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From page 20... ... Odor perception ranked 2.0-2.5 (5 = "unbearable") ; eye irritation ranked 0.8-1.5; throat irritation ranked 0.5-0.7; mild urge to cough; slight general discomfort; pre-expsoure and postexposure measurement of FVC and FEV1 exhibited no change from control; in general, naive subjects rated effects more severely than informed subjects at all exposures 50 2h 16 adults: 8 informed (7 males, 1 female, 29-53 years old) Read the entire page →
From page 21... ... ; healthy adults, 21-47 years old; Ihrig et al. 2006 smoking history unreported; n = 43 Subjects examined by physician before and after exposure; tear-flow rates measured with paper Prepublication Copy strips; lung-function examinations included bronchial responsiveness; individual attention, reaction time, and powers of concentration tested at end of each exposure day; "no relevant effects of the ammonia exposure in these physical and neurophysiological examination could be found" 3 participants exhibited "slight conjunctival hyperemia"; irritative symptom median of 1 ("hardly at all") Read the entire page →
From page 22... ... ; in general, naive subjects rated effects more severely than informed subjects at all exposures Prepublication Copy Read the entire page →
From page 23... ... Prepublication Copy Odor perception ranked 2.0-4.0 (5 = "unbearable") ; eye irritation ranked 2.9-3.2; throat irritation ranked 1.3-4.5; moderate urge to cough; moderate general discomfort; no measurable change from control in respiratory function (FVC, FEV1) Read the entire page →
From page 24... ... (2006) report that, with the exception of three subjects in the 50-ppm exposure group who exhibited "slight conjunctival hyperemia," "no relevant effects of the ammonia exposure in these physical and neuropsychological examinations could be found." Furthermore, comparison of subjective symptoms reported by naive subjects vs ammonia workers indicated that habituation strongly influenced complaint reporting (for example, naive subjects reported more symptoms than experienced subjects at a given exposure) Read the entire page →
From page 25... ... (1977) studied the effects of exercise on 18 servicemen exposed to ammonia vapor at 102, 152, 206, and 336 ppm in an exposure chamber while cycling under a load of 20 W increased to 180 W in 20-W increments for various durations that apparently were 95-120 min (based on assumptions of "zero time" and extrapolation from figures in the report) Read the entire page →
From page 26... ... Subjects underwent exposure at a sodium bicarbonate plant in areas where ammonia concentrations of 25 and 50 ppm were achieved; controlled 100-ppm exposures took place in an exposure chamber. Exposure periods ranged from 2 to 6 h/day for 5 weeks. Read the entire page →
From page 27... ... In addition, there was no characterization of historical occupational ammonia exposures during years before the short period in which they measured workplace concentrations. Effects in Animals Thorough reviews of the results of controlled experimental exposures can be found in NRC (2002, 2007) Read the entire page →
From page 28... ... . Rats exposed to lethal ammonia concentrations exhibited signs of dyspnea and of irritation of the eyes and nose and lung hemorrhage on necropsy (Appelman et al. Read the entire page →
From page 29... ... (2005) evaluated continuous ammonia exposure (at 0.6, 10.0, 18.8, or 37.0 ppm) Read the entire page →
From page 30... ... ; no deaths or clinical signs 57 Continuous, 114 No clinical signs; no significant effects when compared with controls days No clinical signs 182 Continuous, 90 days "Mild" nasal discharge in 25% of test population 375 Continuous, 90 days Day 25: mild dyspnea, nasal irritation, 63% mortality 651 Continuous, 90 days Day 65: 98% mortality 672 Continuous, 90 days 87% mortality Rabbit, guinea 222 8 h/day for 6 weeks Focal pneumonitis in one of three monkeys; no other signs or clinically significant Coon et al. pig, dog, monkey effects 1970 1,101 8 h/day for 6 weeks Dogs and rabbits exhibited transient lacrimation and dyspnea in week 1; nonspecific inflammatory changes in guinea pig lungs Rabbit, guinea 57 Continuous for 90 No signs or clinically significant effects Coon et al. Read the entire page →
From page 31... ... and low lung scores observed and unaffected by exposure to ammonia and dusts; no differences between control and exposed pigs in any respiratory, gastrointestinal, or ocular measure monitored, including nasal discharge and sneezing Rat 4, 24, 44, 165, 714 Continuous for 3 or 7 Minimal lesions in nasal-cavity respiratory epithelium at 7 days (undefined Schaerdel Prepublication Copy days concentration) ; no change in trachea or lungs; no significant effects on blood gases or et al. Read the entire page →
From page 32... ... Immunotoxicity Although secondary infections of respiratory lesions and skin burns can occur after exposure to concentrated ammonia vapors or aerosols (Caplin 1941; Sobonya 1977; Slot 1938; O'Kane 1983) , there is no evidence that ammonia exposure impairs the human immune system (ATSDR 2004) Read the entire page →
From page 33... ... . There is no conclusive evidence that the ammonia exposures induced the observed carcinomas (ATSDR 2004) Read the entire page →
From page 34... ... . When groups of naive and informed subjects were exposed to ammonia for 30 min in a whole-body exposure chamber and mean results were compared, the naive group subjectively judged 50 ppm to be greater than "distinctly perceptible" but less than a "nuisance;" the judgement of Read the entire page →
From page 35... ... Although there are variable results and some debate regarding the concentrations at which respiratory and ocular irritation occurs, there is a consensus that tissue injury occurs at vapor concentrations higher than those at which ammonia can be detected by odor or irritation; thus, sensitivity to the odor of ammonia vapor imparts warning properties via odor and ocular irritation. Susceptible Populations In tests of concentrations required to stimulate reflex glottis closure (NH3TR) Read the entire page →
From page 36... ... Navy values are provided for comparison. The literature contains human-exposure data derived from multiple clinical and monitoring studies that were carried out at ammonia concentrations and for exposure durations of interest and are thus suitable for direct estimation of exposure guidance levels. Read the entire page →
From page 37... ... and no increased bronchial responsiveness to methacholine challenge in healthy and atopic subjects exposed to ammonia continuously for 3 h at 0, 5, or 25 ppm with exposures Read the entire page →
From page 38... ... odor; at 140 ppm, naive subjects withdrew from the exposure chamber before the passage of 2 h because of "offensive" concentrations, but no informed subjects withdrew (the informed group reported "perceptible" and "nuisance" odor and eye irritation at 140 ppm for 2 h ) (see Table 2-3) Read the entire page →
From page 39... ... (1977) evaluated skilled and experienced repair workers at a chemical manufacturing facility who underwent workplace exposure in areas where ammonia concentrations of 25 and 50 ppm were achieved; controlled 100-ppm exposure took place in an exposure chamber. Read the entire page →
From page 40... ... At 10 ppm, the median ranking of olfactory symptoms by naive subjects lay between the qualitative score of 1 ("hardly at all") and 2 ("somewhat") Read the entire page →
From page 41... ... . Finally, there are few contemporary studies of long-term ammonia exposure of laboratory animals; the 90-day studies available for assessment were published in the early 1970s. Read the entire page →
From page 42... ... Presentation at the First Meeting on Emergency and Continuous Exposure Guidance Levels for Selected Submarine Contaminants, January 23, 2003, Washington, DC. Czuppon, T.A., S.A. Read the entire page →
From page 43... ... 1987. Experimental studies of the effect of chronic exposure of suckling pigs with different ammonia concentrations. Read the entire page →
From page 44... ... Pp. 7-15 in Emergency and Continuous Exposure Guidance Levels for Selected Airborne Contaminants, Vol. Read the entire page →
From page 45... ... 1997. Genotoxic effect of ammonia exposure on workers in a fertilizer factory. Read the entire page →
From page 46... ... Navy's current and proposed 1-h, 24-h, and 90-day exposure guidance levels for benzene. The committee's recommendations for benzene exposure levels are provided at the end of this chapter with a discussion of the adequacy of the data for defining the levels and the research needed to fill the remaining data gaps. Read the entire page →
From page 47... ... Benzene is a common contaminant of outdoor and indoor air. Sources of benzene exposure include tobacco smoke, gasoline vapors, exhaust from motor vehicles, and industrial emissions. Read the entire page →
From page 48... ... depression or to pulmonary edema, hemorrhage, and cardiac collapse. At concentrations of 300-3,000 ppm, benzene causes drowsiness, dizziness, headache, vertigo, tremor, delirium, and loss of consciousness. Read the entire page →
From page 49... ... in five of 20 candidate genes; one SNP was associated with an increase in WBC counts. Those results also suggest genetic variability in the individual response to benzene exposure. Read the entire page →
From page 50... ... (1984) evaluated dose-effect and time-effect relationships between benzene exposure and hematologic and behavioral effects to determine whether such effects follow Haber's law -- (concentration [C] Read the entire page →
From page 51... ... . There were also decreases in the percentage of bone marrow precursors of RBCs in mice exposed with benzene at 3.13 ppm and in RBC and WBC precursors at 12.52 ppm. Read the entire page →
From page 52... ... exposed mice to benzene at 300 ppm 6 h/day, 5 days/week for 23 weeks. They observed reduced mitogen-induced proliferation of bone marrow and splenic B and T lymphocytes and reduced counts of bone marrow and splenic B lymphocytes and thymic and splenic T lymphocytes. Read the entire page →
From page 53... ... A cohort of workers exposed to benzene in the manufacture of Pliofilm from rubber hydrochloride has been studied by the National Institute for Occupational Safety and Health (NIOSH) (Rinsky et al. Read the entire page →
From page 54... ... INHALATION EXPOSURE LEVELS FROM THE NATIONAL RESEARCH COUNCIL AND OTHER ORGANIZATIONS A number of organizations have established or proposed acceptable exposure limits or guidelines for inhaled benzene. Selected values are summarized in Table 3-2. Read the entire page →
From page 55... ... Navy values are provided for comparison. TABLE 3-3 Emergency and Continuous Exposure Guidance Levels for Benzene U.S. Read the entire page →
From page 56... ... A minimal narcotic concentration of 5,940 ppm was reported for a 4-h exposure. Increased activity was the most sensitive end point for which they observed a NOAEL of 2,000 ppm. Read the entire page →
From page 57... ... study showing hematotoxicity following benzene exposure to at least 10 ppm. Therefore, the committee used 5 ppm as the point of departure for the 90-day CEGL. Read the entire page →
From page 58... ... Presentation at the First Meeting on Emergency and Continuous Exposure Guidance Levels for Selected Submarine Contaminants, January 23, 2003, Washington, DC. Cronkite, E.P., T Read the entire page →
From page 59... ... 1981. Acute and chronic dose/response effect of benzene inhalation on the peripheral blood, bone marrow, and spleen cells of CD-1 male mice. Read the entire page →
From page 60... ... Pp. 7-33 in Emergency and Continuous Exposure Guidance Levels for Selected Airborne Contaminants, Vol. Read the entire page →
From page 61... ... 1988. The carcinogenicity of discontinuous inhaled benzene exposures in CD-1 and C57BL mice. Read the entire page →
From page 62... ... 1992. Effect of low benzene exposure on neurobehavioral function, AChE in blood and brain and bone marrow picture in mice. Read the entire page →
From page 63... ... Because of the lack of available data, the committee was unable to recommend exposure guidance levels for DBNP. A discussion of the research needed to allow derivation of exposure guidance levels is provided at the end of this chapter. Read the entire page →

From page 20...

... Odor perception ranked 2.0-2.5 (5 = "unbearable") ; eye irritation ranked 0.8-1.5; throat irritation ranked 0.5-0.7; mild urge to cough; slight general discomfort; pre-expsoure and postexposure measurement of FVC and FEV1 exhibited no change from control; in general, naive subjects rated effects more severely than informed subjects at all exposures 50 2h 16 adults: 8 informed (7 males, 1 female, 29-53 years old)