Many pre-employment medicals for jobs that involve dusty workplaces include a 'spirometry' or lung function test. These tests can measure current lung function in terms of lung capacity and speed of exhalation and inhalation.
If you are going to be performing physical tasks in a dusty environment, including working as a firefighter or military officer on deployment, it can be important for you to be able to do heavy physical labour in a dusty environment. Lung function testing may include doing a physical test, which is often running on a treadmill and wearing heavy protective clothing or equipment and a full face offtake mask. The offtake gas is tested and indicates how effectively your lungs are absorbing oxygen during heavy exertion. The test will determine how hard your lungs have to work at different treadmill speeds and give an indication of whether you are likely to be able to perform the job role. The results are compared to other people of your age, height and sex to determine how you perform relative to people of similar backgrounds.
If your work is less physical but may involve contact with dust or other industrial irritants, which can reduce your lung capacity over time, your employer might like you to take a passive lung test as part of your pre-employment medical. These are performed when sitting down and involve you taking a deep breath then expelling the air as quickly as possible. The lung test measures both the amount of air that you expelled and the speed that you could expel it. These tests may be performed at the start of employment and when you leave the company to identify what, if any, reduction in lung capacity occurred due to your work in this environment. Again, results are compared to average results for people of your age, height and sex.
The lung test results may also be checked regularly (such as during an annual check-up) to determine if particular areas or divisions have hazards that need to be controlled better with engineering solutions or appropriate personal protective equipment.
Lung function tests, or spirometry, are an easy and painless way to check that you will be able to physically perform the tasks that you need to do in your role. If you do sustain a loss of lung function due to your role, pre-employment lung function tests can help to establish how much lung function you did lose so that you can be fairly compensated.