By Gary Evans, Medical Writer

Healthcare workers are one of the leading occupational risk groups for asthma and other respiratory problems due to multiple potential allergic “triggers” and sources of exposure in the medical environment, the CDC reports.

“The highest prevalence of current asthma was among workers in the healthcare and social assistance industry and in healthcare support occupations,” according to the CDC.1 “New-onset work-related asthma in these workers has been associated with exposure to cleaning and disinfecting products, powdered latex gloves, and aerosolized medications.”

For example, increasing use of strong sporicidal cleaning and disinfectant solutions to eradicate Clostridium difficile — one of the leading causes of healthcare infections — can lead to asthma and respiratory symptoms in housekeeping and other exposed healthcare workers.2

“There are multiple sources of exposures in the work environment of hospital settings,” says Jacek Mazurek, MD, PhD, surveillance branch chief of the respiratory health division of the CDC’s National Institute of Occupational Safety and Health (NIOSH). “Reporting symptoms and exposures is critical. Avoidance is our main means of preventing asthma. Sometimes, workers have to be removed from the source of exposures.”

That’s one of the take-home messages for employee health professionals, who should underscore the importance of reporting exposures and symptoms and work with colleagues to protect healthcare workers from subsequent attacks.

“It is important to stress that if symptoms are occurring in workers they need to talk to their occupational health providers,” Mazurek says. “The best way of preventing development and exacerbation of their asthma would be avoidance. Those who are sensitized to various products should also wear a bracelet so in case of a severe attack the first responders would be aware.”

The CDC reviewed 2011-2016 data from the National Health Interview Survey (NHIS) to determine industry- and occupation-specific prevalence of asthma, asthma attacks, and asthma-related ED visits among working adults.

For the period, they found 6.8% (11 million) of an estimated 160.7 million working adults had current asthma. Among those with asthma, 44.7% experienced an asthma attack, and 9.9% had an asthma-related ED visit in the previous year. The highest numbers of asthma attacks (307,000) and asthma-related ED visits (75,000) were among people working in ambulatory healthcare. By major occupation group, asthma prevalence was highest among workers in healthcare support (8.8%), followed by personal care and service (8.6%) occupations.

High-level Disinfectants Can Be Triggers

While this broad brush stroke is sufficient to raise alarm, the CDC report was not granular enough to include specific healthcare worker data by occupation. What is known is that there is no shortage of chemicals and procedures in healthcare that can trigger respiratory reactions.

For example, some high-level disinfectants — commonly used for heat-sensitive equipment — have been linked to work-related asthma.

“Both glutaraldehyde and peracetic acids have been recognized as sensitizers that cause asthma in healthcare workers,” Muzarek says. “For that reason, OPA [ortho-phthalaldehyde] was introduced as an alternative for glutaraldehyde in 1999.”

Some subsequent reports raised questions about the occupational effects of OPA, but NIOSH reviewed the data and cleared the high-level disinfectant for use in healthcare.3

“Another exposure group is cleaning products used on surfaces,” he says. “There are studies linking various cleaning products with asthma and rhinitis in cleaning workers. We know that nurses also contact these products that can exacerbate asthma. These include chlorine, ammonia, and quaternary ammonium compounds.”

Work-related rhinitis is defined by NIOSH as nasal congestion, rhinorrhea, sneezing, and/or itching. Importantly, it may be a precursor to occupational asthma, which typically presents as wheezing, shortness of breath, and coughing. It also can result in occupational anaphylaxis, a systemic allergic reaction that can be life-threatening or fatal. “There is some evidence that asthma may be prevented or controlled by appropriate management of rhinitis,” NIOSH notes.4

In addition to sensitizing materials, physical exertion and stress also can spur an asthma attack. Both of those are abundant in hospitals, but researchers do not have the data to link this general finding specifically to healthcare.

“We know these factors are associated with triggering and exacerbating asthma,” he says. “The impact of specific work arrangements on worker health is under investigation.”

In general, clinicians should consider work-related asthma in workers with new-onset or worsening asthma. Again, the preferred primary strategy to prevent work-related asthma is exposure control, which includes elimination or substitution of hazardous products, engineering controls, and in some cases, respiratory protection. That said, simply putting people vulnerable to asthma and respiratory problems in respirators is not the answer, Mazurek says.

“There is very little evidence of the effectiveness of wearing respirators to prevent asthma,” he says. “It’s not currently in our recommendations.”

Respiratory Therapists Also at Risk

Given the potential severity of these exposures, there is a need for data by specific healthcare occupation to separate needed protection measures from “overkill,” says Brian K. Walsh, PhD, RRT-NPS, RRT-ACCS, AE-C, RPFT, FAARC, president of the American Association for Respiratory Care (AARC).

“We need more studies to show what protective precautions should be taken,” he says. “We also need research linking aerosols to specific professions like respiratory therapy. I think it is time for us to look specialty by specialty — nursing, respiratory therapy, anesthesia. There is some literature about their risk of inhaled anesthetics.”

Respiratory therapists treat patients with aerosolized medications and thus may be exposed to the drugs or the viral and bacterial pathogens their patients are infected with. These aerosolized medications include antibiotics like amikacin, the antiprotozoal pentamidine, and antivirals such as ribavirin. These drugs can evoke respiratory symptoms in and of themselves, and the exposure is further complicated by the possibility of an infecting pathogen being released during the process.

“A lot of the aerosols that are created by ventilators and nebulizers have actually gone through the person’s respiratory tract and potentially picked up the [infecting] virus or bacteria,” Walsh says. “[For a] lot of the inhalants and the medications that we give, the aerosol is a larger molecule and the bacteria or viruses can actually ‘ride’ on it.”

Though these aerosols “drop quickly as you get away from the patient,” Walsh says, it is recommended that respiratory therapists wear gloves, gowns, and, if the procedure warrants, a respirator.

However, one study5 found numerous breaches of recommended personal protective equipment (PPE) use by respiratory therapists. Among the findings, 22% of respondents did not always wear protective gloves, 69% did not always wear protective gowns, and 49% did not always wear respiratory protection while administering aerosolized pentamidine, which has been linked to adverse reproductive effects. The reasons most often reported for these lapses by respondents was that it was not part of the protocol, an engineering control was being used, no one else who performs this work uses PPE, and the equipment was not readily available in the work area.

“Some people see it as overkill to wear gloves and gowns, and there is also an associated cost that the hospital has to pick up,” Walsh says. “There is not a lot of evidence supporting the need to wear that. There needs to be more research.”

Indeed, there is an “old school” perception that the measures may be unnecessary, though patients under standard precautions would be indicated for at least appropriate glove use and hand hygiene, he says.

“For certain drugs we should wear an N95 mask, gloves, and gowns,” Walsh says. “Those are kind of best practices to try to minimize the aerosol [exposures]. But often they are seen as ‘inhumane’ if you are just giving an aerosol treatment and the [patient] is not contagious. That is just old school practice.”

The issue of asthma in respiratory therapists is confounded by the fact that many go into the field after life experiences with breathing problems, he says.

“A lot of people go into respiratory therapy because they or a family member had lung disease as a child,” he says. “That triggered their mindset to go into this [field] to help people.”

Indeed, there is an anecdotal perception that respiratory therapists may have breathing issues when they are away from work, which means they are also away from the frequent exposure to the treatments they give to patients.

“We often use bronchial dilators to dilate airways, and we are potentially chronically exposed to those drugs,” Walsh says. “When [respiratory therapists] are away from work and not exposed to those, you wonder if they have exacerbations or problems getting worse.”

Walsh submitted comments similar to those expressed to Hospital Employee Health to public health officials and partners creating the National Occupational Research Agenda for Respiratory Health.6

In another comment on the proposed agenda, Jonathan Rosen, industrial hygiene consultant at AJ Rosen & Associates in Schenectady, NY, said NIOSH should continue to fund and support research that would lead to “a better healthcare disposable N95.”

In addition to better respirators, more research is needed on respiratory protection for first responders and EMTs, who could have close contact with people who may be infected with airborne pathogens, he wrote.

“They also are increasingly called to respond to drug overdoses, which may include potential exposure to fentanyl or its analogues,” Rosen said in the comments. “Research has not evaluated the policies and practices in prehospital programs and among rank and file EMS workers. This is an important gap in a high-risk population that should be included in the agenda.”


1. Mazurek JM, Syamlal G. Prevalence of Asthma, Asthma Attacks, and Emergency Department Visits for Asthma Among Working Adults — National Health Interview Survey, 2011–2016. MMWR 2018;67(13);377–386.

2. CDC. Notes from the Field: Respiratory Symptoms and Skin Irritation Among Hospital Workers Using a New Disinfection Product — Pennsylvania, 2015. MMWR 2016;65(15);400–401.

3. Chen L, Eisenberg J, Mueller C, et al. Health hazard evaluation report: Evaluation of ortho-phthalaldehyde in eight healthcare facilities. NIOSH HHE Report 2006-0238-3239. 2015. Available at:

4. Mazurek JM, Weissman DN. Occupational Respiratory Allergic Diseases in Healthcare Workers. Curr Allergy Asthma Rep 2016;(11):77.

5. Tsai RJ, Boiano JM, Steege AL, et al. Precautionary Practices of Respiratory Therapists and Other Health-Care Practitioners Who Administer Aerosolized Medications. Respir Care 2015 Oct; 60(10):1409–1417.

6. NORA Respiratory Health Cross-Sector Council. National Occupational Research Agenda for Respiratory Health, February 2018. Available at: