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Hearing loss affects many workers including those in the military and may be caused by noise, medications, and chemicals. Exposures to some chemicals may lead to an increase in the incidence of hearing loss when combined with hazardous noise. This retrospective study evaluated the risk for hearing loss among Air Force Reserve personnel exposed to occupational noise with and without exposures to toluene, styrene, xylene, benzene, and JP-8 (jet fuel). Risk factors associated with hearing loss were determined using logistic and linear regression. Stratified analysis was used to evaluate potential interaction between solvent and noise exposure. The majority of the subjects were male (94.6%) and 35 years or older on the date of their first study audiogram (66%). Followed for an average of 3.2 years, 9.2% of the study subjects had hearing loss in at least one ear. Increasing age (odds ratio [OR] = 1.03 per year of age) and each year of follow-up time (OR = 1.23) were significantly associated with hearing loss. Low and moderate solvent exposures were not associated with hearing loss. Linear regression demonstrated that hearing loss was significantly associated with age at first study audiogram, length of follow-up time, and exposure to noise. Hearing decreased by 0.04 decibels for every decibel increase in noise level or by almost half a decibel (0.4 dB) for every 10 decibel increase in noise level. [ABSTRACT FROM AUTHOR]

A concurrent comparison of the concentration, occurrence, and removal efficiency of polybrominated diphenyl ethers (PBDEs) in wastewater from primary, secondary and tertiary wastewater treatment plants was examined. The study area was composed of all three types of wastewater treatment plants in two countries, the United States of America and Mexico. Nineteen PBDEs were analyzed by an environmentally friendly technique, Stir Bar Sorptive Extraction coupled with thermal desorption and gas chromatography and mass spectrometry. This method required no organic solvent and was proven to be effective and sensitive. The most detected PBDEs found in wastewater influent and effluent were BDE-47, BDE-99, BDE-100 and BDE-119. The total concentration of PBDEs (∑BDE47,99,100,119) in the influents ranged from 115.3 to 595.0 ng L−1, and from below method detection limit to 388.2 ng L−1 in the effluent. It was observed that tertiary treatment was the most effective process to remove BDE-47, 99, and 100, while the primary treatment only rendered an average of 27% removal of total PBDEs. Owing to the incomplete removal in wastewater processes, PBDEs are constantly released into the environment, which implies possible hazardous effects on the environment and human health. [ABSTRACT FROM AUTHOR]

Abstract: Cats are among the most popular pets in the U.S., and the majority of these animals are kept indoors where litter boxes containing some type of absorbent litter material are needed. Dried distillers grains (DDGs) are a major co-product of the ethanol industry, and are primarily sold as animal feed. We have been studying value-added uses for DDGs by extracting valuable phytochemicals from them with a variety of organic solvents. The objective of this research was to determine if the extracted DDGs could be formulated as cat litter. Extracted DDGs absorbed significantly more water (termed hydration capacity) than unextracted DDGs, although sorting the extracted DDGs by particle size had no effect on hydration capacity. Through the addition of glycerol as a dust retardant and guar gum as a clumping agent, a formulation was obtained with desirable physical properties. The addition of copper sulfate to this formulation significantly reduced the release of a volatile odor compound that is chemically similar to the odor compound produced by the decomposition of cat urine. From these results it appears that extracted DDGs have potential as commercial cat litter. [Copyright &y& Elsevier]

This article reviews the liquefaction mechanisms of biomass structural constituents. One pivotal study of such liquefaction processes was done in the 1970s funded by the Bureau of Mines of the United States. Liquefaction is a low-temperature, high-pressure thermochemical process using a catalyst. The process produces a marketable liquid product. In the case of liquefaction, macromolecule compounds in biomass are degraded into small molecules with or without catalyst in the aqueous medium or using organic solvent. Thus, obtained small molecules are unstable and reactive and can repolymerize into oily products with a wide range of molecular weight distribution. In the liquefaction process, the micellar-like broken-down fragments produced by hydrolysis are degraded to smaller compounds by dehydration, dehydrogenation, deoxygenation, and decarboxylation. These compounds once produced, rearrange through condensation, cyclization, and polymerization, leading to new compounds. Thermal depolymerization and decomposition of biomass, cellulose, hemicelluloses, and products were formed as well as a solid residue of charcoal. [ABSTRACT FROM AUTHOR]

A safety characterization specific to children was performed for methyl ethyl ketone (MEK) according to the guidelines of the Voluntary Children's Chemical Evaluation Program (VCCEP). The characterization indicates that MEK exposures are not expected to pose an acute or chronic risk to children. Hazard information, summarized as per the VCCEP Tier structure, indicated no need for additional studies. All exposure pathways potentially relevant to children were considered, including child contact with environmental media, food, drinking water, parental transfer to child (human milk or dermal contact), direct consumer product use, and presence during product use. The assessment found that exposures from anthropogenic sources that children may encounter on a daily basis are very low, and in particular well below the chronic inhalation and oral health benchmarks (RfC and RfD) derived by the U.S. Environmental Protection Agency (USEPA). Indoor uses of consumer products can result in higher acute exposures, but these are short-lived and also fall below chronic benchmarks adjusted to an acute timeframe. In addition, MEK is rapidly metabolized and excreted, thus acute exposures do not lead to an increase in body burden over time. The USEPA concluded the VCCEP submission sufficiently characterized potential risks to children, and that no additional toxicity tests were needed for MEK. [ABSTRACT FROM AUTHOR]

Most polluted sites contain mixed waste. This is especially true of the U.S. Department of Energy (DOE) waste sites which hold a complex mixture of heavy metals, radionuclides, and organic solvents. In such environments enzymes that can remediate multiple pollutants are advantageous. We report here evolution of an enzyme, ChrR6 (formerly referred to as Y6), which shows a markedly enhanced capacity for remediating two of the most serious and prevalent DOE contaminants, chromate and uranyl. ChrR6 is a soluble enzyme and reduces chromate and uranyl intracellularly. Thus, the reduced product is at least partially sequestered and nucleated, minimizing the chances of reoxidation. Only one amino acid change, Tyr128Ash, was responsible for the observed improvement. We show here that ChrR6 makes Pseudomonas putida and Escherichia coli more efficient agents for bioremediation if the cellular permeability barrier to the metals is decreased. [ABSTRACT FROM AUTHOR]

A recent accident at the University of California, Irvine involved the purification of an organic solvent using a solvent still resulting in a fire in the lab. A graduate student was seriously burned and $3.5 million in property damage was incurred. In this report, lessons learned from this accident are used to improve the safety of solvent purification operations. Column methods of aprotic solvent purification processes, as well, as the purchasing of ultra-dry organic synthesis solvents are evaluated. Residual risks associated with the solvent still operation are compared with the alternative purification methods. While severity remains unchanged using the column method, employing the column method reduces the likelihood of an accident. For most applications, the column method and the purchase of ultra-dry solvents remove moisture and oxygen at least to the same level as the solvent still method. This is not without additional costs. Column systems have higher upfront capital costs and ultra-dry solvents cost 20–50% more than certified solvents. Cost–benefit analysis argues that the additional costs make alternative purification methods acceptable. In conclusion, column methods of aprotic solvent purification processes and the purchasing of ultra-dry organic synthesis solvents are, in many applications, a cost-effective alternative to solvent stills for producing a moisture- and oxygen-free product. [Copyright &y& Elsevier]

Discusses the development of peripheral neuropathy abnormalities among roofing workers exposed to multiple solvents in roofing systems. Variables used in the assessment of the roofing workers; Exclusion of workers predisposed to peripheral neuropa thy; Detection of abnormal vibrotactile thresholds in the dominant and nondominant toes.

Investigates the claim of scientists regarding the evidence for nuclear fusion in a breaker of organic solvent at the Oak Ridge National Laboratory in Tennessee. Consequences of the claim for nuclear proliferation and energy production; Contradiction of other scientists on the claim; Comparison between nuclear fission and fusion.

Reports the risks of infertility to men with frequent exposure to organic solvents in the U.S. Influence of organic solvents on sperm motility and production; Discussions on alcohol and tobacco smoking; Neuropsychological effects of the solvents.

Focuses on the effect of environmental contamination on congenital malformations and birthweight of infants in San Francisco Bay Area, California. Impact of maternal exposure to organic solvents during pregnancy; Association between birthweight and maternal residence; Elevation of heart and circulatory malformations;