Showing papers in "Archives of Environmental Health in 1970"

Absorption and Elimination of Carbon Monoxide by Inactive Young Men

Abstract: Human volunteers were exposed to carbon monoxide at concentrations of < 1, 25, 50, 100, 200, 500, and 1,000 ppm for periods of one-half to 24 hours. Blood samples for carboxyhemoglobin (COHb) were obtained during the exposures and for up to 23 hours into the postexposure periods. Postexposure treatment with oxygen at 1.0 and 3.0 atmospheres was included. Several model equations were tested against the absorption and excretion data; one theoretical equation accurately predicted COHb levels resulting from continuous and discontinuous exposures to unvarying concentrations and from continuous exposure to a steadily rising concentration.

Studies on, the Biotransformation of 203Hg-labeled Methyl Mercury Chloride in Rats

Abstract: Biotransformation of organic mercury in the rat was followed by specific determination of inorganic mercury after exposure" Inorganic mercury was detected in plasma, brain, and tissues involved in excretion. Inorganic mercury released from the organomercurial redistributes in the body to conform to the pattern of organ distribution of injected mercuric salts" Biotransformation is important in the excretion of mercury after exposure to methyl mercury salts. Inorganic mercury was preferentially excreted in the feces. The delay in the appearance of central nervous system disturbances following exposure to methyl mercury compounds could not be explained by accumulation of inorganic mercury in the tissue. That the unique toxic effects of exposure to methyl mercury salts are caused by the intact mercurial is supported.

δ-Aminolevulinic acid dehydrase as a measure of lead exposure.

Abstract: Close negative correlation between the concentration of lead in blood (Pb-B) and the logarithm of erythrocyte δ-aminolevulinic acid dehydrase (ALA-D) was found for 159 persons with Pb-B levels ranging from 5μg to 95μg per 100 ml. A statistically significant correlation (r = 0.59) between Pb-B and δ-aminolevulinic acid (ALA) in urine was obtained only for Pb-B values over 50μg/100 ml. These results indicate that erythrocyte ALA-D is more accurate and more sensitive than ALA in urine as an indicator of the amount of circulating lead. It is suggested that ALA-D assays can be used as a screening procedure to exclude a lead absorption over a given level. Fairly accurate estimates of the mean Pb-B of groups of people can also be made from their mean ALA-D activity.

Fluid ingestion during distance running.

Abstract: Four highly trained marathon runners were studied 10 determine the influence of fluid loss and replacement on selected physiological variables. Each runner performed three two-hour treadmill runs at about 70% of his aerobic capacity 10 assess the value of drinking a glucose-electrolyte (GE) solution or water ingestion (WI) during exhaustive work. When fluids were ingested during the treadmill runs, a leveling of rectal temperature was observed after about 45 minutes of exercise. Glucose-electrolyte feedings maintained the serum electrolytes near the pre-exercise level, elevated the blood glucose, and maintained carbohydrate metabolism during the final 60 minutes of running. Measurements of the gastric residue after exercise showed no significant difference between the GE and WI volumes. The rate of gastric emptying, fluid loss, and international rules reduce the effectiveness of drinking fluids during marathon competition.

Lead dosage and the role of the intranuclear inclusion body. An experimental study.

Abstract: Biological parameters known to be affected in lead poisoning were measured in rats following ingestion of graded dosages of lead Intranuclear inclusion bodies are formed in renal tubular lining cells with smaller doses of lead than produce other changes Decreased body weight is the next most sensitive abnormality This is followed by increased delta-aminolevulinic acid (ALA) excretion, reticulocytosis, renal edema, and aminoaciduria Anemia only occurs at the highest lead dosage Over a wide range of lead ingestion, urinary lead excretion remains constant, although renal lead content increases Quantitative lead analyses of cell organelles show that lead is concentrated within the inclusion bodies Relatively small amounts of lead are present in the cytoplasm and mitochondria It is suggested that soft-tissue lead accumulates in the intranuclear inclusion body, thereby sparing toxic injury to cytoplasmic organelles

Experimental human exposure to carbon monoxide

Abstract: Human volunteers were exposed to carbon monoxide at concentrations of < 1, 25, 50, 100, 200, 500, and 1,000 ppm for periods of one-half to 24 hours. No untoward effects were observed in sedentary males exposed to 100 ppm for eight hours. Exposures producing carboxyhemoglobin saturations greater than 15% to 20% resulted in delayed headaches, changes in the visual evoked response, and impairment of manual coordination.

Experimental human exposure to tetrachloroethylene.

Abstract: Ten experimental human exposures to frichloro-ethylene vapor, 100 and 200 ppm, for periods of one hour to a five-day work week were conducted. At 200 ppm, untoward subjective responses were mild, inconsistently present, and of doubtful clinical significance. The only troublesome response was a sensation of mild fatigue and sleepiness in five subjects during their fourth and fifth consecutive days of exposure to 200 ppm. Analysis of expired breath of humans by infrared or gas chromatographic techniques provided a means by which to unequivocally establish a diagnosis of exposure. Serial measurements of the solvent present breath in the postexposure period provided the data from which to construct a family of breath excretion curves useful in estimating the magnitude of exposure. Measurement of urinary metabolites of trichloroethylene proved to be an unsatisfactory index of exposure.

Chromosome breakage in humans exposed to methyl mercury through fish consumption. Preliminary communication.

Abstract: Chromosome analysis was performed on cells from lymphocyte cultures from nine subjects with increased levels of mercury in their red blood cells and in four healthy controls. The elevated mercury levels were likely tal have originated from dietary fish with high levels of methyl mercury. A statistically significant rank correlation was found between the frequency of cells with chromosome breaks and mercury concentration. The biological significance of these findings is at present unknown.

Metabolic changes associated with the cessation of cigarette smoking.

Abstract: The person who slops smoking frequently gains weight in the succeeding weeks. To study this phenomenon, subjects were observed before and one month after the cessation of smoking. Statistically significant increases were found in the body weight and body surface area while there were statistically significant decreases in the protein-bound iodine level (PBI), oxygen consumption, heart rate, 30-minute postprandial blood glucose level, and the serum calcium level. These metabolic changes following the cessation of smoking may be one of the reasons for the weight gain observed.

Oral toxicity of mirex in adult and suckling rats. With notes on the ultrastructure of liver changes.

Abstract: The oral toxicity of mirex and its effect on reproduction was studied in rats. The one-dose oral lethal dose for 50% survival of the group (LD50) in females was 365 mg/kg/day; the 90-dose oral LD50 was 6 mg/kglday. The chronicity factor was 60.8. Females fed 25 ppm mirex had fewer offspring born alive, significantly fewer offspring survived to weaning, and many pups developed cataracts. Females fed 5 ppm produced normal litters. Offspring born to mothers fed 25 ppm mirex and nursed by nontreated foster mothers had a low incidence of cataracts and a normal survival rate to weaning. Gas chromato-graphic analysis of milk and fetuses showed excretion of mirex in the milk and passage through the placental barrier. Livers of male and female rats fed 25 ppm mirex weighed significantly more than controls. Proliferation of smooth endoplasmic reticulum and osmiophilic dense bodies were observed in these livers with the electron microscope.

Effects of cigarette smoking on dogs. II. Pulmonary neoplasms.

Abstract: Of 86 dogs trained to smoke through a tracheostoma, 12 dogs (group F) smoked filler-tip, 24 (group H) and 38 (group h) smoked non-filter cigarettes, and 12 (group l), half as many non…filter cigarettes.. Eight dogs (group N) never smokedm By day 875, none of the N dogs, 2 F dogs, 2 L dogs, 12 H dogs, and 12 h dogs had died, and the remaining N, F, L, and H dogs were killede Noninvasive bronchiolo-alveolar tumors were found in dogs of all five groups. Invasive bronchiolo-alveolar tumors were found only in H and h dogs: in two of 12 group h and group H dogs, respectively, which died, and eight of 12 group H dogs which were killed., One extended to and four into the pleura. Early invasive squamous cell carcinoma was found in bronchi of two of group H dogs which were killed.

Light and electron microscope study of chlorobiphenyl poisoning. In mouse and monkey liver.

Abstract: The effects on mouse and monkey liver of long-term oral administration of chlorobiphenyls (CBP), 1.5 mg/day or more, have been investigated at selected intervals by light and electron microscopy. H...

Effects of Various Metals on Behavior of Conditioned Goldfish

Abstract: A conditional avoidance technique was utilized to assess the deleterious effect of four metal ions in the aquatic environment of fish. All test ions, arsenic, lead, mercury, and selenium impaired performance at concentrations below the lethal concentration for 1% (LC1). Mercury was the most potent, producing measurable effects at 0.Q03 ppm. Behavioral toxicity techniques are suggested as useful in setting water quality standards.

A Sensible Look at Air Pollution by Metals

Abstract: (1970) A Sensible Look at Air Pollution by Metals Archives of Environmental Health: An International Journal: Vol 21, No 6, pp 798-806

Chlorinated hydrocarbon pesticide residue in human tissues.

Abstract: Multiple tissues from 70 autopsy cases in Tucson, Ariz, during 1967 and 1968 were analyzed for chlorinated hydrocarbon pesticide residues. Levels of dichlorodiphenyl trichloroethane (DDT), its dehydrochlorinated metabolic derivative, DDE, and dieldrin are not remarkably different from those found in other localities in the United States or from those measured about five years ago in Arizona. No definite associations between pesticide levels and causes of death were evident. Fair intertissue correlations could be shown between certain tissue lipid concentrations of DDT and DDE, but analogous correlations in the case of dieldrin were usually weaker. There is reason to believe that the distribution of dieldrin to nonlipid tissue components exceeds that of DDT and DDE.

Cigarette smoking and changes in respiratory findings.

Abstract: Standardized surveys of cardiorespiratory findings were conducted among male telephone company employees 40 to 59 years of age, and repeated five to six years laterro Cigarette smokers had considerably more cough, phlegm, and chronic wheeze and slightly more nasal catarrh and breathlessness on exertion than nonsmokers. Pipe and cigar smokers had intermediate levels of these symptoms. Men who quit cigarette smoking between two surveys showed considerable improvement in cough and phlegm. Respiratory symptoms were most common among heavy smokers and among smokers of nonfilter cigarettes. Forced expiratory volume decreased and sputum volume increased among an groups over the observation periods Both changes were least marked among men who quit smoking cigarettes and were most marked among those who conrinued to smoke cigarettes, especially the heavy smokers and those who used nonfilter cigarettes.

Respiratory impairment in workers exposed to "safe" levels of toluene diisocyanate (TDI).

Abstract: Workers in a factory producing polyurethane foam have been studied at six-month intervals for a period of 18 months. On each of the four surveys the forced expiratory volume in one second (FEV1) was determined on Monday morning and afternoon. The concentration of toluene diisocyanate (TDI) in air did not exceed 0.014 ppm on any occasion (multiple samples during each survey in all parts of the factory were taken). The exposed workers had reduction of ventilatory capacity at the afternoon measurement; the acute changes were not reversed overnight; cumulative changes exceeding those associated with aging occurred in these workers over 6, 12, and 18 months; symptomatic workers showed a greater response to TDI than asymptomatic ones; and a substantial positive correlation existed between the acute and cumulative changes in FEV1.

Nitrogen dioxide inhibition of viral-induced resistance in alveolar monocytes.

Abstract: Rabbit alveolar monocytes harvested from rabbits injected intratracheally with a 5 × 105 tissue culture infective dose (TCID00) of para-influenza-3 virus are resistant to an in vitro challenge with rabbit pox virus. However, if the rabbits are exposed to 25 ppm nitrogen dioxide (NO2) for three hours immediately after the para-influenza-3 virus inoculation or at 0, 3, 6, 12, or 24 hours before the inoculation of virus, the previously observed resistance does not develop. This refractory state lasts at least 96 hours in that the alveolar macrophages from animals exposed to NO2 are unable to produce interferon when inoculated with para-influenza-3 virus in vitro. Exposure to NO2 also appears to increase the adsorption rate of para-influenza-3 virus in the lungs of rabbits, but it does not inactivate or enhance the infectivity of the virus employed.

Q fever in the Milwaukee area. II. Consumption of infected raw milk by human volunteers.

Abstract: Thirty-four human volunteers consumed unpasteurized raw milk naturally infected with Coxiella burnetii under supervision for a period of one month in attempt to establish the role of oral consumption of infected raw milk on the transmission of Q fever. Serum samples were collected from each individual at the onset of the experiment, also one month and two months after initial ingestion. All serums were tested the complement-fixation test (CFT), the capillary agglutination test (CAT) and the radioisotope precipitin test. None of the 34 human volunteers developed any clinical symptoms or experienced any ill effects, as a result of this experience. Similarly, no detectable antibodies for Q fever could be demonstrated in these individuals.

The Tecumseh study.

Abstract: The Tecumseh Community Health Study has been described in terms of its history, aims, design, conduct and current results, work in progress and future plans. This prospective epidemiological investigation of health and disease, especially cardiovascular disease and related disorders, in a total, natural community has its emphasis on the early detection of disease precursors in susceptible individuals, families, and other groups; the outlook is on prevention. An extensive and intensive study of this kind has been shown to be both feasible and productive. It represents what Dr. Thomas Francis, Jr., has called “clinical investigation on a community level,” including data on man and his environment. The key contribution of Dr. Francis in the establishment and conduct of the study is recalled and remembered with deep appreciation and respect.

Serum proteins and kidney function after exposure to cadmium.

Abstract: Six rabbits were examined seven months after exposure to cadmium for six months., Subcutaneous injections of cadmium chloride had been given five days a weekm One rabbit had nephrosis., The other five rabbits did not differ from a group of nine control rabbits in serum proteins, glomerular filtration rate, or glucose-reabsorption capacity. Hemoglobin was lower in the cadmium group, partly owing to hemolysis., There were large amounts of cadmium in the renal cortex., The alkaline phosphatase activity of the cortex was significantly lower than in the controls. Protein excretion was normal., Electrophoretic examination of urinary proteins revealed tubular patterns in some animalsm These results indicate that after exposure has ceased, a considerable regression of the tubular damage takes place and that large amounts of cadmium in the renal cortex can be tolerated without development of gross abnormalities.