Showing papers in "Archives of Environmental Health in 1977"

Comparison of the Sensory Irritation Response in Mice to Chlorine and Hydrogen Chloride

Abstract: Groups of male Swiss-Webster mice were exposed to concentrations of chlorine varying from 0.7 to 38.4 ppm and to concentrations of hydrogen chloride varying from 40 to 943 ppm. The total exposure time to both gases was 10 minutes. Dose-response curves were plotted for both chlorine and hydrogen chloride, using the percentage decrease in respiratory rate during each exposure as the response reflecting sensory irritation of the upper respiratory tract. The results showed chlorine to be 33.0 times more irritating than hydrogen chloride, with 95% confidence limits of 18.6 and 57.1. Guidelines for obtaining a range of acceptable threshold limit values (TLV) based on sensory irritation of the upper respiratory tract are discussed. It was concluded that the current TLV of 1 ppm for chlorine is the upper acceptable limit, and that the established TLV of 5 ppm for hydrogen chloride lies at the lower limit of the predicted range. The mechanism of chlorine's and hydrogen chloride's sensory irritation may be explained by their reaction with various functional groups in the membranes of the trigeminal nerve endings lining the nasal mucosa.

Sources of lead in blood. Identification by stable isotopes.

Abstract: The isotope ratios of lead in the blood of ten subjects resident in Dallas, Texas, were measured from April 1974 to June 1975. During the same period, the ratios in the city’s air changed linearly by 6%. One subject gave erratic results, but the remainder yielded ratios that changed systematically—some linearly, others cyclically with turning points occurring in August to October and February to April. Two South African subjects were 6 months out of phase with their U.S.-born wives and the other U.S.-born subjects. Since the South Africans are presumed to have in their skeletons lead that is isotopically distinct from that in the U.S. environment, the cycles are attributed to the mixing of skeletal and dietary lead. The dietary component is inferred to be greatest in August to October, which correlates with the time at which 25-hydroxyvitamin D is reported to have maximum concentration in blood. On the assumption that the isotope ratios of dietary lead remained constant, the proportion of airborn...

Fetal Growth Retardation and Increased Infant Mortaliy at High Altitide

Abstract: An examination of recent Colorado vital statistics records was performed. The records included 194,526 live births and 3,100 infant deaths occurring during the years 1969-73, and some 466,000 live births and 71,000 infant deaths occurring during 1960-71. Birth weights at high altitude (2,744 to 3,100 m) were found to be reduced owing to retardation of intrauterine growth rather than preterm delivery. Despite decreased infant mortality at all altitudes in Colorado during the last 20 years, the infant mortality rate at high altitude remains almost twice that seen in Denver. The elevated mortality at high altitude occurred within 28 days after birth, primarily in preterm (< 38 weeks) infants. It appears that high altitude, possibly through the mechanism of exaggerated fetal hypoxia, retards fetal growth and increases the mortality rate of preterm infants.

pH effects on ciliomotility and morphology of respiratory mucosa.

Abstract: Tracheal cilia of cows exposed, in vitro, for 20 hours to different acidities and alkalinities of sulfuric acid and sodium hydroxide, respectively, showed ciliomotility at pH values as low as 4.9, while the epithelial cells began to be expelled from the mucosa at pH 6.7, initiating a reduction of ciliary function around this pH value. In alkaline reactions, ciliostasis occurred at pH 9.76. Destroyed cilia were found above pH 10.15, while they were morphologically unchanged at pH values as low as 4.0, the lowest value examined. The first symptoms, however, of adverse effects were intracellular edema and the simultaneous occurrence of cellular polyps in both acid and alkaline reactions at pH 6.7 and 9.5, respectively. The results indicate that the early effects of air pollutants are better demonstrated by transmission electron microscopy studies than by, e.g., studies of ciliomotility.

Interactions of lead, calcium, vitamin D, and nutrition in lead-burdened children.

Abstract: This study was undertaken to evaluate relationships between blood or serum levels of lead (Pb), calcium, and 25-hydroxyvitamin D (25-OHD), within the framework of a nutritional survey of lead-burdened children. The results demonstrate that: regardless of blood Pb concentration and season of the year, serum 25-OHD concentration reflects vitamin D intake; high blood Pb (≥60μg/dl) was associated with decreased levels of 25-OHD (18 ± 1 ng/ml vs. 32 ± 1 in controls, P

Epidemiology and Pathology of a Tetrachlorodibenzodioxin Poisoning Episode

Abstract: We describe epidemiological and laboratory investigation of a poisoning outbreak that involved three riding arenas and killed fiftyseven horses, five colts, and numerous other animals. The outbreak was traced to the spraying of the arenas with salvage oil contaminated with tetrachlorodibenzodioxin, trichlorophenol, and polychlorinated biphenyls. The contamination of the salvage oil resulted from the improper disposal of toxic industrial waste. In the tissues of the horses available for study, the most prominent lesion was a centrilobular fibrosis of the liver that arose in the wall of the central veins. This lesion resembled the chronic form of veno-occlusive disease of the liver in humans.

Scalp hair as a monitor of community exposure to lead.

Abstract: Lead was measured by photon activation analysis in scalp hair from three population groups with varied types of environmental exposure Concentrations of lead in hair increased from rural to urban to smelter areas with medians of 91, 153, and 485 ppm, respectively Boys under 16 residing near smelters showed consistently higher lead levels than girls of the same age group and from the same area A history of exposure to lead was deduced from the distribution of concentration along the hair length by analyzing 1-or 2-cm segments of hair strands A reasonably good blood lead-hair lead correlation was obtained for individuals who appeared to be in a steady state with respect to intake and excretion of lead The analytical method for the photonuclear determination of lead in hair, the hair washing procedure, and the advantages of using hair as an epidemiologic monitor are described

Effects of ozone exposure in Canadians and Southern Californians. Evidence for adaptation

Abstract: Comparison of published reports on physiological effects of exposure to ozone (O3) suggests that Canadians are more reactive than southern Californians. Responses of subjects and experimental methods were compared in a cooperative investigation of this apparent difference in reactivity. Four Canadians and four Californians were exposed to 0.37 ppm O3 in purified air at 21 degrees C and 50% relative humidity for 2 hours with intermittent light exercise. Exposures to purified air alone served as controls. Responses of subjects were similar to those observed previously: Canadians on the average showed greater clinical and physiological reactivity to exposure than did Californians, who were no more than minimally reactive. Canadians also showed larger increases in erythrocyte fragility following exposure. No methodological differences sufficient to explain different results of previous studies were found. Although other possible explanations have not been ruled out entirely, adaptation of southern Californians to chronic ambient O3 exposure is a rational hypothesis to explain these results.

Biosynthesis of methylmercury compounds by the intestinal flora of the rat.

Abstract: The contents of the rat cecum and, to a lesser extent, those of the small intestine, synthesized methylmercury from mercuric chloride labeled with Hg 203 in vitro under aerobic or anaerobic conditions. The rate of formation was approximately 18 ng/g cecal contents/20 hr. The synthesis of methylmercury was inhibited by antibiotics and by filtration of the cecal contents through membrane filters, indicating that the bacterial flora of the gut participates in the reaction. Pure cultures of bacteria, isolated from the intestinal tract of the rat, could methylate mercuric chloride. It was estimated that the total amount of methylmercury synthesized from ingested inorganic mercury in man in approximately 400 ng/day.

Tooth lead levels in Birmingham children.

Abstract: The mean lead content of deciduous teeth from children living in the city of Birmingham (U.K.) has been shown to be 11.8 ppm dry weight, irrespective of the sex of the donor. Lead content varies according to type of tooth, and there is a gradient from incisors, with the highest level, to second molars, with the lowest. A relationship was shown between age of donor and lead content of canines and (when lognormalized data were considered) first molars. We were not able to demonstrate a correlation between tooth lead levels and residence near a potential industrial lead source, and we conclude that pollution from a general source is responsible for the body burdens we found.

Cancer Mortality in Relation to Asbestos in Municipal Water Supplies

Abstract: The mortality experience of twenty-two municipalities in Quebec grouped by evidence of exposure to asbestos fibers in water supplies (known high, possible high, and probable low exposures) was evaluated. Excess mortality due to cancer of the stomach (males), pancreas (females), and lung (males) was observed in the two municipalities with known high exposures. The excesses among males may have been due to occupational exposure to asbestos. The absence of excess mortality due to pancreatic cancer among males suggested that the excess among females was not due to waterborne asbestos. The study therefore did not reveal evidence of excess cancer mortality that could be attributed to exposure to asbestos in drinking water.

Surveillance of animal-bite cases in the United States, 1971-1972.

Abstract: In January 1971, the Center for Disease Control (CDC) initiated a national animal-bite surveillance program in cooperation with 15 health jurisdictions that agreed to submit data to the center. During the 2-year surveillance period (1971–1972), 196,684 animal-bite cases were reported from the 15 reporting areas. An animal-bite case was defined as any biting of a person by an animal reported to CDC by a participating health department. Data pertaining to some factors associated with animal bites were reported, including the age and sex of the bitten person, the species of the biting animal, and, in some areas, the status of the biting animal with respect to vaccination against rabies.

Lead Effects among Secondary Lead Smelter Workers with Blood Lead Levels below 80 μg/100 ml

Abstract: A subgroup of workers from a secondary lead smelter was defined to include those with blood lead levels not exceeding 80 /μg/100 ml and with no past history of elevated blood lead Central nervous system symptoms (tiredness, sleeplessness, irritability, headache) were reported by 55% of the group and muscle and joint pain by 39% Zinc protoporphyrin (ZPP) levels were elevated in 71% of cases Low hemoglobin levels (less than 14 gm/100 ml) were found in more than a third of the workers While BUN and creatinine were mostly in the normal range, there was nevertheless a correlation between ZPP and both BUN and creatinine Reduced nerve-conduction velocities were present in 25% of the group; this was not significantly different from findings in a control group The data indicate that a blood level of 80 μg/ 100 ml is an inappropriate biological guide in the prevention of lead disease

Cigarette Smoke in Enclosed Public Facilities

Abstract: A portable carbon monoxide detector (catalytic electrode) was used to record carbon monoxide concentrations in enclosed public facilities, including night clubs, bars, restaurants, stores, hospitals, and public transit vehicles. The highest concentrations of carbon monoxide were found in night clubs, where evening indoor readings averaged 13.4 ppm, which was 4.1 +/- 1.5 ppm higher than outdoor readings. In one poorly ventilated establishment, values ranged from 20 to 40 ppm, with substantial gradients around the room. Adequate ventilation and screening of restaurant employees for ischemic heart disease should prevent problems from cigarette-induced build-up of carbon monoxide. Unfortunately, much lower concentrations of other constituents of smoke cause symptoms and changes of pulmonary function in the nonsmoker. If carbon monoxide is used as an indicator of cigarette smoke accumulation, concentrations should not exceed ambient readings by more than 5 ppm.

Effect of Phosgene on Rat Lungs after Single High-Level Exposure

Abstract: Lungs were removed at intervals after rats were exposed under static conditions to phosgene at concentrations within the LCt5Q range and above. Samples were prepared for electron microscopy by standard methodology. This investigation focused on morphologic events taking place in the terminal bronchiolar-alveolar region. The first ultrastructural alteration was vesiculation of cells in the terminal bronchiolar epithelium and most probably represented the beginning of edema in these cells. This was followed by septal extracellular edema with minimal intracellular edema. Intracellular edema developed next and led to cellular disruption and necrosis. As the postexposure period continued, some type II cells developed cellular edema, and on a focal basis type I cells were disrupted. Fluid appeared in the alveoli after the intracellular and extracellular interstitial spaces of the septa became very swollen. In spite of this widespread interstitial edema, large areas of the cells comprising major portion...

Aerosol inhalation and depth of deposition in the human lung. The effect of airway obstruction and tidal volume inhaled.

Abstract: Ten patients with chronic bronchitis, whose FEV-1.0 varied between 0.48 and 3.00 1, inhaled uniform 5-μm particles tagged with technetium-99 in tidal volumes (VT) varying between 750 and 1830 ml. Their chests were scanned after inhalation to ascertain depth of deposition of the particles, and clearance from the lungs was monitored for 5 hr by serial whole-lung gamma counting. A significant inverse relationship (P < .05) was found between depth of deposition after inhalation (D), measured horizontally across the lung as percentage per inch, and rate of clearance of the particles (5-hr retention [%] = 100 - % cleared at 5 hi = 69.12 − 3.02D). This confirmed previous findings. The depth of deposition depended directly on the FEV1.0 and VT (5-hr retention [%] = 0.026VT + 12.67FEV1.0 -4.13); this resulted in a 14%-75% range for 5-hr retention. Regression slopes for VT and FEV1.0 were independently significant (P <.05). The findings suggest that, as commonly administered at present, the therapeutic eff...

Lead, zinc, and erythrocyte delta-aminolevulinic acid dehydratase: relationships in lead toxicity.

Abstract: A lead-intoxicated patient with extremely high blood lead levels and unexpectedly mild symptoms was studied prior to and following treatment with calcium disodium edetate (ethylenediaminetetraacetic acid) and then prior to and following oral administration of zinc sulfate. During chelation therapy, erythrocyte (delta)-aminolevulinic acid dehydratase (ALAD) activity decreased as blood lead levels fell. Urinary excretion of zinc increased and was more than 3.5 times greater than that of lead. The ratio of blood lead to serum zinc was greatest (1.47) when ALAD activity was lowest. Oral administration of zinc sulfate following chelation therapy resulted in a significant increase in mean ALAD activity. In vitro additions of zinc chloride to the patient's erythrocytes resulted in reactivation of ALAD activity. These studies suggest that zinc is an important element in the ALAD system in man. Zinc may play a protective role in lead toxicity, and zinc supplementation may be a useful adjunct to chelation therapy for lead toxicity.

Housing, hygiene, and health; a study in old residential areas in Copenhagen.

Abstract: The effect of 109 social, medical, housing, and hygienic factors on morbidity of 2,096 individuals was studied in 881 apartments in Copenhagen. “Thriving” (satisfaction), followed by “housing standard” and “personal hygiene,” turned out to be the most prominent predictor for health. “Thriving of parents” was also important for the health of children. Excluding “thriving” in the analyses, “housing standard” and “personal hygiene” or components of these group factors were the important predictors for the health of the population studied, except for children below 3 years of age. For the health of these, the number of rooms used for sleeping purposes was the best predictor. The only other parameter found to influence the morbidities investigated was the total yearly income of the family, which was found to be a secondary predictor for adult morbidity during the last month of the investigation (March 1973). The analyses applied were Pearson correlation, AID-program, factor and multiple regression ana...

Effect of phosgene on rat lungs after single high-level exposure. II. Ultrastructural alterations.

Abstract: Lungs were removed at intervals after rats were exposed under static conditions to phosgene at concentrations within the LCt5Q range and above. Samples were prepared for electron microscopy by standard methodology. This investigation focused on morphologic events taking place in the terminal bronchiolar-alveolar region. The first ultrastructural alteration was vesiculation of cells in the terminal bronchiolar epithelium and most probably represented the beginning of edema in these cells. This was followed by septal extracellular edema with minimal intracellular edema. Intracellular edema developed next and led to cellular disruption and necrosis. As the postexposure period continued, some type II cells developed cellular edema, and on a focal basis type I cells were disrupted. Fluid appeared in the alveoli after the intracellular and extracellular interstitial spaces of the septa became very swollen. In spite of this widespread interstitial edema, large areas of the cells comprising major portion...

Elevated blood pressure and high sodium levels in the public drinking water. Preliminary results of a study of high school students.

Abstract: High school sophomores residing in a community with elevated levels of sodium in the drinking water (107 mg/1) exhibited a marked upward shift in blood pressure distribution patterns for systolic and diastolic blood pressures in both males and females as compared with a similar group in the control community (8 mg/1). The student group from the high sodium community appears to exhibit a blood pressure distribution characteristic of persons several years older.

Induced rhinovirus infection under controlled exposure to sulfur dioxide

Abstract: The interaction between short-term sulfur dioxide (SO/sub 2/) exposure and experimentally induced rhinovirus infection was studied in thirty-two volunteers divided into two groups balanced with respect to age, antibody levels, and nasal mucous flow rates. One group was exposed to SO/sub 2/ at the threshold limit value (TLV) of 5 ppM during 4 hours; the other group served as controls exposed to pollution-free air under the same conditions. The SO/sub 2/ exposure caused a 50% decrease in nasal mucous flow rate in the anterior parts of the nose, but there was no difference in the number of colds which developed in the two groups. The group exposed to SO/sub 2/ had fewer symptoms and a possibly shorter incubation period (P = .06), and virus shedding was at a lower level but more persistent than in the control group. No differences were found in antibody response. The rhinovirus infection in the control group caused a gradual decrease in nasal mucus flow rate starting 2 days after the virus instillation, and after 5 days the rate was less than half its initial value. For future experiments on the interaction between airborne pollutants and rhinovirus infections, a virus challenge by aerosol inhalation ismore » recommended. Our study supports an earlier observation that growth of influenza virus in the nasal cavity of mice was inhibited by exposure to SO/sub 2/ concentrations of 6 or 20 ppM.« less

Pulmonary fibrosis from amorphous silica dust, a product of silica vapor.

Abstract: After prolonged occupation exposure to amorphous silica dust-a product of vaporized crystalline silica (quartz)-eleven out of forty workers showed reticular and/or nodular abnormalities in roentgenograms of the chest. From this group, we present three illustrative cases. These had widespread pulmonary disease with granulomatous nodules and fibrosis (documented histologically in two cases), but there was no demonstrable restrictive impairment of pulmonary function. We discuss the possible importance of this previously underestimated toxicity, especially in an industrial setting.

Respiratory status of surface coal miners in the United States.

Abstract: The United States Public Health Service examined 1,438 surface coal miners to determine the prevalence of coal worker's pneumoconiosis (CWP), chronic bronchitis, and ventilatory impairment among them. Four percent (fifty-nine individuals) showed some roentgenographic evidence of pneumoconiosis, but only seven miners had films interpreted as CWP of category 2 or greater (according to the UICC/Cincinnati classification system). Moreover, most of the affected miners had worked in underground coal mines for prolonged periods. Significant decrements in pulmonary function to increasing exposure to surface mine dust were demonstrated only in the forced vital capacity of smokers. Increased prevalence of chronic bronchitis with increasing exposure was found in all smoking categories. However, significant airway obstruction was an uncommon finding (6.6%) in nonsmoking miners. Employment in surface mining was not likely to cause either the development of CWP or clinically significant respiratory impairment.

Effects of ozone and sulfur dioxide on virus growth in mice.

Abstract: Inhalation of ozone and sulfur dioxide inhibited influenza virus growth in the nose of mice. Ozone inhalation caused the more pronounced inhibition of influenza virus growth: 0.6 ppm ozone for 3 hours post-virus exposure almost completely inhibited influenza virus growth in the nose, whereas sulfur dioxide (6 ppm for 7 days) causes only partial inhibition of influenza growth in the nose. Neither gas altered the propagation of influenza virus in the lungs of mice. Vesicular stomatitis virus (VSV) growth was either unaffected by exposure to ozone (0.9 ppm for 3 hours) or, when ozone exposure preceeded VSV exposure, the virus may have grown to slightly higher titer. The inhibitory effect of ozone and sulfur dioxide on influenza virus growth in nasal epithelium suggests a competitive interaction between the chemical inhalant, the virus, and host tissues, with net consequences for the pathogenesis of this disease. If the effcts of these inhalants are to be properly interpreted, they should be determined for all major regions of virus growth and inhalant deposition.

Collagen breakdown and nitrogen dioxide inhalation

Abstract: Measurements of urinary hydroxylysine glycosides indicate that considerable collagen degradation occurred during the reentry into the earth's atmosphere of the American astronauts of the Apollo-Soyuz mission. Since the crew accidentally inhaled nitrogen dioxide, a recognized pulmonary irritant, and showed clinical and roentgenographic signs of diffuse chemical pneumonitis, it is likely that collagen degradation occurred in the pulmonary parenchyma.

Mucociliary transport in chickens infected with Newcastle disease virus and exposed to sulfur dioxide.

Abstract: Mucociliary transport was studied in the nasal mucous membranes and sinuses of 3-week-old chickens which were either exposed to sulfur dioxide (SO2), infected intranasally with the mesogenic strain of Newcastle disease virus (NDV), or exposed to SO2 after NDV infection. A newly developed apparatus was used to follow intranasal transport rates over time in the same animal, and to follow sinus transport rates over time in a separate group of animals. Intermittent exposure to concentrations of 1.4–66.0 ppm SO2 produced peaks of increased intranasal transport time, with intervening recovery periods. This suggests a homeostatic mechanism. Transport was also decelerated in the sinus when concentrations of SO2 were above 10 ppm. NDV infection produced decelerated intranasal transport rates but did not decelerate sinus rates. Combined NDV and SO2 interacted to produce persistent deceleration of the intranasal transport rate. In the sinus, the combination seemed to counteract the decelerating effect of SO...

Respiratory-function changes in textile workers exposed to synthetic fibers.

Abstract: The prevalence of respiratory symptoms and acute and chronic changes in ventilatory function were studied in three groups of textile workers: 68 workers with exposure to synthetic fibers only, 30 with previous exposure to cotton, and 77 with previous exposure to hemp. The prevalence of dyspnea, grade 3 or 4, was significantly lower (P < .0 1 ) in workers with a history of exposure to synthetic fibers only than in those previously exposed to hemp or cotton. No case of byssinosis was found in any of the workers studied. Values in ventilatoryfunction tests (FEV1.0, FVC and MEF 50%) were significantly reduced during the work shift on Monday and Thursday. The Monday MEF 50% preshift values were significantly lower than expected in all three groups of workers. A comparison of the 1963–1973 data on the 77 workers previously exposed to hemp showed a lower prevalence of most chronic respiratory symptoms and smaller acute FEV1.0and FVC reductions when they worked with synthetic fibers (1973) than when they...

Health hazards to timber and forestry workers from the Douglas fir tussock moth.

Abstract: A heavy infestation of the tussock moth caterpillar (Orgyia pseudotsugata McDonnough) in forested areas of Oregon was associated with itching of the skin and eyes, nasal discharge, cough, and, at times, respiratory difficulty, Personal interviews and inspection of forty-one occupationally exposed persons were supplemented by a questionnaire administered to 428 individuals, composing three groups at various degrees of risk and a control group. There was a cause and effect relationship between the adverse symptoms and the exposure to tussock moth larvae. The specific etiologic agent was not identified, but it was felt that the secretion, hairs, or other substances in the larvae or cocoons of the moth acted as a potent allergenic substance and, for some persons, was also a primary skin irritant.

Chronic, inhalation exposure of rats, rabbits, and monkeys to 1,2,4-trichlorobenzene.

Abstract: Three groups composed of rats, rabbits, and monkeys were exposed for 26 weeks to 1,2,4-trichlorobenzene (-TCB), and one group of each species was used as a control group. TTie nominal exposure concentrations of 1,2,4-TCB were 25.0, 50.0, and 100.0 ppm. Pulmonary function and operant behavior tests in monkeys, ophthalmoscopic examinations in rabbits and monkeys, and measurement of body weights and hematologic and serum biochemical determinations in all species were conducted before and during the exposure period. At termination of 1, 3, and 6 months of exposure, microscopic examination of selected rat tissues was performed. Microscopic changes were seen in the parenchymal cells of livers and kidneys from all groups of rats exposed to 1,2,4-TCB when sacrificed after 4 and 13 weeks of exposure, but no exposure-related abnormalities or other effects were seen after 26 weeks of exposure in any species.

Chronic Methylmercury Exposure in the Monkey (Macaca mulatta)

Abstract: Small daily doses of methylmercury hydroxide were administered to rhesus monkeys for periods of up to 17 months. Behavioral tests of peripheral vision and of the accuracy and rapidity of hand movements did not disclose any early subtle deficits preceding the onset of obvious signs of neurotoxicity. These signs appeared suddenly and involved reduced food intake (anorexia), clumsiness of jumping, loss of fine control of the digits, and uncoordinated mastication. With a constant daily dose of 0.1 mg/kg or less, blood concentration of mercury reached a peak after about 2 months, and then decreased to about half the peak value. Subsequently, increasing the daily dose level above 0.1 mg/kg (range of 0.12 to 0.21 mg/kg) produced an increase of blood concentration which tended to stabilize in the range of 2.0 to 2.5 ppM. After several months at these elevated concentrations all animals exhibited signs of neurotoxicity.