occupat Med 19:375, 1977. 8. Air Quality Criteria for Carbon Monoxide. US Environmental Protection Agency. External Review Draft. April, 1979.
Fetal Monitoring in New York State vs. New York City In their Public Health Brief "Prenatal Monitoring in Upstate New York,"' Zdeb and Logrillo state that "as of January 1, 1978, the birth certificate used in Upstate New York (New York State exclusive of New York City) included a question concerning use of special procedures in prenatal monitoring." Comparable data are available for New York City. The items first appeared on the New York City 1978 birth certificates, at the suggestion of our Obstetric Advisory Committee and draft copies of our new certificates were made available to the rest of the State prior to January 1, 1978. Findings for the calendar year 1978 were prepared for discussion with the Obstetric Advisory Committee of the New York City Department of Health. For the record, it should be stated that New York City's experience with fetal monitoring and that reported in this Brief for the rest of the State differ. Zdeb and Logrillo do not state how many hospitals throughout the rest of the State reported doing fetal monitoring. In 1978, there were 56 hospitals reporting on electronic monitoring in New York City. Considerably, more scalp sampling was done in New York City (1.5 per cent) than appears to be the case in the six-month period for upstate New York (0.2 per cent). By hospital, this percentage varied in New York City from none (in eight hospitals) to ten per cent done (in two hospitals). There was considerably more internal monitoring done in New York City (23.6 per cent) than in upstate AJPH August 1979, Vol. 69, No. 8
LETTERS TO THE EDITOR
New York (14.1 per cent), a possible reflection of different levels of sophistication among hospitals within and outside of New York City. Analysis is continuing on the New York City data and further reports will be forthcoming. We believe analysis of data based on at least a one-year experience has greater validity than an initial six-month period following the introduction of newly added items on the birth certificate. Sol Blumenthal, PhD Acting Director for Biostatistics and Frieda Nelson Assistant Director Bureau of Health Statistics & Analysis New York City Department ofHealth 125 Worth Street New York, NY 10013
REFERENCES 1. Zdeb MS, Logrillo VM: Prenatal monitoring in upstate New York. Am J Public Health 69:499-501, 1979.
Medical Alert Center at USC; not at UCLA The article by Dr. James, "Impacts of the Medical Malpractice Slowdown in Los Angeles County: January 1976,"' contains an error on page 440. The Medical Alert Center is erroneously identified as being situated at Los Angeles County-UCLA Medical Center. In fact, the Center is located at the Los Angeles County/University of Southern California Medical Center. Joseph K. Indenbaum, MD Medical Director County of Los Angeles Department of Health Services 313 North Figueroa Street Los Angeles, CA 90012
REFERENCES
1. James JJ: Impacts of the medical malpractice slowdown in Los Angeles County: January 1976. Am J Public Health 69: 437-442, 1979.
In Support of the Child Restraint Law In his evaluation of "The Tennessee Child Restraint Law,"' Williams documents well the increase of hazard AJPH August 1979, Vol. 69, No. 8
to children from a safety law enacted with apparent good intentions. Quite appropriately he calls attention to the "double jeopardy" of an infant held in the arms or lap of an adult in the right front seat of a moving vehicle. In his article, "The Fault Doctrine and Injury Control,"2 Wigglesworth notes the relative futility of attempting to reduce accidents through punitive countermeasures. He cites as an example the ineffective legislative approach in Sweden and Norway to drinking while driving. I suspect that morbidity and mortality data from Tennessee and Kentucky following the enactment of the child restraint law will give further support to the argument favoring the use of passive restraints. John H. Hughes, MD Director, Emergency Services Associate Professor of Surgery, and ofFamily and Community Medicine University of Arizona Tucson, AZ 85724
chased and put jet airplanes into use since 1961! Ridiculous! Let's encourage researchers to recognize that an injury transmitting agent (tractor, airplane, ladder, etc.,) may experience wide variances in both hours of use and type of use over a period of time. Even conclusions based on changes in accidents per million hours of use must consider changes in type of use (i.e., 55 mph speed limit) before comparing findings with prior
REFERENCES
The report, Farm Tractor Fatalities: The Failure of Voluntary Safety Standards, February 1979, is very misleading. First of all, the voluntary safety standard can work if people are educated as to the benefits of protection. At present, there are 850,000 roll over protective structures in use across the United States on agricultural tractors. There are an additional 250,000 in use on industrial tractors. Most of these were put on before promulgation of the agricultural ROPS standard which took effect on October 25, 1976. There are still many old tractors in use without ROPS, however, the percentage of new tractors being sold with ROPS reaches 100 per cent in Nebraska on the tractors of 80 horsepower and above. I am quite disturbed in that authors Karlson and Noren have not referenced any of the true farm tractor overturn studies. Most of those listed relate to information that was gleaned from health statistics. These are only death certificates and do not address themselves to the true circumstances of the fatality. Furthermore, these are only for deaths and not injuries. Nothing is said about the benefits of ROPS. If I didn't know better, I
1. Williams AF: Evaluation of the Tennessee child restraint law, Am J Public Health, 69:455-458, 1979. 2. Wigglesworth EC: The fault doctrine and injury control, Journal of Trauma, 18: 789-794, 1978.
Three Comments Received on Farm Tractor Safety Factors I am disturbed by the erroneous conclusions reported in the Karlson Noren article, "Farm Tractor Fatalities: The Failure of Voluntary Safety Standards,"'I in the February Journal. The authors used the statistic that accidents per 100,000 male farm residents in Wisconsin went up significantly to support a conclusion that "voluntary standards are not protecting the farm population." This conclusion ignores the significant increases in both numbers of tractors and hours of tractor use per 100,000 male farm residents over the past 10 years. Using death rates per capita instead of death rates per hour of use also could have lead Karlson and Noren to conclude that there has been a horrible increased risk of death on airlines that have pur-
years.
Richard G. Pfister, PhD Professor and Extension Safety Engineer Department ofAgricultural
Engineering Michigan State University
REFERENCES 1. Karlson T, Noren J: Farm tractor fatalities: the failure of voluntary safety standards. Am J Public Health 69:146-149,
1979.
823
Author's Explanation of Ambient CO Study The critique by Bader is commendable in its interest, but each assumption falls short. While asking for clarification of items, he is not clear himself in describing carbon monoxide standards, nor does he reference a scientific report substantiating his alleged billion dollar cost. While our investigation did not bring up cost/effectiveness, the implications are appropriate to pursue. We found a 23 per cent excess of chest pain and shortness of breath as presenting complaints on high carbon monoxide days compared to low days. If one calculated the health care costs for these patients, the excesses for our hospital's catchment area alone would be considerable. A recent tobacco study reported American smokers spent $15.7 for tobacco in 1975, while tobacco-related health care costs in the same year totaled $41.5 billion.' Bader's comments further ignore the clinical studies by Aronow and others2' 3 which clearly show that exacerbations of symptoms can occur at low levels of carbon monoxide; Stewart's blood bank study4 confirmed that Denver and Los Angeles nationally are the two "best" locations for a study of this nature. During our study, we reviewed the ambient air pollution data in the Denver basin fromfive CAMP (Continuous Air Monitoring Program) stations in which parallel trends were demonstrated. The station we specifically mention in the report was less than 822
1,000 meters from the hospital's emergency entrance. Shortness of breath did not represent minor respiratory infections, because our Adult Walk-In Clinic for such problems was separated then; instead, it represented manifestations of underlying cardiopulmonary disease; only adults were involved since pediatric emergency services were provided separately. The Baltimore post-mortem study Bader cites can be considered faulted because "sudden death was defined as occurring within 24 hours of onset" and "blood samples were taken postmortem."5 Therefore, oxygen administered in emergency rooms, coronary care units, and during cardiopulmonary resuscitation may have lowered carboxyhemoglobin levels at the significant time, i.e., onset of symptoms. The half life of carboxyhemoglobin while breathing room air at rest is four to six hours, and mask oxygen can lower this to 45 minutes.6 Support from the letter by Goldstein, et al., collapses if one reads the rebuttal by Schimmel and Murawski which follows.7 The external review draft of the new carbon monoxide criteria document covers all these implications more substantially.8 We had intended to ask all the biographic data that Bader suggests in a proposal which had participation from all four major hospitals in Denver's ambulance system. Delays and severe fiscal constraints foiled us,
however. Thomas L. Kurt, MD, MPH Associate Professor University of Colorado Medical Center B-130 Denver, CO 80262
REFERENCES 1. Luce BR, Schweitzer SO: The economic costs of smoking-induced illness. In: Research on Smoking Behavior, Jarvik ME, et al., (eds.) NIDA Research Monograph 17, Dec 1977, pp. 221-229. 2. Aronow WS, Isbell MW: Carbon monoxide effect on exercise-induced angina pectoris. Ann Intern Med 79:392-395, 1973. 3. Aronow WS, Ferlinz J, Glauser F: Effect of carbon monoxide on exercise performance in chronic obstructive pulmonary disease. Am J Med 63:904-908, 1977. 4. Stewart RD, Baretta ED, Platte LR, et al: Carboxyhemoglobin levels in American blood donors. JAMA 229:1187-1191, 1974.
5. Kuller LH, Radford ED, Seift D, et al: Carbon monoxide and heart attacks. Arch Environ Health 30:477-482, 1975 6. Stewart RD, Peterson MR: Experimental human exposure to carbon monoxide. Arch Environ Health 21:154-164, 1970 7. Goldstein IF, Goldstein M, Landovitz L: A critique of "The relation of air pollution to mortality" and Schimmel H, Murawski TJ: Response to Drs. Goldstein and Landowitz. J Occupat Med 19:375, 1977. 8. Air Quality Criteria for Carbon Monoxide. US Environmental Protection Agency. External Review Draft. April, 1979.
Fetal Monitoring in New York State vs. New York City In their Public Health Brief "Prenatal Monitoring in Upstate New York,"' Zdeb and Logrillo state that "as of January 1, 1978, the birth certificate used in Upstate New York (New York State exclusive of New York City) included a question concerning use of special procedures in prenatal monitoring." Comparable data are available for New York City. The items first appeared on the New York City 1978 birth certificates, at the suggestion of our Obstetric Advisory Committee and draft copies of our new certificates were made available to the rest of the State prior to January 1, 1978. Findings for the calendar year 1978 were prepared for discussion with the Obstetric Advisory Committee of the New York City Department of Health. For the record, it should be stated that New York City's experience with fetal monitoring and that reported in this Brief for the rest of the State differ. Zdeb and Logrillo do not state how many hospitals throughout the rest of the State reported doing fetal monitoring. In 1978, there were 56 hospitals reporting on electronic monitoring in New York City. Considerably, more scalp sampling was done in New York City (1.5 per cent) than appears to be the case in the six-month period for upstate New York (0.2 per cent). By hospital, this percentage varied in New York City from none (in eight hospitals) to ten per cent done (in two hospitals). There was considerably more internal monitoring done in New York City (23.6 per cent) than in upstate AJPH August 1979, Vol. 69, No. 8
LETTERS TO THE EDITOR
New York (14.1 per cent), a possible reflection of different levels of sophistication among hospitals within and outside of New York City. Analysis is continuing on the New York City data and further reports will be forthcoming. We believe analysis of data based on at least a one-year experience has greater validity than an initial six-month period following the introduction of newly added items on the birth certificate. Sol Blumenthal, PhD Acting Director for Biostatistics and Frieda Nelson Assistant Director Bureau of Health Statistics & Analysis New York City Department ofHealth 125 Worth Street New York, NY 10013
REFERENCES 1. Zdeb MS, Logrillo VM: Prenatal monitoring in upstate New York. Am J Public Health 69:499-501, 1979.
Medical Alert Center at USC; not at UCLA The article by Dr. James, "Impacts of the Medical Malpractice Slowdown in Los Angeles County: January 1976,"' contains an error on page 440. The Medical Alert Center is erroneously identified as being situated at Los Angeles County-UCLA Medical Center. In fact, the Center is located at the Los Angeles County/University of Southern California Medical Center. Joseph K. Indenbaum, MD Medical Director County of Los Angeles Department of Health Services 313 North Figueroa Street Los Angeles, CA 90012
REFERENCES
1. James JJ: Impacts of the medical malpractice slowdown in Los Angeles County: January 1976. Am J Public Health 69: 437-442, 1979.
In Support of the Child Restraint Law In his evaluation of "The Tennessee Child Restraint Law,"' Williams documents well the increase of hazard AJPH August 1979, Vol. 69, No. 8
to children from a safety law enacted with apparent good intentions. Quite appropriately he calls attention to the "double jeopardy" of an infant held in the arms or lap of an adult in the right front seat of a moving vehicle. In his article, "The Fault Doctrine and Injury Control,"2 Wigglesworth notes the relative futility of attempting to reduce accidents through punitive countermeasures. He cites as an example the ineffective legislative approach in Sweden and Norway to drinking while driving. I suspect that morbidity and mortality data from Tennessee and Kentucky following the enactment of the child restraint law will give further support to the argument favoring the use of passive restraints. John H. Hughes, MD Director, Emergency Services Associate Professor of Surgery, and ofFamily and Community Medicine University of Arizona Tucson, AZ 85724
chased and put jet airplanes into use since 1961! Ridiculous! Let's encourage researchers to recognize that an injury transmitting agent (tractor, airplane, ladder, etc.,) may experience wide variances in both hours of use and type of use over a period of time. Even conclusions based on changes in accidents per million hours of use must consider changes in type of use (i.e., 55 mph speed limit) before comparing findings with prior
REFERENCES
The report, Farm Tractor Fatalities: The Failure of Voluntary Safety Standards, February 1979, is very misleading. First of all, the voluntary safety standard can work if people are educated as to the benefits of protection. At present, there are 850,000 roll over protective structures in use across the United States on agricultural tractors. There are an additional 250,000 in use on industrial tractors. Most of these were put on before promulgation of the agricultural ROPS standard which took effect on October 25, 1976. There are still many old tractors in use without ROPS, however, the percentage of new tractors being sold with ROPS reaches 100 per cent in Nebraska on the tractors of 80 horsepower and above. I am quite disturbed in that authors Karlson and Noren have not referenced any of the true farm tractor overturn studies. Most of those listed relate to information that was gleaned from health statistics. These are only death certificates and do not address themselves to the true circumstances of the fatality. Furthermore, these are only for deaths and not injuries. Nothing is said about the benefits of ROPS. If I didn't know better, I
1. Williams AF: Evaluation of the Tennessee child restraint law, Am J Public Health, 69:455-458, 1979. 2. Wigglesworth EC: The fault doctrine and injury control, Journal of Trauma, 18: 789-794, 1978.
Three Comments Received on Farm Tractor Safety Factors I am disturbed by the erroneous conclusions reported in the Karlson Noren article, "Farm Tractor Fatalities: The Failure of Voluntary Safety Standards,"'I in the February Journal. The authors used the statistic that accidents per 100,000 male farm residents in Wisconsin went up significantly to support a conclusion that "voluntary standards are not protecting the farm population." This conclusion ignores the significant increases in both numbers of tractors and hours of tractor use per 100,000 male farm residents over the past 10 years. Using death rates per capita instead of death rates per hour of use also could have lead Karlson and Noren to conclude that there has been a horrible increased risk of death on airlines that have pur-
years.
Richard G. Pfister, PhD Professor and Extension Safety Engineer Department ofAgricultural
Engineering Michigan State University
REFERENCES 1. Karlson T, Noren J: Farm tractor fatalities: the failure of voluntary safety standards. Am J Public Health 69:146-149,
1979.
823
