Asthma is a heterogeneous clinical syndrome that affects approximately 360 million people worldwide. Studies have found that up to 25% of adult asthma cases are work-related (1). The incidence does not appear to be decreasing (2), which leading to significant social and economic burdens. Recently, new cases of work related asthma due to workplace exposures in many sectors have been reported (3–5). Among all the workplaces, offices are not frequently associated with common agents for occupational asthma, office workers consequently remain a low risk of contracting occupational asthma (6, 7). Among all the workplaces, with relatively few exposure conditions associated with the incidence of occupational asthma, the risk of occupational asthma in the offices is low. However, A prevalence study conducted among office workers found totally 9.6% had doctor-diagnosed asthma (8). Anderson et al. (9) found that administrative support workers, including clerical workers and health service workers had significantly higher prevalence ratios (PR 1.5, 95%CI 1.2–1.9) of current asthma than prevalence in all industries. Thus, attention should be paid to the more specific occupational groups used to be simply classified as office workers.

Asthma can be triggered by factors such as exposure to allergens or irritants (10). A positive association between HDM allergens, dust, indoor air, mold, solvents and respiratory symptoms in office workers was reported (8, 11).

Related studies have shown a positive correlation between HDM allergens, dust, indoor air, mold, solvents and respiratory symptoms in office workers. The influencing factors of asthma are intricate, mainly attributed to genetic and environmental factors (12). Some researches have pointed out that there is also a certain amount of fungal pollution in different working environments, such as hospitals, nursing homes, museums and so on (13–15). When the fungus is exposed to a certain concentration it can cause asthma attacks in residents or staff (16, 17). Among them, archivists are susceptible to asthma due to the influence of working area and working mode.

Archive workers, a more specific occupational group as part of the office workers, besides dealing with relevant works in the office, closely expose to archive documents and document storage environment resulting. Most documents and files deposited in archives are made of paper, which are susceptible to chemical and biological damage. As a consequence of the exposed items degradation, VOCs can be formed from the paper itself (18), including acetic acid, formic acid, furfural, furfural, 4-hydroxy benzoic acid, 4-hydroxy acetophenone (19). Cladosporium, Aspergillus, and Penicillium species are almost ubiquitous in the archives (20), which induces allergic reactions and further developing of asthma (1, 21, 22). Exposure to biological allergens such as insect and microorganism is another crucial potential risk factor associated with incidence of asthma (23, 24). To the best of our knowledge, no studies have investigated asthma among archive workers.

Therefore, we sought to identify the prevalence and factors associated with asthma attacks in archival workers. In this study, a questionnaire-based study was conducted among archivists to investigate the associated factors concerning asthma attacks, and concurrently assessed potential interactions that may augment the risk of asthma attacks.

This study found that the prevalence of asthma attacks was 33.3%, higher among male archivists. The existence of chemically irritating odors and moldy smells within the work environment were associated with higher asthma attacks. We also found a significant synergistic effect between the two risk factors. To the best of our knowledge, this is the first multicenter study focusing specifically on the risk factors related to asthma in archivists and provides a fresh perspective on occupational asthma.

The present study identified a significant association between the presence of chemically irritating odors in archival workplaces and high asthma attacks among archivists. Occupational hazards for archivists primarily stem from indoor air pollution, including conventional indoor chemical pollutants such as formaldehyde, sulfur dioxide, volatile organic compound (26). Additionally, there are archival-specific chemical pollutants such as acetic acid, hydrogen sulfide, ethylene oxide, sulfuryl fluoride, furfural, and other compounds (19). It has been reported that exposure to ozone and sulfur dioxide has deleterious effects on immune competent cells and airway responsiveness (27). Owing to its potential to sensitize airway inflammation, ozone exhibits a propensity to induce various respiratory ailments, encompassing coughing and wheezing (28). It has been extensively elucidated that elevated ozone levels have an inflammatory impact on the respiratory system, thereby contributing to the progression of asthma (29). Interestingly, a study revealed a negative correlation between low-to-moderate atmospheric ozone levels and hospital visits by asthma patients (30). However, the measured median ozone concentration in office environments is 9.04 μg/m³ (31), which were consistent with this study’s results. A noteworthy association between the frequency of printer usage (exceeding seven times per day) and the occurrence of asthma attack was demonstrated in our study. A study conducted in Estonia, with participation from over 50,000 adults, have revealed a significant association between exposure ranging from low to moderate levels of indoor air pollutants and asthma (OR = 1.88, 95%CI 1.48 ~ 2.37) (22). Inhalation of VOCs, in particular, has been implicated in various adverse health effects (32), and their role in triggering asthma is well-documented. VOCs can activate the immune system, cause oxidative stress, and interact with some allergens (33). Metabolites of VOCs have also been found to be correlated with markers of oxidative stress, which are associated with lung function parameters (33–35). Furthermore, multiple studies have reported a connection between exposure to formaldehyde and the development of asthma and asthma symptoms in adults. Formaldehyde, as a respiratory irritant, exerts its effects by inducing inflammation of the airway mucosa and eliciting an inflammatory response via cytokines produced by Th2 cells (34). Additionally, transient decreases in lung function have been attributed to formaldehyde exposure (36).

In addition, this study has indicated mold as an associated factor for asthma among archivists, exhibiting a correlated escalation of 65.1 and 73.8% in warehouses and workplaces, respectively. Molds, being a potent allergens, can trigger allergic reactions, provoke inflammatory responses and augment the susceptibility to asthma via the emission of VOCs (26). A study has revealed a pronounced elevation of Asthma-COPD Overlap Syndrome (ACOS) associated with occupational exposure to mold odor, with an odds ratio (OR) of 3.43(95%CI 1.04–11.29) (37). Although limited research has been conducted among office workers, previous studies have consistently reported a positive correlation between mold odor and adult individuals in residential settings (38–40). Furthermore, a heightened susceptibility to asthma was detected in relation to occupational exposure to mold odor, as opposed to exposure within the confines of one’s abode (37). This could be potentially elucidated by the more pervasive prevalence of mold issues in archives, coupled with a tendency for individuals to expeditiously remedy any mold-related problems within their own dwellings. Another biological factor encountered in the workplace, i.e., dust mites and cockroaches, may contribute to an elevated risk of asthma by 39.5%. A recent study revealed that dust mite allergen concentration of 10 μg g-1 has been proposed as the threshold for asthma development. While the levels of Der p 1 and Der f 1 allergens in dust samples collected from offices in Malaysia were found to be as high as 556 ng/g and 658 ng/g, respectively (8). Our findings align with the previous study, as we have observed an increased asthma attacks in connection with exposure to dust mites and cockroaches (41). Hence, it is crucial to accord primacy to the eradication of dust particles and the implementation of sterilization protocols within archival repositories.

Notably, our data analysis has revealed a strong synergy (OR = 7.098) between chemical odors and molds in the workplace. While the existing literature on this specific interaction remains somewhat limited, previous studies have already demonstrated the potential for chemical irritants, such as sulfur dioxide and ozone, to synergistically interact with inhalable allergens, including fungi, molds and dust mites. Consequently, this interaction serves to exacerbate asthma symptoms and perpetuate untreated exposure (42). Furthermore, in damp and damaged buildings, the presence of microbial components, such as cellular debris or spores released during fungal growth can trigger an inflammatory response, potentially served as a shared pathway for the development of asthma among individuals exposed to these hazardous factors.

Interestingly, contrary to findings from other studies that reported a higher prevalence of asthma among women than men, this study revealed that the prevalence of asthma among archivists was 1.28 times higher among male workers. Stratified analysis by gender demonstrates significantly higher odds ratios (ORs) for males in both chemical and biological factors. More precisely, the presence of chemically irritating odors and biological agents, such as molds and dust mites, in the archival work environment is more robustly correlated with declining pulmonary function in males. This finding in concordance with a previous study carried out in Italy (43).

In conclusion, this survey revealed that approximately one-third of archivists experienced asthma attacks. Chemically irritating odor, Mold odor and insects in the workplaces are associated with asthma attacks. Moreover, chemically irritating gases and molds in the archival workplace were highly associated with asthma attack, with a significant interaction between them. However, the health relevance and mechanism of the work-related exposure in archives need to be further explored by more detailed assessments.