John F. Bedi

Pulmonary function responses of older men and women to ozone exposure

The pulmonary function of 8 men and 8 women (51 to 76 years of age), all nonsmokers, was measured before and after 2-h exposures to filtered air (FA) and 0.45 ppm ozone (O3). The subjects alternated 20-min periods of rest and 20-min periods of cycle ergometer exercise at a workload predetermined to elicit a ventilatory minute ventilation (VE) of approximately 25 L/min (BTPS). Functional residual capacity (FRC) was determined pre- and post-exposure. Forced vital capacity (FVC) was determined before and after exposure, and 5 min after each exercise period. Ventilatory minute volume (VE) was measured during the last 2 min of each exercise period, and heart rate was monitored throughout each exposure. The pulmonary function data were evaluated as the percentage change from pre- to post-exposure to partially remove the effect of differences between men and women in absolute lung volume. There were no statistically significant (p greater than 0.05) differences between the responses of men and women to FA or O3 exposure. There were no significant (p greater than 0.05) changes in any variable consequent to FA exposure. Exposure to O3 induced significant (p less than 0.01) decrements in FVC, FEV1.0, and FEV3.0 at post-exposure compared to pre-exposure. Ozone exposure induced no significant (p greater than 0.05) effect on FEF25-75% or FEF75%. Men had a significantly (p less than 0.05) higher mean exercise VE than women (27.9 +/- 0.29 L vs. 25.4 +/- 0.8 L; mean +/- SD). Since the men and women had similar decrements in pulmonary function, even though the women inhaled less O3, the data suggest that women may be somewhat more responsive to O3 than men. We also compared the responses of our older subjects with those of young men and women that we studied with the same protocol, and with published results of other investigators who have studied young men and women. This comparison suggests that older individuals may be less responsive to O3 than young individuals.

Effect of 0.62 ppm NO2 on cardiopulmonary function in young male nonsmokers

Cardiopulmonary and metabolic responses of three groups, each consisting of five adult males (aged 20 to 25), were determined before, during, and after a 2-hr exposure to 0.62 +- 0.12 ppM NO/sub 2/ at 25/sup 0/C and 45% RH. The three groups exercised during exposure at 40% of V/sub O/sub 2/ max/ for either 15, 30, or 60 min for Groups A, B, and C, respectively. During the exercise periods the ventilation was about 33 liter/min, a fourfold increase over the resting level. There were no physiologically significant cardiovascular, metabolic, or pulmonary function changes which could be attributed to exposure to this level of NO/sub 2/ (0.62 ppM). There were no differences between the groups in their response despite the fact that Groups A and B received more NO/sub 2/ as a result of 28% and 84% greater ventilations, respectively.

Increase in jumping height associated with maximal effort vertical depth jumps

Abstract In order to assess if there existed a statistically significant increase in jumping performance when dropping from different dropping heights, 32 young males, ages 19 to 26, performed a series of maximal effort vertical jumps after dropping from a variable height step onto a force plate. Five trials were performed from each of eight heights of 0, 25, 35, 45, 55, 65, 75, and 85 cm. Subjects were classified into two groups, volleyball players (n = 12) and nonjumpers (n = 20) based upon their current physical activity. Measures of the rise of the center of mass, vertical velocity at takeoff, total time on the platform, and total vertical impulse were obtained. A two-factor analysis of variance with repeated measures across dropping heights was used to assess if there was a difference in the performance of the depth jump between volleyball players and physical education students. There was a significant grouping effect. The volleyball players jumped higher than the physical education students in all ...

Combined effects of ozone and nitrogen dioxide on respiratory function in man

Ten young adult males were exposed to either filtered air or 0.50 ppm ozone plus 0.50 ppm NO2 in filtered air under four environmental conditions: 25 degree C, 45 % rh; 30 degrees C, 85% rh; 35 degrees C, 40% rh; and 40 degrees C, 50% rh. There were eight 2-hour exposures per subject. After 1 hour of sitting exposure the subjects exercised for 30 minutes (35-40% predicted maximum capacity) which increased ventilatory exchange to approximately 40 L/min (BTPS). Pulmonary function tests were performed before, during, and after exposure. Metabolism and ventilation were determined during the last 15 minutes of exercise. A symptom questionnaire was completed at the termination of each exposure following reexamination by a physician. There was a decrease in vital capacity, inspiratory capacity, and several flow-related measures of lung function during exposure. The response to exposure to the combined pollutants (O3 and NO2) was similar to that observed in ozone exposures alone. No synergism was observed.

Exercise respiratory pattern in elite cyclists and sedentary subjects

We investigated the breath-by-breath pattern of ventilatory response to bicycle exercise in seven elite male cyclists (VO2max = 71.7 ml X min-1 X kg-1) and ten sedentary males (VO2max = 47.3 ml X min-1 X kg-1) to analyze differences in breathing patterns between individuals with normal and high exercise ventilations (VE). The mean VEmax of the athletes (ATH) exceeded that of the sedentary subjects (SED) by 34.6% (183 vs 136 l X min-1) and was proportional to the difference in VCO2max between the groups (5.9 vs 4.23 l X min-1). The ATH used an average of 89% of their 15-s maximum voluntary ventilation (MVV) during maximum exercise while SED used only 71%. The ATH had slightly, but not significantly, larger vital capacity (FVC). Both groups used about half of their FVC at maximum tidal volume (VT), VT was 47% and 49% of FVC in ATH and SED, respectively. The ATH achieved the higher VEmax by achieving a greater increase in respiratory frequency (63/min vs 49/min), which was accomplished by significant decreases in both inspiratory (T1) and, more importantly, expiratory (TE) time. There was a tendency for athletes to have a somewhat more regular breathing pattern. Both 1/T1 and mean inspiratory flow (VT/T1) were highly correlated with VE, but there were no differences in these relationships between ATH and SED. Highly-conditioned athletes, therefore, respond to the increased demand for CO2 elimination by utilizing a higher respiratory frequency achieved through a reduction of both inspiratory and expiratory duration, but not by utilizing a larger tidal volume (i.e., as percent FVC) than less fit individuals.

Effects of peroxyacetyl nitrate alone and in combination with ozone in healthy young women

Metabolic and pulmonary functions were investigated in 10 nonsmoking, young adult women who were exposed for 2 h (21 °C WBGT) to four conditions: 1) filtered air (FA), 2) 0.27 ppm peroxyacetyl nitrate (PAN), 3) 0.48 ppm ozone (O3), and 4) 0.48 ppm O3 + 0.27 ppm PAN (PAN/O3). The subjects alternated 15-min periods of rest and 20-min periods of bicycle ergometer exercise eliciting a of 25 L. Functional residual capacity (FRC) was determined preand post-exposure. Forced vital capacity (FVC) was determined before and after exposure, as well as 5 min after each exercise period. Heart rate was monitored throughout the exposure, and metabolic functions were measured during the last 2 min of each exercise period. There were no changes in any variable consequent to FA or PAN exposure. During O3 and PAN/O3 exposures, a decrease in V T, a concomitant increase in f R, and no change in occurred. Both O3 and PAN/O3 induced significant (p < 0.05) decrements in FVC, FEV1.0, FEV2.0, FEV3.0, FEF25-75%, IC, ERV, and TLC, bu...

The “effective dose” concept in older adults exposed to ozone

Previous research on young adults has indicated that the magnitude of pulmonary function decrements induced by exposure to ambient ozone (O3) is related to the effective dose of O3 inhaled. The effective dose is defined as the product of O3 concentration (in ppm), mean minute ventilation (VE) and duration of exposure (min). The relative contributions of the three components of effective dose to the development of pulmonary function decrements in older adults are unknown. Twelve healthy, nonsmoking men and women (60-79 years) participated in each of four experiments: (1) a 1-h continuous exercise protocol, and (2) a 2-h intermittent exercise protocol, each performed while exposed to filtered air (FA), and to 0.45 ppm O3, resulting in different effective doses of O3. Pulmonary function (forced vital capacity, FVC, functional residual capacity, FRC, and associated calculated parameters) was measured pre- and postexposure. Ozone exposure induced significant decrements in forced expiratory volume in 0.5, 1.0 and 3.0 seconds (FEV0.5, 1.0, 3.0), regardless of the exercise protocol. There were no changes in FVC with any exposure protocol. There were significant decrements in forced expiratory flow rate at 25% and 50% of FVC (FEF25%, FEF50%) and in forced expiratory flow rate between 25% and 75% of FVC (FEF25-75%) with all four exposures, suggesting a fatigue effect. There were no differences between the decrements induced in FEV1.0 by O3 exposure under the two exercise protocols. The mean exercise VE was 25.3 l/min for the continuous exercise protocol, and was 25.2 l/min for the three exercise periods of the intermittent exercise protocol.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation by older individuals repeatedly exposed to 0.45 parts per million ozone for two hours.

To test for an increased reaction to ozone (O3) in older individuals following an initial exposure, and to test for adaptation and its duration, we exposed 10 men and 6 women (60-89 years old) in an environmental chamber to filtered air and 3 consecutive days of O3 exposure (0.45 ppm), followed by a fourth O3 exposure day after a two day hiatus. Subjects alternated 20-min exercise (minute ventilation = 27 L) and rest periods for 2 hours during each exposure. Subjects rated from one to five, 16 possible respiratory/exercise symptoms prior to and following the exposure. Pulmonary function tests were performed before, and during each rest period and following the exposure. Metabolic measurements were obtained during each exercise period. No significant changes in any symptom question occurred, in spite of a threefold increase in the total number of reported symptoms during O3 exposure. Small but significant pre-to-post decrements on the first and second O3 days in forced vital capacity (FVC-111 and 104 mL), forced expiratory volume in 1 (FEV1-171 and 164 mL) and 3 seconds (FEV3-185 and 172 mL) occurred without concomitant changes in any flow parameter of the forced expiratory maneuver. No differences in the group mean response in FVC, FEV1 or FEV3 on the third or fourth day of O3 exposure and the filtered air exposure were found. The observed changes were due to significant physiological changes in eight of the subjects. Unlike young subjects, no evidence of an increased pulmonary function response to a second consecutive O3 exposure was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined Effect of Ozone and Sulfuric Acid on Pulmonary Function in Man

A potential effect of the combination of ozone and sulfuric acid mist (H2SO4) on respiratory function has been postulated for humans simultaneously exposed to these two pollutants. Nine young men were exposed to 0.25 ppm ozone (O3), 1200-1600 micrograms/m3 sulfuric acid aerosol (H2SO4), and a combination of O3 and H2SO4. During the 2-hr exposures, the subjects exercised (ventilation = 30 L/min) three times for 20 min each. Air temperature was 35 degrees C and relative humidity 83%. Pulmonary function changes after exposure to ozone alone were not expected and were not demonstrated. If a reaction between the combination of O3 and H2SO4 and pulmonary function occurred, pulmonary function responses may have been anticipated following the combination exposure, but no significant changes were seen. It was concluded that the combination of ozone and sulfuric acid aerosol at levels in excess of Threshold Limit Values (TLV) levels do not cause pulmonary dysfunction.

Duration of increased pulmonary function sensitivity to an initial ozone exposure

The metabolic and pulmonary function effects were investigated in six non-smoking young adults who were exposed for 2 hours (22 degrees C WBGT) to: filtered air (FA) 0.45 ppm ozone (DAY1); and two days later to a second exposure to 0.45 ppm ozone (DAY2). The subjects alternated 20-minute periods of rest and 20-minute periods of bicycle ergometer exercise at a workload predetermined to elicit a ventilatory minute volume (VE) of 27 L/min (BTPS). Functional residual capacity (FRC) was determined pre- and post-exposure. Forced vital capacity (FVC) was determined before and after exposure, as well as 5 minutes after each exercise period. Heart rate was monitored throughout the exposure, and VE, oxygen uptake (VO2), respiratory rate (fR), and tidal volume (VT) were measured during the last 2 minutes of each exercise period. There were no changes in any variable consequent to FA exposure. Both ozone exposures induced significant (P less than 0.05) decrements in FVC; FEV1.0 (forced expiratory volume in 1 second); FEV3.0 (forced expiratory volume in 3 seconds); FEF25-75% (average flow rate between 25% and 75% of FVC); and total lung capacity (TLC). The decrements following the DAY2 ozone exposure were significantly greater than following DAY1, and averaged 7.2 percentage points greater than those following the DAY1 exposure.