Silica and renal diseases: no longer a problem in the 21st century?

Silicosis and other occupational diseases are still important even in the most developed countries. In fact, at present, silica exposure may be a risk factor for human health not only for workers but also for consumers. Furthermore, this exposure is associated with many other different disorders besides pulmonary silicosis, such as progressive systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis, dermatomyositis, glomerulonephritis and vasculitis. The relationships between these silica-related diseases need to be clarified, but pathogenic responses to silica are likely to be mediated by interaction of silica particles with the immune system, mainly by activation of macrophages. As regards renal pathology, there is no single specific clinical or laboratory finding of silica-induced nephropathy: renal involvement may occur as a toxic effect or in a context of autoimmune disease, and silica damage may act as an additive factor on an existing, well-established renal disease. An occupational history must be obtained for all renal patients, checking particularly for exposure to silica, heavy metals, and solvents.     

Epidemiology,Staging, Grading,and Risk Stratification of Bladder Cancer

ContextUnderstanding the epidemiology and risk factors for non–muscle invasive bladder cancer (NMIBC) can assist in the prevention and early detection of the disease. Furthermore, staging, grading, and risk stratification are critical for determining the most appropriate management strategies for NMIBC based on risk of recurrence and progression.ObjectiveTo provide community urologists with an overview of the epidemiology of NMIBC as well as current approaches to staging, grading, and risk stratification.Evidence acquisitionA committee of internationally renowned leaders in bladder cancer management, known as the International Bladder Cancer Group (IBCG), identified current key influencing guidelines and published English-language literature related to the epidemiology, staging, and grading of NMIBC available as of March 2008. The IBCG met on four occasions to review the main findings of the identified literature and the current clinical practice guidelines of the European Association of Urology (EAU), the First International Consultation on Bladder Tumors (FICBT), the National Comprehensive Cancer Network (NCCN), and the American Urological Association (AUA).Evidence synthesisBased on this review, the IBCG provided a summary on the epidemiology of NMIBC and recommendations for the staging, grading, and risk stratification of the disease.ConclusionsUrologists should record the smoking habits of patients and monitor for possible occupational exposure to urothelial carcinogens. The tumour-node-metastases (TNM) classification for tumour staging and both the World Health Organization (WHO) 1973 and 2004 grading systems should be applied for appropriate staging and grading of NMIBC. Urologists should also consider the use of the European Organisation for Research and Treatment of Cancer (EORTC) risk tables for risk stratification of NMIBC based on risk of disease recurrence and progression.     

Occupational exposure in ANCA-positive patients: a case-control study

BACKGROUND: Antineutrophil cytoplasmic autoantibodies (ANCA) are valuable biomarkers for the diagnosis and follow-up of small vessel vasculitis. The role of ANCA has not yet been fully established, but genetic, infectious, and/or environmental factors may increase susceptibility to these diseases. We performed an epidemiologic study to investigate whether the presence of ANCA was associated with silica or any other form of occupational exposure, regardless of the underlying disease. METHODS: All consecutive ANCA-positive patients recorded at the institution's Laboratory of Immunology between 1990 and 2000 were included. Patients hospitalized in a unit of internal medicine matched for age and gender were selected as controls (two controls/case). Qualitative and semiquantitative professional exposure and smoking habits were analyzed by five experts blind to the diagnosis. RESULTS: Univariate analysis showed that patients who reported dust exposure had a 2.6 greater risk of being ANCA-positive (P= 0.007) (odds ratio 2.6; 95% CI 1.3 to 5.3) and individuals with professional exposure to silica had a 3.4 higher risk of being ANCA-positive (P= 0.03) (odds ratio 3.4; 95% CI 1.1 to 9.9). None of the other environmental factors or smoking habits were different between ANCA-positive patients and controls. There was no difference in silica exposure between patients with cytoplasmic ANCA (c-ANCA), perinuclear ANCA (p-ANCA), or atypical ANCA. Semiquantitative analysis showed a dose effect of silica exposure with a nearly sevenfold greater risk of being ANCA-positive compared to controls (P= 0.02) (odds ratio 6.9; 95% CI 1.3 to 35.1). CONCLUSION: These results support the hypothesis that the presence of ANCA in plasma might at least partially be related to occupational exposure.     

Direct Health Care Costs of Occupational Asthma in Spain: An Estimation From 2008

BACKGROUND: Occupational asthma is the most common work-related disease in industrialized countries. In 2008, only 556 cases of occupational asthma had been diagnosed in Spain, which is quite far from even the most conservative estimates. In this context, the aim of this paper is to estimate the number of asthma cases attributable to the work setting in Spain in 2008 as well as the related health care costs for the same year. METHODS: The number of cases of occupational asthma was calculated from estimates of attributable risk given by previous studies. The cost estimation focused on direct health-care costs and it was based both on data from the National Health System's (NHS) analytical accounting and from secondary sources. RESULTS: The number of prevalent cases of work-related asthma in Spain during 2008 ranges between 168,713 and 204,705 cases based on symptomatic diagnosis, entailing an associated cost from 318.1 to 355.8 million Euros. These figures fall to a range between 82,635 and 100,264 cases when bronchial hyperreactivity is included as a diagnostic criterion, at a cost of 155.8 to 174.3 million Euros. Slightly more than 18 million Euros represent the health-care costs of those cases requiring specialized care. CONCLUSIONS: Estimations of occupational asthma are very relevant to adequately prevent this disease. The treatment of occupational asthma, which involves a significant cost, is being financed by the NHS, although it should be covered by Social Security.     

Berufsbedingte Hauterkrankungen—Paradigma der Sekundärprävention

The dermatologist's procedure was introduced in 1972 by employers' liability insurance funds in the industrial, agricultural and public sectors of Germany's statutory occupational accident insurance as a "procedure for early detection of occupational skin diseases". So far, it is still the most relevant tool for secondary prevention in occupational dermatology in Germany. According to the intention of this procedure, insured persons with a skin disease in which an occupational aetiology is suspected must be offered preventive measures and, if necessary, given appropriate treatment to avoid their losing their jobs. On the initiative of the Central Federation of Industrial Professional Associations (HVBG), a study group was set up in 1999 from among its membership in cooperation with the Working Committee of Occupational and Environmental Dermatology (ABD) and the Professional Organisation of German Dermatologists (BVDD) to improve on the efficiency of the "classic" dermatologist's procedure. The proposed "optimised" dermatologist's procedure is based on the assumption that early detection followed by competent and intensified skin protection and skin care will be successful in retarding or stopping the progression of occupational dermatoses, while later treatment is likely to be less effective. In October 2002, a pilot study started in Northwest Germany to establish by scientific evaluation whether the implementation of secondary protective measures is definitively better when the provisional "optimised" dermatologist's procedure is followed. The study results should allow detailed suggestions for an improved dermatologist's procedure before it is introduced nationwide.     

Silicosis in Artificial Quartz Conglomerate Workers

IntroductionSilicosis is a chronic progressive disease caused by inhalation of crystalline silica. Most cases develop in underground mine workers and in subjects involved in the extraction of natural stone (slate and granite). In view of the progressive emergence of new cases of silicosis in artificial quartz conglomerate workers, we performed a study to analyze the characteristics of silicosis produced by this new agent in Spain.MethodsThe study consisted of a series of 96 cases of silicosis diagnosed according to international criteria during the period 2010–2017. We analyzed clinical, radiological, pathological and functional characteristics.ResultsMean age of participants was 45 years; 55% had simple silicosis and 45% had complicated silicosis. Ten patients were diagnosed with accelerated silicosis, with a mean age of 33 years. Mean time of exposure to conglomerates was 15 years, and 77% had not used appropriate protection measures. Half of the patients were asymptomatic and presented different classic forms on chest X-ray and chest high-resolution computed tomography, along with ground-glass images. No lung function changes were recorded.ConclusionsSilicosis in artificial quartz conglomerate workers occurs in a young, actively employed population, a considerable percentage of whom present an accelerated form. They have few symptoms and no functional limitations. Protection measures are scarce. It is important to characterize these features to provide early diagnosis and implement the necessary preventive measures.     

Crystalline silica exposure, radiological silicosis, and lung cancer mortality in diatomaceous earth industry workers.

BACKGROUND: The role of silicosis as either a necessary or incidental condition in silica associated lung cancer remains unresolved. To address this issue a cohort analysis of dose-response relations for crystalline silica and lung cancer mortality was conducted among diatomaceous earth workers classified according to the presence or absence of radiological silicosis. METHODS: Radiological silicosis was determined by median 1980 International Labour Organisation system readings of a panel of three "B" readers for 1809 of 2342 white male workers in a diatomaceous earth facility in California. Standardised mortality ratios (SMR) for lung cancer, based on United States rates for 1942-94, were calculated separately for workers with and without radiological silicosis according to cumulative exposures to respirable crystalline silica (milligrams per cubic meter x years; mg/m3-years) lagged 15 years. RESULTS: Eighty one cases of silicosis were identified, including 77 with small opacities of > or = 1/0 and four with large opacities. A slightly larger excess of lung cancer was found among the subjects with silicosis (SMR 1.57, 95% confidence interval (CI) 0.43 to 4.03) than in workers without silicosis (SMR 1.19, 95% CI 0.87 to 1.57). An association between silica exposure and lung cancer risk was detected among those without silicosis; a statistically significant (p = 0.02) increasing trend of lung cancer risk was seen with cumulative exposure, with SMR reaching 2.40 (95% CI 1.24 to 4.20) at the highest exposure level (> or = 5.0 mg/m3-years). A similar statistically significant (p = 0.02) dose-response gradient was observed among non-silicotic subjects when follow up was truncated at 15 years after the final negative radiograph (SMR 2.96, 95% CI 1.19 to 6.08 at > or = 5.0 mg/m3-years), indicating that the association among non-silicotic subjects was unlikely to be accounted for by undetected radiological silicosis. CONCLUSIONS: The dose-response relation observed between cumulative exposure to respirable crystalline silica and lung cancer mortality among workers without radiological silicosis suggests that silicosis is not a necessary co-condition for silica related lung carcinogenesis. However, the relatively small number of silicosis cases in the cohort and the absence of radiographic data after employment limit interpretations.     

Biological dust exposure in the workplace is a risk factor for chronic obstructive pulmonary disease

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality. Although the main risk factor is smoking, 15-19% of COPD even in smokers has been attributed to occupational exposures. The aim of this study was to investigate the association between occupational exposure and risk of COPD. METHODS: Participants were part of a cross sectional study of risk factors for COPD. A total of 1232 completed a detailed respiratory questionnaire, spirometric testing and measurement of gas transfer. Job histories were coded according to the International Standard Classification of Occupations. These codes were then used to establish occupational exposures using the ALOHA job exposure matrix. RESULTS: The prevalence of emphysema was 2.4%, chronic obstructive bronchitis 1.8%, and COPD 3.4%. Subjects ever exposed to biological dusts had an increased risk of chronic obstructive bronchitis (OR 3.19; 95% CI 1.27 to 7.97), emphysema (OR 3.18; 95% CI 1.41 to 7.13), and COPD (OR 2.70, 95% CI 1.39 to 5.23). These risks were higher in women than in men. For biological dust, the risk of emphysema and COPD was also significantly increased in both the duration of exposure categories, again in women but not in men. No significant increased risks for COPD were found for mineral dust (OR 1.13; 95% CI 0.57 to 2.27) or gases/fumes (OR 1.63; 95% CI 0.83 to 3.22). CONCLUSION: In this general population sample of adults, occupational exposures to biological dusts were associated with an increased risk of COPD which was higher in women. Preventive strategies should be aimed at reducing exposure to these agents in the workplace.     

Hypertension and kidney disease

The relationship between chronic kidney disease and hypertension remains enigmatic and a matter of considerable clinical and academic interest, with evidence suggesting that hypertension is both a cause and a consequence of kidney disease. The kidney has a pivotal role in setting the blood pressure in any individual, and this is likely to be related to that individual's sensitivity to salt. The relationship between low birth weight and subsequent hypertension and kidney disease may be predicated on changes in post glomerular phenomena, including sodium transport, although there are differences observed between white and black populations, there being no such clear relationship demonstrable in the latter. Differences in vascular structure may account for some of this variation. There is , by way of example a considerable difference in the risk of death from cardiovascular disease between blacks and Caucasoid populations with renal disease, the former being at greater risk. International moves are now afoot to reduce dietary salt intake. Successful efforts to reduce blood pressure by these or by pharmacological means are likely to reduce death rates, although precise blood pressure targets remain an elusive concept. The possible role of non muscular heavy chain type II isoform A protein which is associated with non diabetic chronic kidney disease in subjects of African ancestry remains to be determined.     

Occupational diseases in South African mines--a neglected epidemic?

A major difficulty in assessing incidence and prevalence of occupational diseases among the workforce employed on South African mines is the lack of epidemiological data. Published and unpublished data were collated and analysed for the period 1915-1988 in order to provide insights into occupational disease trends. Using proxies for incidence rates, it was demonstrated that the rates of silicosis and tuberculosis were likely to be high. In the case of silicosis among black miners, disease was contracted in a relatively short period on average. The stabilisation of the black workforce on the mines, which started in 1975 and continues, is an important factor likely to lead to an increase in occupational disease rates. Recommendations for improved data reporting and research are made, in particular the need to identify occupational groups at high risk and the calculation of prevalences.     

Toxic solvents in car paints increase the risk of hearing loss associated with occupational exposure to moderate noise intensity

Solvents in car paints are a recognised source of occupational toxicity. In particular, they can cause DNA damage and occupational rhinobronchitis. However, little is known about their toxic effect in noise-induced hearing loss (NIHL) in humans. In this study, a 160 pure tone audiometric test was performed in workers in two independent factories to investigate whether toxic solvents in car paints can result in noise-induced hearing loss in workers exposed to moderate noise levels of less than 85 decibels (dB). It is shown that toxic solvents in car paints increase the risk associated with moderate noise exposure of less than 85 dB, with levels of NIHL being similar to those in workers exposed only to loud noises between 92.5 dB and 107 dB. Tinnitus and spells of dizziness were associated symptoms in all workers with NIHL, and asthma was an associated disease in workers with NIHL exposed to car paints and moderate noises simultaneously. These results may indicate that toxic solvents in car paints act in synergism with moderate noise exposure, damaging the cochlear hair cells. The results also constitute firm grounds for monitoring the hearing of these workers and adherence to strict regulations about wearing special gowns and filtered masks during working hours to protect against this preventable occupational disease.     

Individual and occupational risk factors for knee osteoarthritis – Study protocol of a case control study

Background  

Knee osteoarthritis (OA) is one of the frequent and functionally impairing disorders of the musculoskeletal system. In the literature, a number of occupational risk factors are discussed as being related to the development and progress of knee joint diseases, e.g. working in kneeling or squatting posture, lifting and carrying of heavy weights. The importance of the single risk factors and the possibility of prevention are currently under discussion. Besides the occupational factors, a number of individual risk factors are important, too. The distinction between work-related factors and individual factors is crucial in assessing the risk and in deriving preventive measures in occupational health. In existing studies, the occupational stress is determined mainly by surveys in employees and/or by making assumptions about individual occupations. Direct evaluation of occupational exposure has been performed only exceptionally.     

Epidemiology of pancreatic cancer

Worldwide, over 200000 people die annually of pancreatic cancer. The highest incidence and mortality rates of pancreatic cancer are found in developed countries. In the United States, pancreatic cancer is the 4(th) leading cause of cancer death, and in Europe it is the 6th. Because of high fatality rates, pancreatic cancer incidence rates are almost equal to mortality rates. Pancreatic cancer is diagnosed late in the natural history of the disease, given the few early indicators of illness, and the lack of screening tests for this disease. Treatment has not improved substantially over the past few decades and has little effect on prolonging survival time. Therefore, prevention could play an important role in reducing pancreatic cancer mortality. International variations in rates and time trends suggest that environmental factors are likely to play a role in the etiology of pancreatic cancer. Variations in rates are substantial and occur even within industrialized nations. While rates have been stabilizing over the past 2 decades in many countries where they are already high, they continue to increase in countries where rates were relatively low 4 decades ago, such as Japan. In the US, the highest rates of pancreatic cancer incidence and mortality are observed among blacks, who have some of the highest rates in the world. A known cause of pancreatic cancer is tobacco smoking. This risk factor is likely to explain some of the international variations and gender differences. A number of studies observed a reduction in pancreatic cancer risk within a decade after smoking cessation, when compared to current smokers. With tobacco smoking as an exception, risk factors for pancreatic cancer are not well-established. Over the past 2 decades, epidemiological studies on pancreatic cancer have been plagued with methodological issues associated with studying a highly fatal disease, and inconsistent findings have hindered our understanding of the etiology of pancreatic cancer. Although familial pancreatic cancer is well-documented, the genes responsible for this condition have not been identified and are unlikely to explain more than 5-10% of all pancreatic cancer cases. Chronic pancreatitis and diabetes mellitus are medical conditions that have been consistently related to pancreatic cancer. Data from numerous studies suggest that these conditions are likely to be causally related to pancreatic cancer, rather than being consequences of the cancer. Recent cohort studies, which are less prone to biases than case-control studies, suggest that obesity increases the risk of pancreatic cancer. Other studies support the hypothesis that glucose intolerance and hyperinsulinemia are important in the development of pancreatic cancer. Other potential risk factors include physical inactivity, aspirin use, occupational exposure to certain pesticides, and dietary factors such as carbohydrate or sugar intake.     

Silicosis in non-mining industry on the Witwatersrand

Silicosis outside the mines in South Africa has received little legislative or public attention. Between 1972 and 1986 217 such cases were seen at the National Centre for Occupational Health clinic, including 46 cases of progressive massive fibrosis. The relatively high proportion of cases of progressive massive fibrosis (21%), of patients less than or equal to 40 years at diagnosis (21% of blacks) and with exposures of less than or equal to 10 years (18%) indicate high silica exposures in industry. Four industries accounted for 83% of the cases--foundries, ceramics factories, refractories, and ore and stone crushing. Radiologically, readings of a mixture of rounded and irregular opacities were not uncommon (14%). Lymphadenopathy was very uncommon (less than 1%), while pleural thickening other than loss of the costophrenic angle was absent. Prevalences of symptoms, signs and lung function abnormality were high, probably owing to a range of factors other than silicosis. Cases of progressive massive fibrosis had significantly higher prevalences of these clinical abnormalities. When two separate lung function prediction equations were applied to the observed values in these cases, the number that met criteria for 'abnormality' differed. This finding has important implications for compensation. Recommendations include control of silica-using industries and careful occupational history-taking by clinicians.     

Predictors of bone fractures in a single-centre cohort of hemodialysis patients: a 2-year follow-up study

International Urology and Nephrology - Bone involvement represents one of the complications of end-stage chronic kidney disease, with fractures being its major risk. The aim of our study was to...     

Silica and glomerulonephritis: case report and review of the literature

A 54-year-old foundry worker with extensive silica exposure, but no pulmonary disease, developed the nephrotic syndrome and renal failure over a 3-month period. Renal biopsy demonstrated a proliferative glomerulonephritis; energy dispersive x-ray analysis detected silicon within the renal tubules. Measurements of respirable silica at the foundry revealed levels up to 2.5 times the current occupational standard. Similar glomerular disease has been reported in silica-exposed animals and workers with silicosis. This case suggests that clinicians should include silica exposure in the differential diagnosis of unexplained diffuse proliferative glomerulonephritis, renal disease may occur without clinically evident pulmonary disease in silica exposure, and silica-induced glomerulonephritis warrants further clinical and epidemiologic research.     

Wegener granulomatosis is associated to exposure to silicon compounds: a case-control study

Wegener granulomatosis is a rare disease of unknown aetiology.In the majority of these patients the kidney is involved inthe disease process. We performed a case-control study to evaluatethe role of occupational exposure in the development of Wegenergranulomatosis with renal involvement. The occupational historiesof 16 cases with clearly established diagnosis of Wegener granulomatosiswith renal involvement were compared with those of 32 age- andsex-matched controls. It was observed that inhalation of silicon-containingcompounds such as silica and grain dust gave a nearly sevenfoldrisk for Wegener granulomatosis. Further epidemiological andexperimental work needs to be performed in order to corroboratethese findings.     

Compensating for occupational lung disease

Workers' compensation for occupational lung disease in South Africa and in other countries is reviewed. Compensation legislation in South Africa has a long history of evolution, with important changes expected in the near future. The South African system is similar to that in other countries, but has some unique features. Problems for workers disabled by occupational lung disease include a limited range of compensable conditions, difficulty in establishing a diagnosis, delays in obtaining payment, and small amounts paid. International experience suggests that certain changes would be especially useful. Racial inequalities should be removed, the schedule of compensable occupational diseases needs to be extended, and presumptive standards should be developed for diagnosis and disability assessment.     

Hautkrebs durch UV-Licht

The potentially harmful effects of the sun were recognized early on and we even know of a publication on sunlight-induced skin cancer dating back to the year 1875. In 1992, the International Agency for Research on Cancer classified sunlight as causal in malignant skin diseases. Until recently, the southern hemisphere in particular was burdened with a high incidence of skin diseases; however, cases are now rapidly increasing also in the northern hemisphere due to changes in the ozone layer. The increased occupation-specific risk for certain occupational groups (“outdoor workers”) was already taken into account in the expert recommendations on occupational skin diseases with the supplement of a Part 2,“Skin cancers”. However, due to the distanced attitude of some socio-political decision-makers, a reliable basis for claim for the insured, which goes beyond the approval of individual cases according to §9 para. 2 of the German Social Security Code (SGB) VII, is a long time in the coming. A new occupational disease,“UV light-induced skin cancer”, would not only give the insured and assessors more legal assurance, but would also have a significant impact on prevention.     

Prevalence and clinical impact of systemic autoimmune rheumatic disease in patients with silicosis

BackgroundSilicosis is associated with an increased risk of developing systemic autoimmune rheumatic disease (SARD). The prognostic implications of this association are poorly characterized. The aim of this study was to determine the prevalence of SARD and autoimmune markers in a cohort of patients with exposure to silica and assess their impact on prognosis.MethodWe performed a prospective observational study of all patients attending the dedicated silicosis clinic of our pulmonology unit between 2009 and December 2017. Diagnosis was confirmed by a rheumatologist according to Spanish Rheumatology Society criteria. Autoimmune markers, pulmonary function tests, radiological progression, visits to the emergency department and primary care center, and hospital admissions for respiratory causes, and mortality were analyzed.ResultsOverall, 489 cases of silicosis and 95 cases of exposure were studied. In total, 54 (11.0%) patients with silicosis had SARD: 12 (2.4%) rheumatoid arthritis, 10 (2.0%) systemic lupus erythematosus, 10 (2.0%) systemic sclerosis, 3 (0.6%) Sjögren syndrome, 2 (0.4%) vasculitis associated with anti-neutrophil cytoplasmic antibodies (ANCA +), 6 (1.2%) psoriatic arthritis, 3 (0.6%) ankylosing spondylitis, and 8 (1.6%) other autoimmune diseases with no special features. The patients with SARD visited the emergency room more often (63.0% vs. 42.5%; p = 0.004), and progressed more rapidly (22.2 vs. 11.7%; p = 0.030).ConclusionsThe presence of systemic rheumatic autoimmune diseases involves radiological progression and a higher clinical impact.