Microorganism-induced skin disease in workers exposed to metalworking fluids.
(73/621)BACKGROUND: An outbreak of skin disorders among workers potentially exposed to metalworking fluids prompted the present study. Few studies have described skin disorders associated with microbe-contaminated metalworking fluids. METHODS: Samples of materials contaminated with metalworking fluids were obtained from two manufacturing facilities in Ohio. Pathogenic bacteria and yeasts, in concentrations sufficient to cause skin disease, were cultured from 9 of 12 (75%) sampled materials. RESULTS: Allergic patch testing of five affected people produced negative results for standard allergens, augmented by fluids and items from their workplace. This ruled out allergies as the cause of the skin disease. Improper handling and disposal of cotton gloves, inappropriate use of scouring pads and ineffective hand wiping were apparently responsible for the microbiological contamination. The hands and forearms were most commonly affected. CONCLUSION: Improper handling of soluble, synthetic and semi-synthetic metalworking fluids provides an excellent environment for the growth of a range of microorganisms, including bacteria and fungi. If allowed to grow because of poor occupational hygiene, these microorganisms can cause skin disorders among workers. Soiled protective clothing (gloves, coveralls and work boots) should be cleaned or discarded on a regular basis. When washing up, workers should not use metalworking fluids and items used to clean machinery. (+info)
Commentary: variability in workplace exposures and the design of efficient measurement and control strategies.
(74/621)Kromhout et al.'s (1993) well-cited publication presented detailed information on statistical procedures to estimate the magnitude of exposure variability within and between workers, drawing from a large database on chemical exposures throughout industry. It convincingly demonstrated that the construct of homogeneous exposure groups often does not hold true and suggested ways to improve measurement strategies. The authors hit a rich vein of research, and many publications, not at least by the authors themselves, followed in the decade after publication. In recent years the principles of estimating the variation in exposure have been applied in new methods for optimization of sampling strategies, for compliance testing, for quantifying exposures in epidemiologic studies, and for identifying important sources of emissions and suggesting strategies for controlling exposures. Many occupational hygienists across the globe have adopted these new methods as powerful tools in their exposure assessment strategies. (+info)
Partitioning theory for respiratory deposition of semivolatile aerosols.
(75/621)The objective of this work is to model the deposition of semivolatile aerosols in the lungs based on gas-particle and tissue-air partitioning theory. Semivolatile compounds exist in air as both particles and gases simultaneously. Mass distributes between the two phases according to a gas-particle partitioning ratio, R(pg) = K(p)(TSP). Particle deposition in the lungs is a function of aerodynamic diameter, whereas gas deposition is a function of tissue solubility, which is related to the air-lung partitioning ratio, K(la). Therefore, deposition to the lungs will vary with R(pg) and K(la). These and other parameters determine a dimensionless deposition number, D, which indicates whether particles or gases are most responsible for deposition of semivolatile chemicals in the lung. The deposition number allows industrial hygienists to design effective air sampling strategies and control measures that will minimize risks associated with exposure to semivolatiles. Examples of deposition numbers for common semivolatile pollutants are provided, including alkanes, polycyclic aromatic hydrocarbons, pesticides and polychlorinated biphenyls. (+info)
Risks to children from exposure to lead in air during remedial or removal activities at Superfund sites: a case study of the RSR lead smelter Superfund site.
(76/621)Superfund sites that are contaminated with lead and undergoing remedial action generate lead-enriched dust that can be released into the air. Activities that can emit lead-enriched dust include demolition of lead smelter buildings, stacks, and baghouses; on-site traffic of heavy construction vehicles; and excavation of soil. Typically, air monitoring stations are placed around the perimeter of a site of an ongoing remediation to monitor air lead concentrations that might result from site emissions. The National Ambient Air Quality (NAAQ) standard, established in 1978 to be a quarterly average of 1.5 microg/m(3), is often used as a trigger level for corrective action to reduce emissions. This study explored modeling approaches for assessing potential risks to children from air lead emissions from the RSR Superfund site in West Dallas, TX, during demolition and removal of a smelter facility. The EPA Integrated Exposure Uptake Biokinetic (IEUBK) model and the International Commission of Radiologic Protection (ICRP) lead model were used to simulate blood lead concentrations in children, based on monitored air lead concentrations. Although air lead concentrations at monitoring stations located in the downwind community intermittently exceeded the NAAQ standard, both models indicated that exposures to children in the community areas did not pose a significant long-term or acute risk. Long-term risk was defined as greater than 5% probability of a child having a long-term blood lead concentration that exceeded 10 microg/dl, which is the CDC and the EPA blood lead concern level. Short-term or acute risk was defined as greater than 5% probability of a child having a blood lead concentration on any given day that exceeded 20 microg/dl, which is the CDC trigger level for medical evaluation (this is not intended to imply that 20 microg/dl is a threshold for health effects in children exposed acutely to airborne lead). The estimated potential long-term and short-term exposures at the downwind West Dallas community did not result in more than 5% of children exceeding the target blood lead levels. The models were also used to estimate air lead levels for short-term and long-term exposures that would not exceed specified levels of risk (risk-based concentrations, RBCs). RBCs were derived for various daily exposure durations (3 or 8 h/day) and frequencies (1-7 days/week). RBCs based on the ICRP model ranged from 0.3 (7 days/week, 8 h/day) to 4.4 microg/m(3) (1 day/week, 3 h/day) for long-term exposures and were lower than those based on the IEUBK model. For short-term exposures, the RBCs ranged from 3.5 to 29.0 microg/m(3). Recontamination of remediated residential yards from deposition of air lead emitted during remedial activities at the RSR Superfund site was also examined. The predicted increase in soil concentration due to lead deposition at the monitoring station, which represented the community at large, was 3.0 mg/kg. This potential increase in soil lead concentration was insignificant, less than 1% increase, when compared to the clean-up level of 500 mg/kg developed for residential yards at the site. (+info)
Health risks from exposure to metal-working fluids in machining and grinding operations.
(77/621)Metal-working fluids (MWFs) are used in machining and grinding operations to cool the tool and work, reduce the friction between the tool and work, improve the surface integrity of the work piece, and increase tool life and productivity. Health problems have been reported among workers exposed to MWFs, including incidences of respiratory, digestive and skin cancers, and increased rates of cough and phlegm. This paper reviews and discusses issues concerning health risks from exposure to MWFs in machining and grinding operations, the various factors that influence the degree of exposure, and control methods to reduce exposure to metal-working fluids. (+info)
Type A lactic acidosis in occupational heat exhaustion.
(78/621)BACKGROUND: This paper presents a further analysis of biochemical data collected during a 1 year prospective study of 106 cases of heat exhaustion at a deep underground metalliferous mine. RESULTS: Multiple regression analysis results indicate that the haemoglobin, serum creatinine and plasma lactate concentrations are statistically significant predictors of the anion gap. Together, they explain 65% of the variance in the anion gap (R(2) = 0.650). Spearman's rho correlation results also confirm that haemoglobin, creatinine and lactate are each statistically significantly correlated with the anion gap (P < 0.001). CONCLUSIONS: These results indicate that dehydration and lactate are important determinants of the metabolic acidosis previously observed in occupational heat exhaustion. It is likely that dehydration in these workers has resulted in poor muscle perfusion, anaerobic conditions and elevated lactate. This constitutes Type A lactic acidosis. Creatine kinase is not a statistically significant predictor of the anion gap in multiple regression (P = 0.956). Furthermore, the Spearman's rho correlation coefficient for creatine kinase versus the anion gap is weak (r(s) = 0.175) and is not statistically significant (P = 0.073). These results suggest that there was no rhabdomyolysis contributing to the metabolic acidosis. (+info)
Genotoxicity of samples of nickel refinery dust.
(79/621)At the International Nickel Company (INCO) nickel refinery in Clydach, Wales, U.K., which has operated since 1901, 365 respiratory cancers, including 85 nasal cancers and 280 lung cancers, have occurred in workers since the 1920s. From 1901 to 1923, incidences of these cancers were high. In 1923, the refining process was changed, eliminating a nickel arsenide, Ni5As2, called orcelite, from the refinery. Incidences of respiratory cancers decreased substantially from 1925 to 1930. Refinery dust samples were obtained in 1920 and in 1929; both of these samples contain primarily nickel oxide (NiO), but the 1920 sample also contains orcelite. The orcelite content of the 1920 sample is approximately 10%, while that of the 1929 sample is approximately 1%. We hypothesized that orcelite in the 1920 sample was partially responsible for inducing nasal and lung cancers in the refinery workers, and we tested this hypothesis. The 1920 and 1929 samples and orcelite were phagocytosed by cultured C3H/10T1/2 Cl 8 (10T1/2) mouse embryo cells to similar extents and were similarly cytotoxic to 10T1/2 cells. The 1920 sample and orcelite induced dose-dependent morphological transformation of 10T1/2 cells; the 1929 sample did not. The cell transforming ability of the 1920 sample, and therefore its probable carcinogenicity, correlates with induction of respiratory cancers in refinery workers exposed to orcelite-containing nickel refinery dust before 1923. Inability of the 1929 sample to induce morphological transformation correlates with decreased human respiratory tumor incidence at this plant after 1923. This data supports our hypothesis that orcelite in the 1920 refinery sample contributed to its carcinogenicity to nickel refinery workers. (+info)
Two cases of occupational allergic contact dermatitis from a cycloaliphatic epoxy resin in a neat oil: case report.
(80/621)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)