Bauxite mine and alumina refinery workers: mortality and cancer risk.

BACKGROUND: Aluminium industry workers are at risk of long-term health consequences. AIMS: To investigate mortality and cancer incidence in bauxite mine and alumina refinery workers. METHODS: A pre-existing cohort of workers was re-linked with the Australian National Death Index, and the Australian Cancer Database to provide additional death (7 years) and cancer (9 years) data. Standardized mortality ratios (SMRs) and standardized incidence rates (SIRs) were estimated by job category, duration of employment and time since first employment. RESULTS: Linkage was performed for 6935 (6207 male) workers. Compared with the general population, there was a reduced or similar risk of death for mine/refinery workers for all causes except mesothelioma which was increased amongst male production workers [SMR 2.42, 95% CI 1.11-4.60]. Mesothelioma incidence was also increased amongst males [SIR 2.50, 95% CI 1.60-3.71]. Male office workers had a greater incidence of prostate cancer [SIR 1.30, 95% CI 1.06-1.57] and thyroid cancer [SIR 3.47, 95% CI 1.66-6.38]. Melanoma incidence was increased in female office workers [SIR 2.27, 95% CI 1.36-3.54]. Lip cancer incidence was increased in male maintenance/production workers [SIR 2.04, 95% CI 1.02-3.65]. Overall cancer incidence was otherwise similar to the general Australian population. CONCLUSIONS: Overall risk of death and incidence of cancer for bauxite mine and alumina refinery workers was similar to the general population. Incidence and risk of death from mesothelioma were higher, likely due to historic asbestos exposure in this and other industries. The increased risk of melanoma, lip, prostate and thyroid cancers requires further investigation.

Alumina Ceramic Exacerbates the Inflammatory Disease by Activation of Macrophages and T Cells.

(1) Background: Aluminum oxide (Al2O3) ceramic is one of the materials used for artificial joints, and it has been known that their fine particles (FPs) are provided by the wear of the ceramic. Al2O3 FPs have been shown to induce macrophage activation in vitro; however, the inflammatory effect in vivo has not been studied. (2) Methods: We examined the in vivo effect of Al2O3 FPs on the innate and adaptive immune cells in the mice. (3) Results: Al2O3 FPs promoted the activation of spleen macrophages; however, conventional dendritic cells (cDCs), plasmacytoid DCs (pDCs), and natural killer (NK) cells were not activated. In addition, increases in the CD4 and CD8 T cells was induced in the spleens of the mice treated with Al2O3 FPs, which differentiated into interferon-gamma (IFN-γ)-producing helper T1 (Th1) and cytotoxic T1 (Tc1) cells. Finally, the injection of Al2O3 FPs exacerbated dextran sulfate sodium (DSS)-induced inflammation in the colon, mediated by activated and increased number of CD4 and CD8 T cells. (4) Conclusions: These data demonstrate that FPs of Al2O3 ceramic may contribute to the exacerbation of inflammatory diseases in the patients.

Effects of Bauxite and Alumina Exposure on Incidence of Cancer - Meta-analysis.

Bauxite is an ore from which Aluminium is produced. Malaysia, once the leading producer of bauxite has reduced production as mining activity has caused community outrage. Due to concerns about health concerns, rising pollution and environmental hazards, the government has revoked the licenses of bauxite miners. We therefore did a meta-analysis to assess the relationship between exposure to Bauxite and Alumina with incidence of various types of cancers. Bauxite mines and alumina refineries. Individuals of all ages exposed to Bauxite and Alumina. Exposure to bauxite and alumina. Incidence due to overall cancers and specific types of cancers. Exposure to bauxite and alumina did not cause variations in incidence of overall cancer and specific types of cancer such as cancer of lip, cancer of the oral cavity and pharynx, cancer of digestive organs and others. We conclude that there is no evidence that bauxite or alumina exposure cause increase incidence of cancer but due to the small number of studies included in this review, we recommend more cohort studies to be done in future.

Biocompatibility of alumina-based biomaterials-A review.

In today's medicine world, alumina-based biomaterials owing to their excellent biomechanical, and biocompatibility properties play a key role in biomedical engineering. However, the literature still suffers from not having a valid database regarding the protein adsorption and subsequently cell responses to these surfaces. Proteins by adsorption on biomaterials surfaces start interpreting the construction and also arranging the biomaterials surfaces into a biological language. Hence, the main concentration of this review is on the protein adsorption and subsequently cell responses to alumina's surface, which has a wide range biomedical applications, especially in dentistry and orthopedic applications. In the presented review article, the general principles of foreign body response mechanisms, and also the role of adsorbed proteins as key players in starting interactions between cells and alumina-based biomaterials will be discussed in detail. In addition, the essential physicochemical, and mechanical properties of alumina surfaces which significantly impact on proteins and cells responses as well as the recent studies that have focused on the biocompatibility of alumina will be given. An in depth understanding of how the immune system interacts with the surface of alumina could prove the pivotal importance of the biocompatibility of alumina on its success in tissue engineering after implantation in body.

Artificial shear stress effects on leukocytes at a biomaterial interface.

Medical devices, such as ventricular assist devices (VADs), introduce both foreign materials and artificial shear stress to the circulatory system. The effects these have on leukocytes and the immune response are not well understood. Understanding how these two elements combine to affect leukocytes may reveal why some patients are susceptible to recurrent device-related infections and provide insight into the development of pump thrombosis. Biomaterials-DLC: diamond-like carbon-coated stainless steel; Sap: single-crystal sapphire; and Ti: titanium alloy (Ti6 Al4 V) were attached to the parallel plates of a rheometer. Whole human blood was left between the two discs for 5 minutes at +37°C with or without the application of shear stress (0 s-1 or 1000 s-1 ). Blood was removed and used for complete blood cell counts, flow cytometry (leukocyte activation, cell death, microparticle generation, phagocytic ability, and reactive oxygen species [ROS] production), and the production of pro-inflammatory cytokines. L-selectin expression on monocytes was decreased when blood was exposed to the biomaterials both with and without shear. Applying shear stress to blood on a Sap and Ti surface led to activation of neutrophils shown as decreased L-selectin expression. Sap and Ti blunted the LPS-stimulated macrophage migration inhibitory factor (MIF) production, most notably when sheared on Ti. The biomaterials used here have been shown to activate leukocytes in a static environment. The introduction of shear appears to exacerbate this activation. Interestingly, a widely accepted biocompatible material (Ti) utilized in many different types of devices has the capacity for immune cell activation and inhibition of MIF secretion when combined with shear stress. These findings contribute to our understanding of the contribution of biomaterials and shear stress to recurrent infections and vulnerability to sepsis in some VAD patients as well as pump thrombosis.

Removal of unwanted hair: efficacy, tolerability, and safety of long-pulsed 755-nm alexandrite laser equipped with a sapphire handpiece.

Due to the difference in refraction coefficients between air and the corneal epithelium, irradiation of the skin with a light source can lead to reflection of the energy and its leakage to the skin causes epidermal injury. All of which decreases the efficacy of treatment. We evaluated cooling sapphire handpieces' efficacy in decreasing pain and epidermal injuries and enhancing the treatment outcome in laser hair removal. A total of 49 patients with Fitzpatrick skin types of II to IV were treated for laser hair removal on face, limbs, inguinal, and axillary areas with pulsed 755-nm alexandrite laser equipped with a sapphire handpiece and the cooling system. Hair counts were performed by two independent observers at the baseline and 3 months after the final treatment. A marked reduction in hair regrowth was noted 3 months after the final treatment in all body locations studied. Clinical hair reduction was observed and fully assessed. There were no serious side effects with an average pain score of 4.6 out of 40. The cooled sapphire cylinder tip has been shown to minimize epidermal injury and reduce the system energy leaks to the skin.

[Using of specialized food for the workers with skin occupational eczema of perlite production].

The research was conducted with participation of the perlite production workers with professional eczema (165 people in the main group and 152 from the control group without skin pathology). The effectiveness of the use of a specialized prophylactic food in the diet of workers was assessed on the basis of the study of the dynamics of the indicators of nutritional and clinical status. Inclusion of kissel, containing pectin, vitamin A (300% from RDA), vitamin E and zinc (40% from RDA), biologically active substances of plant origin in the diet of the examined against the background of the course of complex therapy, has resulted in a positive influence on individual laboratory values, demonstrating the optimization of metabolic processes, which characterize the pathogenesis of skin inflammation. Thus, the concentration of ascorbic acid in blood serum statistically significant (p<0.05) increased by 30.0%, tocopherol - by 36.3%, carotenoids - by 27.3%, phosphorus - by 28.9%, calcium level elevated by 16.3% (p<0.10). There was a decrease in the level of MDA in blood serum by 12.3% (p<0.05) and an increase in catalase activity by 12.2% (p>0.05). There was a tendency to reduce itching, infiltration, erythematous and eczematous manifestations of the disease. The data obtained make it possible to consider the use of a specialized food product of dietary preventive nutrition by workers in pearlite production as a mean to enhance the body's adaptive reserves and to prevent the occurrence, progression and development of occupational skin diseases (eczema) in the workplace.

Inflammation in induced sputum after aluminium oxide exposure: an experimental chamber study.

INTRODUCTION: Workers in aluminium production are exposed to a complex mixture of particles and gases potentially harmful to the airways, among them aluminium oxide (Al2O3). With the use of an exposure chamber, we aimed to examine the effects of short-term controlled exposure to Al2O3 on lung function and inflammatory markers in healthy volunteers. METHODS: 15 men (age 19-31) were exposed in random order to clean air or Al2O3 particles (3.8-4.0 mg/m(3)) for 2 h including 30 min exercise (stationary bike, 75 W). The permissible exposure level (PEL) for Al2O3 by Occupational Safety and Health Administration, USA, is 5 mg/m(3) time weighted average (TWA). Sham and particle exposures were separated by at least 2 weeks. Spirometry was carried out, and induced sputum and blood samples were collected 48 h before and 4 and 24 h after exposure. RESULTS: Levels of sputum neutrophils (mean (±SEM)) was increased 24 h post-Al2O3 vs pre-Al2O3 exposure (43% (4) vs 31% (4), p=0.01) and the protein level of interleukin (IL)-8 had a 4.8 (0.9)-fold change increase 24 h after exposure (p<0.01). Following Al2O3 exposure, gene signatures in sputum were significantly increased related to several pathways. CONCLUSIONS: The present study suggests that controlled exposure to Al2O3 particles at levels below PEL (TWA) induces airway inflammation in healthy humans marked by elevated neutrophils and elevated IL-8. In addition, increased expression of genes associated with several biological processes was observed in sputum. Interestingly, inhaled Al2O3-induced effects were localised to the airways and not systemic.

Studying the General Toxicity and Cumulative Properties of a Radiopharmaceutical Nanocolloid, (99m)Tc-Al2O3.

We studied toxicity of a new Russian radiopharmaceutical Nanocolloid, (99m)Tc-Al2O3. Tests for acute toxicity showed that this agent belongs to a class of moderate-toxicity substances and does not have cumulative properties. The evaluation of subchronic toxicity after subcutaneous injection of this product to rats (0.04, 0.2, and 0.4 ml/kg) and rabbits (0.02 and 0.2 ml/kg) for 7 days did not reveal changes in the general state, temperature, body weight, indices of the peripheral blood and bone marrow, functions of the heart, liver, kidneys, and nervous system, and morphological characteristics of the internal organs in animals. The drug does not produce a local irritant effect.

[STUDYING ACUTE TOXICITY OF NEW RADIOPHARMACEUTICAL 99MTC-AL2O3 NANOCOLLOIDS FOR ONCOLOGICAL DIAGNOSTICS].

The acute toxicity of a new drug based on nanocolloidal gamma alumina labeled with technetium-99m (99mTc) has been studied on 80 rats (40 females and 40 males) and 80 mice (40 females and 40 males) with intraperitoneal and subcutaneous drug administration. A single administration of the pharmacological agent was followed by observation of the survival of animals for 14 days with determining tolerable, toxic, and lethal doses for intraperitoneal and subcutaneous administration according to the Litchfield - Wilcoxon method, establishing the causes of animal death within 14 days of observation, and studying the drug influence on the general condition and some functional and morphological indices. Based on the established boundaries of toxicity and the classification of toxicity, the 99mTc-Al2O3 nanocolloids can be classified into conditionally moderately toxic substances. The actual values of LD5 of the radiopharmaceutical fall in the range of large doses. The safety factor for the drug studied significantly exceeds the minimum permissible value of 100.

Radiological assessment for bauxite mining and alumina refining.

OBJECTIVE: Two international benchmarks assess whether the mining and processing of ores containing Naturally Occurring Radioactive Material (NORM) require management under radiological regulations set by local jurisdictions. First, the 1 Bq/g benchmark for radionuclide head of chain activity concentration determines whether materials may be excluded from radiological regulation. Second, processes may be exempted from radiological regulation where occupational above-background exposures for members of the workforce do not exceed 1 mSv/year. This is also the upper-limit of exposure prescribed for members of the public. Alcoa of Australia Limited (Alcoa) has undertaken radiological evaluations of the mining and processing of bauxite from the Darling Range of Western Australia since the 1980s. Short-term monitoring projects have demonstrated that above-background exposures for workers do not exceed 1 mSv/year. A whole-of-year evaluation of above-background, occupational radiological doses for bauxite mining, alumina refining and residue operations was conducted during 2008/2009 as part of the Alcoa NORM Quality Assurance System (NQAS). The NQAS has been guided by publications from the International Commission on Radiological Protection (ICRP), the International Atomic Energy Agency (IAEA) and the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). The NQAS has been developed specifically in response to implementation of the Australian National Directory on Radiation Protection (NDRP). METHODS: Positional monitoring was undertaken to increase the accuracy of natural background levels required for correction of occupational exposures. This is important in view of the small increments in exposure that occur in bauxite mining, alumina refining and residue operations relative to natural background. Positional monitoring was also undertaken to assess the potential for exposure in operating locations. Personal monitoring was undertaken to characterise exposures in Similar Exposure Groups (SEGs). The monitoring was undertaken over 12 months, to provide annual average assessments of above-background doses, thereby reducing temporal variations, especially for radon exposures. The monitoring program concentrated on gamma and radon exposures, rather than gross alpha exposures, as past studies have shown that gross alpha exposures from inhalable dust for most of the workforce are small in comparison to combined gamma and radon exposures. RESULTS: The natural background determinations were consistent with data in the literature for localities near Alcoa's mining, refining and residue operations in Western Australia, and also with UNSCEAR global data. Within the mining operations, there was further consistency between the above-background dose estimates and the local geochemistry, with slight elevation of dose levels in mining pits. Conservative estimates of above-background levels for the workforce have been made using an assumption of 100% occupancy (1920 hours per year) for the SEGs considered. Total incremental composite doses for individuals were clearly less than 1.0 mSv/year when gamma, radon progeny and gross alpha exposures were considered. This is despite the activity concentration of some materials being slightly higher than the benchmark of 1 Bq/g. CONCLUSIONS: The results are consistent with previous monitoring and demonstrate compliance with the 1 mSv/year exemption level within mining, refining and residue operations. These results will be of value to bauxite mines and alumina refineries elsewhere in the world.

Number size distribution of fine and ultrafine fume particles from various welding processes.

Studies in the field of environmental epidemiology indicate that for the adverse effect of inhaled particles not only particle mass is crucial but also particle size is. Ultrafine particles with diameters below 100 nm are of special interest since these particles have high surface area to mass ratio and have properties which differ from those of larger particles. In this paper, particle size distributions of various welding and joining techniques were measured close to the welding process using a fast mobility particle sizer (FMPS). It turned out that welding processes with high mass emission rates (manual metal arc welding, metal active gas welding, metal inert gas welding, metal inert gas soldering, and laser welding) show mainly agglomerated particles with diameters above 100 nm and only few particles in the size range below 50 nm (10 to 15%). Welding processes with low mass emission rates (tungsten inert gas welding and resistance spot welding) emit predominantly ultrafine particles with diameters well below 100 nm. This finding can be explained by considerably faster agglomeration processes in welding processes with high mass emission rates. Although mass emission is low for tungsten inert gas welding and resistance spot welding, due to the low particle size of the fume, these processes cannot be labeled as toxicologically irrelevant and should be further investigated.

[Aerogenic risk factors and diagnosis of bauxite pneumoconiosis].

The research purpose is an estimation of influence of the bauxite dust on the state of the bronchopulmonary system of workers. It has been indicated that exposure of the poor fibrogenic dust while the process of the bauxite ore extraction, results in development of pnevmokoniosis characterized by substantial ventilatory and haemodynamic disorders limiting the workability of patients.

Toll-like receptor 4 is a key regulator of asthma exacerbation caused by aluminum oxide nanoparticles via regulation of NF-κB phosphorylation.

Aluminum oxide nanoparticles (Al2O3 NPs) have recently been reported to cause an inflammatory response in the lungs, and studies are being conducted on their adverse effects, especially in patients with underlying lung diseases such as asthma. However, the underlying mechanism of asthma aggravation caused by Al2O3 NPs remains unclear. This study investigated whether Al2O3 NPs exacerbate ovalbumin (OVA)-induced asthma and focused on the correlation between toll-like receptor 4 (TLR4) signaling and Al2O3 NP-induced asthma exacerbation. Al2O3 NP exposure in asthmatic mice resulted in increased inflammatory cell counts in the lungs, airway hyperresponsiveness, and increased levels of inflammatory cytokines compared with only OVA-induced mice, and excessive secretion of mucus was observed in the airways. Moreover, Al2O3 NP exposure in OVA-induced mice increased the expression levels of TLR4, phospho-nuclear transcription factor-kappa B (p-NFκB), myeloid differentiation factor 88 (MyD88), and phospho-NF kappa B inhibitor alpha (p-IκBα). Furthermore, in the lungs of TLR4 knockout mice exposed to Al2O3 NPs and in a human airway epithelial cell line with down regulated TLR4, the expression levels of MyD88, p-NFκB, and p-IκBα were decreased, and asthma-related allergic responses were reduced. Therefore, we demonstrated that TLR4 is important for aggravation of asthma induced by Al2O3 NPs, and this study provides useful information regarding as yet undiscovered novel target signaling.

Malignant fibrous histiocytoma at the site of an alumina-on-alumina-bearing total hip arthroplasty mimicking infected trochanteric bursitis.

Although the incidence of malignant tumors in patients undergoing total hip arthroplasties (THAs) is known to be lower than the general population, there exist several reports on the development of malignant tumors at the site of THAs. We report another case of malignant fibrous histiocytoma at the site of a THA, which was developed in an older patient who presented a cystic mass around the total hip prosthesis using a ceramic-on-ceramic bearing system, even without evidence of osteolysis or loosening of implants. This is the second case associated with an aluminum oxide prosthesis in English literature.

[Studies of effects of aluminum oxide nanoparticles after intragastric administration].

Growing Wistar rats received intragastrically nanoparticles (NPs) of aluminum oxide (Al2O3) daily during 28 days at doses of 1 or 100 mg per kg body mass. There were studied body mass of animals, relative mass of internals, rate of protein macromolecules absorption in the gut, oxidative damage of DNA, pool of tissue thiols, activity of hepatic enzymes of xenobiotic detoxication system, biochemical and hematological blood indices, stability of lysosome membranes, condition of antioxidant defense system, apoptosis of hepatocytes. Conducted experiments didn't reveal any marked toxic action of Al2O3 NPs on rats after 28 days of administration both in high and low dose. Among effects probably related to NPs influence on animals there were lowering of relative liver and lung masses, decrease of hepatic thiol pool, activity of CYP1A1 isoform in liver and glutathione reductase in erythrocytes, increase of diene conjugates of fatty acids in blood plasma. Said shifts were small in magnitude, didn't come out of margins of physiological norm and didn't show any distinct relation to NPs dose. However considering great importance of this nanomaterial as probable environmental contaminant the studies of it's toxicity must be continued in conditions of low doses (less than 1 mg per kg body mass) for long period of time.

Edible algae (Ecklonia cava) bioprocessed with mycelia of shiitake (Lentinula edodes) mushrooms in liquid culture and its isolated fractions protect mice against allergic asthma.

BACKGROUND: Ecklonia cava is an edible marine brown alga harvested from the ocean that is widely consumed in Asian countries as a health-promoting medicinal food The objective of the present study is to evaluate the anti-asthma mechanism of a new functional food produced by bioprocessing edible algae Ecklonia cava and shiitake Lentinula edodes mushroom mycelia and isolated fractions. METHODS: We used as series of methods, including high performance liquid chromatography, gas chromatography, cell assays, and an in vivo mouse assay to evaluate the asthma-inhibitory effect of Ecklonia cava bioprocessed (fermented) with Lentinula edodes shiitake mushroom mycelium and its isolated fractions in mast cells and in orally fed mice. RESULTS: The treatments inhibited the degranulation of RBL-2H3 cells and immunoglobulin E (IgE) production, suggesting anti-asthma effects in vitro. The in vitro anti-asthma effects in cells were confirmed in mice following the induction of asthma by alumina and chicken egg ovalbumin (OVA). Oral administration of the bioprocessed Ecklonia cava and purified fractions suppressed the induction of asthma and was accompanied by the inhibition of inflammation- and immune-related substances, including eotaxin; thymic stromal lymphopoietin (TSLP); OVA-specific IgE; leukotriene C4 (LTC4); prostaglandin D2 (PGD2); and vascular cell adhesion molecule-1 (VCAM-1) in bronchoalveolar lavage fluid (BALF) and other fluids and organs. Th2 cytokines were reduced and Th1 cytokines were restored in serum, suggesting the asthma-induced inhibitory effect is regulated by the balance of the Th1/Th2 immune response. Serum levels of IL-10, a regulatory T cell (Treg) cytokine, were increased, further favoring reduced inflammation. Histology of lung tissues revealed that the treatment also reversed the thickening of the airway wall and the contraction and infiltration of bronchial and blood vessels and perialveolar inflammatory cells. The bioprocessed Ecklonia cava/mushroom mycelia new functional food showed the highest inhibition as compared with commercial algae and the fractions isolated from the bioprocessed product. CONCLUSIONS: The in vitro cell and in vivo mouse assays demonstrate the potential value of the new bioprocessed formulation as an anti-inflammatory and anti-allergic combination of natural compounds against allergic asthma and might also ameliorate allergic manifestations of foods, drugs, and viral infections.

Cytotoxicity of Al2O3 nanoparticles at low exposure levels to a freshwater bacterial isolate.

The cytotoxicity of Al(2)O(3) nanoparticles (NP) at very low exposure levels (1 µg/mL and less) to a dominant bacterial isolate from freshwater (lake water), Bacillus licheniformis, was examined. Sterile lake water was directly used as a test medium or matrix to simulate the freshwater environment. Exposure to 1 µg/mL Al(2)O(3) NP for 2 h caused a 17% decrease in cell viability (as determined by plate count and MTT assay). During the test period, the particles were found to be stable against aggregation in the matrix and exerted a nano-size effect on the exposed test organisms. The decrease in cell viability was proven not to be due to the release of Al(3+) ions from the nanoparticles in the dispersion. The zeta potential and FT-IR analyses suggested that the surface charge based attachment of nanoparticles on to the bacterial cell wall was responsible for flocculation leading to toxicity. The cell wall damage confirmed through SEM and the lipid peroxidation assay also contributed toward toxicity. This study warns of possible ecotoxicity of nanoparticles even at environmentally relevant concentrations. However, detailed studies need to be carried out to establish probable mechanistic aspects of this low concentration toxicity phenomenon.

Zirconia toughened alumina (ZTA) powders: ultrastructural and histological analysis.

Ceramic materials, as Alumina and Zirconia, has made an improvement in the choice of new biomaterials for the load bearing application in dental and orthopaedic implants. These materials has shown mechanical resistance to high stress related to weight bearing and low debris in time. For this reason they are indicated on young patients implant, with high demanding activities and long life expectance. In literature however the risk of chronic inflammation due to chronic wear debris release and the possibility of carcinogenesis, is still to be definitively investigated. Another point to investigate is the acute reaction of the tissue in case of acute release of powders of these materials. The aim of this study was to investigate the possible local and systemic acute effects of ceramic precursors in form of powders of different size when released into articular joint. Powders of ZTA were implanted in the knee joint of twenty-four New Zealand white adult rabbits, that were sacrificed at 1,3,6, and 12 months. Radiographic, histological and immunoistochemestry analysis were conducted on periprosthetic tissue and peripheral organs, to verifying local host response and systemic toxic effects.