[The assessment of asbestos exposure of mesothelioma cases registered in Italy: which problems more than thirty years after the birth of the first regional archives]. / La valutazione dell'esposizione ad amianto dei casi di mesotelioma maligno registrati in Italia: quali problematiche a più di trent'anni dalla nascita dei primi archivi regionali.

More than 30 years have passed since the beginning of the epidemiological surveillance of mesothelioma (MM). The Italian National Mesothelioma Register (ReNaM), part of the research department of the National Institute for insurance against industrial injuries (INAIL), has published 7 reports with the description of the cas-es concerning the assessment of diagnoses and exposures to asbestos suffered mainly during working activities but also environmental, in the family premises and during personal activities.Today we are witnessing a reduction in the commitment by some regions which negatively affects those who develop the pathology. Reading the ReNaM reports it emerges, among others, the problem of the delay in reporting new cases which limits the collection of information directly from patients. This contribution, discussing various topics, invites to develop a debate that should allow to update and resolve the critical aspects that arise after decades of activity regarding, in particular, the asbestos exposure assessment. It is the primary interest of the authors to give continuity and improve the ReNaM which remains the most prestigious MM register among those active in other countries.

Lung Cancer and Pleural Mesothelioma Risk Assessment for the General Population Exposed to Asbestos in Different Regions of Tehran, Iran.

BACKGROUND: Asbestos is a natural fiber leading to health risks like chronic lung diseases. The current study aimed to estimate pleural mesothelioma and lung cancer risk for population exposure to asbestos in Tehran, Iran. STUDY DESIGN: A cross-sectional study. METHODS: According to the annual report of Air Quality Control Company (AQCC), from 2011-2020, carcinogenic risk and mesothelioma were assessed based on the Environmental Protection Agency (EPA) method using the Monte Carlo simulation (MCS). The relative risk (RR) of mortality cancer was calculated based on Camus and colleagues' model. Moreover, mesothelioma risk was estimated by Bourgault and colleagues' model. RESULTS: The mean concentration and health risk of asbestos in ambient air generally reduced from 2011 to 2020. The highest mortality risk for lung cancer was 8.4 per 100000 persons in 2011 and reduced to 1.8 in 2017. For mesothelioma, the corresponding values were 8.96 per 100000 persons in 2011 and reduced to 1.92 in 2017. CONCLUSION: The findings of this study could be helpful to health policymakers in the management of asbestos risk.

Reconstruction of asbestos exposure in workers suffering from pleural neoplasms and employed in sectors not generally associated with high exposure levels: the importance of an accurate standardized assessment of occupational medicine.

INTRODUCTION: Malignant pleural mesothelioma onset in workers exposed to asbestos is well known with reference to multiple working sectors. In some cases, occurring among workers of sectors characterized by a presumed lower relevance of asbestos exposure, the absence of a well-defined correlation can prevent their emergence and compensation. To improve definition of these cases, this article underlines the importance of a standardized approach to occupational anamnesis. METHODS: Thorough standardized occupational health assessment method application in a case of pleural malignant neoplasm occurred in a hauler, a job generally not associated with high levels of exposure to asbestos fibres. RESULTS: Assessment of malignant pleural mesothelioma diagnosis and dual mode relevant occupational exposure to asbestos during both truck driving and loading and unloading operations of asbestos-containing goods. CONCLUSIONS: Systematic occupational medicine assessment with accurate standardized approach is essential for reconstruction of asbestos exposure, in order to highlight every aspect useful to establish causal link between cases of pleural mesothelioma and possible occupational and non-occupational exposure to the mineral, even in cases where the first-level occupational history does not appear to be suggestive.

Mesothelioma: Scientific clues for prevention, diagnosis, and therapy.

Mesothelioma affects mostly older individuals who have been occupationally exposed to asbestos. The global mesothelioma incidence and mortality rates are unknown, because data are not available from developing countries that continue to use large amounts of asbestos. The incidence rate of mesothelioma has decreased in Australia, the United States, and Western Europe, where the use of asbestos was banned or strictly regulated in the 1970s and 1980s, demonstrating the value of these preventive measures. However, in these same countries, the overall number of deaths from mesothelioma has not decreased as the size of the population and the percentage of old people have increased. Moreover, hotspots of mesothelioma may occur when carcinogenic fibers that are present in the environment are disturbed as rural areas are being developed. Novel immunohistochemical and molecular markers have improved the accuracy of diagnosis; however, about 14% (high-resource countries) to 50% (developing countries) of mesothelioma diagnoses are incorrect, resulting in inadequate treatment and complicating epidemiological studies. The discovery that germline BRCA1-asssociated protein 1 (BAP1) mutations cause mesothelioma and other cancers (BAP1 cancer syndrome) elucidated some of the key pathogenic mechanisms, and treatments targeting these molecular mechanisms and/or modulating the immune response are being tested. The role of surgery in pleural mesothelioma is controversial as it is difficult to predict who will benefit from aggressive management, even when local therapies are added to existing or novel systemic treatments. Treatment outcomes are improving, however, for peritoneal mesothelioma. Multidisciplinary international collaboration will be necessary to improve prevention, early detection, and treatment.

[Malignant pleural mesothelioma].

Malignant pleural mesothelioma (MPM) is a rare cancer with a poor prognosis. The disease is of importance, since the incidence in Denmark is increasing despite cessation of the use of asbestos in the 1980s. MPM has a long latency period, and the first symptom is often dyspnoea, typically caused by pleural effusion. The diagnosis is a challenge, because cytology often is non-conclusive, and thoracoscopy is needed to obtain biopsies for immunohistochemistry. The occupational history is important, since the patients are entitled to compensation. The treatment is often limited to palliation.

Pleural mesothelioma and occupational and non-occupational asbestos exposure: a case-control study with quantitative risk assessment.

OBJECTIVES: Casale Monferrato (north west Italy) is an area with an exceptionally high incidence of mesothelioma caused by asbestos contamination at work and in the general environment from the asbestos-cement Eternit plant that was operational until 1986. The purpose of this study was to quantify the association between pleural malignant mesothelioma (PMM) and asbestos cumulative exposure using individual assessment of environmental and domestic exposure, as well as of occupational exposure. METHODS: This population-based case-control study included cases of PMM diagnosed between January 2001 and June 2006 among residents in the Casale Monferrato Local Health Authority. Population controls were randomly sampled, matched by age and sex to cases. Cumulative exposure was estimated to account for the lifelong exposure history. Analyses were conducted using unconditional logistic regression models adjusting for gender, age at diagnosis and type of interview (direct or proxy respondents). RESULTS: 200 PMM cases of 223 eligible cases (89.7%) and 348 (63%) of 552 eligible controls accepted to be interviewed. ORs increased with cumulative exposure index (p<0.0001) from 4.4 (CI 95% 1.7 to 11.3) (<1 f/mL-years) to 62.1 (CI 95% 22.2 to 173.2) (≥10 f/mL-years). Among subjects never occupationally exposed, corresponding ORs were 3.8 (CI 95% 1.3 to 11.1) and 23.3 (CI 95% 2.9 to 186.9) (reference: background level of asbestos exposure). ORs of about 2, statistically significant, were observed for domestic exposure and for living in houses near buildings with large asbestos cement parts. CONCLUSIONS: Risk of PMM increased with cumulative asbestos exposure and also in analyses limited to subjects non-occupationally exposed. Our results also provide indication of risk associated with common sources of environmental exposure and are highly relevant for the evaluation of residual risk after the cessation of asbestos industrial use.

Estimating the social cost of respiratory cancer cases attributable to occupational exposures in France.

PURPOSE: The objective of this article was to estimate the social cost of respiratory cancer cases attributable to occupational risk factors in France in 2010. METHODS: According to the attributable fraction method and based on available epidemiological data from the literature, we estimated the number of respiratory cancer cases due to each identified risk factor. We used the cost-of-illness method with a prevalence-based approach. We took into account the direct and indirect costs. We estimated the cost of production losses due to morbidity (absenteeism and presenteeism) and mortality costs (years of production losses) in the market and nonmarket spheres. RESULTS: The social cost of lung, larynx, sinonasal and mesothelioma cancer caused by exposure to asbestos, chromium, diesel engine exhaust, paint, crystalline silica, wood and leather dust in France in 2010 were estimated at between 917 and 2,181 million euros. Between 795 and 2,011 million euros (87-92%) of total costs were due to lung cancer alone. Asbestos was by far the risk factor representing the greatest cost to French society in 2010 at between 531 and 1,538 million euros (58-71%), ahead of diesel engine exhaust, representing an estimated social cost of between 233 and 336 million euros, and crystalline silica (119-229 million euros). Indirect costs represented about 66% of total costs. CONCLUSION: Our assessment shows the magnitude of the economic impact of occupational respiratory cancers. It allows comparisons between countries and provides valuable information for policy-makers responsible for defining public health priorities.

Post-occupational health surveillance of asbestos workers.

BACKGROUND: Italian law requires an extensive health surveillance of workers after cessation of their employment status in the case of occupational exposure to carcinogens, including asbestos. Nonetheless, Italian law does not specify the timeframe of these clinical checks, nor who has financial and organizational responsibility for this surveillance. A literature search confirmed a lack of consensus around the objectives and methods to follow up workers with past occupational exposure to asbestos. OBJECTIVES: To develop an updated evidence-based methodology for an appropriate health surveillance programme. METHODS: We present an overview of the field experience developed by the Veneto Region from 2000 to 2011, and new studies that could contribute to establishing a national policy for the medical surveillance of workers with past asbestos exposure. RESULTS: There were three specific topics: (1) definition of a reliable method to identify asbestos workers (through multiple sources and procedures that meet current confidentiality regulations); (2) detection of asbestos fibres in biological media (to support the etiological diagnosis of asbestos-related diseases); (3) creation of a national protocol of health surveillance (through the assessment of policies developed by other Regions in this field, and recruiting from these regions a cohort of past-exposed workers: the epidemiological study should offer relevant suggestions for specific surveillance approaches, based on either estimated cumulative asbestos exposure or detection of x-ray patterns of pleural plaques and/or asbestosis). CONCLUSIONS: These studies will support the Regions in setting up health care policies directed at workers with past asbestos exposure.

Compensation of pleural mesothelioma in France: data from the French National Mesothelioma Surveillance Programme.

BACKGROUND: The aim of this study was to determine the rates of compensation awarded to patients presenting with pleural mesothelioma and factors linked to such compensation in France. METHODS: The study population consisted of 2,407 patients presenting with pleural mesothelioma, recorded by the National Mesothelioma Surveillance Programme between January 1, 1999 and December 31, 2009. Analysis of claims for recognition as "occupational disease" (OD) and claims for compensation by the Compensation Fund for Asbestos Victims (FIVA) were analyzed. RESULTS: Approximately 30% of subjects presenting with pleural mesothelioma, affiliated to the General National Health Insurance fund, neither sought recognition as an OD nor claimed for FIVA compensation. Gender, age at diagnosis, type of health insurance, and socio-professional category influence the likelihood of patients presenting with mesothelioma seeking compensation for this disease. CONCLUSIONS: Results show an under-compensation of pleural mesothelioma as OD and by the FIVA in France.

Missed opportunities to counsel patients with malignant pleural mesothelioma about causation and potential compensation.

INTRODUCTION: Malignant pleural mesothelioma (MPM) is a lethal malignancy strongly associated with occupational exposure to asbestos. The aims of this study were to assess the quality of counseling provided to patients with MPM about the causation of MPM and the potential for compensation. METHODS: The authors conducted a structured retrospective chart review of patients with a diagnosis of MPM. They abstracted demographic data, occupational and environmental history and exposure data. They also searched for documentation of patient education and counseling. RESULTS: The authors identified 16 patients with a new diagnosis of MPM during the study period. A job title was documented at least once in the records of 12 (75%) patients. Documentation of occupational exposure to asbestos was found in the records of 12 (75%) patients. Two patients (13%) were presumed to have had bystander exposure to asbestos. Education about MPM causation and counseling about opportunities for compensation were documented in the record of 1 patient (6%). CONCLUSIONS: Among patients with MPM, documentation of some elements of an occupational history, including an occupational asbestos exposure history, was common. Advice to pursue compensation for potential occupation related MPM was rare. Physicians may be missing opportunities to provide beneficial information to patients with newly diagnosed MPM regarding potential legal redress and compensation.

[The effectiveness of compensation system for mesotheliomas due to occupational exposure to asbestos and determinants for requests and awards: an evaluation based on record-linkage between the Veneto Mesothelioma Register and the claims and compensations recorded by the National Insurance Institute (INAIL)]. / I fattori che influenzano in Italia la domanda e il riconoscimento dei mesoteliomi di origine professionale: analisi basata su record-linkage tra dati del registro regionale del Veneto e INAIL.

AIM: To determine the rate of requests for compensation and of compensations awarded for mesothelioma cases due to occupational exposure to asbestos; to identify factors that may influence the outcome; to provide an appreciation of the amount of compensation. DESIGN AND MAIN OUTCOME MEASURES: Record-linkage study at individual level between the new cases of mesothelioma occurred among the residents of the Veneto Region (Northern Italy) between 1999- 2007 and the file of the Insurance Institute, with individual data on all claims and compensations. Adjusted logistic regression models were used to estimated the association between submitting claims and obtaining an award and socio-demographic and other characteristics. RESULTS: 349 on 499 mesotheliomas considered to be due to occupational exposure to asbestos submitted a claim (70% of those of occupational origin) and 72%of claims were accepted. The welfare system covers only 35%of mesothelioma occurred. The probability of submitting and obtaining a claim was associated with gender, cancer site, age at diagnosis, vital status, and residence or local office in charge of the evaluation. A strong discrimination against women is observed. If exposure to asbestos at work was due to a direct manipulation of asbestos, claims were more easily accepted.As a consequence,mesothelioma occurred among construction workers, the occupational activity at the origin of the largest number of occurring mesotheliomas, are more frequently rejected.When submitted by a relative, the lag between a request for compensation and the decision is on average of about two years. CONCLUSION: This is the first study in Italy using a record-linkage method and was made possible thanks to a population based mesothelioma Register and the availability of memorized information of the Insurance Institute.The welfare system shown clear limitations and there is the need for more appropriate strategies.

[Follow-up of subjects occupationally exposed to asbestos, what are the objectives, the benefits, and the possible risks?]. / Quels sont les objectifs du suivi post-professionnel, les bénéfices attendus et les risques possibles? Objectifs médicaux en termes de morbidité, mortalité et qualité de vie.

The follow-up of workers occupationally exposed to asbestos has two possible beneficial effects: (1) individually, both medical by screening for diseases related to asbestos and social by notification of occupational disease and/or compensation from the indemnity funds for asbestos victims; (2) collectively, by the establishment of epidemiological surveillance (follow-up of cohorts) and evaluation of the impact of follow-up in terms of health benefits and compensation. The respiratory disorders related to asbestos are: cancer (malignant pleural mesothelioma and bronchial carcinoma), asbestos-related pulmonary fibrosis, and pleural disease (plaques, pleural fibrosis and benign pleurisy). In the light of the data currently available and the effectiveness of the tools used, medical and public health benefits of screening for mesothelioma have not been demonstrated. The early diagnosis of primary bronchial carcinoma can theoretically improve the prognosis of the subjects screened, particularly by identification of stage I disease on CT (pulmonary nodules). This is a common finding but there are a large number of false-positives. While we await the results of several international randomised trials, the benefits of a screening programme for bronchial carcinoma in the population at risk have not been demonstrated. There is no effective treatment for asbestosis but this is an independent risk factor for bronchial carcinoma and it is evidence of heavy asbestos exposure. Stopping smoking in subjects suffering from asbestosis will reduce the incidence of bronchial carcinoma. There is no effective treatment for asbestos-related benign pleural diseases but these are markers of exposure. The presence of pleural plaques has not been shown to be an aetiological factor for thoracic cancers. Post-occupational follow-up may involve risks to health, particularly repeated irradiation and invasive diagnostic procedures. It is also necessary to consider the psychological consequences inherent in all screening programmes. In conclusion, post-occupational follow-up might reduce the mortality of lung cancer by screening for localised disease and its incidence by a targeted anti-smoking programme. The theoretical benefits, that have not yet been demonstrated, have to be seen in perspective with the risks to physical and psychological health related to both screening and diagnostic procedures.

Asbestos in Poland: occupational health problems.

The presentation addresses current problems of health risk and health effects associated with exposure to asbestos, including data on historical exposure and on currently valid occupational exposure limits. The quantity and types of the raw material used for the production of various asbestos products have also been discussed in relation to the particular types of asbestos-induced occupational diseases. The authors describe the medical care system for former asbestos workers and those currently exposed during removal of asbestos-containing products. The national system for medical certification of occupational asbestos-related diseases and the compensation procedure have been outlined as well. According to the parliamentary Act of 1997, importing, manufacture and sale of asbestos and asbestos-containing materials are prohibited in Poland. Thus, the assessment of asbestos exposure and the monitoring of health conditions of workers at asbestos-processing plants have become irrelevant. However, the delayed health effects attributable to past exposure continue to be the matter of concern for public health. Likewise, the environmental pollution from asbestos waste landfills in the vicinity of asbestos-processing plants (where high levels of asbestos fibre in ambient air have been recorded) will continue to be a serious public health problem. Presently, two programmes aimed at minimising the adverse effects of asbestos on population health are underway. One of them is the governmental programme for "Elimination of asbestos and asbestos-containing products used in Poland, 2002-2032". The programme was updated in 2009 to cover the workers contracted to perform demolition works and provide protective covers to asbestos waste landfills. This will be the exposed group who need prophylactic health care. The other is a programme of prophylactic examinations for former asbestos workers and is referred to as the AMIANTUS programme. Both programmes have been briefly described.

Asbestos-related disease.

Inhalation of airborne asbestos fibres causes several diseases. These include asbestosis, lung cancer, malignant mesothelioma as well as pleural effusion, discrete (plaques) or diffuse benign pleural fibrosis and rolled atelectasis. The lag time between exposure and the development of disease may be many decades, thus the health risks of asbestos continue to be relevant despite bans on the use of asbestos and improvements in safety regulations for those who are still exposed. Asbestos was mined and used extensively in Australia for over 100 years and Australia is now experiencing part of a worldwide epidemic of asbestos-related disease. This review provides insight into the history and epidemiology of asbestos-related disease in Australia and discusses relevant clinical aspects in their diagnosis and management. The past and current medico-legal aspects of asbestos as well as currently evolving areas of research and future projections are summarized.

Malignant pleural mesothelioma: the standard of care and challenges for future management.

This review addresses the management of MPM. In an introductory section, the etiology, epidemiology, presentation, diagnosis and staging of MPM will be reviewed. The evidence was collected by a systematic analysis of the literature (2000-2009) using the databases Medline (National Library of Medicine, USA), Embase (Elsevier, Netherlands), Cochrane Library (Great Britain), National Guideline Clearinghouse (USA), HTA Database (International Network of Agencies for Health Technology Assessment - INAHTA), NIH database (USA), International Pleural Mesothelioma Program - WHOLIS (WHO Database) with the following keywords and filters: pleura, cancer, mesothelioma, guidelines, treatment, surgery, chemotherapy, radiotherapy, palliation, supportive care, pleurodesis, review.

[Algorithm for assessment of exposure to asbestos]. / Proposta di algoritmo per la valutazione stimata dell'esposizione lavorativa ad amianto.

There is no universally approved method in the scientific literature to identify subjects exposed to asbestos and divide them in classes according to intensity of exposure. The aim of our work is to study and develope an algorithm based on the findings of occupational anamnestical information provided by a large group of workers. The algorithm allows to discriminate, in a probabilistic way, the risk of exposure by the attribution of a code for each worker (ELSA Code--work estimated exposure to asbestos). The ELSA code has been obtained through a synthesis of information that the international scientific literature identifies as the most predictive for the onset of asbestos-related abnormalities. Four dimensions are analyzed and described: 1) present and/or past occupation; 2) type of materials and equipment used in performing working activity; 3) environment where these activities are carried out; 4) period of time when activities are performed. Although it is possible to have informations in a subjective manner, the decisional procedure is objective and is based on the systematic evaluation of asbestos exposure. From the combination of the four identified dimensions it is possible to have 108 ELSA codes divided in three typological profiles of estimated risk of exposure. The application of the algorithm offers some advantages compared to other methods used for identifying individuals exposed to asbestos: 1) it can be computed both in case of present and past exposure to asbestos; 2) the classification of workers exposed to asbestos using ELSA code is more detailed than the one we have obtained with Job Exposure Matrix (JEM) because the ELSA Code takes in account other indicators of risk besides those considered in the JEM. This algorithm was developed for a project sponsored by the Italian Armed Forces and is also adaptable to other work conditions for in which it could be necessary to assess risk for asbestos exposure.

La prevención de las patologías del asbesto: perspectivas operativas de la cooperación italiana con los países de América Latina / Preventing asbestos-related diseases: operative action for Italian cooperation with Latin-American countries

El propósito del presente estudio es el de valorar la tesis de que el impacto a la salud de la exposición a fibras de asbesto presentes en los lugares de trabajo y en el ambiente requiere contramedidas basadas en la evidencia científica y la cooperación internacional. La evidencia científica adquirida a nivel internacional sobre el asbesto, la experiencia pluridecenal madurada en Italia sobre este tema, así como la conciencia de que la adaptación de medidas para combatir los efectos en la salud causados por la exposición a asbesto debe ser verificada considerando la especificidad de los diversos contextos nacionales y locales en América Latina, constituyen la base para la identificación de las cuatro principales directrices de intervención (Promoción del acceso a la documentación sobre el asbesto - Realización de intervenciones para reducir la exposición al asbesto - Vigilancia sanitaria de los sujetos expuestos - Detección del mesotelioma) - que pueden ser desarrolladas en el ámbito de la cooperación técnico-científica entre Italia y los países de América Latina. La integración de las capacidades de los investigadores colombianos e italianos podrá permitir conseguir estos resultados, contribuyendo al proceso de eliminación del asbesto ya en curso en América Latina.

The present paper was aimed at promoting countermeasures based on scientific evidence and international cooperation for evaluating the impact on health caused by exposure to asbestos fibres in the workplace and the environment. Scientific evidence regarding asbestos made available by the international scientific community, decades of experience gained in Italy on this issue and being aware that adopting measures to combat the health effects caused by asbestos exposure should be verified considering the specificity of various national and local contexts in Latin-America form the basis for identifying four main areas for intervention which may be developed in the field of technical and scientific cooperation between Italy and Latin-America countries: promoting access to information about asbestos, interventions for reducing exposure to asbestos, health surveillance of exposed subjects and mesothelioma detection. Integrating Colombian and Italian researchers' abilities may lead to such results being achieved, thereby contributing to banning asbestos, which is already underway in Latin-America.

[Preventing asbestos-related diseases: operative action for Italian cooperation with Latin-American countries]. / La prevención de las patologías del asbesto: perspectivas operativas de la cooperación italiana con los países de América Latina.

The present paper was aimed at promoting countermeasures based on scientific evidence and international cooperation for evaluating the impact on health caused by exposure to asbestos fibres in the workplace and the environment. Scientific evidence regarding asbestos made available by the international scientific community, decades of experience gained in Italy on this issue and being aware that adopting measures to combat the health effects caused by asbestos exposure should be verified considering the specificity of various national and local contexts in Latin-America form the basis for identifying four main areas for intervention which may be developed in the field of technical and scientific cooperation between Italy and Latin-America countries: promoting access to information about asbestos, interventions for reducing exposure to asbestos, health surveillance of exposed subjects and mesothelioma detection. Integrating Colombian and Italian researchers' abilities may lead to such results being achieved, thereby contributing to banning asbestos, which is already underway in Latin-America.

[Medical insurance aspects of peritoneal tumors with particular attention to peritoneal mesotheliomas]. / Versicherungsmedizinische Aspekte bei peritonealen Mesotheliomen und sonstigen peritonealen Tumoren.

Malignant peritoneal mesotheliomas arise mainly in male patients and the median age of initial diagnosis is about 56 years. Epitheloid subtype predominates in peritoneal mesotheliomas. Asbestos exposure is the best-known and most common risk factor associated with the development of both pleural and peritoneal mesotheliomas and, therefore, about 90% of cases can be assessed as asbestos-associated. Patients with peritoneal mesotheliomas have distinctly higher asbestos burden of the lungs than patients with pleural mesotheliomas. The mean latency period between exposure and diagnosis of peritoneal mesothelioma ranges from 35 to 40 years and is comparable to that of pleural mesothelioma. Mesothelioma of the tunica vaginalis testis also belongs to the group of peritoneal mesotheliomas. No significant evidence exists for the classification of well-differentiated papillary mesothelioma, solitary fibrous tumor, adenomatoid tumor, primary peritoneal serous borderline tumor, and benign multicystic mesothelioma as asbestos-associated tumors. Except malignant mesotheliomas, the induction of other abdominal tumors is independent of an exposure to asbestos dust.