Asthma can occur in certain individuals at work if they are exposed to respiratory sensitisers. Respiratory sensitisers, also known as asthmagens, are substances that cause occupational asthma. These substances include chemicals (isocyanates), wood dust, flour and grain dust, soldering fumes (colophony), dust from latex rubber and dust from animals and insects. Including these, there are over 200 respiratory sensitisers that cause asthma in the workplace. Occupational asthma can result in a very serious health problem if not tackled head on. Not everybody who becomes sensitized develops asthma. However, the lungs may become hypersensitized, which may trigger an asthma attack later on, even at low exposures of the asthmagen. Symptoms of asthma include wheezing, shortness of breath, painful coughing and chest tightness. Associated symptoms include runny nose and sore and itchy eyes. There may also be ‘work aggravated asthma’, this is where the worker has a pre-existing condition and the work environment is now triggering acute asthmatic symptoms.
The occupations where the highest incidents of asthma are present include bakers and vehicle paint sprayers. Other job occupations with asthmagen risk include that of the solderer, healthcare worker, agricultural worker, engineering worker, woodworker and laboratory animal worker. The most common causes of occupational asthma continue to be isocyanates and flour/grain. Because the range of industries that use these substances is quite broad, it is difficult to estimate the total number of workers at risk. And not all workers in these industries will be exposed. However, as a general rule, employers have a responsibility to prevent or control the exposure of workers to hazardous substances in the workplace, and all work places that use asthmagens are included. The regulations include the Control of Substances Hazardous to Health Regulations 2002 (COSHH). A COSHH assessment must be carried out in these workplaces to control risk. There are various steps that can be followed to prevent occupational asthma. If one is diagnosed with asthma, they should avoid exposure or reduce working with the offending substance. It may be possible to get the respiratory sensitisers removed within the workplace and replaced with a safer alternative. If these approaches are not practical, then respiratory protective equipment (RPE) should be used. All workers in these environments should be given information on how to recognize early signs of occupational asthma and regular medical checkups should be carried out.
Using RPE at work may be the best approach to preventing ill-health. Work activities such as using volatile solvents, cutting wood, handling a dusty powder, welding, soldering will require RPE. Also working in confined spaces where oxygen levels are low will require this extra protection. However, respirators must not be used in oxygen deficient atmospheres, but where oxygen levels are low. A suitable breathing apparatus should be used for the former. The RPE must not restrict the worker from carrying out their task and it must be suitable for the job. Another solution when working with dust and fumes is to try and clean the air. Local exhaust ventilation (LEV) is a ventilation system that takes dust, mists, gases or fumes out of the air so they cannot be breathed in. Properly designed LEV may help with adhering with COSHH. However, the LEV must be installed properly, fully maintained and checked that it is indeed cleaning the air.