Work -related asthma among dental and radiography professionals
Rationale. Occupational asthma is the most frequently reported diagnosis of occupational respiratory disease in developed nations. Dental and radiography professionals are potentially exposed to a number of asthmagens including acrylates, sensitizing metals, latex, cleaning products and x-ray developing solutions. Still, gaps exist in the health care worker literature in regard to risk characterization for these professions. Objectives. To evaluate the association between occupational exposures and asthma in dental and radiography professionals using a cross-sectional survey and an asthma-specific job exposure matrix. Methods. A detailed questionnaire was mailed to a random, representative sample (n=2800) of Texas dentists, dental hygienists, dental assistants, dental laboratory technicians and radiographers with an active license in 2007. Self-reported occupational exposures were derived from the questionnaire and externally determined exposures from the job exposure matrix. The job exposure matrix expanded upon a previous matrix by adding new occupation and exposure categories and was coded by an expert panel. Two outcome variables were defined from the questionnaire, bronchial hyperresponsiveness (BHR)-related symptoms, based on a previously validated 8-item predictor, and a history of physician-diagnosed asthma occurring after entry into the healthcare profession ('reported asthma'). Main results. Surveys were received from 1515 participants for an overall response rate of 57%. From the self-reported occupational exposures, employment as a dental hygienist was associated with a 60% increase in risk of BHRrelated symptoms (OR: 1.60, 95% CI: 1.04-2.45). Developing dental films (OR: 1.42, 95% CI: 1.05-1.93) and using manual x-ray films (OR: 1.46, 95% CI: 1.01-2.10) were both associated with more than a 40% increase in the risk of BHR-related symptoms. The use of stone glaze was associated with an increased risk of reported asthma (OR: 4.82, 95% CI: 1.53-15.14) while the risk was significantly reduced among participants using fluxes (OR: 0.19, 95% CI: 0.05-0.68). From the job exposure matrix-derived exposures, powdered latex glove use after 2000 was associated with a 60% decrease in risk of reported asthma (OR: 0.40 95% CI: 0.20-0.81). No other significant associations were found. Conclusion. The finding of an increased risk of occupational asthma due to the manual development of x-ray film concurs with the conclusions from previous studies. Changes in certain practices, such as the move away from manual x-ray developing to digital radiography, are a step in the right direction to ensuring a safe work environment for all practitioners. Dental and radiography professionals are potentially exposed to several asthmagens in their work settings, and as the field grows and employs greater numbers of people, the contribution of these occupational exposures should be better characterized. However, results from this study did not uncover any increased risks associated with a wide range of tasks and products typical of dental settings. The finding of an increased risk among dental hygienists is new and warrants further evaluation, as it was not explained by the tasks or products measured in this study.