bluuebunny/crossref_metadata_2025_split huggingface dataset:
Health Effects of Gasoline Refueling Vapors and Measured Exposures At Service Stations
Authors: Page Norbert P. , Mehlman Myron 
Published: September 2013

Liquid gasoline is a complex mixture of at least 150 hydrocarbons with about 60-70% alkanes (paraffins), 25-30% aromatics, and 6- 9% alkenes. In order to evaluate the potential for health effects from inhaling gasoline vapors, it is essential to understand the major differences in the composition of vapors versus liquid gaso line. The small chain, low carbon-numbered components are more volatile and thus in higher percentages in the vapor phase than the larger and heavier molecules. It is noteworthy that the concentrations of aromatics (the more toxic of the gasoline components), are depleted to about 2% in the vapor phase, with the light paraffins (the less toxic) enriched to about 90%. Actual measurements of vapor exposure at service sta tions confirm that the vapor composition is primarily to low weight alkanes although benzene is also emitted and represents the chemi cal of greatest concern. A perceived health concern from inhaling gasoline vapors is the potential for carcinogenicity based on the induction of kidney tumors in male rats and liver tumors in female mice exposed to wholly-vaporized gasoline. However, the results of the animal stud ies are of questionable relevance for human risk assessment due to the unique mechanism operative only in the male rat and since the exposure was to wholly-vaporized gasoline rather than the gasoline vapor mixture to which humans are exposed. Recent research supports the hypothesis that branched-chain alkanes bind to a globulin specific to make rats, alpha 2-u-globulin. The protein complex can not be degraded in the usual manner so that protein accumulation occurs in renal cells, leading to cytotox icity, death, proliferation, and with prolonged exposure, kidney cancer. The results of epidemiology studies fail to link an increase in cancer to exposure to gasoline vapors.
The Determination of the Repeated Oral Toxicity of Halocarbon Oil, Series 27-S
Authors: Kinkead Edwin R. , Culpepper Brenda T. , Henry Sandra S. , Szotak Phyllis S. , Flemming Carlyle D. , Kutzman Raymond S. , Bruner Richard H. , Wyman John F. , Mattie David R. 
Published: September 2013

Halocarbon 27-S (HC 27-S), a polymer of chlorotrifluoroethylene (CTFE), is used as a lubricating oil for pumps in hyperbaric chambers. Although monomeric CTFE has been shown to produce renal lesions in rats, the toxicity of CTFE polymers have not been investigated. To assess the toxicity of repeated exposure to HC 27–S, three groups (N = 6/group) of male and female Fischer-344 rats were dosed with 2.5 g HC 27-S/kg for 7 or 21 consecutive days. Groups were sacrificed at 7, 21, and 35 days (14 days after the 21-day dosing). Corresponding control groups (N = 6) were dosed with deionized water. Decreased water consumption and urine output were apparent in all test groups. Statistically significant increases in fluoride excretion were noted in 24-hr urine samples assessed periodically during the study. Neurotoxic signs were observed in female rats but not in male rats. Significant increases in liver and kidney weights were seen in all rats, regardless of number of dosing days. The increased fluoride burden in treated animals appeared sufficient to alter bone calcium/phosphate ratios in male rats but not female rats. Gross liver enlargement and hepatocellular cytomegaly indicated that the liver was probably the primary target organ following repeated administration of HC 27-S. (Supported by US Navy through Air Force Contract # F33615-085-C-0532.)
The Reproductive and Developmental Toxicity of High Flash Aromatic Naphtha
Authors: Mckee Richard H. , Wong Zachary A. , Schmitt Susan , Beatty Patrick , Swanson Mark , Schreiner Ceinwen A. , Schardein James L. 
Published: September 2013

Catalytic reforming is a refining process that converts naphthenes to aromatics by dehydrogenation to make higher octane gasoline blending components. A portion of this wide boiling range hydrocarbon stream can be separated by distillation and used for other purposes. One such application is a mixture of predominantly 9-carbon aromatic molecules (C9 aromatics, primarily isomers of ethyltoluene and trimethylbenzene), which is removed and used as a solvent—High Flash Aromatic Naphtha. A program was initiated to assess the toxicological properties of High Flash Aromatic Naphtha since there may be human exposure through inhalation or external body contact. The current study was conducted to assess the potential for developmental toxicity in the mouse and for reproductive toxicity in the rat. In the developmental toxicity study in CD-I mice, exposure of dams by inhalation to near lethal levels (1500 ppm) resulted infetal mortality, reduced weight, delayed ossification, and an increased incidence of cleft palate. At 500 ppm, a level at which maternal weight gain was slightly reduced, fetal weight gain was also reduced, but there was no other evidence of developmental effects. The lowest exposure level (100 ppm) did not cause any maternal or developmental toxicity. There was no consistent evidence of reproductive toxicity in rats, even at exposure levels which resulted in significantly reduced parental weight gain. In addition, when parental exposure was stopped on GD (gestation day) 20, birth weights as well as posh natal survival were generally similar to control values, even in the 1500 ppm exposure group. Postnatal weight gain was also similar to controls early in weaning, but, if maternal exposure was reinitiated, weight gain was reduced in the high exposure group. However, when exposure was continued until delivery, pups in the high exposure group exhibited reduced litter size, birth weight and poor survival. Thus it was likely that the reduction in fetal weight, seen in the developmental toxicity study in mice, was transient and had no postnatal consequences if maternal exposure was terminated at any time prior to delivery.
Personal Exposure To 25 Volatile Organic Compounds Epa's 1987 Team Study in Los Angeles, California
Authors: Wallace Lance A. 
Published: September 2013

The US EPA and the California Air Resources Board studied the exposures of 51 residents of Los Angeles, CA to 25 volatile organic chemicals in air and drinking water in February and July of 1987. Participants carried a personal air monitor consisting of a Tenax cartridge and a small sampling pump for two consecutive 12-hour periods. Concurrently, outdoor air samples were collected in the back yards and indoor air samples were collected in the kitchen and living room. Breath samples were collected at the beginning, middle, and end of the 24-hour monitoring period using a van- mounted spirometer employing Tedlar bags followed by collection on Tenax cartridges. All analyses were by GC/MS. Air exchange measurements were made at all homes using the perfluorotracer method. For most chemicals, personal air concentrations were greater than indoor air levels, which were in turn greater than outdoor air concentrations. Breath concentrations were more stable than air exposures and were significantly correlated with previous exposure. Using the air exchange measurements, whole-house source strengths were estimated to range between approximately zero for carbon tetrachloride to 10,000 μg/h for para-dichlorobenzene. Ambient concentrations in February were two-three times those in July, perhaps due to strong inversions.
Heavy Metals and the Mammalian Thymus: In Vivo and In Vitro Investigations
Authors: Ficek Wanda 
Published: September 2013

This experiment was performed to investigate changes in the thymus of Wistar-strain male rats administered cadmium chloride (CdCl2), mercuric chloride (HgCl2), and lead chloride (PbCl2) salts. The study involved measurement of: 1) deoxyribonucleic acid (DNA) content; 2) ascorbic acid (vitamin C) content; 3) incorporation of 3h-thymidine during in-vitro investigation; and 4) histological and morphological changes. It was shown in investigations on DNA content that administration of heavy metal salts caused an average 76% decrease in DNA content compared to the control. Moreover, in the thymus of experimental animals, an average 69% decrease in vitamin C content was recorded. In in vitro cultures, heavy metal salts decreased the incorporation of 3H-thymidine in thymic cells.
Application of Beryllium Antibodies in Risk Assessment and Health Surveillance: Two Case Studies
Authors: Clarke Sara M. , Thurlow Salome M. , Hilmas Duane E. 
Published: September 2013

This paper demonstrates that current standards used by the Occupational Safety and Health Administration (OSHA) to establish an area free from potential beryllium contamination may be inadequate. Using the Beryllium Antibody Assay, it was shown that workers exposed to former beryllium work areas, thought to be sanitized and to meet OSHA standards, experienced statistically significant rises in blood beryllium antibody titers. This finding raises the question of whether the equipment currently required to protect workers in beryllium-laden environments is sufficient. The project mission of decommissioning/decontaminating the former nuclear weapons plant at Rocky Flats Environmental Technology Site (RFETS), instituted in 1992, has necessitated development of new technology directed toward safe and responsible cleanup. Challenges have been posed not only by the need to dispose of radioactive and chemical waste, but also by the problem of cleaning up hazardous metals such as the element beryllium. Beryllium was used extensively in research and the manufacture of nuclear weapons components at Rocky Flats for over 40 years. Since inhalation of this element can induce chronic beryllium disease (Eisenbud and Lisson, 1983), an antibody assay was developed to screen workers for internal exposure to beryllium. Exposure is indicated by a titer of antibodies greater than twostandard deviations above a normal population control (defined as the mean titer of pooled samples from 51 individuals with no known exposure to beryllium) and a p-value of < 0.05. This paper uescribes two new applications for the assay: risk assessment and health surveillance. Case study 1 involves a team of three workers who cleaned a beryllium plenum and whose beryllium antibody titers provided a quantitative assessment of their exposure. Case study 2 describes the use of the antibody assay to determine the probable manner in which one worker was exposed to beryllium while performing his duties as an architectural engineer.
Strategic Elements of Atsdr's Great Lakes Human Health Effects Research Program
Authors: Derosa Christopher T. , Johnson Barry L. 
Published: September 2013

The goal of the Agency for Toxic Substances and Disease Registry's (ATSDR) Great Lakes Human Health Effects Research Program is to identify at-risk populations and to prevent potential human health effects associated with exposure to chemical contaminants in the Great Lakes basin. While this research effort is mandated by the Great Lakes Critical Programs Act of 1990, it also represents a significant opportunity to define a broader model or strategy for other regional or systems-level studies of potential health effects in at-risk populations. This article describes the strategy developed by ATSDR for this purpose in the Great Lakes Basin, as well as the program's specific research objectives and current status. It also outlines the projected implications of this research effort for greater comprehension of the potential health effects of exposure to contaminants in the Great Lakes Basin.
Latent Effects of Pesticides and Toxic Substances On Sexual Differentiation of Rodents
Authors: Gray L. Earl , Kelce William R. 
Published: September 2013

In humans and rodents, exposure to hormonally active chemicals during sex differentiation can produce morphological pseudohermaphrodism (Schardein, 1993; Gray, 1992). For example, hormonally active drugs like DES (estrogenic), Danazol (androgenic), and progestins cause urogenital malformations in the reproductive tracts of humans and rodents. The current discussion will present new information on the effects of toxic chemicals and pesticides that act on reproductive development via novel mechanisms, including germ cell toxicity, antiandrogenicity, and Ah-receptor binding. Information will be presented that describes how exposure during critical stages of life to synthetic chemicals present in our environment, such as benzidine- based dyes, antiandrogenic fungicides, 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD), and PCB congener 169, result in abnormal rodent sex differentiation. In rodents, perinatal exposure to fetal germ cell toxicants reduced the reproductive potential of female, and permanently reduced sperm production in male progeny. Phenotypic sex differentiation, however, was unaffected by these germ cell toxicants. In contrast, antiandrogenic drugs and fungicides induced profound alterations in phenotypic sex differentiation. Effects such as hypospadias, ectopic testes, vaginal pouches, agenesis of the ventral prostate, and nipple retention in male rats were observed commonly. Although these antiandrogens induced no permanent effects in female progeny, another class of chemicals, the Ah-receptor mediated toxicants, did reduce fertility in both male and female rat offspring. Cauda epididymal sperm numbers were reduced permanently in TCDD-exposed male rat and hamster progeny, and female progeny displayed malformations of the external genitalia. Other toxicants produced dramatic alterations of sex differentiation (uterus unicornis, agenesis of the vas and epididymis, and undescended testes), via mechanisms that have not been characterized yet. Since these adult/pubertal alterations resulted from gestational and/or neonatal exposures, future studies should include a comprehensive assessment of reproductive function after perinatal exposure because the developing animal is extremely sensitive to toxicants during sex differentiation, and many of the effects are difficult to detect until late in life.
Treatment of Organic Water Contaminants in Oil Refinery Effluents Investigated By Using a Simulation Model
Authors: Siljeholm Jørn 
Published: September 2013

In this paper the wastewater treatment of organic compounds, particularly the water soluble (polar) compounds in refinery effluents, is simulated by addressing biodegradation, adsorption, and stripping/volatilization. The study examines pollutant data from two refineries in Norway and one in the United States. Previously, little attention has been paid to polar compounds. However, they are present in effluents, sometimes in large amounts, and are difficult to characterize and quantify. The study shows that many polar compounds, including the recently introduced methyl-tertiary-butyl-ether, are biodegraded by <10% in simulated wastewater treatment. The concentrations of some polymers are barely reduced at all, and some metabolites of nonionic surfactants increase in toxicity along the route of degradation, resulting in an end product of the highest toxicity. The study demonstrates that of the substances entering the treatment systems, the residual of selected polar compounds is 38% of the incoming amount, while oil is reduced to 8%. It can be inferred from the study that polar compounds are contaminants, many of which may pose a pollution problem, and that reduction of polar compounds in effluents should be carried out upstream at the source of pollution, rather than downstream by end-of-pipe treatment.
A Hazard Ranking of Organic Contaminants in Refinery Effluents
Authors: Siljeholm Jørn 
Published: September 2013

An environmental hazard ranking model (benchmark ranking model) has been developed and used for the ranking of organic compounds likely to be found in petroleum refinery effluents. The hazardfunction is essentially a multiplication of variables for toxicity (as LC50), octanol-water ratio (Kow), soil adsorption (Koc), solubility (S), and half-life (T1/2). The final score is obtained by taking the logarithm of the hazard and normalizing the values from 1-10. It is a benchmark ranking (BR) approach in the sense that the hazard for chemicals with essentially unknown environmental behaviors may be compared with the hazard for chemicals with well-known behaviors. In general, debates on water pollution have focused on non-polar (hydrophobic) compounds whereas polar (water soluble) compounds have attracted much less attention and regulation. This study focuses on a number of the polar compounds (methyl-tertiary butyl-ether [MTBE], morpholine, metanolamine and others) since there are indications that some of these may cause environmental damage. While non-polar compounds receive the highest score in the study, the combination of frequently large volumes, low biodegradability, low treatability, and analytical detection problems suggest caution when neglecting polar compounds in waste minimization pursuits and in the assessment of environmental hazard and damage. The ranking results are compared to those obtained by using three regulatory systems for the screening and classification of chemicals from the USA and Western Europe. Only the environmental dimension, not the human health dimension, is incorporated in the comparisons and final scores. Although there is good agreement, the number of compounds that get a low score (1-3 on the 1-10 scale) are fewer in the BR system than in the other systems, partly due to the weight of degradation as T½ in the function. The lack of accurate input data, in particular for biodegradation, is a major problem in the ranking. Data for biological oxygen demand (BOD), or from major biodegradation models such as BIODEG and AERUD, give little or no distinction between compounds that biodegrade in four months or forty years.
Protection From Jp-8 Jet Fuel Induced Immunotoxicity By Administration of Aerosolized Substance P
Authors: Harris David T. , Sakiestewa Debbie , Robledo Raymond F , Witter Mark 
Published: September 2013

Chronic exposure to jet fuel has been shown to cause human liver dysfunction, emotional dysfunction, abnormal electroencephalograms, shortened attention spans, and decreased sensorimotor speed. The United States Air Force has decided to implement the widespread use of JP-8 jet fuel in its operations, although a thorough understanding of its potential effects upon exposed personnel is unclear. Exposure to potential environmental toxicants such as JP-8 may have significant effects on host physiology. Previous studies in mice have shown that short-term, low concentration JP-8 exposure had significant effects on the immune system; e.g., decreased viable immune cell numbers, decreased immune organ weights, and loss of immune function that persisted for extended periods of time (i.e., up to 4 weeks post-exposure). Previous studies have shown that JP-8 induced pulmonary dysfunction was associated with a decrease in levels of the neuropeptide substance P (SP) in lung lavage fluids. It was found that administration of aerosolized SP was able to protect exposed animals from such JP-8 induced pulmonary changes. In the current study, aerosolized SP was analyzed for its effects on JP-8 induced immunotoxicity in exposed mice. It was observed that SP administration could protect JP-8 exposed animals from losses of viable immune cell numbers, but not losses in immune organ weights. Further, exposure of animals to SP inhibitors generally increased the immunotoxicity of JP-8 exposure. SP appeared to act on all immune cell populations equally as analyzed by flow cytometry, as no one immune cell population appeared to be preferentially protected by SP. Also, SP administration was capable of protecting JP-8 exposed animals from loss of immune function at all concentrations of JP-8 utilized (250-2500 mg/m3). Significantly, SP only needed to be administered for 15 minutes after JP-8 exposure, and was active at both 1 uM and 1 nM concentrations. Thus, SP administration appears to be a relatively simple and efficient means to reverse the immunotoxicity due to hydrocarbon exposure.
Possible Aluminum Content of Canned Drinks
Authors: Abercrombie David E. , Fowler Richard C. 
Published: September 2013

Preliminary analyses by a commercial laboratory demonstrated varying amounts of aluminum in a small sampling of canned drinks, which had been stored at 15-20 degrees C., ranging from <0.1 to 74 ppm depending on the product and storage time. Aluminum foil wrap immersed in several drinks demonstrated varying rates of dissolution from nearly zero to 100% over a 7 months period when stored at an incubator temperature of 32-34 degrees C. Should aluminum prove to be of significant pathophysiologic consequence, some consideration should be given to all possible sources, including canned drinks which are consumed in copious quantities. When internal protective coatings are complete and remain intact, the cans stored properly and the contents consumed within a reasonable period of time, there appears to be little basis for concern about the ingestion of aluminum from the consumption of the canned drinks tested, as things now stand.
Tall fescue endophyte effects on tolerance to water-deficit stress
Authors: Nagabhyru Padmaja , Dinkins Randy D , Wood Constance L , Bacon Charles W , Schardl Christopher L 
Published: September 2013

AbstractBackgroundThe endophytic fungus,Neotyphodium coenophialum, can enhance drought tolerance of its host grass, tall fescue. To investigate endophyte effects on plant responses to acute water deficit stress, we did comprehensive profiling of plant metabolite levels in both shoot and root tissues of genetically identical clone pairs of tall fescue with endophyte (E+) and without endophyte (E-) in response to direct water deficit stress. The E- clones were generated by treating E+ plants with fungicide and selectively propagating single tillers. In time course studies on the E+ and E- clones, water was withheld from 0 to 5 days, during which levels of free sugars, sugar alcohols, and amino acids were determined, as were levels of some major fungal metabolites.ResultsAfter 2–3 days of withholding water, survival and tillering of re-watered plants was significantly greater for E+ than E- clones. Within two to three days of withholding water, significant endophyte effects on metabolites manifested as higher levels of free glucose, fructose, trehalose, sugar alcohols, proline and glutamic acid in shoots and roots. The fungal metabolites, mannitol and loline alkaloids, also significantly increased with water deficit.ConclusionsOur results suggest that symbioticN. coenophialumaids in survival and recovery of tall fescue plants from water deficit, and acts in part by inducing rapid accumulation of these compatible solutes soon after imposition of stress.