Response to: Correspondence on ‘Demographic, exposure and clinical characteristics in a multinational registry of engineered stone workers with silicosis’ by Hoy et al

We thank Dr Hoy and Dr Sim for their comments on our recent study. We wish to respond to three key points raised in their letter to the editor. First, we agree that the number of workers enrolled in the Engineered Stone Silicosis Investigators (ESSI) Global Silicosis Registry is indeed a small subset of those with engineered stone (ES) silicosis. We welcome the inclusion of many more Australian workers with silicosis in the registry to better define the demographic, exposure and clinical features that vary widely among patients from different countries, due in part to differences in case ascertainment. We have been particularly eager to involve our colleagues from China, the largest exporter of ES products worldwide, in this work. Efforts to build cooperation with China and other countries (eg, Turkey, India and Russia) producing much of the world’s ES have been stymied by international political challenges that limit, and in some cases preclude, scientific collaboration. Scientists and advocates in these countries along with external support from international policy leaders may help promote such partnerships. Second, we applaud the Queensland Government in Australia for creating an industrybased screening programme for stone masons exposed to crystalline silica. While such programmes importantly focus on the health of individual atrisk workers, they are generally not designed or funded to provide the aggregate data required to determine risk factors for disease and disease progression at a population level. This is where efforts such as the ESSI registry play a valuable role. Our hope is that, through international collaborations facilitated by the ESSI registry, investigators will share lessons learnt and approaches to early disease recognition, treatment, exposure control and prevention of the multiorgan system effects of crystalline silica. In the USA, the Occupational Safety and Health Administration (OSHA) only recently updated its Respirable Crystalline Silica Standards, and the Mine Safety and Health Administration (MSHA) still has to respond to the resurgence of severe progressive massive fibrosis linked to silica exposure in US coal miners. 4 Both OSHA and MSHA are understaffed and underfunded, and when exposure monitoring and enforcement do occur, weak monetary and criminal penalties do little to encourage employerled improvements in hazardous practices. It is clear that much remains to be done. Third, we believe that cases of ES silicosis will continue to emerge and that increasing clinical recognition will further underscore the burgeoning epidemic of new and previously unrecognised cases in countries where ES products are produced and installed. We owe particular gratitude to colleagues in Spain, Israel and Italy who first reported sentinel cases of silicosis in ES workers a decade ago and who continue to develop methods for case ascertainment as well as longitudinal followup of affected workers. We hope that the ESSI registry will help create a foundation for sharing successful strategies for early disease detection, learning from regulatory and implementation failures, and exploring evidencebased practices for treatment and prevention. We invite Dr Sim and Dr Hoy and other interested international collaborators to join in this coordinated effort on behalf of ES workers worldwide.