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Correlation coefficients Between Cross-Country
Track Performance and Air Pollutants As expected, the average running time for the group of boys who ran in all the home meets for Correlation of Decreased
No. a year tended to improve throughout the season Oxidant
1 hr boforo race
0.079 (Fig 1). The four meets in which the average team
2 hr before race
0.774 time did not improve were the four worst days of
3 hr before race
0.731 the series for air pollution as measured by oxidant
Hour of race
Suspended particulates level in the hour before the race.
Ihr before race
2 hr before race The percent of team members who failed to ini
Carbon monoxide prove their performance is highly correlated to the
Ihr before race level of oxidant in the air (Fig 2). This correlation Correlation of Oxidants
1 hr Before Race and is highest during the hour before the meets (prod
Oxidant uct moment correlation coefficient (r) = 0.88).
2 hr before race
0.884 19 3 hr belore race
0.810 19 Oxidant levels at hours further from the time of
Hour of race
0.910 20 the meet show progressively lower correlations Particulates
1 hr before race
0.718 20 (Table).
2 hr before race
0.538 20 Correlations with other measures of air pollu- Carbon monoxide
1 hr before race
0.076 17 tion are less striking or absent. Total suspended
*Total of 21 meets analyzed, 1959 to 1964. Number varies because particulate matter in the hour before the races
missing values for some pollutant levels has a lower correlation than oxidant (r 0.62). Correlations with particulates at other hours are the race implies that the differences probably are even lower. Carbon monoxide levels show no re- real and that the maximum effect was during the lationship to performance (r = 0.08). Too few de- hour before the race. terminations for oxides of nitrogen are available Because the pollution at one hour is highly defor calculation of meaningful hourly correlations; pendent on the level at the preceding hour, the however, the average level for the day shows no intercorrelations between various measurements relationship at all. Neither temperature, relative must be considered before a causal relationship humidity, wind velocity, nor wind direction shows can be assumed. For example, even if the oxidant any relationship to performance.
effect on performance was limited to the hour be. Although all of the oxidant concentrations are fore the race, some correlation of performance with significantly different from zero, the differences the level two hours before would be expected bebetween them are not statistically significant by cause of the high intercorrelation between the two the usual test. The consistent trend, however, of oxidant levels. When these interrelationships are decreasing correlations at times further away from examined by the use of partial correlation tech
niques, the effect on performance ap1. Mean running times for home "monts for boys who ran in all pears to be limited to oxidant in the home meets of the year. Number of boys (n) for 1959 was 17;
hour before the race. That is, the cor1960, n = 11; 1961, n = 16; 1962, n = 25; 1963, n = 17; and
relation with performance of all the 1964, n = 30.
measurements except oxidant in the hour before the race can be fully explained by the correlations between pollutant levels.
Examination of plots for each of the
vears indicates a. difference in the oxi380
clant to perform inice relationship between the first and last three years of the study. When the races in the periods 1959 to 1961 and 1962 to 1964 ari analyzedd sep::rately, each group has . cor. relation with oxii ant of 0.945 (Fig 3). The slopes of the two regression lines
are almost identical, but for a given oxi360
dant level during the period 1962 to 1964 a larger percent of the team decreased their performance than during the earlier three years. We do not have any simple explanation for this difference. The method of measuring oxidant
did not change during the six years, and 340
the running-time curves in Fig 1 do not 20 28
show this grouping. Differences in inSept Oct
tensity of preseason training or changes
Mean time (sec /mile)
% of team with decreased performance
30 Oxidant (p phm)
20 30 Oxidant (pphm)
r. 62 604
15 Particulates (km x 10) Carbon monoxide (ppm) 2. Correlations between selected pollutant levels and the percent of team members whose performance decreased compared to that in the previous home meet (pphm signifies parts per hundred million).
An attempt to identify individual runners who were particularly susceptible to the effects of air pollution was unsuccessful. Careful examination of the team roster for each year indicated that none of the boys were consistently affected when they ran on heavily polluted days. Nor was there any tendency for the runners whose performance decreased to come from any particular school grade; seniors were affected as often as sophomores. Actually, this finding is not surprising since a boy whose performance drops at one meet may be strongly motivated to do well in succeeding meets. Also, any boy who showed frequent decreases in performance would hardly be desirable on a competitive team.
If the observed marked association of oxidant levels were for less specific measures of pollution, such as daily averages, then an explanation other than that oxidants were dirictly causal inight be plau-ible. For example, other variables such as day of the week might be related to both performance orded vir pollution. Our results, however, inclicate
ile relationship is app: rently limited to the owicient level in the hour lefore the race. This Mecificity to a biologically neaningful time and ile ütremely high correlation (r = 0.95) are conVisite evidence tha: sonne component of the air which is measured as oxidant has a causal effect on team performance. That a long-range, chronic ellect of air pollution is not also operative can not be inferred, since the study was designed to detect immediate effects only.
The level of oxidant in the air reflects the con
in individuals on the team could be responsible.
: to accomplish early in the season, : tensie or the days with high pollution to con
tlle season could produce a spurious post. tive correlation. Days with high pollution, hun ever, appear to be scattered randomly through... the ta'o-month cross-country running season 1: each ci the six years. For example, in 1962 t.lice worst jollution was during the first meet, whercos in 1963 the highest level was reached in the sixtis meet. Fu i hermore, the average pollution level for meets held in the first half of the season is almost identical to the average for the last half. A bias also might result if the opposing team were the same on days of similar pollution; however, this was not the case.
centration of a number of specific compounds including ozone. The exact mechanism by which one or several of these components affects performance is not clear. Smith' claims that athletes require more oxygen during exercise when they breathe air polluted with one of the oxidant components, peroxyacetyl nitrate (PAN). His observed difference in oxygen consumption, ho is srnali (2.3% increase). In addition, his failure to describe adequately the experimental design and statistics used makes the results essentially uninterpretable.
Ozone at levels several times higher than those usually reached in Los Angeles seems to have some effect on pulmonary function.2.3 That breathing some of the oxidant compounds might cause an increase in airway resistance and hence an increase in work of breathing is not unreasonable. Maximal exertion in healthy boys, especially at sea level, however, is not limited by ventilation or work of breaihing.* Thus, it seems unlikeiy that the observed effect of oxidants on performance is due to decreased availability of oxygen
Oxidizing pollution is definitely irritating to the eyes, and athletes often complain of chest discomfort after exercising in the Los Angeles area on clints with high pollution. Thus, the observed effects may be more related to lack of maximal effort due to increasing discomfort than directly to physiologie capability.
Determination of exactly how oxidants affect performance in these athletes is of great importance. For example, the relevance of these results to patients with borderline cardiac competence or chron
ic lung disease is completely different if the effect
directly on physiologic mechanisms such as ventilatory capacity rather than secondarily through an effect on motivation. Careful studies of pulmonary function and oxygen debt incurred during a race might help clarify the issue. Analyses of other types of athletic events requiring less ventilation and less aerobic metabolism are also needed.
Our results should not be interpreted as representing an esfect of air pollution in general, since a predominately oxidizing type of pollution is not present in most cities. Repetition of the study is necessary in situations where oxidant pollution is not present. Care should his taken to be sure that oxidants are really nonexi-te'ni, however, a: high levels of common pollutants such as sulfur dioxide can interfere with the usual tests for oxidants and give a false zero level."
This investigation was supporteri in part by US Public Health Service contract SAph 78639 from the National Center for Air Pol. lution Control and by the Hastings Foundation Fund.
Jack Bradford provided the athletic data.
1. Smith. L.E.: Peroxyacetyl Nitrate Inhalation, Arch Environ lealth 10:161-164 (Feb) 1965.
2. Hallet, W.Y.: Effect of Ozone and Cigarette Smoke on Lung Function, Arch Environ Health 10:295-302 (Feb) 1965.
3. Young. W.A., et al.: Effect of Low Concentrations of Ozone on l'ulmonary Function in Man, J Appl Physiol 19:765-768 (July) 1964.
4. Mitchell, J.H., et al: The Physiologic Meaning of the Maximal Oxygen Intake Test, J Clin Invest
87:538-547 (April) 1858. 5. Saltzman, B.E., and Wartburg. A.F.: Absorption Tube for Removal of Interfering Sulfur Dioxide in Analysis of Atmospheric Oxidant, Anal Chem 37:779-782 (May) 1966.
Radiology Board Sets Written Examination
The American Board of Radiology wishes to announce the institution of a written exam-
Applications for the written examination or either of the oral examinations (June or December) in any given year must be filed before Jan 1 of the year in which the examination is given.
The present examination fee of $150 will, as of July 1, 1967, be increased to $200. This fee, however, will cover both the written and oral examinations where both are required. Candidates eligible for the oral examinations in June 1968 will not be required to take the written examination. All reexamination fees will be increased from $75 to $100 as of the above date.
The December 1967 examination will be held at the Statler Hilton Hotel, Dallas, Dec 4-8, inclusive; the deadline for filing applications 18 June 30, 1967.
The June 1968 examination will be held at the Fontainebleau Hotel, Miami Beach, Fla, June 10-14, inclusive; the deadline date for Aling applications is Dec 31, 1967. Deadline for filing for the written examination in June 1968 or the oral examination in December 1968 is Dec 31, 1967.
Mr. MULTER. Does your last reference refer to the bill, H.R. 12232? Have you seen that biti ?
Dr. KAILIN. No. I was referring to H.R. 6981.
Mr. MULTER. You might look at that bill and then send us a supplemental statement to indicate your thoughts as to whether that is covered by your statement. If you want to add anything to your statement with reference to that bill, you may do so.
Dr. KAILIN. Thank you.
Mr. Winn. Dr. Kailin, has the District of Columbia Medical Society run any tests?
Dr. KATILIN. Tests? No. Surveys? Yes.
Dr. KAILIN. I decided to do something about it, sir. In the last two days I have sent out 172 questionnaires. We handled it this way.
I placed 16 questionnaires in an office, a member of one of my family in Suitland, Maryland. The question that we asked was, “Do you believe that air pollution causes eye irritation? Does it actually occur or do you believe it occurs ?” So it is not a measurement of a physiological thing. With this approach of the 16 subjects, ten reported that in some circumstances air pollution did irritate their eyes. We asked a little bit further questions. "Is this only under special circumstances, such as being behind a bus or in a parking garage, or is it true of a more general area." 75% of the group, 12 of the 16, had symptoms under some circumstances. 44% of the group found—7 of the group told us they did have eye irritation in a more general area. We took 24 questionnaires asking the staff of a cancer clinic, at 23rd and Pennsylvania, these other nurses, the secretaries, the technicians, the medical students, the doctors, of those 24 people 15 in all felt that air pollution affected their eyes under some circumstances and 11 of them felt that the air in general on at least several occasions a year bothered their eyes.
Mr. MULTER. Without objection, copy of your questionnaire will be included in the record.
(The document referred to follows:)
QUESTIONNAIRE SURVEY OF EYE SYMPTOMS
Question: The D.C. Medical Society would like to know whether people feel that air pollution in the Washington Metropolitan area at times has an irritating effect on their eyes.
I. Have you felt such irritation in the last 12 months ?
III. Do you know other people who live or work near you who have complained that air pollution irritates their eyes?
IV. Do you have an allergy to anything that affects your nose?
Of the 52 persons in all of the above groups who reported nasal allergy, 43 or 83 percent attributed eye irritation to air pollution under at least some circumstances.
Mr. WINN. Not being a doctor I cannot get the tie between and checking people's eyes. Why were you asking people in a cancer clinic about eyes? Just a place to poll people ?
Dr. KAILIN. A place to ask people working in a downtown area and because one of my colleagues works there. My own office staff and people dropping in the office, people without allergies, just people coming in-we found again 45% of these people had eye irritation in a general area and about 66% complained about eye irritation when it included heavy spot exposure such as behind a bus.
Mr. Winn. Are you an eye doctor?
Dr. KAILAN. No I am an allergist. We did a telephone survey. We just picked names out of the D.C. telephone directory and we reached 89 people. 63 Percent of those people had symptoms under the whole spectrum of possible circumstances.
Mr. WINN. What question did you ask them on the telephone? How did you pose the question?
Dr. KAILIN. The D.C. Medical Society would like to know whether people feel that air pollution in the Washington metropolitan area at times have an irritating effect on their eyes. Are you willing to answer four questions? First, have you felt such irritation in the last 12 months, not at all, one, two, three occasions, four or more occasions? And then, if you noticed such irritation did you associate it with a special location such as being behind a bus or in a parking garage; being almost any place in downtown Washington on a smoggy day; being in the suburbs of Washington on a smoggy day?
Mr. Winn. Was there a difference between downtown Washington and the suburbs in your percentages? Did pollution or irritants seem higher downtown.
Dr. KAILIN. I couldn't answer that question. I will know more when I go over the data again. But many of these people never went into the suburbs. If we went back over our data and searched a little deeper I had one person who said she had trouble in Washington once but she almost never goes into Washington. The one day she went in she had trouble.
Mr. Winn. Anything further you can give us on that will be appreciated.
Dr. KAILIN. On our telephone survey we also found half the people complained of eye irritation from the general air. Among allergic