Laboratory worker allergies go under the microscope
8 Feb 2022
To date, there are relatively few studies on the relationship between exposure to laboratory allergens and animals and the incidence of lab-related allergies. Here, Jennifer Wright looks at newer studies which seek to explore the matter in more depth and where lab managers can access guidance on allergen control in laboratories to help ensure the health and wellbeing of their employees.
According to L. Elliot et al at the University of North Carolina, research investigating links between lab-related allergens and exposure to lab animals is limited. Generally, studies include exposure-response relations that are cross-sectionally designed, or they focus narrowly on exposure to laboratory animals such as rats and mice. With that said, some studies have estimated that 10% to 23% of exposed workers regularly report symptoms of allergy to laboratory animals and their dander.
Newer studies, including the one conducted by L. Elliot and his team, have explored the prevalence of allergies in laboratory workers in greater depth. The aforementioned study used longitudinal data collected over a period of 12 years to describe the relations between exposure to lab animals and the development of laboratory animal allergies (LAA). The study suggests that the risk of developing LAA increases with the duration of exposure to animals and work in animal-related activities.
A less common suspect - mould
Another less common suspect at the root of lab-related allergies is mould contamination. A study by D. Matuka et al in the Current Allergy and Clinical Immunology found that mould contamination and exposure triggered occupational allergic rhinitis in a 52-year-old laboratory worker. NC State University notes that mould growth may occur on pipe chases and utility tunnels, or walls behind furniture. It’s also prevalent in condensate drain pans inside air handling units, porous thermal and acoustic liners inside ductwork and roof materials above ceiling tiles. Proper treatment of mould growth and contamination is essential in reducing the prevalence of allergies among lab workers. Additionally, it prevents contamination of sterile environments and equipment.
Which animals pose the greatest risk for LAA?
According to Dr David Weissman at the CDC, rats are likely the most common research animal species present in labs. The primary sources of rat allergens seem to be saliva and urine. Research has shown that handling rate faeces can introduce large amounts of allergens. More specifically, small particle allergens that remain airborne for up to 35 minutes. Mice also carry urinary proteins that are identified as a major allergy trigger for animal lab workers.
Cats, dogs, and birds may pose significant sensitisation risks in laboratories, whether they’re in the workplace or at home. Cat allergens are present in the animals’ sebaceous glands and saliva. These allergens can transfer to humans, even when cats are not physically present. Exposure to birds has also shown to trigger rhinitis and hypersensitivity pneumonitis, a potentially dangerous pneumonia-like condition of the lungs.
Methods of allergen control
Many laboratories are implementing allergen control protocols. These protocols are guided by information from guidelines such as the NIH’s Laboratory Animal Allergy Prevention Program. Interventions such as engineering controls of facility design and ventilation and the use of high efficiency particulate air filtration systems have proven successful. As have administrative controls, including pre-placement screening evaluations of lab employees for risk factors and histories of allergy.
Lab Manager notes that education and training of staff are important in preventing LAA. Each lab worker must understand the risks involved and the symptoms of allergies. Employees should adhere to best practices and proper equipment usage. Knowing how to use personal protective equipment like gloves, head and foot coverings and respirators is essential. Doing so goes a long way towards protecting employees from lab-related allergy development.
Author: Jennifer Wright worked in occupational health before turning her hand to science writing