Abstract
Objectives: Aims to identify and review all previously published reports of outbreaks of ill health due to water-based metalworking fluids (MWFs), in order to identify aetiological risk factors for disease, and highlight areas requiring further research.
Methods: A multidisciplinary team agreed appropriate search terms for a systematic literature review. From a total of 1346 titles, 35 relevant articles, relating to 29 separate outbreaks of ill health attributed to MWF exposure were selected.
Results: 17 outbreaks related to respiratory disease, 4 to skin disease, and 8 to a combination of both. There was a peak incidence between 1996 and 2000. The majority were from the United States, from large car manufacturing plants using a central sump.The mean attack rate for allergic respiratory disease during outbreaks was 5.9% of the exposed workforce. Outbreaks were identified with all types of water-based MWFs, and mean MWF aerosol levels were below recommended exposure limits in most cases. For respiratory disease outbreaks, bacteria were isolated in 76%, fungi in 71% and opportunistic mycobacteria in 59% of workplaces. Endotoxin contamination of MWF ranged from non-detectable to 5.3×105 EU/ml, and measured airborne endotoxin levels ranged from 0.52 EU/m3 to 126 EU/m3.
Conclusions: Despite numerous investigations, significant knowledge gaps remain, particularly regarding the aetiology, natural history and risk factors for these outbreaks. The available evidence supports the hypothesis that microbial contamination is important in the aetiology of occupational lung disease in this group, and improvements in workplace hygiene have generally been associated with a cessation of new cases.
- © 2011 ERS