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Mesotheliomas are neoplasia developed from the mesothelium, a layer covering the viscera (visceral layer) and the cavity where the organs are (parietal layer). The best known, and the most frequently encountered is the pleural mesothelioma. This disease has a close link with exposure to asbestos, a mineral fibre now banned in several countries. However, other exposure factors have also been incriminated, including another one recognised as a certain carcinogenic agent for several years now : erionite. We present the case of a patient with pleural mesothelioma whose exposure to erionite could be demonstrated. The presentation of this clinical case will be complemented by a literature review on this less known and mostly environmental exposure, contrary to asbestos which is mostly professional.

Objective: To examine the incidence and epidemiology of malignant mesothelioma in immigrants from Karain where there is an extraordinarily high incidence of mesothelioma, Cappadocia, Turkey, to Stockholm, Sweden, and their children over 20 years of age born in Stockholm, i.e. two genetically similar populations with and without erionite exposure., Methods: This survey was conducted as a retrospective cohort study. Standardized average annual mesothelioma incidence rates (AAMIRs) and mesothelioma standardized incidence ratio (mSIR) were calculated. Cox regression analysis was used to determine the importance of different factors related to mesothelioma risk., Results: The cohort consisted of 337 people, 203 of whom were born and/or lived in Karain before immigrating to Sweden (erionite-exposed), and 134 who were born in Stockholm (erionite-unexposed). There were 69 deaths, 42 (61%) due to mesothelioma, and two patients with the disease who were still alive. Of these 44 patients, 22 were men. All mesothelioma patients were in the erionite-exposed group. In the age group 30-49 years, mesothelioma developed in 11 of 38 (29%) with erionite exposure, while there were no cases among 86 persons in the non-exposed group. For men, the AAMIR was 253.9 per 100,000 persons in the whole cohort, and for women, it was 350.9. The mSIR was 71.9 for men and 393.1 for women. Exposure to erionite exceeding 20 years and age over 40 years were associated with increased mesothelioma risk., Conclusion: Exposure to erionite is the leading cause of mesothelioma in Karain villagers, and genetic factors are probably of minor importance., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Asbestos and zeolites are silicate-based minerals, linked inextricably via paradoxical similarities and differences which have emanated from different geological epochs. Both have been employed in the service of humanity through millennia: asbestos, for its "inextinguishable" quality of being an insulator against heat and fire; zeolite, a "boiling stone" with its volcanic and marine sedimentary rock origins, for its propensity to adsorb water and remove metals and toxins. Serious adverse health effects observed in asbestos miners as long ago as the 1st Century AD did not halt the rising popularity of asbestos. As the miracle material of the 1900s, asbestos production and consumption exploded, culminating in its ubiquity in ships, vehicles, homes, commercial buildings, and over 3000 different industrial and household products. Through the 1940s and 1950s, epidemiological studies concluded that asbestos was a likely cause of asbestosis, lung cancer, and malignant mesothelioma, and it is now banned in many but far from all countries. The long latency between exposure to asbestos and the occurrence of cancer has obscured the deadly consequences of asbestos exposure for centuries. Even today, a considerable part of the world population is insufficiently aware of the dangers of asbestos, and millions of tons of this carcinogen continue to be mined and used worldwide. Zeolites, both natural and synthetic, are microporous aluminosilicate minerals commonly used in a myriad of processes, in the petrochemical industry, in domestic appliances and cleaning agents, as commercial adsorbents and exchangers for toxins and pollutants, and as catalysts. Zeolites are found in agriculture, veterinary science, and human health. More recently, new materials such as carbon nanotubes are being employed in materials requiring durability and thermal and electrical conductivity, yet nanotubes are now joining the ranks of more established particulates such as asbestos and silica, in causing human disease. In this review, we compare and contrast the similarities and differences of these two groups of silicate minerals and their waxing and waning use in the employ of humanity.

Overseas, emerging research has shown that where erionite is present in bedrock as a zeolite, and then subsequently disturbed and blown into the atmosphere, resulting exposure is associated with health effects similar to those caused by asbestos, including malignant mesothelioma (MM). Erionite-induced MM is thought to be particularly prevalent in the construction and quarrying industries, in regions where rock containing erionite is disturbed. In 2015, the then Government Chief Scientist, Sir Peter Gluckman, reported that erionite was a more potent carcinogen than asbestos, and more recent studies have established its presence in the Auckland Region. However, globally at present, there are no established occupational exposure limits for erionite, standard sampling and analytical methods or exposure mitigation guidelines. Given the many major construction projects being carried out in Auckland at the present time, which involve the removal of large quantities of bedrock containing erionite, an assessment of the health risks such activities pose to the public is needed., Competing Interests: Nil.

Context: - Although many mesotheliomas are related to asbestos exposure, not all are, and there is increasing information on other causes of mesothelioma., Objective: - To provide a review of non-asbestos causes for malignant mesothelioma., Data Sources: - Review of relevant published literature via PubMed and other search engines., Conclusions: - Currently, most pleural mesotheliomas (70% to 90%) in men in Europe and North America are attributable to asbestos exposure; for peritoneal mesothelioma the proportion is lower. In North America few mesotheliomas in women at any site are attributable to asbestos exposure, but in Europe the proportion is higher and varies considerably by locale. In certain geographic locations other types of mineral fibers (erionite, fluoro-edenite, and probably balangeroite) can induce mesothelioma. Therapeutic radiation for other malignancies is a well-established cause of mesothelioma, with relative risks as high as 30. Carbon nanotubes can also induce mesotheliomas in animals but there are no human epidemiologic data that shed light on this issue. Chronic pleural inflammation may be a cause of mesothelioma but the data are scanty. Although SV40 can induce mesotheliomas in animals, in humans the epidemiologic data are against a causative role. A small number of mesotheliomas (probably in the order of 1%) are caused by germline mutations/deletions of BRCA1-associated protein-1 ( BAP1) in kindreds that also develop a variety of other cancers. All of these alternative etiologies account for a small proportion of tumors, and most mesotheliomas not clearly attributable to asbestos exposure are spontaneous (idiopathic).

A semi-quantitative screening method was used to compare the killing efficacy of Ag zeolites against bacteria and yeast as a function of the zeolite type, crystal size and concentration. The method, which substantially reduced labor, consumables and waste and provided an excellent preliminary screen, was further validated by quantitative plate count experiments. Two pairs of zeolite X and zeolite beta with different sizes (ca. 200nm and 2μm for zeolite X and ca. 250 and 500nm for zeolite beta) were tested against Escherichia coli (E. coli) and Candida albicans (C. albicans) at concentrations in the range 0.05-0.5mgml -1 . Reduction of the zeolite crystal size resulted in a decrease in the killing efficacy against both microorganisms. The semi-quantitative tests allowed convenient optimization of the zeolite concentrations to achieve targeted killing times. Zeolite beta samples showed higher activity compared to zeolite X despite their lower Ag content, which was attributed to the higher concentration of silver released from zeolite beta samples. Cytotoxicity measurements using peripheral blood mononuclear cells (PBMCs) indicated that Ag zeolite X was more toxic than Ag zeolite beta. However, the trends for the dependence of cytotoxicity on zeolite crystal size at different zeolite concentrations were different for the two zeolites and no general conclusions about zeolite cytotoxicity could be drawn from these experiments. This result indicates a complex relationship, requiring the necessity for individual cytotoxicity measurements for all antimicrobial applications based on the use of zeolites., (Copyright © 2017 Elsevier B.V. All rights reserved.)

This review analytically examines the published data for erionite-related malignant pleural mesothelioma (E-MPM) and any data to support a genetically predisposed mechanism to erionite fiber carcinogenesis. Adult patients of age ≥18 years with erionite-related pleural diseases and genetically predisposed mechanisms to erionite carcinogenesis were included, while exclusion criteria included asbestos- or tremolite-related pleural diseases. The search was limited to human studies though not limited to a specific timeframe. A total of 33 studies (31042 patients) including 22 retrospective studies, 6 prospective studies, and 5 case reports were reviewed. E-MPM developed in some subjects with high exposures to erionite, though not all. Chest CT was more reliable in detecting various pleural changes in E-MPM than chest X-ray, and pleural effusion was the most common finding in E-MPM cases, by both tests. Bronchoalveolar lavage remains a reliable and relatively less invasive technique. Chemotherapy with cisplatin and mitomycin can be administered either alone or following surgery. Erionite has been the culprit of numerous malignant mesothelioma cases in Europe and even in North America. Erionite has a higher degree of carcinogenicity with possible genetic transmission of erionite susceptibility in an autosomal dominant fashion. Therapeutic management for E-MPM remains very limited, and cure of the disease is extremely rare.

Nanoclays have potential applications in biomedicine raising the need to evaluate their toxicity in in vitro models as a first approach to its biocompatibility. In this study, in vitro toxicity of clinoptilolite and sepiolite nanoclays (NC) was analyzed in highly phagocytic cultures of amoebas and human and mice macrophages. While amebic viability was significantly affected only by sepiolite NC at concentrations higher than 0.1 mg/mL, the effect on macrophage cultures was dependent on the origin of the cells. Macrophages derived from human peripheral blood monocytes were less affected in viability (25% decrease at 48 h), followed by the RAW 264.7 cell line (40%), and finally, macrophages derived from mice bone marrow monocytes (98%). Moreover, the cell line and mice macrophages die mainly by necrosis, whereas human macrophages exhibit increased apoptosis. Cytokine expression analysis in media of sepiolite NC treated cultures showed a proinflammatory profile (INFγ, IL-1α, IL-8, and IL-6), in contrast with clinoptilolite NC that induced lees cytokines with concomitant production of IL-10. The results show that sepiolite NC is more toxic to amoebas and macrophages than clinoptilolite NC, mostly in a time and dose-dependent manner. However, the effect of sepiolite NC was comparable with talc powder suggesting that both NC have low cytotoxicity in vitro.

Topical delivery of nitric oxide (NO) through a wound dressing has the potential to reduce wound infections and improve healing of acute and chronic wounds. This study characterized the antibacterial efficacy of an ointment containing NO-loaded, zinc-exchanged zeolite A that releases NO upon contact with water. The release rate of NO from the ointment was measured using a chemiluminescence detection system. Minimum bactericidal concentration assays were performed using five common wound pathogens, including Gram-negative bacteria (Escherichia coli and Acinetobacter baumannii), Gram-positive bacteria (Staphylococcus epidermidis and meticillin-resistant Staphylococcus aureus) and a fungus (Candida albicans). The time dependence of antimicrobial activity was characterized by performing log-reduction assays at four time points after 1-8 h ointment exposure. The cytotoxicity of the ointment after 24 h was assessed using cultured 3T3 fibroblast cells. Minimum microbicidal concentrations (MMCs) for bacterial organisms (5×10(7) c.f.u.) ranged from 50 to 100 mg ointment (ml media)(-1); the MMC for C. albicans (5×10(4) c.f.u.) was 50 mg ointment (ml media)(-1). Five to eight log reductions in bacterial viability and three log reductions in fungal viability were observed after 8 h exposure to NO-zeolite ointment compared with untreated organisms. Fibroblasts remained viable after 24 h exposure to the same concentration of NO-zeolite ointment as was used in antimicrobial tests. In parallel studies, full-thickness cutaneous wounds on Zucker obese rats healed faster than wounds treated with a control ointment. These data indicate that ointment containing NO-loaded zeolites could potentially be used as a broad-spectrum antimicrobial wound-healing dressing.

Aim: To examine the changes in electrolyte concentrations after addition of zeolite-based hemostat QuikClot in blood and the effects of zeolite on blood coagulation in vitro., Methods: Fresh blood was taken from healthy adult volunteers and sheep, and the electrolyte concentrations in blood were measured using a blood electrolyte analyzer. Zeolite Saline Solution (ZSS) was prepared by addition of 2 g zeolite to 0.9% NaCl solution (4, 8, or 16 mL). The electrolytes in ZSS were measured using inductively coupled plasma atomic emission spectroscopy. The prothrombin time (PT) and activated partial thromboplastin time (APTT) of blood were measured using the test tube method. The activated clotting time (ACT) and clotting rate (CR) of blood were measured with Sonoclot Coagulation and Platelet Function Analyzer., Results: Addition of zeolite (50 and 100 mg) in 2 mL human blood significantly increased Ca(2+) concentration, while Na(+) and K(+) concentrations were significantly decreased. Addition of zeolite (50 and 100 mg) in 0.9% NaCl solution (2 mL) caused similar changes in Ca(2+) and Na(+) concentrations. Si(4+) (0.2434 g/L) and Al(3+) (0.2575 g/L) were detected in ZSS (2 g/8 mL). Addition of ZSS in sheep blood shortened APTT in a concentration dependent manner, without changing PT. ZSS or aqueous solution of CaCl2 that contained Ca(2+) concentration identical to that of ZSS significantly shortened ACT in human blood without significantly changing CR, and the effect of ZSS on ACT was not significantly different from that of CaCl2., Conclusion: Zeolite releases Ca(2+) into blood, thus accelerating the intrinsic pathway of blood coagulation and shortening the clot formation time.

Malignant mesothelioma is an aggressive malignancy related to asbestos and erionite exposure. AP-1 transcriptional activity and the NF-κB signaling pathway have been linked to mesothelial cell transformation and tumor progression. HGF and c-Met are highly expressed in mesotheliomas. Phosphoinositide 3-kinase, AKT, and the downstream mTOR are involved in cell growth and survival, and they are often found to be activated in mesothelioma. p16(INK4a) and p14(ARF) are frequently inactivated in human mesothelioma, and ∼50% of mesotheliomas contain the NF2 mutation. Molecular therapies aimed at interfering with these pathways have not improved the dismal prognosis of mesothelioma, except possibly for a small subset of patients who benefit from certain therapies. Recent studies have shown the importance of asbestos-induced inflammation in the initiation and growth of mesothelioma, and HMGB1 and Nalp3 inflammasome have been identified as key initiators of this process. Asbestos induces cell necrosis, causing the release of HMGB1, which in turn may activate Nalp3 inflammasome, a process that is enhanced by asbestos-induced production of reactive oxygen species. HMGB1 and Nalp3 induce proinflammatory responses and lead to interleukin-1β and TNF-α secretion and NF-κB activity, thereby promoting cell survival and tumor growth. Novel strategies that interfere with asbestos- and erionite-mediated inflammation might prevent or delay the onset of mesothelioma in high-risk cohorts, including genetically predisposed individuals, and/or inhibit tumor growth. The very recent discovery that germline BAP1 mutations cause a new cancer syndrome characterized by mesothelioma, uveal melanoma, and melanocytic tumors provides researchers with a novel target for prevention and early detection.

Air-collected erionite series minerals from Cappadocia region of Turkey were characterized quantitatively by using transmission electron microscopy (TEM) equipped with energy dispersive spectroscopy (EDS). Field emission scanning electron microscopy aided identification of fibrous minerals. Quantitative characterization guidelines for positive identification of erionites proposed by Dogan and Dogan (2008) was applied and the modified balance error formula (E%<10) and Mg-content test <0.80 were performed for each analysis. Erionite species computation showed that the mineral is erionite-K and a mean chemical formula is proposed based upon the TEM-EDS results. Among the 60 analyses, 11 passed E% test (18.3%), 33 passed Mg-content test (55.0%), and only 3 passed both E% and Mg-content tests (5.0%). This shows difficulty of quantitative characterization of the erionite series minerals. However, as erionite is the most carcinogenic mineral known and is classified by IARC as a Group-I (human) carcinogen, it requires special attention from the mineralogical community to help establish its true mineralogical properties. Quantitatively characterized erionite data are very scarce in literature. Correctly identified erionite mineral types will be useful to medical researchers in their search to find a possible cure for the deadly disease of mesothelioma., (© Wiley Periodicals, Inc.)

Exposure to erionite, an asbestos-like mineral, causes unprecedented rates of malignant mesothelioma (MM) mortality in some Turkish villages. Erionite deposits are present in at least 12 US states. We investigated whether increased urban development has led to erionite exposure in the United States and after preliminary exploration, focused our studies on Dunn County, North Dakota (ND). In Dunn County, ND, we discovered that over the past three decades, more than 300 miles of roads were surfaced with erionite-containing gravel. To determine potential health implications, we compared erionite from the Turkish villages to that from ND. Our study evaluated airborne point exposure concentrations, examined the physical and chemical properties of erionite, and examined the hallmarks of mesothelial cell transformation in vitro and in vivo. Airborne erionite concentrations measured in ND along roadsides, indoors, and inside vehicles, including school buses, equaled or exceeded concentrations in Boyali, where 6.25% of all deaths are caused by MM. With the exception of outdoor samples along roadsides, ND concentrations were lower than those measured in Turkish villages with MM mortality ranging from 20 to 50%. The physical and chemical properties of erionite from Turkey and ND are very similar and they showed identical biological activities. Considering the known 30- to 60-y latency for MM development, there is reason for concern for increased risk in ND in the future. Our findings indicate that implementation of novel preventive and early detection programs in ND and other erionite-rich areas of the United States, similar to efforts currently being undertaken in Turkey, is warranted.

Objective: To identify any adverse effects on health or performance in young dairy calves fed clinoptilolite mixed with milk replacer., Animals: 26 male Holstein calves (1 to 7 days old)., Procedures: Twice daily for 28 days, calves were fed milk replacer with no clinoptilolite (control group; n=8), 0.5% clinoptilolite (low-dosage group; 9), or 2% clinoptilolite (high-dosage group; 9); each calf consumed approximately 12% of its body weight (based on the replacer solids in the milk replacer mixture)/d. For each calf, subjective health assessments, weight and rectal temperature measurements, and CBC and serum biochemical analyses were performed at intervals. All calves underwent necropsy., Results: 2 calves were euthanized during the experiment because of bronchopneumonia or enteritis. Body weight and average daily gain did not differ among treatment groups. The percentage of monocytes and serum total protein concentration in the low-dosage group were higher than values in the control and high-dosage groups. Compared with values for either clinoptilolite-treated group, BUN concentration was greater in the control group. Serum globulin concentration differed significantly among groups (2.77, 2.50, and 2.36 g/dL in the low-dosage, control, and high-dosage groups, respectively). At necropsy, gross lesions associated with clinoptilolite treatment were not detected in any of the calves., Conclusions and Clinical Relevance: Even under stressful conditions, clinoptilolite fed at low or high dosages did not affect the performance of dairy calves and had no negative effect on WBC count and blood metabolite concentrations and enzyme activities. Clinoptilolite ingestion was not associated with treatment-specific gross changes.

Mediterranean regions such as Greece, Turkey, Cyprus, Corsica and New Caledonia have experienced epidemics of malignant mesothelioma as a result of non-occupational, "domestic" exposure to tremolite asbestos and fibrous erionite. This exposure to tremolite asbestos and fibrous erionite is typified "domestic" due to its prevalence in regions with natural deposits of tremolite asbestos (or fibrous erionite) where the material from tremolite asbestos or fibrous erionite is used for domestic applications such as whitewashing. However, these exposures may be useful in examining the potential consequences of even small amounts of amphibole asbestos fibers in the ambient air. It can also elucidate the effects of fibers that behave like amphibole asbestos. However, this type of exposure is not useful for studying the potential effects of small amounts of asbestos in the ambient air of big cities due to the differing nature of the fiber types and modes of exposure between the regions.

Background: Zeolites have hemostatic properties used to stop bleeding in severe hemorrhage. Manufactured QuikClot is an approved zeolite-based hemostatic agent for battlefield use. The exothermic reaction associated with QuikClot as loose granules or as granules packaged in a mesh bag has potential burn effects; this led to the development of a formulation of "cooler" non-exothermic QuikClot. The goal of this study was to compare the elevation of temperature of these formulations upon contact with blood., Methods: Following full transection of the femoral vasculature, anesthetized Yorkshire pigs (n = 15) (28.8 +/- 1.5 kg) were hemorrhaged for 2 min and treated with 100 g of bagged QuikClot (Advanced Clotting Sponge (ACS) (n = 4)) or a modified non-exothermic formulation (ACS+ (n = 11)). Vital signs and temperature at the dressing/tissue interface were continuously recorded for 3 h. Additional procedures were used to examine effects of different ratios of blood to zeolite on temperature elevation., Results: Total post-treatment blood loss was comparable for ACS+&#95;E and ACS&#95;E groups (overall average: 18.6 +/- 10.5% EBV). Temperature recorded at the dressing/tissue interface was significantly lower with ACS+ vs. ACS (40.3 +/- 1.8 vs. 61.4 +/- 10.7 degrees C, respectively, p < 0.01) and was 3.2 +/- 2.6 degrees C higher than rectal temperature (38.0 +/- 0.7 degrees C, p < 0.01). Survival at endpoint (7/11 vs. 4/4) and average survival time (134 +/- 64 vs. 180 min) were greater for both ACS+ and ACS in comparison to Standard Dressing. The wound temperature with ACS was reduced with greater blood to product ratios and this pattern was paralleled with in vitro measurements., Conclusions: The lower heat release with ACS+ compared to ACS was confirmed in an animal model and ACS+ had similar efficacy in arresting bleeding when compared to Standard Dressing.

Erionite is a human and animal carcinogen and one of the most toxic minerals known. Erionite deposits have been reported in many countries; however, it is only in the area of three villages of Cappadocia, Turkey, that environmental exposure to erionite has been demonstrated to be the cause of an epidemic of the disease mesothelioma. In the USA, no cases of mesothelioma have been reliably proven to be the result of erionite exposure, though the possibility exists. Erionite samples from three villages of the Cappadocia region were characterized mineralogically and compared with three different standards from the USA. Micro morphological details of erionite minerals using a high-resolution field-emission SEM showed that microstructures of "bundles", "fibers", and "fibrils" are important physical properties of fibrous erionite minerals. Typical lung burden of erionite and asbestos fibers were compared in terms of number of fibers. Assuming the lung burden of fibers in a human mesothelioma victim is about 1 mg, and the hazardous fibers are approximately 1 mum in diameter and 10 mum long, that milligram contains approximately 40 million asbestos and 50 million erionite fibers. These microstructures of erionite minerals draw attention to the concepts of surface area or surface-area-to-volume ratio and their relationship to the carcinogenicity of the mineral. The larger surface area creates a wider platform for mineral-cell interaction and thus more possibilities of proliferative transformation of mesothelial cells. Consequently, understanding the exact mineralogical properties will help determination of the true carcinogenic mechanism(s) of the mineral for prevention and possibly treatment of malignant mesothelioma.

The objective was to determine the effects of sodium zeolite A (SZA) on mineral metabolism and tissue mineral composition in calves. Twenty calves were placed on study at 3 days of age and were placed into one of two groups: SS, which received 0.05% BW SZA added to their milk replacer, and CO, which received only milk replacer. Blood samples were taken on days 0, 30, and 60 for mineral analysis. Urine and feces were collected on day 30 for mineral metabolism, and on day 60, the calves were euthanized, and samples were taken from numerous organs for mineral analyses. Aluminum retention was increased in the SS calves (p = 0.001). Silicon concentrations were increased in the aorta, spleen, lung, muscle, and kidney of the SS calves, and aluminum was increased in all SS tissues (p < 0.05). Calcium concentrations were increased in aorta, liver, muscle, and tendon; phosphorus concentrations were increased in aorta, but decreased in plasma; magnesium concentrations were increased in aorta, heart, kidney, liver, and pancreas, but decreased in plasma; and iron concentrations were decreased in kidney and liver (p < 0.05). The accumulation of tissue aluminum and therefore potential adverse consequences may preclude any benefits of using SZA as a dietary supplement.

Nitric oxide (NO) plays an important role in the cutaneous response to UV radiation and in cutaneous inflammation. The presence of inducible NO synthase protein in a number of inflammatory dermatoses, coupled with the induction of an intense cutaneous inflammatory infiltrate following topical application of the NO donor-acidified nitrite (NO2(-)), has set the paradigm of NO being an inflammatory mediator in human skin. Using zeolite NO (Ze-NO), a chemically inert, pure NO donor, we have shown that NO per se produces little inflammation. Biologically, relevant doses of Ze-NO induce a dermal CD4-positive T-cell infiltrate and IFN-gamma secretion. In contrast acidified nitrite, releasing equal quantities of NO (measured by dermal microdialysis and cutaneous erythema), induces an intense epidermal infiltrate of macrophages with a similar dermal infiltrate of CD3-, CD4-, CD8-, and CD68-positive cells and neutrophils. Suction blisters were created in Ze-NO-treated and control skin. IFN-gamma, but not IL-4, was detected in Ze-NO-treated skin (mean control 0.1+/-0.07 pg mg(-1) protein, mean IFN-gamma 0.6+/-0.4 pg mg(-1) protein). We suggest that the potent inflammation induced by acidified NO2(-) is secondary to the release of additional mediators.

Twenty calves were placed on study at 3 days of age and were placed according to birth order into one of two groups: SS, which received 0.05% BW sodium zeolite A (SZA) added to their milk replacer, and CO, which received only milk replacer. Blood samples were taken on days 0, 30, and 60 for osteocalcin (OC) and deoxypyridinoline (DPD) analysis. On day 60, the calves were euthanized, and synovial fluid, articular cartilage, and both fused metacarpals were collected for bone quality analyses such as architecture and mechanical properties, mineral composition, and glycosaminoglycan concentration. There were no differences in OC concentrations because of treatment (p = 0.12), and CO calves had lower DPD concentrations than SS calves (p = 0.01), but the OC-to-DPD ratio was not different between treatments (p = 0.98). No differences in bone architecture or mechanical properties were detected. SZA supplementation increased cortical bone (p = 0.0002) and articular cartilage (p = 0.05) aluminum content. Glycosaminoglycan concentrations were not different in synovial fluid or cartilage. Supplementation of SZA appeared to alter the rate of bone turnover without altering bone strength. Aluminum concentrations in the bone and cartilage increased, which may be a concern, although the long-term consequences of such remain to be determined.

Four cases are presented to illustrate cutaneous burns sustained with the use of zeolite in the treatment of major hemorrhage secondary to combat wounds. Zeolite, a microporous crystalline aluminosilicate granular hemostatic agent, can cause secondary thermal injuries through an exothermic reaction that is likely related to the absorption of free fluid at the hemorrhage site. Understanding of this process may help both military and civilian EMS personnel avoid or minimize secondary thermal injury while still benefiting from zeolite's hemostatic capabilities.

Fifty-two clinically healthy Holstein cows were randomly assigned to one of three groups according to their age and parity. The first group (A) consisted of 17 cows that were fed a concentrate ration supplemented with 1.25 per cent clinoptilolite, the second group (B) consisted of 17 cows fed a ration supplemented with 2.5 per cent clinoptilolite, and the third group (C) consisted of 18 cows, which were fed the basal ration containing no clinoptilolite. The rations were fed from four weeks before the cows' expected parturition dates until the beginning of the next dry period. Blood samples were collected from each animal at the start of the experiment, on the day of calving and then monthly, and analysed for serum glucose, ketone bodies, liver enzymes, blood urea nitrogen (BUN) and total proteins. The milk yield of each cow was recorded monthly. The cows in group B had significantly fewer cases of clinical ketosis during the first month after calving and a higher total milk yield. Feeding the cows with clinoptilolite for a long period had no apparent adverse effects on their liver function, and did not significantly affect the concentrations of glucose, ketone bodies, BUN and total proteins in their serum.

Introduction: The United States military currently outfits our soldiers with a zeolite-based hemostatic agent (HA) that is applied directly onto a traumatic wound to induce hemostasis and prevent loss of life from exsanguination. The goals of this work were to identify and implement strategies to attenuate a tissue burning side effect associated with the HA, resulting from a large release of heat upon hydration, without adversely affecting the wound healing properties. Five ion exchanged derivatives of the parent HA were prepared and characterized with regard to their material and thermal properties, in vitro hemostatic efficacy, and antibacterial activity., Methods: The five host-guest high-surface-area HAs were prepared by ion exchanging the zeolite linde type 5A with aqueous salt solutions under controlled conditions. The modified HAs were characterized by TGA, DSC, Thermal Imaging, SEM, XRD, XPS, BET, and a Thromboelastograph (TEG) was employed to assay the in vitro hemostatic efficacy. Antibacterial activity was assayed by measuring the zone of no growth of Pseudomonas aeruginosa biofilms growing in contact with the ion exchanged HAs., Results: The heat released during application of the HA can be minimized from 680 J/g to 420 J/g by ion exchanging the calcium ions in zeolite linde type 5A with cations of a reduced hydration enthalpy. Zeolite-based HAs that demonstrate in vitro clot induction time of R < or = 1.8 min, and with surfaces areas > or = 634 m2/g, correlate with 75% in vivo swine survivability of a universally lethal groin injury. Silver exchanged HA maintained a zone of no growth of P. aeruginosa with a surface area twice the geometrical surface area of an HA pressed pellet for 24 hours in an LB Agar assay., Conclusions: Two strategies for reducing the large amount of heat released by a zeolite-based HA during application have been described and quantified: (1) ion exchange and (2) prehydration. Five ion-exchanged derivatives of the original HA have been prepared and assayed for hemostatic efficacy both in vitro, by TEG, and in vivo, by clinical swine trials. Contact activation coagulation rates, alpha, were found to increase with the amount of heat released by the HA. In Vitro clot induction time, R, and HA surface area have been identified as predictors of in vivo hemostatic performance. A proposed rationale for selecting hemostatic materials based on these parameters will likely reduce the quantity of experiments involving animals, and the associated labor and capital costs, necessary to test a new HA. A method for incorporating antibacterial activity against gram negative P. aeruginosa into the Ag-exchanged formulation of zeolite LTA-5A has been described and substantiated.

Mesothelioma incidence is high in certain villages on the Anatolian plateau in Turkey, where environmental exposure includes erionite, a form of zeolite fibers, from the local volcanic tuff. Previous studies of this exposure were cross-sectional or with a follow-up period of only a few years. A prospective study of residents of two exposed and one nearby control village was initiated in 1979 and continued through December 31, 2003. A total of 891 men and women, aged 20 years or older, were included, 230 of them residing in the village without known exposure to erionite. Mortality data were obtained from hospital records and death certificates. During the 23-year follow-up, 372 deaths occurred; 119 of these were from mesothelioma, which was the cause of 44.5% of all deaths in the exposed villages. Seventeen patients had peritoneal mesothelioma; the rest had pleural mesothelioma. Only two cases of mesothelioma, one of each type, occurred in the control village-both in women born elsewhere. When standardized to the world population, the pleural mesothelioma incidence was approximately 700 and 200 cases per 100,000 people annually in the two exposed villages and about 10 cases per 100,000 people in the control village. When we used Danish data for comparison, the standardized pleural mesothelioma mortality rate was 485 (95% confidence interval = 395 to 590). Our results emphasize the severity of the mesothelioma endemic in erionite-exposed areas of Turkey and call for intensified prevention of mesothelioma by limiting environmental exposures to these fibers.

The objective of the experiment was to investigate the effect of clinoptilolite (a natural zeolite) supplementation in the ration of dairy cows on serum copper (Cu), zinc (Zn), and iron (Fe) concentrations. Fifty-two clinically healthy Holstein cows were randomly assigned to one of three groups according to their age and parity. The first group (group A) comprised 17 cows fed a ration supplemented with 1.25% clinoptilolite, the second group (group B) comprised also 17 cows was given a ration with 2.5% clinoptilolite, and the third group (group C, the control), comprised 18 cows fed the basal ration that did not contain any clinoptilolite. The experiment started when the cows entered the fourth week before the expected parturition and lasted until the end of lactation. All cows were fed the above concentrates during the entire experimental period. Blood samples were collected from each animal at the starting day of the experiment, at the day of calving, and at monthly intervals thereafter. All samples were tested for serum Cu, Zn, and Fe concentrations. The results showed that the 1.25 and 2.5% supplementation of clinoptilolite did not have any adverse effects on serum concentrations of Cu, Zn, and Fe.

The objective of the experiment was to investigate the effect of clinoptilolite (a natural zeolite) supplementation in the ration of dairy cows on serum beta-carotene, vitamins A and E concentrations. Fifty-two clinically healthy Holstein cows were randomly assigned to one of three groups according to their age and parity. The first group (group A, n = 17), was offered a concentrate feed supplemented with 1.25% clinoptilolite. The second group (group B, n = 17), was offered a concentrate feed supplemented with 2.5% clinoptilolite. The third group (group C, n = 18), which served as controls, was offered the same concentrate feed without clinoptilolite supplementation. All cows were fed the above concentrates continuously starting 30 days before the expected parturition up to the end of lactation. Blood samples from individual animals were collected just before the start of experiment, at the day of calving and, thereafter, at monthly intervals. All samples were tested for serum beta-carotene, vitamins A and E concentrations. The results showed that the 1.25 and 2.5% supplementation of clinoptilolite had no adverse effect on serum concentrations of beta-carotene, vitamins A and E.

This paper discusses the different explanatory models and the contested perceptions of cancer etiology among residents of two Anatolian villages and migrants from these villages in Turkey, Sweden, and Germany. These communities suffer from an endemic, deadly cancer called mesothelioma, the cause of which is associated with exposure to an environmental carcinogenic substance, erionite, which is present in large deposits in the ground, in the stones, and white stucco that the villagers used to build their homes, and in the air in the form of dust. However, an examination of patients' disease trends, experiences, and local explanations has led to new investigations of possible familial risk cofactors. This paper selectively focuses on different aspects of cancer risk and its manifested metaphors, aesthetics, and perceptions. The different categories of cancer risk freely interact, derive an important part of their meaning from the context of the doctor-cancer patient relationship, and are created and navigated by the cancer narrative.

This paper is based on fieldwork done from 1996-1999 in different locations among village communities from Central Anatolia afflicted with the deadly malignancy of mesothelioma. Medical research has long established the relationship between mesothelioma and the environment; yet in earlier work correlations deduced through my genealogies provide evidence of a possible genetic cofactor causing these cancer deaths. This paper illustrates how medical research becomes an arena for local and global political interests and how the disruption of the doctor-cancer patient relationship impedes medical research. Methods include illness and clinical narratives, kinship charts and pedigrees, and observation of involved doctors and patients in multiple sites and geographical locations. Under focus are the anthropologist's involvement in global biomedical research and her interconnectedness with its political events.

Background: Uncontrolled hemorrhage accounts for the majority of deaths in combat. Effective topical hemostatic agents suitable for use on the battlefield may be valuable in controlling hemorrhage until definitive surgical intervention is possible. In an effort to identify a hemostatic agent suitable for battlefield use, we evaluated several potential hemostatic agents in a swine injury model and noted thermal injury to tissues with a granular mineral hemostatic agent (QuikClot)., Methods: Anesthetized swine were maintained with a mean arterial pressure in excess of 60 mm Hg. Cutaneous, muscular, hepatic, splenic, venous, and arterial wounds were created in a standardized fashion. Topical hemostatic agents were immediately applied to the wounds and the amount of bleeding and time to hemostasis were noted., Results: The results reported here are part of a larger study in which a variety of hemostatic agents were evaluated. Only the findings related to the granular mineral hemostatic agent are discussed here. Application of the agent resulted in elevated tissue surface temperatures in excess of 95 degrees C and internal tissue temperatures exceeding 50 degrees C, 3 mm deep to the bleeding surface. Necrosis of fat and muscle were noted as well as full and partial thickness cutaneous burns., Conclusions: Topical administration of a granular mineral hemostatic agent to a variety of wounds in an experimental swine model resulted in thermal tissue injury and necrosis. Suggestions for reducing the extent of injury with this product are offered.

Both asbestos and erionite related malignant pleural mesothelioma (MPM) is a serious health problem in Turkey. Erionite has a higher potency in the lung than asbestos and familial clustering of malignant mesothelioma suggests a genetic predisposition to this cancer among affected individuals. Neither Simian virus 40 (SV40) nor human herpes virus 8 (HHV-8) are co-factors in the pathenogenesis of environmentally induced mesothelioma. A survival advantage has been demonstrated in patients with asbestos-induced mesothelioma compared with erionite-induced mesothelioma. This together with the proliferation index (PI) can be used as an independent prognostic factor for patients with malignant pleural mesothelioma. It is envisaged that the application of these prognostic approaches together with the new TNM staging system will allow investigations to be more precisely carried out and evaluated.

Background: Malignant mesothelioma (MM) is a fatal neoplasm which frequently results from exposure to asbestos or erionite., Method: Sixty-seven patients with MM were seen between 1990 and 2001. Their clinical and radiological features, as well as the therapy, were retrospectively evaluated., Results: In 51 patients (76.1%), the MM was confined to the pleura, in 14 patients it was exclusively peritoneal and in two patients, it involved both areas. Of the 67 cases, 35 (52.2%) were women. The mean (+/- SD) age for all cases was 57.6+/-11.5 years. Dyspnea (67.2%), cough (55.2%) and chest pain (50.7%) were the most frequent symptoms of onset. Pleural effusion (92.4%) was the most common chest x-ray finding, whereas pleural effusion (60.8%), pleural nodules (34.7%) and pleural thickening (34.7%) were the most common computed tomography findings in pleural MM patients. The histological subtypes of MM were determined as epithelial in 60 patients (89.5%), sarcomatous in four patients (5.9%) and mixed in three patients (4.4%). Although 50.7% and 25.4% of the cases were exposed to erionite and asbestos, respectively, 23.9% of the cases recalled no exposure to asbestos or erionite. Exposures were environmental as opposed to occupational. Thirty-five patients (52.2%) were administered chemotherapy, and follow-up data were available for 22 patients. For these patients, the two-year survival rate was 22% and the two-year progression-free interval was 15.7%. There were no differences between patients with asbestos and erionite exposure., Conclusion: MM should be considered when exudative pleural effusion is detected in a patient who has been exposed to asbestos or erionite. MM is a major public health problem in parts of Turkey and compulsory environmental control of fibrous mineral should be considered.

Epidemiological data has demonstrated that environmental and/or occupational exposure to mineral particulates may result in the development of pulmonary fibrosis, bronchogenic carcinoma and malignant mesothelioma many years following exposure. It has been suggested that the genotoxic effects of fibrous particulates, such as asbestos, is due in part to the generation of reactive oxygen species (ROS) from iron associated with the particulates. However, the molecular mechanisms by which mineral particulates induce ROS that results in genotoxic damage remains unclear. The naturally occurring zeolites, erionite and mordenite share several physiochemical properties but they elicit very different biological responses, with erionite, a fibrous particulate, being highly toxic, and mordenite, a nonfibrous particulate, being relatively benign. We are using these natural zeolites as a model system to determine what physicochemical properties of these zeolites are responsible for their biological response(s) and to evaluate the parameters that influence these responses. The purpose of the present study was to determine the mutagenic potential of erionite and mordenite and to determine whether this mutagenic potential was modulated by iron. The results of this study using the Chinese hamster ovary cell line AS52 demonstrated that erionite was more cytotoxic than mordenite. However, the cytotoxicity of both zeolites was increased in the presence of physiological concentrations of ferrous chloride. Ferrous ions (5-20 microM) significantly (p<0.001) increased the cytotoxicity of mordenite, but only at the highest concentration (16 microg/cm(2)) of mordenite tested. Conversely, only the highest concentration (20 microM) of ferrous ion significantly (p<0.001) increased the cytotoxicity of erionite, but this enhanced cytotoxicity occurred over a wider concentration range (6-16 microg/cm(2)) of erionite. Mordenite was not mutagenic at any of the concentrations tested, and the mutagenic potential of mordenite was not enhanced by the addition of ferrous ion. Conversely, erionite was mutagenic in a dose-response manner at concentrations greater than 6 microg/cm(2) and the mutagenic potential of erionite was significantly enhanced by the addition of ferrous ions. These results suggest that while the cytotoxicity of mordenite and erionite may be related to the ability of these fibers to transport iron into a cell, the different coordination state of iron associated with the two fiber surfaces is critical for inducing genotoxic damage.

The carcinogenic activity of the enterosorbent optisorb (pure zeolite) and the biologically active food additive litovite [zeolite and rye brans (1:1)] based on zeolite-clinoptololite from the Kholinsk deposit was studied. The intrapleural three-fold administration of optisorb (20 mg x 3) to rats and the inclusion of optisorb (5% of the feed) and litovite (5 and 0.06%) into the feed showed that these agents had no carcinogenic activity.

Environmental and/or occupational exposure to minerals, metals, and fibers can cause lung diseases that may develop years after exposure to the agents. The presence of toxic fibers such as asbestos in the environment plus the continuing development of new mineral or vitreous fibers requires a better understanding of the specific physical and chemical features of fibers/particles responsible for bioactivity. Toward that goal, we have tested aluminosilicate zeolites to establish biological and chemical structure-function correlations. Zeolites have known crystal structure, are subject to experimental manipulation, and can be synthesized and controlled to produce particles of selected size and shape. Naturally occurring zeolites include forms whose biological activity is reported to range from highly pathogenic (erionite) to essentially benign (mordenite). Thus, we used naturally occurring erionite and mordenite as well as an extensively studied synthetic zeolite based on faujasite (zeolite Y). Bioactivity was evaluated using lung macrophages of rat origin (cell line NR8383). Our objective was to quantitatively determine the biological response upon interaction of the test particulates/fibers with lung macrophages and to evaluate the efficacy of surface iron on the zeolites to promote the Fenton reaction. The biological assessment included measurement of the reactive oxygen species by flow cytometry and chemiluminescence techniques upon phagocytosis of the minerals. The chemical assessment included measuring the hydroxyl radicals generated from hydrogen peroxide by iron bound to the zeolite particles and fibers (Fenton reaction). Chromatography as well as absorption spectroscopy were used to quantitate the hydroxyl radicals. We found that upon exposure to the same mass of a specific type of particulate, the oxidative burst increased with decreasing particle size, but remained relatively independent of zeolite composition. On the other hand, the Fenton reaction depended on the type of zeolite, suggesting that the surface structure of the zeolite plays an important role.

Asbestos deposits have been used locally by the rural inhabitants of Central and Southeastern Anatolia for domestic purposes for many years. Mineralogical analysis revealed that tremolite is the most prominent asbestos type found in the region. There is in addition another mineral fiber found particularly in three villages located in the Cappadocian region of Central Anatolia (zeolite villages). This is a non-asbestos mineral, which has been identified as the fibrous zeolite, erionite. This fiber is present in the volcanic tuffs, which are used as building stone. Hence, exposure to erionite fibers is always possible in the houses, annexes, and streets of the villages. It has been demonstrated that both asbestos and erionite cause a variety of benign and malignant chest diseases. Among the diseases, calcified pleural plaques (CPP) are the most frequently seen and may be used as an indicator of mineral fiber exposure. Asbestos and erionite exposure are the main causes of malignant mesotheliomas in Turkey. In zeolite villages malignant mesothelioma is responsible for more than 50% of the total deaths. A recent study showed that simian virus 40 is not a cofactor in the pathogenesis of environmental malignant mesothelioma in Turkey. An additional recent genetic-epidemiological study showed that there are some families, which are genetically predisposed to mesothelioma.

About 80% of malignant mesotheliomas (MM) in the Western World develop in individuals with higher than background exposure to asbestos. Only a fraction of those exposed to asbestos develop mesothelioma, indicating that additional factors play a role. Simian virus 40 (SV40), a DNA tumor virus that preferentially causes mesothelioma in hamsters, has been detected in several human mesotheliomas. The expression of the SV40 large tumor antigen in mesothelioma cells, and not in nearby stromal cells, and the capacity of antisense T-antigen treatment to arrest mesothelioma cell growth in vitro suggest that SV40 contributes to tumor development. The capacity of T-antigen to bind and inhibit cellular p53 and retinoblastoma (Rb)-family proteins in mesothelioma, together with the very high susceptibility of human mesothelial cells to SV40-mediated transformation in vitro, supports a causative role of SV40 in the pathogenesis of mesothelioma. Asbestos appears to increase SV40-mediated transformation of human mesothelial cells in vitro, suggesting that asbestos and SV40 may be cocarcinogens. p53 mutations are rarely found in mesothelioma; p16, p14ARF, and NF2 mutations/losses are frequent. Recent studies revealed the existence of a genetic factor that predisposes affected individuals to mesothelioma in the villages of Karain and Tuzkoy, in Anatolia, Turkey. Erionite, a type of zeolite, may be a cofactor in these same villages, where 50% of deaths are caused by mesothelioma. Mesothelioma appears to have a complex etiology in which environmental carcinogens (asbestos and erionite), ionizing radiation, viruses, and genetic factors act alone or in concert to cause malignancy., (Copyright 2002 by W.B. Saunders Company.)

The study was conducted to evaluate the effect of the long-term dietary use of a natural zeolite (clinoptilolite, NZ) on health status and reproductive performance of sows/gilts and performance of their litters, along with its compatibility with antibacterials (chlortetracycline, CTC) periodically used in medication programmes. Two hundred and forty sows/gilts and their litters were assigned to two main experimental groups and four subgroups, depending on the inclusion of NZ and CTC in their feed. During the trial, frequent sampling of pregnancy feed for mycotoxicological analysis revealed a high contamination level with zearalenone. No adverse or side effects attributed to NZ were noticed. Furthermore, the combined use of NZ and CTC revealed no clinically apparent interactive effect on the availability of the latter. Reproductive performance was significantly improved by the dietary inclusion of both NZ and CTC. The results also suggested that the beneficial effect of NZ could be additionally considered as an indicator of the amelioration of zearalenone exposure consequences.

Environmental exposure to tremolite and erionite causes endemic diseases of the lung and pleura in Turkey. This study aimed to evaluate the impact of these exposures and further occupational exposures on fibre-related diseases in Turkish immigrants living in Belgium. The study included 51 males and 17 females that emigrated < 1-38 yrs ago. Most of them (n=46) had nonmalignant pleural lesions, one had asbestosis and one had mesothelioma. Environmental asbestos exposure was likely for the majority of patients (60%), but there were also reports of possible occupational asbestos (n = 14) and erionite (n = 2) exposure. Tremolite was the main fibre type in bronchoalveolar lavage fluid (BALF). Elevated concentrations of amosite or crocidolite were detected in only two patients. The delay elapsed since the end of the environmental exposure had no influence on the asbestos body or the tremolite fibre concentrations in the BALF of Turkish immigrants. Most fibre-related diseases in Turkish immigrants are probably due to environmental rather than occupational exposure. Precise information about geographical origin and occupation should be obtained when investigating these patients. Mineralogical analysis of bronchoalveolar lavage fluid gives valuable information on the type and intensity of exposure, especially in patients with both environmental and occupational exposure.

Natural silicate materials, including zeolite clinoptilolite, have been shown to exhibit diverse biological activities and have been used successfully as a vaccine adjuvant and for the treatment of diarrhea. We report a novel use of finely ground clinoptilolite as a potential adjuvant in anticancer therapy. Clinoptilolite treatment of mice and dogs suffering from a variety of tumor types led to improvement in the overall health status, prolongation of life-span, and decrease in tumors size. Local application of clinoptilolite to skin cancers of dogs effectively reduced tumor formation and growth. In addition, toxicology studies on mice and rats demonstrated that the treatment does not have negative effects. In vitro tissue culture studies showed that finely ground clinoptilolite inhibits protein kinase B (c-Akt), induces expression of p21WAF1/CIP1 and p27KIP1 tumor suppressor proteins, and blocks cell growth in several cancer cell lines. These data indicate that clinoptilolite treatment might affect cancer growth by attenuating survival signals and inducing tumor suppressor genes in treated cells.

Objective: The aim of the present study was to evaluate the pericardial involvement in patients with malignant mesothelioma caused by exposure to different minerals., Methodology: Forty-two patients (mean age of 52 +/- 12 years) with malignant mesothelioma were examined with transthoracic echocardiography. Thirty-three (78.9%) patients had a history of environmental exposure to asbestos and nine (21.4%) had a history of environmental exposure to erionite., Results: In 19 (45.2%) patients with malignant pericardial mesothelioma, pericardial involvement was determined by echocardiography. The other 23 (54.8%) patients had no pericardial involvement. Pericardial effusion was detected in nine (64.3%) patients and pericardial effusion was small in six (14.3%) patients, moderate in one (2.4%) patient and large in two patients. Thickening of the pericardium was observed in eight (19%) patients. In another two (7.1%) patients pericardial calcification was observed. Among the 33 patients who had been exposed to asbestos, 15 (45.5%) had pericardial involvement, and among the nine patients with a history of exposure to erionite, four (44.4%) had pericardial involvement. There was no difference in terms of pericardial involvement in different stages of the tumour (P > 0.05)., Conclusions: Pericardial involvement is commonly seen in patients with malignant mesothelioma. Among patients exposed to asbestos or zeolite there was no difference in terms of pericardial involvement. Furthermore, pericardial involvement was not related with the stage of the tumour.

The effects of samples of crystalline quartz, diatomaceous earth, mordenite and clinoptilolite were investigated in vitro (as concerns erythrocyte haemolysis and lactate dehydrogenase (LDH) release from peritoneal macrophages) and in vivo (on LDH, protein and phospholipids in rat bronchoalveolar lavage (BAL), and phospholipids in rat lung tissue). The respirable mineral samples were instilled intratracheally. Determinations in the BAL were carried out after 15, 60 and 180 days, and in the lung tissue after 90, 180 and 360 days. Quartz DQ and quartz FQ induced acute, subacute and chronic inflammation and progressive fibrosis. However, due to the Al2O3 contamination on the surface of the particles quartz FQ caused a delayed response in vivo. Diatomaceous earth produced acute/subacute inflammation that gradually became more moderate after 60 days. Clinoptilolite was inert, whereas the other zeolite sample, mordenite, was cytotoxic in vivo. The reason for this was presumably the needle and rod-shaped particles in the mordenite samples. The investigation revealed that different in vitro and in vivo methods canprovide valuable data concerning the pulmonary toxicity of minerals.

The incidence of malignant mesothelioma is extremely high in some Turkish villages where there is a low-level environmental exposure to erionite, a fibrous zeolite. The best known example is the village of Karain. However, since epidemiological studies are difficult to perform in Turkey, the incidence and the dose-response curve have not been thoroughly examined. A small cohort of immigrants from Karain who have lived in Sweden for many years were studied. Exposure data, i.e. the time residing in Karain, and hospital records including pathological diagnosis, were recorded. The cohort consisted of 162 people. During the observation time, 18 deaths occurred, 14 (78%) of which were due to malignant pleural mesothelioma. In addition, there were five patients with mesothelioma who were still alive, one of whom had a peritoneal mesothelioma. Thus, the risk of mesothelioma is 135-times and 1,336-times greater in males and females, respectively, than for the same sex and age groups in Sweden. The risk increased with duration of residence.