Influence of paternal exposure to oil and oil products on time to pregnancy and spontaneous abortions.
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The objective of this study was to evaluate the influence of exposure to oil and oil products among men on the time taken for their wives to conceive and on the incidence of spontaneous abortion among them. A cross-sectional study was performed by posting questionnaires to 1,269 men employed as offshore mechanics, offshore operators, offshore drilling personnel, car mechanics (the 'exposed' occupations) and carpenters ('unexposed'). The married men were asked to give a separate questionnaire to their wives for details about their pregnancies. The time elapsed between the beginning of coitus without contraception and the wife becoming pregnant (time to pregnancy) was analyzed with Cox regression analysis by calculating fecundability ratios for the pregnancies for the men exposed to oil and oil products as compared with the men who were not exposed. Spontaneous abortions were analyzed with logistic regression by calculating odds ratios for the pregnancies in which the men were exposed vs. not exposed. A total of 741 (58%) men returned the questionnaires. A total of 301 pregnancies were analyzed for time taken to conceive and 580 for spontaneous abortion. The results were adjusted for variables that could significantly influence conception time (previous infections of the reproductive system and coffee drinking) or the incidence of spontaneous abortion (mother's age, parity and smoking). The outcomes between the exposed and unexposed pregnancies showed no significant differences. Car mechanics had a lower fecundability ratio before 1992 than after 1992. Paternal exposure to hydrocarbons in the occupations studied did not seem to have had a major influence on time to conception or the incidence of spontaneous abortion among the wives of the men exposed to oil products. (+info)
A model for predicting endotoxin concentrations in metalworking fluid sumps in small machine shops.
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METHODS: In British Columbia, Canada, nineteen small machine shops which used water-based metalworking fluids (MWF) were examined. One bulk MWF sample was taken from each independent sump (N=140) and tested for endotoxin using the Limulus Amoebocyte Lysate assay. Factors that might influence the MWF sump endotoxin concentration were investigated using mixed effect multiple regression modelling to control for repeated measures within shops. RESULTS: The geometric mean (GM) endotoxin concentration was 6791 EU/ml. Contamination of MWF with tramp oil, MWF pH, MWF temperature, and MWF type were significant predictors of sump fluid endotoxin concentration (model P=0.0001, ordinary least squares R(2) =0.36). Concentrations of endotoxin in sump fluids were increased by MWF contamination with tramp oils such as hydraulic oils, preservative oils, spindle oils, slidway lubricants, gear lubricants, and greases (model predicted GM=17400 EU/ml vs. 1600 EU/ml without tramp oil). Concentrations were also elevated where pH was lower than 8.5 (predicted GM=10600, vs 3600 EU/ml for pH 8.5 to 9.5), where soluble fluids were used (predicted GM=11800 vs. 2800 EU/ml for synthetic fluids), and where sump fluid temperatures were higher (predicted GM=2600 EU/ml at 11 degrees C vs. 21500 EU/ml at 32 degrees C). The within-shop correlation of sump bulk fluid endotoxin concentrations was 38%. CONCLUSIONS: Minimizing tramp oil contamination, using synthetic fluids, and monitoring pH and temperature would be valuable tools for controlling endotoxin contamination in MWF sumps. In addition, since there was correlation within-shop, contamination of one sump in a shop may suggest changing the fluids in all. (+info)
Exposure to organic solvents during cosmetic finishing of cars.
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The objectives of this study were to assess the exposure to organic solvents during degreasing, washing and polishing of cars, and to obtain information about acute health symptoms in car-finishing workers. Fifteen car shops participated in this study, and at these locations 36 workers had car finishing as their main working task. All 36 car-finishing workers and 17 randomly selected office workers from six of these car shops completed questionnaires on acute health symptoms. Personal monitoring of exposure to organic solvents was carried out in three representative shops. The highest exposure levels were found during degreasing of new cars, the median level of aliphatic hydrocarbons (C9-C13) being 22 p.p.m. (range 7-215 p.p.m.). This exposure level represents 50% (range 20-540%) of the Norwegian 8 h limit value for additive factor for these compounds. Only 28% of the workers used gas respirators regularly during this process. Very low exposure levels were detected during washing of second-hand cars and during polishing processes. The present study shows that car-finishing workers are exposed to high levels of organic solvents only for short periods of time. It seems that they are not adequately protected during these periods. However, the presence of acute symptoms was low, i.e. comparable to the prevalences in the reference group. (+info)
Respiratory illness in workers exposed to metalworking fluid contaminated with nontuberculous mycobacteria--Ohio, 2001.
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In January 2001, three machinists at an automobile brake manufacturing facility in Ohio (plant A) were hospitalized with respiratory illness characterized by dyspnea, cough, fatigue, weight loss, hypoxia, and pulmonary infiltrates. Hypersensitivity pneumonitis (HP) was diagnosed in all three workers. In March 2001, additional employees began seeking medical attention for respiratory and systemic symptoms. In May 2001, union and management representatives requested assistance from CDC's National Institute for Occupational Safety and Health (NIOSH) in determining the cause of the illnesses and preventing further illness in employees. This report describes two case reports and the preliminary results of the ongoing investigation, which found that exposure to aerosolized nontuberculous mycobacteria (NTM) might be contributing to the observed respiratory illnesses in this manufacturing facility. Clinicians and public health professionals should be alert to the variable presentation of occupational respiratory disease that might occur in workers in the machining industry. (+info)
Diversity and abundance of bacteria in an underground oil-storage cavity.
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BACKGROUND: Microorganisms inhabiting subterranean oil fields have recently attracted much attention. Since intact groundwater can easily be obtained from the bottom of underground oil-storage cavities without contamination by surface water, studies on such oil-storage cavities are expected to provide valuable information to understand microbial ecology of subterranean oil fields. RESULTS: DNA was extracted from the groundwater obtained from an oil-storage cavity situated at Kuji in Iwate, Japan, and 16S rRNA gene (16S rDNA) fragments were amplified by PCR using combinations of universal and Bacteria-specific primers. The sequence analysis of 154 clones produced 31 different bacterial sequence types (a unique clone or group of clones with sequence similarity of > 98). Major sequence types were related to Desulfotomaculum, Acetobacterium, Desulfovibrio, Desulfobacula, Zoogloea and Thiomicrospira denitrificans. The abundance in the groundwater of bacterial populations represented by these major sequence types was assessed by quantitative competitive PCR using specific primers, showing that five rDNA types except for that related to Desulfobacula shared significant proportions (more than 1%) of the total bacterial rDNA. CONCLUSIONS: Bacteria inhabiting the oil-storage cavity were unexpectedly diverse. A phylogenetic affiliation of cloned 16S rDNA sequences suggests that bacteria exhibiting different types of energy metabolism coexist in the cavity. (+info)
Occupational exposure to metalworking fluid mist and sump fluid contaminants.
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This paper summarizes the analytical and occupational hygiene findings from a recent survey of occupational exposure to metalworking fluids (MWFs) in the engineering industry. The aim of the survey was to link MWF mist exposure measurements with particular engineering processes and controls, and utilize the data obtained to develop exposure standards. At the same time the opportunity was taken to assess fluid management and control, including bacterial and fines contamination in the machine sumps. In general, occupational exposure to mineral oil MWF mist was controlled to <3 mg/m(3) (8 h time-weighted average) and to <1 mg/m(3) for water-mix MWF mist (in terms of the concentrate). These exposure values do not necessarily represent best practice, but are believed to be achievable and representative of industry as a whole. Gravimetric analysis of the total inhalable particulate was found to be a good predictor of mineral oil MWF mist but not for water-mix MWF mist. Grinding and drilling operations produced higher exposures than turning and milling for water-mix fluids. There were insufficient data to compare machining operations for mineral oil MWFs. On the whole, fluid management was found to be poor, with most sites failing to meet industry good practice or Health & Safety Executive (HSE) standards. Some of the operating procedures utilized were deficient or unsatisfactory. Poor standards of fluid management were found at all sizes of company. High levels of bacteria, endotoxin and fines were found in sumps, and control of other factors, such as water-mix fluid concentration, was often poor. Mineral oils had higher levels of fines than water-mix fluids (medians of 395 and 18 mg/l, respectively), and grinding produced high levels of fines in both types of MWF. Many water-mix sumps contained bacterial levels of >1 x 10(6) CFU/ml, and endotoxin levels of >100 000 EU/ml were not uncommon. The median values were 109 000 CFU/ml and 8039 EU/ml, respectively. Mists could potentially contain extensive contamination from bacteria and endotoxin. Analysis of the data suggests that sumps operating under typical conditions for machining (a temperature of 20 degrees C, a pH of 9 and a fluid strength below 10%), also appear to provide optimum conditions for the proliferation of bacteria. Low levels of benzo[a]pyrene (median 0.03 micro g/g) were found in the mineral oils, and low levels of N-nitrosodiethanolamine (median 0.4 micro g/ml) were found in the water-mix MWFs. The results of this work will contribute to guidance from the HSE, setting out accepted industry good practice, including guide values for MWF mist and sump fluid contaminants, with significant emphasis on sump fluid management (maintenance and monitoring), as well as control issues. (+info)
Evaluation of five extraction protocols for quantification of endotoxin in metalworking fluid aerosol.
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OBJECTIVES: Occupational exposures to endotoxin-contaminated, water-based metalworking fluids (MWFs) are thought to contribute to cases of respiratory illness. Before occupational exposure limits for endotoxin can be proposed, accuracy and reproducibility of laboratory measurements must be established. The method most commonly used to quantify endotoxin is the Limulus amebocyte lysate (LAL) assay and this is the basis for the American Society for Testing and Materials (ASTM) method E2144-01. This study was conducted to generate multiple samples with similar mass and endotoxin loading in order to compare four alternative extraction methods with the ASTM method. METHODS: Using an exposure chamber system that provides a uniform distribution of MWF mist, aerosols with three concentrations of endotoxins (4.5, 350 and 1141 EU/m(3)) were collected simultaneously on multiple filter samples. The filters were examined for endotoxin concentration using five different extraction protocols: extraction with 1 h shaking at 25 degrees C in 30 ml pyrogen-free water (PFW) (protocol 1) or in PFW with 0.05% Tween-20 (protocol 2); or shaking at 68 degrees C in 30 ml PFW (protocol 3) or PFW with Tween-20 (protocol 4); or extraction into 20 ml PFW with sonication at 25 degrees C and pH adjustment to 7.5 (ASTM protocol). RESULTS: The uniformity of the aerosol mass yielded coefficients of variation of 12.7, 7.7 and 1.4% for the low, medium and high exposure groups, respectively. The variance in the endotoxin extraction protocols was highest for the ASTM method for the low, medium and high concentration trials. Low, medium and high endotoxin groups were statistically different (P < 0.001), but there were no statistical differences between extraction protocols within these exposure levels. CONCLUSIONS: ASTM method E2144-01 yielded comparable estimations of MWF endotoxin aerosol concentrations but with higher variability than the four other extraction methods. This study shows that extraction into PFW at 25 degrees C with or without Tween-20 was an improvement over the ASTM method in that the estimation was more precise and the method is simpler. (+info)
Two cases of occupational allergic contact dermatitis from a cycloaliphatic epoxy resin in a neat oil: case report.
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BACKGROUND: Metal-working fluids contain complex mixtures of chemicals and metal workers constitute a potential risk group for the development of allergic contact dermatitis. CASE PRESENTATION: Two metal workers developed allergic contact dermatitis on the hands and lower arms from exposure to a neat oil used in metal processing. Patch testing revealed that the relevant contact allergen was a cycloaliphatic epoxy resin, 1,2-cyclohexanedicarboxylic acid, bis(oxiranylmethyl) ester, added to the oil as a stabilizer. None of the patients had positive reactions to the bisphenol A-based epoxy resin in the standard series. CONCLUSIONS: These cases emphasize that well-known contact allergens may show up from unexpected sources of exposure. Further, it can be a long-lasting, laborious process to detect an occupational contact allergen and cooperation from the patient and the manufacturer of the sensitizing product is essential. (+info)