Bioremediation capability evaluation of benzene and sulfolane contaminated groundwater: Determination of bioremediation parameters.

Benzene and sulfolane are commonly used but hazardous chemicals in the petrochemical industry and their leakage and inappropriate disposal certainly causes serious soil and groundwater contamination. In this research, the bioremediation potential of groundwater contaminated with benzene and sulfolane was evaluated, and the operating parameters for bioremediation were established through laboratory batch experiments. Among the various bacterial consortia, the bacterial population of monitoring well c (MWc) contained the highest sulfolane and benzene removal efficiencies. When the dissolved oxygen (DO) level was >1 mg L-1, the bacterial population of MWc showed excellent removal efficiencies toward high and low concentrations of benzene and sulfolane. The C:N:P ratio of 100:10:1 in media facilitated sulfolane and benzene biodegradation, and the degradation time was greatly reduced. Adding additional phosphate into real groundwater could slightly increase benzene removal efficiency. Trace elements only slightly enhanced benzene degradation. On the contrary, additional phosphate and trace elements supplementary did not enhance sulfolane degradation. However, sulfolane removal efficiency could be significantly improved through bioaugmentation of specific sulfolane degrading bacterium and 100% sulfolane removal efficiency was achieved.

Recipes for simulated vomitus.

We developed and demonstrated the stability of recipes for simulated vomitus for use in experiments characterizing occupational exposures to body fluid during simulated healthcare activities. The recipes can be easily adapted to make other simulated bodily fluids at low costs and surrogates added to facilitate detection.

Environmental and body contamination from cleaning vomitus in a health care setting: A simulation study.

BACKGROUND: Environmental service workers may be exposed to pathogens during the cleaning of pathogen-containing bodily fluids. METHODS: Participants with experience cleaning hospital environments were asked to clean simulated, fluorescein-containing vomitus using normal practices in a simulated patient room. Fluorescein was visualized in the environment and on participants under black lights. Fluorescein was quantitatively measured on the floor, in the air, and on gloves and shoe covers. RESULTS: In all 21 trials involving 7 participants, fluorescein was found on the floor after cleaning and on participants' gloves. Lower levels of floor contamination were associated with the use of towels to remove bulk fluid (ρ = -0.56, P = .01). Glove contamination was not associated with the number or frequency of contacts with environmental surfaces, suggesting contamination occurs with specific events, such as picking up contaminated towels. Fluorescein contamination on shoe covers was measured in 19 trials. Fluorescein was not observed on participants' facial personal protective equipment, if worn, or faces. Contamination on other body parts, primarily the legs, was observed in 8 trials. Fluorescein was infrequently quantified in the air. CONCLUSIONS: Using towels to remove bulk fluid prior to mopping is part of the recommended cleaning protocol and should be used to minimize residual contamination. Contamination on shoes and the floor may serve as reservoirs for pathogens.

Contact patterns during cleaning of vomitus: A simulation study.

BACKGROUND: Environmental service workers cleaning bodily fluids may transfer pathogens through the environment and to themselves through contacts. METHODS: Participants with experience in cleaning of hospital environments were asked to clean simulated vomitus using normal practices in a simulated patient room while being videorecorded. Contacts with environmental surfaces and self were later observed. RESULTS: In 21 experimental trials with 7 participants, environmental surfaces were contacted 26.8 times per trial, at a frequency of 266 contacts per hour, on average. Self-contact occurred in 9 of 21 trials, and involved 1-18 contacts, mostly to the upper body. The recommended protocol of cleaning bodily fluids was followed by a minority of participants (2 of 7), and was associated with fewer surface contacts, improved cleaning quality, and different tool use. Participants used different cleaning practices, but each employed similar practices each time they performed an experimental trial. CONCLUSIONS: Training in the use of the recommended protocol may standardize cleaning practices and reduce the number of surface contacts.

Bipaddled anterolateral thigh perforator flap for simultaneous reconstruction of bilateral buccal defects following oral cancer ablation or release of oral submucous fibrosis.

It is a challenge to simultaneously reconstruct bilateral buccal defects following oral cancer ablation or release of oral submucous fibrosis. In this study, we report two cases where bipaddled anterolateral thigh perforator flaps were used to resurface two separate buccal defects.

Free anterolateral thigh flap harvesting from paralytic limbs in post-polio syndrome.

We report two cases of poliomyelitis in which an anterolateral thigh myocutaneous free flap was harvested from the paralytic limb for oral reconstruction. We observed a decrease in the pedicle diameter of the anterolateral thigh flap, but the blood supply to the skin paddle was adequate.

Self-inflicted, trans-optic canal, intracranial penetrating injury with a ballpoint pen.

Trans-orbital penetrating injuries are not common. If not promptly treated, these injuries can lead to serious disabilities and even death. A 60-year-old man, who had multiple underlying diseases, was admitted to our medical ward for the treatment of aspiration pneumonia; he attempted suicide by inserting a ballpoint pen into his left eye. CT of the brain showed a foreign body penetrating through the left optic canal into the intracranial parasellar region without obvious intracranial haemorrhage. The foreign body was withdrawn smoothly at bedside without a craniotomy. The patient was then transferred to the ICU for neuro-observation. The patient recovered with complete left ophthalmoplegia but intact visual function. Acute management of a trans-orbital penetrating injury involves prompt neuroimaging examinations and knowledge of common recurring patterns of injury. All clinicians should be aware of the psychological condition of each patient, and suicide precautions should be considered during clinical practice.

Dose-response models for selected respiratory infectious agents: Bordetella pertussis, group a Streptococcus, rhinovirus and respiratory syncytial virus.

BACKGROUND: Dose-response assessment is one step in quantitative microbial risk assessment (QMRA). Four infectious microbes capable of causing respiratory diseases important to public health, and for which dose-response functions have not been available are: Bordetella pertussis (whooping cough), group A Streptococcus (pharyngitis), rhinovirus (common cold) and respiratory syncytial virus (common cold). The objective of this study was to fit dose-response functions for these microbes to published experimental data. METHODS: Experimental infectivity data in human subjects and/or animal models were identified from the peer-reviewed literature. The exponential and beta-Poisson dose-response functions were fitted using the method of maximum likelihood, and models compared by Akaike's Information Criterion. RESULTS: Dose-response functions were identified for each appropriate data set for the four infectious microbes. Statistical and graphical measures of fit are presented. CONCLUSIONS: With the fitted dose-response functions it will be possible to perform QMRA for these microbes. The dose-response functions, however, have a number of limitations associated with the route of exposure, use of animal hosts, and quality of fit. As a result, thoughtfulness must be used in selecting one dose-response function for a QMRA, and the function should be recognized as a significant source of uncertainty. Nonetheless, QMRA offers a transparent, systematic framework within which to understand the mechanisms of disease transmission, and evaluate interventions.

Airborne fungi and bacteria in child daycare centers and the effectiveness of weak acid hypochlorous water on controlling microbes.

A three-week-long biological sampling scheme was conducted in two child daycare centers (CDCCs) in order to investigate interdiurnal and diurnal variations in indoor airborne microbes as well as the efficiency of weak acid hypochlorous water (WAHW) on disinfecting indoor microbes. During the second week of sampling, WAHW was sprayed using a fogger in the classroom after children had left and before they returned the next morning. An identical cycle of experiments was performed twice in the winter and spring. Without WAHW intervention, the respective mean of the indoor concentrations and I/O ratios were 8732-47581 CFU m(-3) and 0.96-2.53 for fungi, and 6706-28998 CFU m(-3) and 1.10-11.92 for bacteria, showing severe bio-contamination in the CDCCs. Moreover, a relatively high level of bacterial pollution was found at noon, whereas a greater fungal pollution could be detected in the morning and at noon. Among five school days, the fungal and bacterial pollution may be higher on Monday and on Wednesday, Thursday, and Friday, respectively. Furthermore, with WAHW intervention, the indoor microbial concentrations and I/O ratios were decreased significantly. The reduction of I/O ratios caused by WAHW disinfection was accomplished in the morning for bacteria and in the morning, at noon, and in the afternoon for fungi. In conclusion, this study clearly clarified the risky period during which children may be exposed to hazardous environments, and demonstrated the effectiveness of spraying WAHW the night before on decontaminating indoor airborne microbes on the following day, especially in the case of fungi.

Factors affecting the mortality of necrotizing fasciitis involving the upper extremities.

PURPOSE: Necrotizing fasciitis involving the upper extremities is an uncommon, but potentially life-threatening infection. Surgical records were reviewed to identify its mortality risk factors. METHODS: A 10-year retrospective review was conducted of all patients with upper limb necrotizing fasciitis treated in a tertiary care hospital in northern Taiwan. The demographic data, physical and laboratory findings and salient information with respect to the treatment and clinical outcome were collected and analyzed. RESULTS: Fourteen patients were identified. The mean age of the all-male cohort was 60.2 years (range, 44-83 years). Five of the patients died, yielding a mortality rate of 35.7%. At the time of presentation, all 14 patients had pain and swelling, but fever occurred in only 7 patients. Associated chronic debilitating diseases, of which diabetes mellitus was the most common, were present in 9 individuals. Patients underwent an average of two surgical debridements. The initial presentation in a state of altered consciousness or respiratory distress was found to be a statistically significant factors for eventual mortality (P < 0.05). CONCLUSION: The results showed that necrotizing fasciitis of the upper extremity is associated with a high mortality rate. Early diagnosis and referral for aggressive surgical treatment before the development of systemic toxic signs are therefore considered to be essential for survival.

Estimation of autotrophic maximum specific growth rate constant--experience from the long-term operation of a laboratory-scale sequencing batch reactor system.

The autotrophic maximum specific growth rate constant, muA,max, is the critical parameter for design and performance of nitrifying activated sludge systems. In literature reviews (i.e., Henze et al., 1987; Metcalf and Eddy, 1991), a wide range of muA,max values have been reported (0.25 to 3.0 days(-1)); however, recent data from several wastewater treatment plants across North America revealed that the estimated muA,max values remained in the narrow range 0.85 to 1.05 days(-1). In this study, long-term operation of a laboratory-scale sequencing batch reactor system was investigated for estimating this coefficient according to the low food-to-microorganism ratio bioassay and simulation methods, as recommended in the Water Environment Research Foundation (Alexandria, Virginia) report (Melcer et al., 2003). The estimated muA,max values using steady-state model calculations for four operating periods ranged from 0.83 to 0.99 day(-1). The International Water Association (London, United Kingdom) Activated Sludge Model No. 1 (ASM1) dynamic model simulations revealed that a single value of muA,max (1.2 days(-1)) could be used, despite variations in the measured specific nitrification rates. However, the average muA,max was gradually decreasing during the activated sludge chlorination tests, until it reached the value of 0.48 day(-1) at the dose of 5 mg chlorine/(g mixed liquor suspended solids x d). Significant discrepancies between the predicted XA/YA ratios were observed. In some cases, the ASM1 predictions were approximately two times higher than the steady-state model predictions. This implies that estimating this ratio from a complex activated sludge model and using it in simple steady-state model calculations should be accepted with great caution and requires further investigation.