IntroductionArtificial 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.AimTo report the characteristics of a clinical series of Australian workers with artificial stone-associated silicosis.MethodsRespiratory 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.ResultsSeven 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).ConclusionsThis 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.

Background and aims-Photodynamic therapy (PDT) is a treatment in which cell damage is achieved by the action of light on a photosensitising agent. We have assessed the potential use of PDT in the ablation of Barrett's oesophagus. Methods-Thirty six patients with dysplastic Barrett's oesophagus receiving acid suppression medication with omeprazole were randomised to receive oral 5-aminolaevulinic acid (ALA) 30 mg/kg or placebo, followed four hours later by laser endoscopy. Follow up endoscopy was performed at one, six, 12, and 24 months. Results-Of 18 patients in the ALA group, a response was seen in 16 (median decrease in area in the treated region 30%; range 0-60%). In the placebo group, a decrease in area of 10% was observed in two patients with no change in 16 (median 0%; range 0-10%; treatment v placebo, p<0.001). No dysplasia was seen in the columnar epithelium within the treatment area of any patient in the PDT group. However, in the placebo group, persistent low grade dysplasia was found in 12 patients (p<0.001). There were no short or long term major side eVects. The eVects of treatment were maintained for up to 24 months. Conclusions-This is the first randomised controlled trial of PDT for Barrett's oesophagus. It demonstrates that ALA induced PDT can provide safe and eVective ablation of low grade dysplastic epithelium. (Gut 2000;47:612-617)

This is the first large-scale prospective study of SMRP for screening for malignancy in asbestos-exposed individuals. A high false-positive rate was observed. SMRP seems unlikely to prove useful in screening for MM.

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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.