Novel treatment of dihydrogen sulfide inhalation using hyperbaric oxygen during mass casualty.

Hydrogen sulfide (H2S) is a toxic gas produced via breakdown of organic matter. Hydrogen sulfide exposure can cause symptoms ranging in severity from mild effects (dizziness, headache, nausea) to severe lactic acidosis, respiratory failure, pulmonary edema, cardiac arrhythmias and death. Treatment modalities include oral countermeasures and 100% FiO2 with supportive therapy. However, case studies utilizing hyperbaric oxygen (HBO2) therapy have been reported with general benefit seen in severe cases of toxicity. In this report, cases of mild to moderate H2S toxicity occurred aboard a U.S. Navy ship, resulting in a mass casualty incident of more than 30 patients. Patient symptoms included dizziness, headaches, nausea, vomiting, and one patient with altered mental status. Most patients' symptoms resolved after several hours of supportive therapy, but six patients had symptoms refractory to 100% FiO2 at 1 atm. These six patients received HBO2 therapy with a USN Treatment Table 9 after consultation with the local emergency room and hyperbaric assets. Four separate chambers were utilized, including two chambers onboard USN ships and the local explosive ordnance disposal (EOD) chamber. Complete resolution of symptoms in all six patients was achieved within the first breathing period. Patients were monitored after treatment aboard the USN ship medical department. No patients required emergency department care. These cases demonstrate an expanded use of HBO2 to include moderate cases of H2S toxicity refractory to first-line therapy.

[Value of DNA content in comet tail in predicting changes in blood cell counts in workers exposed to benzene].

Objective: To investigate the value of DNA content in comet tail (TailDNA) in predicting the changes in peripheral blood cell counts in workers exposed to benzene. Methods: In 2011, cluster sampling was used to select 150 male workers exposed to benzene in a petrochemical factory. Cubital venous blood and urine samples were collected for routine blood rest, comet assay, and measurement of s-phenylmercapturic acid (SPMA) and urine creatinine. The population was divided into groups according to urinary SPMA or TailDNA, and routine blood test results within 3 years were collected to analyze the changes in blood cell counts. Results: The low-SPMA group had significantly higher white blood cell and neutrophilcounts in all years than the high-SPMA group (P<0.05) . The low-Tail DNA group had a significant increase in platelet count from 2012 to 2014 (P<0.05) , while the high-Tail DNA group had no significant change (P>0.05) . During the 4-year period, the high-TailDNA group had a significantly lower red blood cell count than the low-TailDNA group (P<0.05) . The high-TailDNA group showed a gradual reduction in white blood cell count over time (ß=-0.113, P<0.05) , and the low-TailDNA group showed no trend of the reduction in white blood cell count (P>0.05) . Conclusion: TailDNA can be used to predict the changes in blood cell counts in workers exposed to benzene.

Risks associated with endotoxins in feed additives produced by fermentation.

Increasingly, feed additives for livestock, such as amino acids and vitamins, are being produced by Gram-negative bacteria, particularly Escherichia coli. The potential therefore exists for animals, consumers and workers to be exposed to possibly harmful amounts of endotoxin from these products. The aim of this review was to assess the extent of the risk from endotoxins in feed additives and to calculate how such risk can be assessed from the properties of the additive. Livestock are frequently exposed to a relatively high content of endotoxin in the diet: no additional hazard to livestock would be anticipated if the endotoxin concentration of the feed additive falls in the same range as feedstuffs. Consumer exposure will be unaffected by the consumption of food derived from animals receiving endotoxin-containing feed, because the small concentrations of endotoxin absorbed do not accumulate in edible tissues. In contrast, workers processing a dusty additive may be exposed to hazardous amounts of endotoxin even if the endotoxin concentration of the product is low. A calculation method is proposed to compare the potential risk to the worker, based on the dusting potential, the endotoxin concentration and technical guidance of the European Food Safety Authority, with national exposure limits.

Outbreak of Mysterious Illness Among Hospital Staff: Poisoning or Iatrogenic Reinforced Mass Psychogenic Illness?

BACKGROUND: Hospitals are rarely reported as settings for mass psychogenic illness (MPI). The present report scrutinizes an outbreak of probable MPI among hospital staff, with medical intervention reinforcing the course of the illness. CASE REPORT: Four of seven staff members in an emergency department became acutely ill with nonspecific symptoms. After uneventful observation they were discharged, but symptoms worsened at reassembly for debriefing. Poisoning with hydrogen sulfide was suspected, and the victims were transferred by helicopter for hyperbaric oxygen (HBO) treatment. During the following 9 days, 14 possible poisoning victims were identified, 6 of whom were transferred for HBO. After hospital stays with repeated HBO treatment and examinations without identification of significant physical disease, the majority of the 10 HBO-treated victims remained symptomatic, some on prolonged sick leave. The ward was closed for several weeks during comprehensive but negative investigations for toxic chemicals. Clinical data and lack of indication of chemical exposure, together with an attack pattern with only some individuals becoming ill in a shared environment, suggest MPI. Iatrogenic influence from dramatic intervention was probably a strong driving force in the outbreak. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Awareness of MPI may prevent unnecessary and potentially harmful treatment as well as improve health care resilience, particularly with respect to preparedness. Outbreaks of illness in a group of symptomatic victims without indication of significant physical disease should be managed by observation and limited intervention.

Avoid Toxic Gas Exposures.

Two 2016 OSHA enforcement cases are object lessons in the importance of using the latest gas monitoring technology to protect workers.

[THE RISK OF THE DEVELOPMENT OF OCCUPATIONAL CHRONIC FLUORIDE POISONING].

On the basis of individual occupational fluoride loads (IOFN) it was established that under current levels of air pollution of the working area by fluorine compounds, occupational fluorosis can occur in mostly sensitive workers with 66 or more years of accumulated period of work, while the most vulnerable are workers with of 9.4 or more years of accumulated period of work. The results obtained in comparison of clinical data with individual fluoride load, testify that in the high-risk group for the development of occupational fluoride intoxication include workers with an average accumulated period of work of 10.5 years or more and Individual Occupational Fluoride Load (IOFL) as 67,7 or more grams. In the high-risk group there are included workers with an average accumulated period ofwork of 13.7 years and IOFL as 89.8 grams or more. With the use of ultrasound densitometry there was revealed a clear cut dynamics of the increase of the speed of ultrasonic wave with the rise in the accumulated period of work at the plant, which indicates to a gradual increase in bone tissue density.

Fatalities due to dichloromethane in paint strippers: a continuing problem.

BACKGROUND: Exposure to dichloromethane (DCM or methylene chloride - CH2 Cl2 ) in paint strippers continues to be an avoidable source of morbidity and mortality. DCM has been under regulatory scrutiny by occupational and consumer product agencies since the identification of its carcinogenicity in the mid-1980s. METHODS: We investigated two independent workplace incidents that resulted in three cases of DCM intoxication from paint stripper use. RESULTS: Each incident investigated resulted in a fatality. A third worker suffered obtundation requiring hospitalization and intubation. CONCLUSIONS: The continued occurrence of fatalities and other serious injuries due to DCM-containing paint strippers in the United States calls for a re-evaluation of existing regulatory strategies.

Poultry and livestock exposure and cancer risk among farmers in the agricultural health study.

PURPOSE: The purpose of this study is to evaluate cancer risk associated with raising animals as commodities, which is associated with a variety of exposures, such as infectious agents and endotoxins. METHODS: Information was available for 49,884 male farmers in the Agricultural Health Study, who reported livestock and poultry production at enrollment (1993-1997). Cancer incidence data were obtained through annual linkage to state registries. Using Poisson regression analyses, we evaluated whether the number and type of animals raised on the farm impacted cancer risk. RESULTS: Overall, 31,848 (63.8%) male farmers reported raising any animals. Lung cancer risk decreased with increasing number of livestock on the farm (p trend = 0.04) and with raising poultry (Relative Risk (RR) = 0.6; 95% confidence interval (CI): 0.4-0.97). Raising poultry was associated with an increased risk of colon cancer (RR = 1.4; 95% CI: 0.99-2.0) with further increased with larger flocks (p trend = 0.02). Risk of non-Hodgkin lymphoma was also elevated in those who raised poultry (RR = 1.6; 95% CI: 1.0-2.4), but there was no evidence of increased risk with larger flocks (p trend = 0.5). Raising sheep was associated with a significantly increased risk of multiple myeloma (RR = 4.9; 95% CI: 2.4-12.0). Performing veterinary services increased the risk of Hodgkin lymphoma (RR = 12.2; 95% CI: 1.6-96.3). CONCLUSIONS: We observed an inverse association between raising poultry and livestock and lung cancer risk and some evidence of increased risk of specific lymphohematopoietic malignancies with specific types of animals and performing veterinary services. Further research into associations between raising animals and cancer risk should focus on identification of etiologic agents.

The association between symptoms and exposure is stronger in dropouts than in non-dropouts among employees in Norwegian smelters: a five-year follow-up study.

PURPOSE: We have investigated the association between respiratory symptoms and dust exposure among employees in 18 Norwegian smelters using a longitudinal design. METHODS: All employees (N = 3,084) were examined annually for 5 years (12,996 health examinations). At each examination, the subjects reported if they had respiratory symptoms, coded as 1 (yes) or 0 (no), on a respiratory questionnaire. Symptom score was constructed as the sum of symptoms (0-5). Full-time workers in the production line were classified as line operators; subjects never exposed in the production line were regarded as non-exposed. The remaining individuals were classified as non-line operators. A job-exposure matrix regarding dust exposure was also available. Analyses of repeated measurements were performed using generalised linear mixed model with log-link (Poisson regression). Adjustments were made for overdispersion. RESULTS: The mean age at inclusion was 39.0 years, and 89% were men. The median dust exposure in tertiles 1-3 was 0.19, 1.76 and 3.47 mg/m(3). The longitudinal analyses showed that the association between symptoms-score ratio (SSR) and job category was significantly stronger in dropouts compared with non-dropouts (p = 0.01). Among the dropouts, SSR was 1.61 (95% confidence interval: 1.27-2.05) and 1.39 (1.09-1.77) in line operators and non-line operators compared with non-exposed employees, respectively. The corresponding SSR for subjects who completed the study was 1.13 (1.01-1.27) and 1.12 (1.00-1.26), respectively. Similarly, among the dropouts, the SSR between the second and the first tertile was 1.28 (1.05-1.55) and 1.37 (1.13-1.66) between the third tertile and the first tertile. CONCLUSIONS: Line operators had more respiratory symptoms than non-exposed employees. This effect was significantly stronger in dropouts than in those who continued their jobs, indicating that there is a selection of subjects without respiratory symptoms in this industry.

Hydrogen fluoride inhalation injury because of a fire suppression system.

Automatic fire suppression systems (FSSs) use hydrofluorocarbons (HFCs) to chemically extinguish fires. At high temperatures, HFC can release hydrogen fluoride (HF), a toxic and potentially lethal gas. We report the deaths of three U.S. military personnel at Bagram Air Base from acute respiratory failure after the FSS in their vehicle received a direct hit from a rocket-propelled grenade. Despite presenting with little to no additional signs of trauma, these individuals all died within 24 hours from HF-induced respiratory failure. When two patients later presented with similar symptoms after damage to their vehicle's FSS, they were aggressively treated with nebulized calcium and positive pressure ventilation. Both survived. The presence of HFC-containing FSSs in military vehicles may lead to future cases of HF inhalation injury, and further research must be done to help rapidly diagnose and effectively treat this injury.

[Toxicological characteristic of indole as a basis for its hygienic regulation].

The toxic properties of indole have been studied in terms of LD50 indole was established to refer to moderately hazardous substances: in case of indole introducing into the stomach in rats and mice, DL50 is 1200 mg/kg and 750 mg/kg respectively Indole has a weak ability to cumulation, and has a strong irritant effect to the eyes and a moderate one to the skin. Indole has indiscriminate irritating effect on the respiratory tract: Limir is at Limac (77,8 mg/m3). The occupational exposure of indole in the working area is 1 mg/m3.

Exposure to formaldehyde and its potential human health hazards.

A widely used chemical, formaldehyde is normally present in both indoor and outdoor air. The rapid growth of formaldehyde-related industries in the past two decades reflects the result of its increased use in building materials and other commercial sectors. Consequently, formaldehyde is encountered almost every day from large segments of society due to its various sources. Many governments and agencies around the world have thus issued a series of standards to regulate its exposure in homes, office buildings, workshops, public places, and food. In light of the deleterious properties of formaldehyde, this article provides an overview of its market, regulation standards, and human health effects.

The utility of naphthyl-keratin adducts as biomarkers for jet-fuel exposure.

We investigated the association between biomarkers of dermal exposure, naphthyl-keratin adducts (NKA), and urine naphthalene biomarker levels in 105 workers routinely exposed to jet-fuel. A moderate correlation was observed between NKA and urine naphthalene levels (p = 0.061). The NKA, post-exposure breath naphthalene, and male gender were associated with an increase, while CYP2E1*6 DD and GSTT1-plus (++/+-) genotypes were associated with a decrease in urine naphthalene level (p < 0.0001). The NKA show great promise as biomarkers for dermal exposure to naphthalene. Further studies are warranted to characterize the relationship between NKA, other exposure biomarkers, and/or biomarkers of biological effects due to naphthalene and/or PAH exposure.

Secondhand smoke (SHS) exposures: workplace exposures, related perceptions of SHS risk, and reactions to smoking in catering workers in smoking and nonsmoking premises.

INTRODUCTION: Smoke-free workplace legislation often exempts certain venues. Do smoking (exempted) and nonsmoking (nonexempted) catering premises' workers in Hong Kong report different perceptions of risk from and reactions to nearby smoking as well as actual exposure to secondhand smoke (SHS)? METHODS: In a cross-sectional survey of 204 nonsmoking catering workers, those from 67 premises where smoking is allowed were compared with workers from 36 nonsmoking premises in Hong Kong on measures of perceptions of risk and behavioral responses to self-reported SHS exposure, plus independent exposure assessment using urinary cotinine. RESULTS: Self-reported workplace SHS exposure prevalence was 57% (95% CI = 49%-65%) in premises prohibiting and 100% (95% CI = 92%-100%) in premises permitting smoking (p < .001). Workers in smoking-permitted premises perceived workplace air quality as poorer (odds ratio [OR] = 9.3, 95% CI = 4.2-20.9) with higher associated risks (OR = 3.7, 95% CI = 1.6-8.6) than workers in smoking-prohibited premises. Workers in smoking-prohibited premises were more bothered by (OR = 0.2, 95% CI = 0.1-0.5) and took more protective action to avoid SHS (OR = 0.2, 95% CI = 0.1-0.4) than workers in smoking-permitted premises. Nonwork exposure was negatively associated with being always bothered by nearby smoking (OR = 0.3, 95% CI = 0.1-0.9), discouraging nearby smoking (OR = 0.5, 95% CI = 0.2-1.1), and discouraging home smoking (OR = 0.4, 95% CI = 0.2-0.9). Urinary cotinine levels were inversely related to workers' avoidance behavior but positively related to their perceived exposure-related risks. CONCLUSIONS: Different workplace smoking restrictions predicted actual SHS exposure, exposure-related risk perception, and protective behaviors. Workers from smoking-permitted premises perceived greater SHS exposure-related risks but were more tolerant of these than workers in smoking-prohibited premises. This tolerance might indirectly increase both work and nonwork exposures.

Airborne asbestos exposures associated with work on asbestos fire sleeve materials.

Asbestos-containing fire sleeves have been used as a fire protection measure for aircraft fluid hoses. This investigation was conducted to determine the level of airborne asbestos fiber exposure experienced by mechanics who work with fire sleeve protected hoses. Duplicate testing was performed inside a small, enclosed workroom during the fabrication of hose assemblies. Personal air samples taken during this work showed detectable, but low airborne asbestos fiber exposures. Analysis of personal samples (n=9) using phrase contract microscopy (PCM) indicated task duration airborne fiber concentrations ranging from 0.017 to 0.063 fibers per milliliter (f/ml) for sampling durations of 167-198 min, and 0.022-0.14 f/ml for 30 min samples. Airborne chrysotile fibers were detected for four of these nine personal samples, and the resulting asbestos adjusted airborne fiber concentrations ranged from 0.014 to 0.025 f/ml. These results indicate that work with asbestos fire sleeve and fire sleeve protected hose assemblies, does not produce regulatory noncompliant levels of asbestos exposure for persons who handle, cut and fit these asbestos-containing materials.

Hazard report. Don't use industrial-grade gases for clinical applications.

The use of industrial-grade gases instead of medical-grade gases for clinical applications increases the risk of introducing undesirable and even toxic contaminants into the clinical environment. Hospitals should have policies in place to ensure that gases of the appropriate type and grade are used for the intended application.

Engineering control technologies to reduce occupational silica exposures in masonry cutting and tuckpointing.

OBJECTIVES: A number of tasks in construction generate worker overexposures to respirable crystalline silica dust, which is a significant contributor to occupational mortality and morbidity. This study evaluated the performance of commercially available engineering controls used in dusty construction tasks commonly performed by bricklayers. METHODS: Local exhaust ventilation (LEV) controls for a portable abrasive cutter and for tuckpointing grinders were examined at a bricklayers' training center, as were two stationary wet saws. Personal breathing zone air samples were collected with and without the use of LEV or water suppression during simulated concrete block cutting, brick cutting, and tuckpointing. RESULTS: Compared with the use of no exposure control during block and brick cutting, the portable LEV unit significantly reduced mean respirable quartz exposures by 96% for block cutting and 91% for brick cutting (p < 0.01). The use of stationary wet saws was also associated with 91% reductions in exposure (p < 0.01). For tuckpointing, the reductions in mean respirable quartz concentrations were between 91% and 93% with the LEV controls (p < 0.05). CONCLUSIONS: Reductions of up to 96% in mean respirable quartz concentration were observed between control and no-control scenarios. These reductions with commercially available off-the-shelf tools demonstrate the effectiveness of engineering control interventions to reduce crystalline silica exposures in construction. Strategies to further improve control performance and approaches for increasing control interventions in construction are needed.

Efficacy of a program to prevent beryllium sensitization among new employees at a copper-beryllium alloy processing facility.

OBJECTIVES: In 2000, 7% of workers at a copper-beryllium facility were beryllium sensitized. Risk was associated with work near a wire annealing/pickling process. The facility then implemented a preventive program including particle migration control, respiratory and dermal protection, and process enclosure. We assessed the program's efficacy in preventing beryllium sensitization. METHODS: In 2000, the facility began testing new hires (program workers) with beryllium lymphocyte proliferation tests (BeLPTs) at hire and at intervals during employment. We compared sensitization incidence rates (IRs) and prevalence rates for workers hired before the program (legacy workers) with rates for program workers, including program worker subgroups. We also examined trends in BeLPTs from a single laboratory. RESULTS: In all, five of 43 legacy workers (IR = 3.8/1,000 person-months) and three of 82 program workers (IR = 1.9/1,000 person-months) were beryllium sensitized, for an incidence rate ratio (IRR) of 2.0 (95% confidence interval [CI] 0.5, 10.1). Two of 37 pre-enclosure program workers (IR = 2.4/1,000 person-months) and one of 45 post-enclosure program workers (IR = 1.4/1,000 person-months) were beryllium sensitized, for IRRs of 1.6 (95% CI 0.3, 11.9) and 2.8 (95% CI 0.4, 66.2), respectively, compared with legacy workers. Test for trend in prevalence rates was significant. Among 2,159 first-draw BeLPTs during 95 months, we identified seven months when high numbers of redraws were required, with one possible misclassification in this facility. CONCLUSIONS: Fewer workers became sensitized after implementation of the preventive program. However, low statistical power due to the facility's small workforce prevents a definitive conclusion about the program's efficacy. These findings have implications for other copper-beryllium facilities, where program components may merit application.

N-nitrosamines in the southern Swedish rubber industries - exposure, health effects, and immunologic markers.

OBJECTIVES: The aim of this study was twofold: (i) to evaluate the air levels of N-nitrosamines in the Swedish rubber industry and (ii) to estimate the risk of symptoms and changed levels of immunologic markers in relation to these levels. METHODS: Using adsorption tubes, we collected samples of N-nitrosamines in the breathing zone of 96 rubber workers and analyzed them with liquid chromatography tandem mass spectrometry. Of these 96 workers, 66 were included in a medical examination and blood analysis together with an additional 106 rubber workers and 118 unexposed subjects. Medical and occupational histories were obtained in structured interviews, symptoms were recorded and immunologic markers analyzed in blood. RESULTS: The sum of N-nitrosamines ranged from less than the limit of detection to 36 microg/m (3)and differed with the vulcanization (ie, curing process) method used. Workers vulcanizing with a salt bath had the highest levels (median 4.2 microg/m (3)). Compared to the unexposed subjects, the rubber workers had an increased risk of nosebleeds, eye and throat symptoms, hoarseness, cough, nausea, headache, and changed levels of eosinophils and total immunoglobulin G (IgG). However, we found no clear exposure-response relationship with the symptoms or the immunologic markers studied. CONCLUSIONS: High levels of N-nitrosamines were found and must be lowered considerably in order to decrease the risk of cancer. There is a need for an occupational exposure limit for N-nitrosamines in Sweden. The lack of exposure-response relationships with the subacute symptoms examined in this study may be due to a healthy-worker selection or to the possibility that the symptoms are caused by an exposure not co-varying with N-nitrosamines.