Dose-response relationship between lung function and chest imaging response to silica exposures in artificial stone manufacturing workers.

BACKGROUND: Occupational exposure to artificial stone, a popular material used for countertops, can cause accelerated silicosis, but the precise relationship between silica dose and disease development is unclear. OBJECTIVES: This study evaluated the impact of silica exposure on lung function and chest imaging in artificial stone manufacturing workers. METHODS: Questionnaire and spirometry assessments were administered to workers in two plants. A high-exposure subset underwent further evaluation, including chest CT and DLco. Weighting factors, assigned as proxies for silica exposure, were based on work tasks. Individual cumulative exposures were estimated using area concentration measurements and time spent in specific areas. Exposure-response associations were analyzed using linear and logistic regression models. RESULTS: Among 65 participants, the mean cumulative silica exposure was 3.61 mg/m3-year (range 0.0001 to 44.4). Each 1 mg/m3-year increase was associated with a 0.46% reduction in FVC, a 0.45% reduction in FEV1, and increased lung function abnormality risk (aOR = 1.27, 95% CI = 1.03-1.56). Weighting factors correlated with cumulative exposures (Spearman correlation = 0.59, p < 0.0001), and weighted tenure was associated with lung function abnormalities (aOR = 1.04, 95% CI = 1.01-1.09). Of 37 high-exposure workers, 19 underwent chest CT, with 12 (63%) showing abnormal opacities. Combining respiratory symptoms, lung function, and chest X-ray achieved 91.7% sensitivity and 75% specificity for predicting chest CT abnormalities. CONCLUSION: Lung function and chest CT abnormalities occur commonly in artificial stone workers. For high-exposure individuals, abnormalities on health screening could prompt further chest CT examination to facilitate early silicosis detection.

Physiology and Biomarkers for Surveillance of Occupational Lung Disease.

Respiratory surveillance is the process whereby a group of exposed workers are regularly tested (or screened) for those lung diseases which occur as a result of a specific work exposure. Surveillance is performed by assessing various measures of biological or pathological processes (or biomarkers) for change over time. These traditionally include questionnaires, lung physiological assessments (especially spirometry), and imaging. Early detection of pathological processes or disease can enable removal of a worker from a potentially harmful exposure at an early stage. In this article, we summarize the physiological biomarkers currently used for respiratory surveillance, while commenting on differences in interpretative strategies between different professional groups. We also briefly review the many new techniques which are currently being assessed for respiratory surveillance in prospective research studies and which are likely to significantly broaden and enhance this field in the near future.

Asthma and landscape fire smoke: A Thoracic Society of Australia and New Zealand position statement.

Landscape fires are increasing in frequency and severity globally. In Australia, extreme bushfires cause a large and increasing health and socioeconomic burden for communities and governments. People with asthma are particularly vulnerable to the effects of landscape fire smoke (LFS) exposure. Here, we present a position statement from the Thoracic Society of Australia and New Zealand. Within this statement we provide a review of the impact of LFS on adults and children with asthma, highlighting the greater impact of LFS on vulnerable groups, particularly older people, pregnant women and Aboriginal and Torres Strait Islander peoples. We also highlight the development of asthma on the background of risk factors (smoking, occupation and atopy). Within this document we present advice for asthma management, smoke mitigation strategies and access to air quality information, that should be implemented during periods of LFS. We promote clinician awareness, and the implementation of public health messaging and preparation, especially for people with asthma.

Work-related asthma: A position paper from the Thoracic Society of Australia and New Zealand and the National Asthma Council Australia.

Work-related asthma (WRA) is one of the most common occupational respiratory conditions, and includes asthma specifically caused by occupational exposures (OA) and asthma that is worsened by conditions at work (WEA). WRA should be considered in all adults with asthma, but especially those with new-onset or difficult to control asthma. Improvement in asthma symptoms when away from work is suggestive of WRA. Clinical history alone is insufficient to diagnose WRA; therefore, objective investigations are required to confirm the presence of asthma and the association of asthma with work activities. Management of WRA requires pharmacotherapy similar to that of non-WRA, however, also needs to take into account control of the causative workplace exposure. Ongoing exposure will likely lead to decline in lung function and worsening asthma control. WRA is a preventable condition but this does rely on increased awareness of WRA and thorough identification and control of all potential occupational respiratory hazards.

Respiratory surveillance for coal mine dust and artificial stone exposed workers in Australia and New Zealand: A position statement from the Thoracic Society of Australia and New Zealand.

Coal mine lung dust disease (CMDLD) and artificial stone (AS) silicosis are preventable diseases which have occurred in serious outbreaks in Australia recently. This has prompted a TSANZ review of Australia's approach to respiratory periodic health surveillance. While regulating respirable dust exposure remains the foundation of primary and secondary prevention, identification of workers with early disease assists with control of further exposure, and with the aims of preserving lung function and decreasing respiratory morbidity in those affected. Prompt detection of an abnormality also allows for ongoing respiratory specialist clinical management. This review outlines a medical framework for improvements in respiratory surveillance to detect CMDLD and AS silicosis in Australia. This includes appropriate referral, improved data collection and interpretation, enhanced surveillance, the establishment of a nationwide Occupational Lung Disease Registry and an independent advisory group. These measures are designed to improve health outcomes for workers in the coal mining, AS and other dust-exposed and mining industries.

Artificial stone-associated silicosis: a rapidly emerging occupational lung disease.

INTRODUCTION: Artificial stone is an increasingly popular material used to fabricate kitchen and bathroom benchtops. Cutting and grinding artificial stone is associated with generation of very high levels of respirable crystalline silica, and the frequency of cases of severe silicosis associated with this exposure is rapidly increasing. AIM: To report the characteristics of a clinical series of Australian workers with artificial stone-associated silicosis. METHODS: Respiratory physicians voluntarily reported cases of artificial stone-associated silicosis identified in their clinical practices. Physicians provided information including occupational histories, respiratory function tests, chest radiology and histopathology reports, when available. RESULTS: Seven male patients were identified with a median age of 44 years (range 26-61). All were employed in small kitchen and bathroom benchtop fabrication businesses with an average of eight employees (range 2-20). All workplaces primarily used artificial stone, and dust control measures were poor. All patients were involved in dry cutting artificial stone. The median duration of exposure prior to symptoms was 7 years (range 4-10). Six patients demonstrated radiological features of progressive massive fibrosis. These individuals followed up over a median follow-up period of 16 months (IQR 21 months) demonstrated rapid decline in prebronchodilator forced expiratory volume in 1 s of 386 mL/year (SD 204 mL) and forced vital capacity of 448 mL/year (SD 312 mL). CONCLUSIONS: This series of silicosis in Australian workers further demonstrates the risk-associated high-silica content artificial stone. Effective dust control and health surveillance measures need to be stringently implemented and enforced in this industry.

Coal workers' pneumoconiosis: an Australian perspective.

Coal workers' pneumoconiosis (CWP) is an untreatable but preventable lung disease arising from chronic inhalation of coal dust. Recent reports of CWP in Queensland, along with international data, suggest that there is a resurgence in pneumoconiosis. The prevalence of CWP varies considerably between countries. In Australia, there is no mandatory reporting system and no national data on the prevalence of CWP. The symptoms and manifestations of CWP vary depending on the composition of the inhaled dust, duration of exposure, stage of disease and host-related factors. CWP may develop into progressive massive fibrosis (PMF), which can be fatal. Radiological assessment should be performed according to evidence-based standards using the ILO (International Labour Office) International Classification of Radiographs of Pneumoconioses. As preventing exposure to coal dust prevents CWP, it is important to implement and enforce appropriate standards limiting exposure. In Australia, these standards currently vary between states and are not in keeping with international understanding of the levels of coal dust that cause disease. Longitudinal screening programs are crucial for monitoring the health of coal workers to identify individuals with early-stage disease and prevent progression from mild disease to PMF. We recommend: standardisation of coal dust exposure limits, with harmonisation to international regulations; implementation of a national screening program for at-risk workers, with use of standardised questionnaires, imaging and lung function testing; development of appropriate training materials to assist general practitioners in identifying pneumoconiosis; and a system of mandatory reporting of CWP to a centralised occupational lung disease register.

Asbestos exposure during home renovation in New South Wales.

OBJECTIVE: Asbestos exposure is causally associated with the development of malignant mesothelioma (MM), which is increasingly being reported after exposure to asbestos fibro sheeting in Australia. In this study, we investigate self-reported non-occupational asbestos exposure during home renovation in New South Wales. DESIGN AND SETTING: Cross-sectional mailed questionnaire examining renovation activity, tasks undertaken during renovation and self-reported exposure to asbestos among respondents and their family members in NSW between January and June 2008. PARTICIPANTS: 10 000 adults aged 18-99 years, randomly selected from the NSW electoral roll. We received 3612 responses, while 365 questionnaires did not reach addressees, giving an overall response rate of 37.5%. MAIN OUTCOME MEASURES: Differences in self-reported asbestos exposure between do-it-yourself (DIY) and non-DIY renovators. RESULTS: 1597 participants (44.2%) had renovated their home and among these, 858 participants (53.7%) self-reported as DIY renovators. Of these, 527 (61.4%) reported asbestos exposure during home renovations, 337 (39.3%) reported that their partner had been exposed to asbestos during renovations, and 196 (22.8%) reported that their children had been exposed. More than 20% of renovators planned to further renovate their current homes within the next 5 years. CONCLUSIONS: Self-reported asbestos exposure during home renovation is common. This preventable exposure could place adults and children at risk of MM many years into the future. Although such exposure is self-reported and ideally should be verified, this study identifies a potentially important problem in NSW.

Everolimus treatment of abdominal lymphangioleiomyoma in five women with sporadic lymphangioleiomyomatosis.

OBJECTIVE: Lymphangioleiomyomatosis (LAM) is a rare systemic disease of young women arising from mutations in the tuberous sclerosis complex (TSC) genes, TSC1 or TSC2. This disrupts the mammalian target of rapamycin (mTOR) pathway, affecting cellular proliferation and growth. mTOR inhibitors are a promising novel therapy in LAM. The mTOR inhibitor sirolimus is reported to produce resolution of lymphatic abnormalities in LAM, but the efficiacy of the mTOR inhibitor everolimus has not been assessed. We aimed to examine the efficacy of everolimus on lymphatic abnormalities in LAM. DESIGN, SETTING AND PARTICIPANTS: Open-label treatment of five patients with sporadic LAM (sLAM) and abdominopelvic and lung involvement at the outpatient LAM clinic of a tertiary city teaching hospital. Clinical data were collected during treatment of the women and included regular clinical reviews, everolimus levels, lung function and computed tomography assessment before and after 6 months of everolimus treatment. MAIN OUTCOME MEASURES: Symptoms and level of resolution of lymphangioleiomyomas. RESULTS: All five women experienced significant shrinkage or complete resolution of the lymphangioleiomyomas during treatment. In one woman, cessation of everolimus resulted in recurrence of symptoms. Adverse events were compatible with the known side-effect profile of everolimus, but overall the drug was well tolerated. CONCLUSIONS: This is the first report to suggest that everolimus has efficacy in the treatment of lymphangioleiomyoma and chylous ascites in sLAM.

Non-invasive biomarkers in exacerbations of obstructive lung disease.

BACKGROUND AND OBJECTIVE: Current methods of diagnosing exacerbations of asthma and chronic obstructive pulmonary disease (COPD) shed little light on their aetiology or pathophysiology. This study aimed to define the inflammatory biomarker profile of subjects with obstructive lung disease and to compare these with control subjects also with respiratory infections, using exhaled breath condensate (EBC) and induced sputum biomarker analysis. METHODS: EBC, induced sputum and C-reactive protein were collected from subjects with exacerbations of asthma (n = 28), exacerbations of COPD (n = 29) and otherwise healthy controls with symptoms of respiratory tract infection (n = 28). Subjects were tested again after recovery. EBC and induced sputum were analysed for protein, hydrogen peroxide, interferon gamma inducible protein-10 (IP-10), neopterin, interleukin (IL)-6, IL-8, leukotriene B4 and tumour necrosis factor (TNF)-α. Sputum cell counts and EBC pH were also analysed. RESULTS: EBC pH was significantly lower in exacerbation compared with recovery (5.54 0.07 vs 6.04 ± 0.08; P < 0.001). The novel markers IP-10 and neopterin were significantly increased in induced sputum supernatant (pooled groups pre and post exacerbation: IP-10: 188.6 ± 102.1 vs 5.40 ± 1.28 pg/mL, P = 0.006; neopterin: 15.81 ± 2.50 vs 5.38 ± 0.45 nmol/L, P < 0.0001), as was TNF-α (137.8 ± 49.64 vs 71.56 ± 45.03 pg/mL, P = 0.018). Few other biomarkers proved significantly different in exacerbation, although C-reactive protein was raised. CONCLUSIONS: Non-invasive biomarker assessment may provide useful information in exacerbation of obstructive lung diseases, particularly sputum IP-10 and neopterin and EBC pH.

A breath test for malignant mesothelioma using an electronic nose.

Malignant mesothelioma (MM) is a rare tumour which is difficult to diagnose in its early stages. Earlier detection of MM could potentially improve survival. Exhaled breath sampling of volatile organic compounds (VOCs) using a carbon polymer array (CPA) electronic nose recognises specific breath profiles characteristic of different diseases, and can distinguish between patients with lung cancer and controls. With MM, the potential confounding effect of other asbestos-related diseases (ARDs) needs to be considered. We hypothesised that as CPA electronic nose would distinguish patients with MM, patients with benign ARDs, and controls with high sensitivity and specificity. 20 MM, 18 ARD and 42 control subjects participated in a cross-sectional, case-control study. Breath samples were analysed using the Cyranose 320 (Smiths Detection, Pasadena, CA, USA), using canonical discriminant analysis and principal component reduction. 10 MM subjects created the training set. Smell prints from 10 new MM patients were distinguished from control subjects with an accuracy of 95%. Patients with MM, ARDs and control subjects were correctly identified in 88% of cases. Exhaled breath VOC profiling can accurately distinguish between patients with MM, ARDs and controls using a CPA electronic nose. This could eventually translate into a screening tool for high-risk populations.