The air we breathe in the workplace: Is it safe?

What used to to be a place that holds a perception of relative safety and minimal health risk to its occupants, the office now appears to be a place that is inching its way towards the other side of the respiratory health spectrum, with office-related occupational asthma on the rise, according to findings from a UK cross-sectional study presented at ERS 2021.

“Office environments can be a cause of occupational asthma, either due to internal or external exposures, or office ventilation systems,” said Dr Christopher Huntley from the University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK, during his poster presentation. “Anecdotally, we have recognized an increase in the number of cases over recent years of work-related asthma in patients who work in offices.”

Huntley and his team sought to explore the causes of office-related occupational lung disease, focusing on occupational asthma. They used data from the Birmingham NHS Occupational Lung Disease Service, which has been recording all new occupational lung diseases diagnosed since 2000 on a clinical database. [ERS 2021, poster ID 1904]

Of the 54 individuals identified to have office-related occupational lung disease*, 47 had a diagnosis of occupational asthma (mean age 47 years, 70 percent female), 11 of whom had pre-existing asthma. Other causes of office-related occupational lung disease were occupational dysfunctional breathing disorder, hypersensitivity pneumonitis, acute irritant asthma, allergic bronchopulmonary aspergillosis, and occupational bronchitis.

Three main categories of exposure were identified: internal office environment, office ventilation system, and external environment adjacent to the office.

Contrary to perception that ventilation systems are a primary cause, printer and photocopier toner – which falls under the internal office environment category – was the most commonly reported cause of office-related occupational asthma, accounting for seven of the occupational asthma cases, noted Huntley. “[This is] likely due to either laminating adhesives containing isocyanate prepolymers, benzalkonium chloride, lubricating sprays, or the diazonium salts found in dye in photocopier paper.”

“We also recognized outbreaks of occupational asthma in offices with new flooring lace (n=4), the most likely cause due to the adhesives used, which contain acrylates,” he continued.

Other internal office environment causes were cleaning agents (n=4), mould/damp objects (n=3), and air freshener/perfume and office dust (two cases each).

Although the printer/photocopier toner was the most common cause, ventilation systems are still an important cause of occupational asthma in offices, owing primarily to air conditioning mould/aspergillus containment (n=5) or incorrect installation of ventilation shafts (n=2). “In one case, the office ventilation system was pumping air from the swimming pool [into] the office, exposing workers to airborne chloramines,” said Huntley.

In external environments adjacent to offices (eg, workshops), the most common causes of occupational asthma were isocyanates and diesel fumes (n=3 and 2, respectively), followed by paint, demolition dust, medium-density fibreboard, metal working fluid, nematocide, and recycling waste (one case each).

The odds of an employee leaving their workplace were a hundredfold if no workplace adjustments were made (odds ratio, 101.3, 95 percent confidence interval, 10.4–990.3).

“As with all cases of occupational asthma, identification of the cause and removal/workplace adjustments increase the odds of the employee remaining in employment, [thus improving] the long-term outcome,” said Huntley.

In the face of the pandemic

Office workers have adapted to new working patterns and environments – primarily in a home environment – owing to the COVID-19 pandemic. “We have already seen the benefits of this in some patients, with resolution of symptoms and peak flow recording improvement. It remains to be seen if the risk of office-related occupational asthma alters these results,” said Huntley.