Indoor mold odor in the workplace increases the risk of Asthma-COPD Overlap Syndrome: a population-based incident case-control study

[Medical clinical diagnostics for indoor mould exposure - Update 2023 (AWMF Register No. 161/001)]

This article is an abridged version of the updated AWMF mould guideline "Medical clinical diagnostics in case of indoor mould exposure - Update 2023", presented in July 2023 by the German Society of Hygiene, Environmental Medicine and Preventive Medicine (Gesellschaft für Hygiene, Umweltmedizin und Präventivmedizin, GHUP), in collaboration with German and Austrian scientific medical societies, and experts. Indoor mould growth is a potential health risk, even if a quantitative and/or causal relationship between the occurrence of individual mould species and health problems has yet to be established. There is no evidence for a causal relationship between moisture/mould damage and human diseases, mainly because of the ubiquitous presence of fungi and hitherto inadequate diagnostic methods. Sufficient evidence for an association between moisture/mould damage and the following health effects has been established for: allergic respiratory diseases, allergic rhinitis, allergic rhino-conjunctivitis, allergic bronchopulmonary aspergillosis (ABPA), other allergic bronchopulmonary mycosis (ABPM), aspergilloma, Aspergillus bronchitis, asthma (manifestation, progression, exacerbation), bronchitis (acute, chronic), community-acquired Aspergillus pneumonia, hypersensitivity pneumonitis (HP; extrinsic allergic alveolitis (EEA)), invasive Aspergillosis, mycoses, organic dust toxic syndrome (ODTS) [workplace exposure], promotion of respiratory infections, pulmonary aspergillosis (subacute, chronic), and rhinosinusitis (acute, chronically invasive, or granulomatous, allergic). In this context the sensitizing potential of moulds is obviously low compared to other environmental allergens. Recent studies show a comparatively low sensitization prevalence of 3-22,5 % in the general population across Europe. Limited or suspected evidence for an association exist with respect to atopic eczema (atopic dermatitis, neurodermatitis; manifestation), chronic obstructive pulmonary disease (COPD), mood disorders, mucous membrane irritation (MMI), odor effects, and sarcoidosis. (iv) Inadequate or insufficient evidence for an association exist for acute idiopathic pulmonary hemorrhage in infants, airborne transmitted mycotoxicosis, arthritis, autoimmune diseases, cancer, chronic fatigue syndrome (CFS), endocrinopathies, gastrointestinal effects, multiple chemical sensitivity (MCS), multiple sclerosis, neuropsychological effects, neurotoxic effects, renal effects, reproductive disorders, rheumatism, sick building syndrome (SBS), sudden infant death syndrome, teratogenicity, thyroid diseases, and urticaria.The risk of infection posed by moulds regularly occurring indoors is low for healthy persons; most species are in risk group 1 and a few in risk group 2 (Aspergillus fumigatus, A. flavus) of the German Biological Agents Act (Biostoffverordnung). Only moulds that are potentially able to form toxins can be triggers of toxic reactions. Whether or not toxin formation occurs in individual cases is determined by environmental and growth conditions, water activity, temperature and above all the growth substrates.In case of indoor moisture/mould damage, everyone can be affected by odor effects and/or mood disorders.However, this is not an acute health hazard. Predisposing factors for odor effects can include genetic and hormonal influences, imprinting, context and adaptation effects. Predisposing factors for mood disorders may include environmental concerns, anxiety, condition, and attribution, as well as various diseases. Risk groups to be protected particularly regarding infection risk are immunocompromised persons according to the classification of the German Commission for Hospital Hygiene and Infection Prevention (Kommission für Krankenhaushygiene und Infektionsprävention, KRINKO) at the Robert Koch-Institute (RKI), persons suffering from severe influenza, persons suffering from severe COVID-19, and persons with cystic fibrosis (mucoviscidosis); with regard to allergic risk, persons with cystic fibrosis (mucoviscidosis) and patients with bronchial asthma must be protected. The rational diagnostics include the medical history, physical examination, and conventional allergy diagnostics including provocation tests if necessary; sometimes cellular test systems are indicated. In the case of mould infections, the reader is referred to the specific guidelines. Regarding mycotoxins, there are currently no useful and validated test procedures for clinical diagnostics. From a preventive medical point of view, it is important that indoor mould infestation in relevant magnitudes cannot be tolerated for precautionary reasons.For evaluation of mould damage in the indoor environment and appropriate remedial procedures, the reader is referred to the mould guideline issued by the German Federal Environment Agency (Umweltbundesamt, UBA).

Insights into uncovered public health risks. The case of asthma attacks among archival workers: a cross-sectional study

Objective

To ascertain the prevalence of asthma attacks among archivists and identify the associated occupational factors in this understudied professional population.

Methods

We conducted a cross-sectional, questionnaire-based study among 1,002 archival workers. A multiple logistic regression was conducted to identify the association between asthma attacks and occupational exposures. The Strobe Protocol was applied.

Results

999 workers were included in the final analysis with the asthma prevalence of 33.3%. Main factors associated with asthma attacks (OR [95% CI]) were the presence of chemically irritating odors (2.152 [1.532-3.024]), mold odors (1.747 [1.148-2.658]), and insects (1.409[1.041-1.907]). A significant synergistic effect was observed between chemical irritants and mold, the odds ratio was 7.098 (95% CI, 4.752-10.603).

Conclusion

There was a high prevalence of asthma attacks among archival workers, an under-studied population. Chemical irritants, molds and insects were associated with their asthma attacks. Notably, this study's data analysis has revealed a strong synergy (OR = 7.098) between chemical odors and molds in the workplace. While the existing international 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 seems to exacerbate asthma symptoms and perpetuate untreated exposure. 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.

Respiratory Diseases Associated With Organic Dust Exposure

Organic dusts are complex bioaerosol mixtures comprised of dust and par ticulate matter of organic origin. These include components from bacteria, fungi, pollen, and viruses to fragments of animals and plants commonplace to several environmental/occupational settings encompassing agriculture/farming, grain processing, waste/recycling, textile, cotton, woodworking, bird breeding, and more. Organic dust exposures are linked to development of chronic bronchitis, chronic obstructive pulmonary disease, asthma, asthma-like syndrome, byssinosis, hypersensitivity pneumonitis, and idiopathic pulmonary fibrosis. Risk factors of disease development include cumulative dust exposure, smoking, atopy, timing/duration, and nutritional factors. The immunopathogenesis predominantly involves Toll-like receptor signaling cascade, T-helper 1/T-helper 17 lymphocyte responses, neutrophil influx, and potentiation of manifestations associated with allergy. The true prevalence of airway disease directly attributed to organic dust, especially in a workplace setting, remains challenging. Diagnostic confirmation can be difficult and complicated by hesitancy from workers to seek medical care, driven by fears of potential labor-related consequence. Clinical respiratory and systemic presentations coupled with allergy testing, lung function patterns of obstructive versus restrictive disease, and radiological characteristics are typically utilized to delineate these various organic dust-associated respiratory diseases. Prevention, risk reduction, and management primarily focus on reducing exposure to the offending dust, managing symptoms, and preventing disease progression.

AWMF mold guideline "Medical clinical diagnostics for indoor mold exposure" - Update 2023 AWMF Register No. 161/001

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What should be tested in patients with suspected mold exposure? Usefulness of serological markers for the diagnosis

The associations of mold exposure, IgE-mediated sensitization, inflammatory markers, and respiratory symptoms were analyzed in 46 exposed and 23 non-exposed individuals. Both exposure and clinical symptoms were assessed by questionnaire. Specific (s)IgE to mold mixture (mx1) was significantly higher and found more frequently in exposed (41%) than non-exposed individuals (17%), which was not observed for sIgG to mold mix (Gmx6). Notably, exposed asthmatics were more frequently sensitized to molds (55%) compared to exposed non-asthmatics (18%). In addition, the serum concentrations of club cell protein (CC16) were significantly lower in exposed subjects, especially in asthmatics. Positive associations were observed among mold sensitization, asthma, and mold exposure, but not in subjects with predominantly environmental sensitizations without mold sensitization. Thus, sIgE to mx1 but not sIgG to Gmx6 is a useful diagnostic marker to verify mold-associated respiratory symptoms.

Clinical relevance of Alternaria alternata sensitization in patients within type 2-high and type 2-low asthma

Alternaria sensitization is correlated with persistent asthma. Type 2 (T2)-asthma endotypes are characterized by the release of eosinophils. However, the prevalence and sensitization patterns in patients with Alternaria asthma between T2-high and T2-low endotypes are unknown. We retrospectively reviewed 582 patients with Alternaria asthma and divided them into T2-high (n = 376) and T2-low (n = 206) groups with a threshold of 300 cells/µL in blood eosinophil counts. Data for basic information, skin test or IgE detection results, and blood eosinophil counts were collected. The age of patients in the T2-high group (13.66 ± 13.23) was lower than that of the T2-low group (18.02 ± 15.03). Patients with T2-high asthma had relatively higher rates of taking inhaled corticosteroids (ICS) and positive family history than the T2-low group. Pet keepers and allergen immunotherapy (AIT) patients were comparable between these groups, In the T2-high group, patients had higher levels of total serum IgE (T-IgE) and showed a significant positive correlation with eosinophil counts (r = 0.166, P = 0.001), followed by higher Alternaria-specific IgE (sIgE) levels (median, 13.7; range, 4.86-25.3). Compared to the T2-low group, the frequency of poly-sensitized patients and the rate of each allergen among the nine common allergens were all higher in the T2-high group; the statistical differences mainly focused on pollens such as birch (P = 0.005), firmiana (P = 0.004), and mugwort (P = 0.005). Young, male patients had a high prevalence of T2-high Alternaria asthma, along with higher rates of T-IgE, sIgE levels, and poly-sensitized patterns.

Asthma-COPD Overlap: What Are the Important Questions?

Asthma-COPD overlap (ACO) is a heterogeneous condition that describes patients who show persistent airflow limitation with clinical features that support both asthma and COPD. Although no single consensus definition exists to diagnose this entity, common major criteria include a strong bronchodilator reversibility or bronchial hyperreactivity, a physician diagnosis of asthma, and a ≥ 10-pack-year cigarette smoking history. The prevalence of ACO ranges from 0.9% to 11.1% in the general population, depending on the diagnostic definition used. Notably, patients with ACO experience greater symptom burden, worse quality of life, and more frequent and severe respiratory exacerbations than those with asthma or COPD. The underlying pathophysiologic features of ACO have been debated. Although emerging evidence supports the role of environmental and inhalational exposures in its pathogenesis among patients with a pre-existing airway disease, biomarker profiling and genetic analyses suggest that ACO may be a heterogeneous condition, but with definable characteristics. Early-life factors including childhood-onset asthma and cigarette smoking may interact to increase the risk of airflow obstruction later in life. For treatment options, the population with ACO historically has been excluded from therapeutic trials; therefore strong, evidence-based recommendations are lacking beyond first-line inhaler therapies. Advanced therapies in patients with ACO are selected according to disease phenotypes and are based on extrapolated data from asthma and COPD. Research focused on defining biomarkers and evidence-based treatment options for ACO is needed urgently.

Novel approaches in occupational asthma diagnosis and management

PURPOSE OF REVIEW

To describe the recent findings of the last 2 years on the epidemiology and phenotypes of occupational asthma, as well as new developments in its diagnosis and management.

RECENT FINDINGS

Data from nine longitudinal studies showed a population attributable fraction for the occupational contribution to incident asthma of 16%. The main phenotypes of occupational asthma are: occupational asthma caused by high-molecular-weight (HMW) or low-molecular-weight (LMW) agents, irritant-induced asthma and occupational asthma-chronic obstructive pulmonary disease overlap. Among the variety of causative agents of occupational asthma, food-derived components are increasingly being reported, accounting for up to 25% cases of occupational asthma and/or occupational rhinitis. Recently, a specific inhalation challenge (SIC)-independent model has been developed to calculate the probability of occupational asthma diagnosis in workers exposed to HMW agents. In this model, work-specific sensitization, bronchial hyperresponsiveness, inhaled corticosteroid use, rhinoconjunctivitis and age 40 years or less were the most relevant predictive factors. Specific IgE measurements showed a pooled sensitivity of 0.74 and a specificity of 0.71 in the diagnosis of occupational asthma for HMW agents, while a lower sensitivity (0.28) and a higher specificity (0.89) was shown for LMW agents. Cessation of exposure to workplace sensitizers is the cornerstone of management of work-related conditions.

SUMMARY

An early and precise diagnosis of occupational asthma is crucial, allowing appropriate management and implementation of preventive strategies.

Occupation and subcategories of asthma: a population-based incident case-control study

Background

We hypothesised that occupational exposures differently affect subtypes of adult-onset asthma.

Objective

We investigated potential relations between occupation and three subtypes of adult asthma, namely atopic asthma, non-atopic asthma and asthma–COPD overlap syndrome (ACOS).

Methods

This is a population-based case–control study of incident asthma among working-age adults living in Pirkanmaa Hospital District in Southern Finland. The determinant of interest was occupation at the time of diagnosis of asthma or the job that the subject had quit due to respiratory symptoms. Asthma was divided into three mutually exclusive subtypes on the basis of any positive IgE antibody (atopic and non-atopic asthma) and presence of persistent airways obstruction in spirometry (ACOS). We applied unconditional logistic regression analysis to estimate adjusted OR (aOR), taking into account gender, age and smoking.

Results

The following occupational groups showed significantly increased risk of atopic asthma: chemical industry workers (aOR 15.76, 95% CI 2.64 to 94.12), bakers and food processors (aOR 4.69, 95% CI 1.18 to 18.69), waiters (aOR 4.67, 95% CI 1.40 to 15.56) and those unemployed (aOR 3.06, 95% CI 1.52 to 6.17). The following occupations showed clearly increased risk of non-atopic asthma: metal workers (aOR 8.37, 95% CI 3.77 to 18.59) and farmers and other agricultural workers (aOR 2.36, 95% CI 1.10 to 5.06). Some occupational groups showed statistically significantly increased OR of ACOS: electrical and electronic production workers (aOR 30.6, 95% CI 6.10 to 153.35), fur and leather workers (aOR 16.41, 95% CI 1.25 to 215.85) and those retired (aOR 5.55, 95% CI 1.63 to 18.97).

Conclusions

Our results show that different occupations are associated with different subtypes of adult-onset asthma.

Association of toxic indoor air with multi-organ symptoms in pupils attending a moisture-damaged school in Finland

BACKGROUND

There is an on-going debate on how best to test toxic indoor air. Toxicological methods based on condensed water samples and cell culture technique are newly introduced research tools which were tested in this study.

METHODS

Pupils (n=47) from a water-damaged and (n=56) healthy schools were interviewed using a questionnaire. Indoor air was collected with a novel condensed water sampling technique and human THP-1 macrophages were exposed to the condensate. The cytotoxicity of cotton wool swab samples was tested using human BJ fibroblasts. Conventional microbiological culture methods were also performed.

RESULTS

Gastrointestinal problems (GI) were reported by 51% from the study cohort but only 4% of the control cohort, relative risk RR=14.30. For any neurological or neuropsychological symptoms, the RR was 63.04, muscular-skeletal pain RR=58.28, headache RR=31.00, respiratory symptoms RR=22.64, fatigue RR=21.45, sub febrility RR=15.49, ear infections RR=7.74, skin rash RR=5.96, all being statistically significant (P<0.001). All indoor air (n=7) and cotton wool samples (n=2) taken from the water-damaged classroom or in proximity of the problematic classrooms were toxic in cell culture assays. Low numbers of moisture-damage indicators were recovered from wall, passive air, and swab samples, namely Aspergillus ochraceus species group, Aspergillus, Eurotium species group, Fusarium, Tritirachium, Scopulariopsis genus group and Aspergillus versicolores species group.

CONCLUSIONS

Indoor air toxicity and dampness-related microbiota recovered from the classrooms were associated with multi-organ morbidity of the school occupants. These results corroborated our previous reports from two adult cohorts i.e. evidence of causality. These new toxicological methods based on condensed water and cell culturing techniques seem to be superior to conventional microbiological methods in correlating with clinical symptoms.

Impact of Identification of Clinical Phenotypes in Occupational Asthma

Phenotypic differences and similarities in the spectrum of occupational asthma (OA) subtypes reflect the underlying mechanisms of the diverse forms of the disease, and these phenotypes provide information as to diagnostic steps and approaches to management. In large part, the phenotype reflects the existence of immunologic mechanisms and the presence or absence of a specific IgE-antibody response to a work sensitizer. However, further differences occur between OA from high- and low-molecular-weight sensitizers (chemical sensitizers), which potentially might be relevant for nonoccupational asthma. Chemical sensitizers cause a specific response that is more likely to be a late asthmatic response and specific IgE can be identified only in a minority. Irritant-induced asthma is most easily recognized when it occurs with 1 or more high-level respiratory irritant exposure(s) but is also possible with chronic low-level exposures as in cleaners, farmers, and woodworkers, as suggested from epidemiologic studies. OA chronic obstructive pulmonary disease overlap is more common in older patients and with OA from low-molecular-weight sensitizers. Removal from exposure to the causative agent is currently advised for those with OA from sensitization: further studies with omalizumab and other biologic agents are needed to determine whether these might allow return to the same exposure.