First Day Of Exposure Research Articles

Biochemical Changes in Humans upon Exposure to Sulfuric Acid Aersol and Exercise

Abstract This study evaluated the effect of a single exposure to sulfuric acid aerosol on six human biochemical blood parameters. A total of 18 human subjects were exposed to ambient air for 4 hr on the first day of exposure and to 100 μg/m3 (0.033 μM) sulfuric acid aerosol (0.5 μm mean mass diameter) for 4 hr on the second day. A total of 17 human subjects were exposed for 4 hr to ambient air on both exposure days. On each exposure day, at 30 min and 90 min after exposure was initiated, all subjects engaged in a 15-min exercise period (walking 4 mph on a treadmill inclined at 10°). Six biochemical blood parameters were measured before and after exposure: glutathione, lysozyme, glutathione reductase, serum glutamic oxaloacetic acid transaminase, serum vitamin E, and 2, 3-diphosphoglyceric acid. The results indicate no significant effect of one 4-hr exposure of humans to 100 μg/m3 sulfuric acid aerosol. One significant post-exposure effect did occur—an increase in glutathione reductase—for both the control and acid-exposed group. It is concluded that at the levels studied, sulfuric acid aerosol is neutralized in the upper airways; consequently, no cellular damage is measurable.

Biochemical Changes in Humans upon Exposure to Sulfuric Acid Aerosol and Exercise

This study evaluated the effect of a single exposure to sulfuric acid aerosol on six human biochemical blood parameters. A total of 18 human subjects were exposed to ambient air for 4 hr on the first day of exposure and to 100 microgram/m3 (0.033 microM) sulfuric acid aerosol (0.5 micrometer mean mass diameter) for 4 hr on the second day. A total of 17 human subjects were exposed for 4 hr to ambient air on both exposure days. On each exposure day, at 30 min and 90 min after exposure was initiated, all subjects engaged in a 15-min exercise period (walking 4 mph on a treadmill inclined at 10 degrees). Six biochemical blood parameters were measured before and after exposure: glutathione, lysozyme, glutathione reductase, serum glutamic oxaloacetic acid transaminase, serum vitamin E, and 2, 3-diphosphoglyceric acid. The results indicate no significant effect of one 4-hr exposure of humns to 100 microgram/m3 sulfuric acid aerosol. One significant post-exposure effect did occur--an increase in glutathione reductase--for both the control and acid-exposed group. It is concluded that at the levels studied, sulfuric acid aerosol is neutralized in the upper airways; consequently, no cellular damage is measurable.

Stomatal responses of white bean to O 3 and SO 2 singly or in combination

The gas mixture of 0.15 ppm O 3 and 0.15 ppm SO 2 increased stomatal resistance of both the upper and lower primary leaf surfaces of Phaseolus vulgaris L. (cv. Sanilac) much more than did O 3 or SO 2 alone. The change in resistance occurred from the first day of exposure and was unrelated to the visible injury of the leaves. It is important when measuring effects on stomatal resistance that both upper and lower leaf surfaces be considered since stomatal responses vary. The difference in stomatal response does not seem to explain the differences in injury development between O 3 alone and O 3 and SO 2 combined.

Effects of NO 2 on the lungs of aging rats : I. Morphology

This research was undertaken to study the early effects of NO 2 on the lungs of aging rats. Male rats 1, 3, 11, 19, and 25 months old were exposed to NO 2 for up to 15 days. At various intervals during exposure, rats were sacrificed and studied by light and electron microscopy. Older rats had a higher mortality rate than young rats during the first day of exposure. Death in these rats was due to pulmonary edema. Morphologically, rats of all ages had injury to ciliated cells in the terminal bronchioles and Type 1 cells in the alveoli. In the older rats, the amount of tissue so damaged was much greater than that in young rats. After injury, rats of all ages began repair of the epithelium; however, the onset was slower in the older rats than in young rats. These two factors probably accounted for the larger accumulation of edema in alveoli of older rats, resulting in their increased mortality.

Motivation for alcohol in rats: Position and bottle preferences do not cause drinking

Position preference, i.e., the tendency to drink from one location rather than the other, was found to be relatively unimportant in determining the drinking behavior of rats presented with a choice between water and a 7% (v/v) ethanol solution in typical two-bottle choice situations. It accounted for essentially none of the variance in rats generally drinking more alcohol solution than water after prolonged previous alcohol experience, and in rats consuming very little alcohol; only in rats drinking slightly less alcohol solution than water was it found to have an influence. Similarly, bottle preference, i.e., the tendency to drink from one of the two bottles regardless of its position or contents, and position preference were found to have almost no effect on heavy-drinking rats even on their first day of exposure and on low-drinking rats after about three days-of access to alcohol.

Nitrate Uptake during Recovery from Nitrogen Deficiency

AbstractTwo‐week‐old nitrogen‐deficient wheat plants attained a high rate of nitrate uptake on the first day of exposure to nutrient solutions supplemented with KNO3. Ammonium uptake from similar solutions supplemented with NH4NO3 was also high during the first day of exposure, but nitrate uptake from this solution was lower than from the KNO3 treatment. During the next two to three days there was a progressive decrease in uptake of both nitrogen ions. A steady increase in uptake then occurred as the plants fully recovered from the nitrogen‐deficient state.The transient low nitrate uptake after three or four days of exposure to KNO3 was not due to an excessive accumulation of nitrate in the tissue, nor to a failure in nitrate reduction as indicated by the rate of nitrate accumulation relative to the uptake rate. Nitrogen supplied as 15N‐nitrite during the low uptake period was effectively incorporated into organic forms and effectively translocated to the shoots. Failure of the root tissue to increase in soluble carbohydrates during illumination was characteristic of the low uptake period. This contrasted with an increase in root soluble carbohydrates in the light during rapid uptake associated with full recovery from the nitrogen‐deficient state. It is concluded that carbohydrate translocation to the root system was insufficient during the intermediate recovery period for optimal nitrate uptake, although it was sufficient for effective reduction and translocation of nitrate and reduced nitrogen.Ammonium uptake from NH4NO3 was restricted during darkness by the third day whereas there was little difference between light and dark periods in nitrate uptake from KNO3 until about the sixth day of recovery. The extent to which ammonium restricted nitrate uptake increased progressively for two or three days following which a lessening influence seemed evident, and the effects were not directly associated with the rate of ammonium uptake.

The effect of changes in nitrate concentration in drinking water on methemoglobin levels in infants

For a five‐day period infants consuming powdered milk formula made up with tap water were exposed to water of controlled nitrate content. There was a significant rise in MetHb levels above normal in most children after the first day of exposure to high nitrate water (108 mg/1 NO3). This was followed by some indication of a drop in MetHb levels despite the continued exposure and finally a return to normal levels when the exposure to nitrates stopped. No clinical signs of methemoglobinemia developed. The possible existence of an adaption mechanism is suggested but requires further elucidation.

Runway Building and Food Exploration Strategy of Pseudacanthotermes militaris (Insecta: Isoptera)

Runway Building and Food Exploration Strategy of Pseudacanthotermes militaris (Insecta: Isoptera)

Acoustic Trauma in Monkeys Related to the Frequency Spectrum of the Noise

Old World monkeys were exposed to octave-band or wide-band noise at 117–120 dB SPL, 8 hours daily, five days per week for four weeks. The octave bands were centered at 500, 2000, 4000, or 8000 Hz. Thresholds for frequencies 63–40 000 Hz were measured daily before, during, and for one month after exposure, by the staircase method, using operant conditioning procedures with positive reinforcement. After the final threshold measurements the temporal bones were fixed and the inner ears examined by microdissection and phase-contrast microscopy. Maximum TTS, usually attained on the first day of exposure, ranged from 60 to 100 dB; PTS, from 40 to 60 dB. Both temporary and permanent loss involved at least two or three octaves and for the most part were greatest at, or within the octave above, the center of the exposure band. Hair cell counts showed reasonable correspondence between the location, severity, and extent (5–12 mm) of outer hair cell loss and the degree of PTS, in accordance with the place principle. In addition, most animals showed complete loss of outer and inner hair cells at the extreme basal end, usually correlated with a hearing loss for the highest frequencies. [Research supported by grants from NIH.]

Erythrocyte delta-aminolevulinic acid dehydratase in new lead exposure: a longitudinal study.

The time course of the lead-induced inhibition of erythrocyte δ-aminolevulinic acid dehydratase (ALA-D) was studied in 29 new lead workers. Samples were performed before commencement of exposure, two to three times during the first week, once a week for three months, and twice during the fourth month of exposure. The rise of the concentration of lead in the blood (Pb-B) was accompanied by a rapid decrease of ALA-D activity, measurable even during the first days of exposure. The rate of decrease of ALA-D was proportional to the rise in Pb-B. After ALA-D had reached a steady state, the variation within each subject was very small. Since ALA-D activity fell in all 29 subjects, the causative effect of lead must be considered proven. ALA-D provides a sensitive and accurate measure of circulating lead. The test is reliable even during the first few days of initial exposure.

The serum trypsin inhibitor capacity during ozone exposure.

Six young New Zealand rabbits were exposed to 0.4 ppm ozone for six hours a day, five days a week, for a calendar period of six months. Blood was drawn from the marginal vein of the ear at three-week intervals, and the trypsin inhibitor capacify (TIC) of the serum was determined and compared with the serum TIC values of six controls. Except for a sharp rise after the first day of exposure to ozone, the TIC values remained within normal limits. These results imply that long-term exposure to low concentrations of ozone does not destroy the serum antitrypsin factor.

Acclimation to heat of the beagle dog.

Four beagle dogs showed evidence of heat acclimation (reduced post-exercise heart rate and body temperature) within 10 days of first exposure of one hour a day in a hot environment (38 ± 2°C). One hour of daily exercise (110 m/min, 0% grade) in the heat (as with human subjects) was adequate to produce the effects of heat acclimation. The physiological changes observed were due to heat exposure alone since the work which was done for training (110 m/min, 4% grade) at the control temperature (20 ± 2°C), was reduced in the heat (0% grade).

Hemoconcentration at altitude.

ArticleHemoconcentration at altitude.D B Dill, S M Horvath, T E Dahms, R E Parker, and J R LynchD B Dill, S M Horvath, T E Dahms, R E Parker, and J R LynchPublished Online:01 Oct 1969https://doi.org/10.1152/jappl.1969.27.4.514MoreSectionsPDF (1 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformationCited ByHypoxia and hemorheological properties in older individualsAgeing Research Reviews, Vol. 79Modeling the oxygen transport to the myocardium at maximal exercise at high altitude19 April 2022 | Physiological Reports, Vol. 10, No. 8Myocardial adaptability in young and older-aged sea-level habitants sojourning at Mt Kilimanjaro: are cardiac compensatory limits reached in older trekkers?19 February 2020 | European Journal of Applied Physiology, Vol. 120, No. 4Evolution of blood rheology and its relationship to pulmonary hemodynamic during the first days of exposure to moderate altitudeClinical Hemorheology and Microcirculation, Vol. 74, No. 2A novel mixed living high training low intervention and the hematological module of the athlete biological passport30 December 2019 | Drug Testing and Analysis, Vol. 12, No. 3Some metrological aspects of measurements of quantitative characteristics during a hypoxic training of elite rowersBody Composition and Body Weight Changes at Different Altitude Levels: A Systematic Review and Meta-Analysis16 April 2019 | Frontiers in Physiology, Vol. 10The University of California Institute of Environmental Stress marathon field studiesMichael B. Maron1 March 2014 | Advances in Physiology Education, Vol. 38, No. 1Analysis of High-Altitude De-Acclimatization Syndrome after Exposure to High Altitudes: A Cluster-Randomized Controlled Trial1 May 2013 | PLoS ONE, Vol. 8, No. 5Endurance Training at AltitudeHigh Altitude Medicine & Biology, Vol. 10, No. 2Haematological and respiratory gas changes in horses and mules exercised at altitude (3800 m)10 June 2010 | Equine Veterinary Journal, Vol. 38, No. S36Errors of measurement for blood volume parameters: a meta-analysisChristopher J. Gore, Will G. Hopkins, and Caroline M. Burge1 November 2005 | Journal of Applied Physiology, Vol. 99, No. 5Airline Chair-Rest DeconditioningSports Medicine, Vol. 34, No. 11Blood volume: importance and adaptations to exercise training, environmental stresses, and trauma/sicknessMedicine & Science in Sports & Exercise, Vol. 32, No. 2Criteria for Psychological Adaptation to High-Altitude Hypoxia31 August 2016 | Perceptual and Motor Skills, Vol. 89, No. 1Atrial natriuretic peptide levels and plasma volume contraction in acute alveolar hypoxiaT. S. E. Albert, V. L. Tucker, and E. M. Renkin1 January 1997 | Journal of Applied Physiology, Vol. 82, No. 1Erythropoietin, 2,3 diphosphoglycerate and plasma volume during moderate-altitude training30 January 2007 | Scandinavian Journal of Medicine & Science in Sports, Vol. 2, No. 1Respiratory and hematological adaptations of young and older Aymara men native to 3600MAmerican Journal of Human Biology, Vol. 4, No. 1Maximal oxygen uptake and erythropoietic responses after training at moderate altitudeEuropean Journal of Applied Physiology and Occupational Physiology, Vol. 62, No. 5Approach to Mild Anemia in the ElderlyClinics in Geriatric Medicine, Vol. 4, No. 1Changes in the Rheologic Properties of Blood after a High Altitude Expedition2 July 2016 | Angiology, Vol. 35, No. 7Studies on some biochemical aspects in the toad after 48 hours of exposure to simulated high altitudeInternational Journal of Biometeorology, Vol. 27, No. 2ADAPTATION TO HIGH ALTITUDEMaintained stroke volume but impaired arterial oxygenation in man at high altitude with supplemental CO2.Circulation Research, Vol. 38, No. 5Physiological Changes in Blood Volume27 September 2008 | CRC Critical Reviews in Clinical Laboratory Sciences, Vol. 6, No. 1 More from this issue > Volume 27Issue 4October 1969Pages 514-8 https://doi.org/10.1152/jappl.1969.27.4.514PubMed5822560History Published online 1 October 1969 Published in print 1 October 1969 Metrics

Influence of Prolonged Carbon Monoxide Exposure and High Altitude on the Composition of Blood and Urine in Man

The influence of exposure to carbon monoxide [average carboxyhaemoglobin saturation 13 per cent) and high altitude (3.454 m) on a number of compounds in blood and urine was investigated in 8 healthy volunteers for 8 and 10 days respectively. Reticulocyte counts increased 2–3 fold; moderate increases were seen in the urinary volume, on an average 400–800 ml/24 hrs. Compared to the remaining days of the study significantly higher amounts of sodium, chloride and calcium were excreted on the first day of exposure to both forms of hypoxia.

Rat adrenal cortical activity during exposure to a high (34°C) ambient temperature

A highly significant (P<.01) elevation of plasma corticosterone concentration was observed in rats exposed to heat (34°C) for periods ranging from 6 hours to 12 days. The highest level of plasma glucocorticoid (corticosterone) was attained at the end of the first day of exposure. At all exposure times with the exception of the animal groups at 30 hours and 13 days, the values were significantly higher than the 28°C average control values. These data suggested the occurrence of a transient rise in adrenocortical activity at 24 hours, followed by an under-compensation at 30 and 48 hours with some continued elevation of activity for most of the remainder of this exposure period. The increase in plasma corticosterone, a calorigenic hormone, may serve as a precursor for increased aldosterone production during acclimation to heat.

AGTH Stimulation and Dexamethasone Inhibition in Newcomers to High Altitude.

SummaryThe response to ACTH stimulation and to dexamethasone inhibition was studied in young adult males acutely exposed to an altitude of 14,000 feet. The results indicate that the adrenal cortex can be further stimulated with exogenous ACTH during the first day of exposure to an environment of low oxygen tension. Dexamethasone administration was started the day before the trip to high altitude and depressed the excretion of urinary steroids despite the hypoxic stimulus.

Temporary Theshold Shifts in the Auditory Sensitivity of the Chinchilla after Exposure to Low-Frequency Noise

Three monaural chinchillas were exposed to noise (300–600 Hz, 100-dB SPL) for an effective duration of 193 min. The experiment was replicated six times each at two-week intervals. Tests of quiet thresholds at 715 Hz were interspersed within each exposure. Threshold levels increased from 0- to 38-dB SPL with the logarithm of exposure duration. Postexposure audibility curves were uniform across low frequencies but increased to maximum at 2.0 kHz for two of the animals. All thresholds returned to normal in about 48 h. Two chinchillas were then exposed to this noise for seven days. Thresholds measured during brief quiet periods increased during the first day of exposure and remained about constant thereafter. After completion of the exposure, threshold shifts were found throughout the audible range and they recovered nearly to normal in about one week. However, small permanent threshold shifts are probably present below 1 kHz. [Work supported by the National Institutes of Health, Public Health Service, U. S. Department of Health, Education, and Welfare.]

Influence of altitude changes on intestinal iron absorption.

Abstract : The absorption of iron in the form of ferrous sulfate was studied in 82 subjects and under various conditions of altitude exposure. Intestinal absorption of iron increased during the first days of exposure to an altitude of 14,900 feet and reached a maximum at the end of a week. It was less marked 4 weeks later. Iron absorption decreased in natives of high altitude brought down to sea level, reached a minimum in 3 weeks, and then returned to normal within 16 months. Studies on the recovery of iron in feces confirmed the changes that were interpreted on the basis of the amount of iron appearing in the red blood cells plus the iron that presumably reached the circulating plasma but was not used in red cell formation. The possible significance of failure in some cases to recover a small fraction of the total iron that was administered is discussed.

Decompression sickness during construction of the Dartford Tunnel.

A clinical, radiological and statistical survey has been made of decompression sickness during the construction of the Dartford Tunnel. Over a period of two years, 1,200 men were employed on eight-hour shifts at pressures up to 28 pounds per square inch (p.s.i.). There were 689 cases of decompression sickness out of 122,000 compressions, an incidence of 0·56%. The majority of cases (94·9%) were simple “bends”. The remainder (5·1%) exhibited signs and symptoms other than pain and were more serious. All cases were successfully treated and no fatality or permanent disability occurred. In two serious cases, cysts in the lungs were discovered. It is suggested that these gave rise to air embolism when the subjects were decompressed, and pulmonary changes may contribute more than hitherto believed to the pathogenesis of bends. Some other clinical features are described, including “skin-mottling” and an association between bends and the site of an injury. The bends rate is higher for the back shift (3 p.m. to 11 p.m.) and the night shift (11 p.m. to 7 a.m.) than for the day shift. In the treatment of decompression sickness it appears to be more satisfactory to use the minimum pressure required for relief of symptoms followed by slow decompression with occasional “soaks”, than to attempt to drive the causative bubbles into solution with high pressures. During the contract the decompression tables recently prescribed by the Ministry of Labour were used. Evidence was obtained that they could be made safer, and that the two main assumptions on which they are based (that sickness will not occur at pressures below 18 p.s.i., and that a man saturates in four hours) may be incorrect. It is desirable to test tables based on 15 p.s.i. and eight-hour saturation. The existence of acclimatization to pressure was confirmed; it is such that the bends rate may fall in two to three weeks to 0·1% of the incidence on the first day of exposure. Acclimatization is lost again, with a “half-time” of about seven days, if a man is away from work. A study of bone damage in compressed air work has been started. In certain radiographs, abnormalities have been seen which may represent an early stage of caisson disease of bone.

ELECTROLYTE METABOLISM IN THE RAT EXPOSED TO A LOW ENVIRONMENTAL TEMPERATURE

Some aspects of electrolyte metabolism in the rat exposed to a low environmental temperature have been examined. The first day of exposure at 2 °C. was accompanied by a loss of chloride. Continued exposure to cold resulted in a retention of sodium, and to a lesser extent, of potassium. Exposure to cold for 45 days (at 2 °C.) caused a sustained elevation of concentration of sodium in the plasma, with a transient increase in potassium and no change in the chloride concentration. Prolonged exposure to cold resulted in an increased blood volume and total body water content. These observations suggest that the rats acclimatized to cold have a larger proportion of actively metabolizing tissues than do comparable animals at room temperature.