W Anees, et al. - In occupational asthma continued workplace exposure to the causative agent is associated with a poor prognosis. However, there is little information available on how rapidly lung function declines in those who continue to be exposed, nor how removal from exposure affects lung function...Conclusion: FEV1 declines rapidly in exposed workers with occupational asthma. Following removal from exposure, FEV1 continued to decline but at a slower rate, similar to the rate of decline in healthy adults