Medical diagnostics for indoor mold exposure

The impact of mold exposure on anxiety symptoms in the older adults: A moderated mediation model based on CLHLS

BACKGROUND

Mold exposure is a common environmental issue that can adversely affect health, particularly among older adults. The impact of mold exposure on anxiety symptoms in this population has not been extensively studied.

OBJECTIVE

This study aims to examine the relationship between mold exposure and anxiety symptoms in older adults, considering the mediating role of cognitive function and the moderating effects of open window ventilation and multivitamin supplementation.

METHODS

Data from the eighth wave of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) was utilized, including 11,021 participants aged 65 and older. Logistic regression models and moderated mediation analysis were employed to explore these relationships.

RESULTS

Mold exposure was significantly associated with increased anxiety symptoms (OR=1.831, 95 % CI=1.588-2.110). Cognitive impairment partially mediated this relationship. Open window ventilation (B=-0.040, P<0.001) and multivitamin supplementation (B=-0.197, P<0.001) served as protective factors. Subgroup analysis indicated higher vulnerability among females (OR=1.72, P<0.001), those aged 65-79 (OR=1.86, P<0.001), urban residents (OR=2.50, P<0.001), individuals not living with family members (OR=1.89, P<0.001), those with higher education (OR=2.01, P<0.001), married individuals (OR=1.80, P<0.001), and those in very good health (OR=2.11, P=0.026).

CONCLUSION

Mold exposure contributes to anxiety symptoms in older adults, with cognitive decline playing a mediating role. Effective interventions, including improved ventilation and multivitamin supplementation, can mitigate these effects. These findings highlight the need for targeted public health strategies to enhance the well-being of older adults.

Clinical characteristics and outcomes of pleural aspergillosis: a review of 13 cases

Aspergillus pleurisy is a rare complication of invasive pulmonary aspergillosis (IPA), which mostly occurs in the immunocompromised host. The clinical condition is critical, especially to those who develop bronchopleural fistula. This study aimed to assess the characteristics and the prognosis of aspergillus pleurisy. Clinical data from 13 patients diagnosed with aspergillus pleurisy in our hospital from January 2000 to December 2022 were retrospectively studied. Thirteen patients with Aspergillus pleurisy were included. There were 10 males and 3 females, with a median age of 65 (range: 18-79) years. Bronchopleural fistula was present in eight patients. A proven diagnosis of Aspergillus pleurisy was based on positive pleural fluid culture in seven cases and histopathological examination of pleural biopsies in six cases. Four patients refused further treatment and were discharged from the hospital against medical advice. Nine cases recovered and were discharged after multiple antifungal treatments (systemic and topical antifungal therapies, pleural drainage and irrigation, and surgical repair). During follow-up, one patient, who suffered underlying bronchiectasis, died of massive hemoptysis 2 years after discharge. The remaining eight cases are still under close follow-up, with a median follow-up of 5.4 (range: 1.3-18.9) years. The prognosis of aspergillus pleurisy complicated with bronchopleural fistula is poor. Thoracic surgery, especially lung resection, is a risk factor associated with the incidence of Aspergillus pleurisy. Systemic antifungal therapy and adequate pleural irrigation could improve the prognosis.

IMPORTANCE

Aspergillus pleurisy is a rare complication of invasive pulmonary aspergillosis (IPA), associated with a poor prognosis. The morbidity and mortality of this condition have not been thoroughly studied, and recent research on this topic is limited. The current study included 13 patients diagnosed with Aspergillus pleurisy, with the majority presenting concomitantly with a bronchopleural fistula. Among these patients, nine had a history of thoracic surgery, including lung transplantation and lobectomy. Four patients refused further treatment and were discharged against medical advice, while one patient succumbed to massive hemoptysis 2 years after discharge. This case series provides essential insights into Aspergillus pleurisy and evaluates the therapeutic strategy based on a limited cohort.

Assessment of mould remediation in a healthcare setting following extensive flooding

BACKGROUND

A new hospital building was close to completion when a large pipe carrying clean water broke, causing extensive flooding.

AIM

To determine the flood-associated fungal risk to susceptible patients who would use that building.

METHODS

Though standard flood remediation by the builders was relatively straightforward, there was no model for specialist assessment of patient risk due to the flood-associated mould growth. As levels of background airborne fungal spores can be expected to vary significantly over time, we could not use absolute levels to indicate either an excess of airborne fungal spores or successful remediation. Therefore it was decided to use weekly settle plates, exposed at the same time in flooded (test) and equivalent non-flooded (control) areas to compensate for variations in background levels. Flood-related risk was estimated by the ratio between fungal colonies on the test and control sets of settle plates, rather than absolute number.

FINDINGS

Whereas the physical flood remediation, including the use of 'anti-fungal' treatments, was completed in three weeks post flooding, fungal contamination in flooded areas took 38 weeks to return to control levels and remained so for a further six weeks of observation.

CONCLUSION

By the use of this method, we were able to assure the absence of flood-associated fungal risk to susceptible patients who would use that building. We recommend that infection prevention and control teams consider using this approach should they be faced with similar situations.

Evaluating the mechanism of soybean meal protein for boosting the laccase-catalyzed of thymol onto lignosulfonate via restraining non-specific adsorption

The control of laccase-catalyzed efficiency often relies on the utilization of modifying enzyme molecules and shielding agents. However, their elevated costs or carcinogenicity led to the inability for large-scale application. To address this concern, we found that a low-cost protein from soybean meal can reduce lignin's ineffective adsorption onto enzymes for improving the efficiency of thymol grafting to lignosulfonate. The results demonstrated that by adding 0.5 mg/mL of additional soybean meal protein, the thymol reaction ratio of the modified lignosulfonate (L-0.5 S) significantly boosted from 18.1 % to 35.0 %, with the minimal inhibitory concentrations of the L-0.5 S against Aspergillus niger dramatically improved from 12.5 mg/mL to 3.1 mg/mL. Multiple characterization methods were employed to better understand the benefit of the modification under the addition of the soybean meal protein. The CO and R1-O group content increased from 20.5 % to 37.8 % and from 65.1 % to 75.5 %, respectively. The proposed potential reaction mechanism was further substantiated by the physicochemical properties. The incorporation of soybean meal effectively mitigated the non-specific adsorption of lignosulfonate, resulting in a reduction of the surface area of lignin from 235.0 to 139.2 m2/g. The utilization of soybean meal as a cost-effective and efficient shielding agent significantly enhanced the efficiency of subsequent enzyme catalysis. Consequently, the application of soybean meal in commercial enzyme catalysis holds considerable appeal and amplifies the relevance of this study in preservative industries.

Effects of ZnO/trimethylsilyl cellulose nano-composite coating on anti-UV and anti-fungal properties of papers

Trimethylsilyl cellulose (TMSC) was employed as the coating matrix for the application of zinc oxide nanoparticles (ZnO) onto paper surfaces and the protections of ZnO/TMSC coating against UV-induced damages and fungal spoilage were evaluated. Filter papers were immersed in 2% w/v TMSC solution loaded with ZnO and air-dried. Three ZnO/TMSC suspensions were prepared with 0.1, 0.5, and 1% w/v ZnO NPs. The presences of ZnO/TMSC protective layers were confirmed with ATR-IR spectroscopy. The coated papers exhibited high surface hydrophobicities. After the coated papers were subject to 365-nm UV irradiation at 400 W for 3 h, the contact angles dramatically dropped. The trimethylsilyl (TMS) groups exposed on the surface formed a moisture barrier and were partially removed on UV exposure. ATR-IR revealed that more TMS groups were removed in the protective layer with no ZnO. UV-irradiated papers turned yellow and papers protected with 1% ZnO/TMSC exhibited significantly lower color changes than that of the uncoated one. Compared to the TMSC-coated paper, the addition of ZnO resulted in a significant reduction in tensile strength at maximum. However, after UV irradiation, significant increases in both the strain at break and strength at maximum were only observed in 1% ZnO/TMSC-protected papers. Regarding their anti-fungal properties, the 1% ZnO/TMSC films were effective in growth inhibitions of Aspergillus sp. and Penicillium sp. on the nonirradiated papers. Despite being hydrophilic after UV-irradiation, growths of the molds were severely suppressed on the UV-irradiated paper.

Laboratory Test Results in Patients with Workplace Moisture Damage Associated Symptoms—The SAMDAW Study

The mechanisms of health effects of moisture damage (MD) are unclear, but inflammatory responses have been suspected. The usefulness of laboratory and allergy tests among patients in secondary healthcare with symptoms associated with workplace MD were examined. Full blood count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), total serum immunoglobulin E (IgE), fractional exhaled nitric oxide (FeNO), and skin prick testing were assessed and analyzed in relation to multiple chemical sensitivity (MCS) and perceived stress in 99 patients and 48 controls. In analysis, t-tests, Mann-Whitney tests, and chi-squared tests were used. Minor clinically insignificant differences in blood counts were seen in patients and controls, but among patients with asthma an elevated neutrophil count was found in 19% with and only in 2% of patients without asthma (p = 0.003). CRP levels and ESR were low, and the study patients’ FeNO, total IgE, or allergic sensitization were not increased compared to controls. The level of stress was high among 26% of patients and 6% of controls (p = 0.005), and MCS was more common among patients (39% vs. 10%, p < 0.001). Stress or MCS were not significantly associated with laboratory test results. In conclusion, no basic laboratory or allergy test results were characteristic of this patient group, and neither inflammatory processes nor allergic sensitization were found to explain the symptoms among these patients. While the value of basic laboratory tests should not be ignored, the use of allergy tests does not seem necessary when symptoms are indicated to be workplace-related.

Differential effects of exposure to toxic or nontoxic mold spores on brain inflammation and Morris water maze performance

People who live or work in moldy buildings often complain of "brain fog" that interferes with cognitive performance. Until recently, there was no published research on the effects of controlled exposure to mold stimuli on cognitive function or an obvious mechanism of action, fueling controversy over these claims. The constellation of health problems reported by mold-exposed individuals (respiratory issues, fatigue, pain, anxiety, depression, and cognitive deficits) correspond to those caused by innate immune activation following exposure to bacterial or viral stimuli. To determine if mold-induced innate immune activation might cause cognitive issues, we quantified the effects of both toxic and nontoxic mold on brain immune activation and spatial memory in the Morris water maze. We intranasally administered either 1) intact, toxic Stachybotrys chartarum spores; 2) ethanol-extracted, nontoxic Stachybotrys chartarum spores; or 3) control saline vehicle to mice. Inhalation of nontoxic spores caused significant deficits in the test of long-term memory of platform location, while not affecting short-term memory. Inhalation of toxic spores increased motivation to reach the platform. Interestingly, in both groups of mold-exposed males, numbers of interleukin-1β-immunoreactive cells in many areas of the hippocampus significantly correlated with latency to find the platform, path length, and swimming speed during training, but not during testing for long-term memory. These data add to our prior evidence that mold inhalation can interfere with cognitive processing in different ways depending on the task, and that brain inflammation is significantly correlated with changes in behavior.

ZnO recovered from spent alkaline batteries as antimicrobial additive for waterborne paints

Biocides are employed to prevent biodeterioration in waterborne paints. In the present study, we used zinc oxide nanoparticles (obtained from spent alkaline batteries) as biocide for indoor waterborne paint at 1.5% of the total solid content in paint. Two different zinc oxides synthesized from spent alkaline batteries, which showed photocatalyst activity, were employed as an antimicrobial agents. After leaching the anode of alkaline batteries, zinc was precipitated from the leachate liquor by introducing oxalic acid (O-ZnO) or sodium carbonate (C-ZnO). The antimicrobial properties of the prepared oxides were tested against Staphylococcus aureus (bacteria), Chaetomium globosum, and Aspergillus fumigatus (fungi) using agar well diffusion method. C-ZnO inhibited the growth of all the strains studied and presented enhanced activity than O-ZnO. The better performance as antimicrobial agent of C-ZnO compared to O-ZnO was attributed to its lower crystallite size, higher amount of oxygen monovacancies, and to its lower band gap energy. The oxide with the best performance in antimicrobial activity, C-ZnO, was employed for the formulation of waterborne acrylic paints. It was observed that 1.5% C-ZnO improved the antifungal properties and antibacterial properties compared to the control sample.

Characteristics of annual mold variations and association with childhood allergic symptoms/diseases via combining surveys and home visit measurements

The presence of dampness and visible molds leads to concerns of poor indoor air quality which has been consistently linked with increased exacerbation and development of allergy and respiratory diseases. Due to the limitations of epidemiological surveys, the actual fungal exposure characteristics in residences has not been sufficiently understood. This study aimed to characterize household fungal diversity and its annual temporal and spatial variations. We developed combined cross-sectional survey, repeated air sampling around a year, and DNA sequencing methods. The questionnaire survey was conducted in 2019, and 4943 valid cases were received from parents; a follow-up case-control study (11 cases and 12 controls) was designed, and onsite measurements of indoor environments were repeated in typical summer, transient season, and winter; dust from floor and beddings in children's room were collected and ITS based DNA sequencing of totally 68 samples was conducted. Results from 3361 children without changes to their residences since birth verified the significant associations of indoor dampness/mold indicators and prevalence of children-reported diseases, with increased adjusted odd ratios (aORs) >1 for studied asthma, wheeze, allergic rhinitis, and eczema. The airborne fungal concentrations from air sampling were higher than 1000 CFU/m³ in summer, regardless of indoors and outdoors, indicating an intermediate pollution level. The DNA sequencing for dust showed the Aspergillus was the predominant at genus level and the Aspergillus_penicillioides was the most common at species level; while the fungal community and composition varied significantly in different homes and seasons, according to α and β diversity analyses. The comprehensive research methods contribute to a holistic understanding of indoor fungal exposure, including the concentrations, seasonal variations, community, and diversity, and verifies the relations with children's adverse health outcomes. The study further elucidates the role of microbiome in human health, which helps setting health-protective thresholds and managing mold treatments in buildings, to promote indoor air quality and human well-beings.

Transferring from moisture damaged school building to clean facilities - The avoidance of mold exposure induces a decline in symptoms and improvement in lung function among personnel

Working in a moisture-damaged building can cause different symptoms and effects on lung functions. Moving to a clean environment, it is believed to reduce symptoms and alleviate potential adverse health effects. This case study monitors the health effects of personnel in one school building before and after all school activities were transferred from a moisture-damaged school building to clean premises. The whole school staff was invited to attend this follow-up study. All participants (N = 45) were interviewed, and pulmonary functions were measured by spirometry and exhaled nitric oxide testing (FE_NO) before transferring the school activities to a new building and the control measurements were performed twice; three months and six months after the transfer. After transferring to temporary facilities, 82% of participants felt that their symptoms were improved or resolved and the pulmonary functions were improved; 50% of those who had decreased pulmonary functions at the beginning, their pulmonary function values returned to normal after three months. Over the next six months, the perceived symptoms continued to reduce so that 93% of the respondents felt fully asymptomatic with respect to indoor air, and the spirometry results improved further. Transferring workers from the damaged building to healthy environment provided beneficial health effects on pulmonary functions and to perceived symptoms even in a relatively short time period. Based on this study, and from the perspective of promoting and protecting the health and well-being of personnel, transferring school activities from a moisture damaged building to clean facilities brought considerable advantages, despite the possible cost and difficulties of finding replacement facilities.

A new headspace solid-phase microextraction coupled with gas chromatography-tandem mass spectrometry method for the simultaneous quantification of 21 microbial volatile organic compounds in urine and blood

Mold growth can cause the development of several metabolites including microbial volatile organic compounds (mVOCs). These latter may be considered as potential biomarkers of fungal presence and have been detected in human biological matrices such as urine and blood. Exposure to molds and their metabolites (e.g., mVOCs, mycotoxins) in occupational settings, is responsible for several health effects. Thus, this exposure cannot be neglected and must be evaluated. Herein, a method has been developed to quantify 21 mVOCs in urine and human blood by headspace solid phase micro-extraction (HS-SPME) coupled with gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). The parameters influencing the extraction process, such as the type of fiber, the incubation and extraction time and temperature and the desorption time, have been optimized to ensure better mVOCs extraction. The developed method showed good linearity over the concentration range of the compounds (R² ˃ 0.995) for all the mVOCs in all the matrices. The low limits of detection (LOD) ranging from 0.7 to 417 ng/L in urine and from 1 to 507 ng/L in blood, make the developed methods sensitive and effective for biomonitoring of exposure at low levels. Recoveries, at low and high concentrations, were between 87% and 120% in urine and between 83% and 118% in blood. The repeatability and the intermediate precision in terms of coefficients of variation (CV%) was lower than 13% and 8.58% respectively for all compounds in all matrices. These values show satisfactory accuracy and precision of the developed method. Thus, this practical, simple, and sensitive method is well suited for the simultaneous quantification of target mVOCs.

Prevalence of Hoarseness in Primary Health Care and Hospitals-Associations With Different Work Tasks and Environmental Factors Among Nurses

OBJECTIVES

The voice is one of the most essential tools necessary for nurses achieve high care satisfaction and safety. Research on hoarseness has mainly focused on professional speakers, like teachers. The aim of this study was to determine the current prevalence of hoarseness among six subgroups of nurses (registered nurses, primary care nurses, pediatric nurses, laboratory nurses, dental nurses, and midwives) and also to identify potential environmental risk factors in their working environment.

METHODS

The health data was collected in collaboration with two health care professional trade unions. The findings are based on 15,553 returned health questionnaires which were statistically analyzed.

RESULTS

The 1-year prevalence of hoarseness among all participating nurses was 30.2 % in this data, but the variation between different occupational subgroups was significant; ranging from 25 % for laboratory nurses to 38 % for midwives. These findings were in line with perceived environmental problems and the differences between the sub-groups were not explained by the participants suffering from asthma, sinusitis, rhinitis, or common respiratory infections; there were no explanatory differences in the prevalence's of the above-mentioned diseases.

CONCLUSIONS

The variation in prevalence of hoarseness between the different occupational subgroups was significant and the prevalence was found to be in line with perceived environmental problems. The most common problems were stuffiness, dry air, and inadequate ventilation. In addition, both a perceived "sewer odor" and "smell of mold or cellar" in one's own working environment were also found to be significant risk factors for hoarseness. Based on this study, the current indoor air problems in Finnish health care facilities can be verified and are a source of risk to nurses' voices.

Clinical Findings among Patients with Respiratory Symptoms Related to Moisture Damage Exposure at the Workplace-The SAMDAW Study

BACKGROUND

Respiratory tract symptoms are associated with workplace moisture damage (MD). The focus of this observational clinical study was patients with workplace MD-associated symptoms, to evaluate the usefulness of different clinical tests in diagnostics in secondary healthcare with a special interest in improving the differential diagnostics between asthma and laryngeal dysfunction.

METHODS

In patients referred because of workplace MD-associated respiratory tract symptoms, we sought to systematically assess a wide variety of clinical findings.

RESULTS

New-onset asthma was diagnosed in 30% of the study patients. Laryngeal dysfunction was found in 28% and organic laryngeal changes in 22% of the patients, and these were common among patients both with and without asthma. Most of the patients (85%) reported a runny or stuffy nose, and 11% of them had chronic rhinosinusitis. Atopy was equally as common as in the general population.

CONCLUSIONS

As laryngeal changes were rather common, we recommend proper differential diagnostics with lung function testing and investigations of the larynx and its functioning, when necessary, in cases of prolonged workplace MD-associated symptoms. Chronic rhinosinusitis among these patients was not uncommon. Based on this study, allergy testing should not play a major role in the examination of these patients.

Evaluating the effect of building construction periods on household dampness/mold and childhood diseases corresponding to different energy efficiency design requirements

Despite concerns about building dampness and children' health, few studies have examined the effects of building energy efficiency standards. This study explored the connections between self-reported household dampness and children' adverse health outcomes across buildings corresponding to construction periods (pre-2001, 2001-2010, post-2010). Significant differences of dampness-related indicators were found between buildings; the prevalence was remarkable in pre-2001 buildings. The prevalence of lifetime-ever doctor-diagnosed diseases for children was significantly associated with building dampness (adjust odd ratios > 1), but was not affected by construction periods. The hygrothermal performance for a typical residence was simulated, varying in U-values of envelopes and air change rates. The simulated performance improvement increased indoor temperatures in 2001-2010 and post-2010 buildings. The frequency with higher indoor relative humidity was higher in pre-2001 buildings, leading to the highest values for maximum mold index (M_max ) on wall surface, especially in winter. Compared to buildings in 2001-2010, increased insulation and lower air change rate led to a relatively higher relative humidity in post-2010 buildings, adversely increasing the M_max values. The findings addressed the positive and negative role of building standard development, which help suggesting appropriate environmental and design solutions to trade-off energy savings and dampness/mold risk in residences.

Quantification of seven microbial volatile organic compounds in human serum by solid-phase microextraction gas chromatography-tandem mass spectrometry

Microbial volatile organic compounds (MVOCs) are primary and secondary metabolites of fungal and bacterial growth. Changes in environmental conditions (e.g., humidity, light, oxygen, and carbon dioxide) influence microbial growth in indoor environments. Prolonged human exposure to MVOCs has been directly associated with sick building syndrome (SBS), respiratory irritation, and asthma-like symptoms. However, no method exists for assessing MVOC exposure by quantifying them in human serum. We developed a novel, high-throughput automated method for quantifying seven MVOCs (3-methylfuran, 2-hexanone, 2-heptanone, 3-octanone, 1-octen-3-ol, 2-ethyl-1-hexanol, and geosmin) in human serum. The method quantifies the target analytes using solid-phase microextraction gas chromatography-tandem mass spectrometry at low parts-per-billion levels. Limits of detection ranged from 0.076 to 2.77 μg/L. This method provides excellent linearity over the concentration range for the analytes, with coefficients of determination >0.992. Recovery in human serum was between 84.5% and 113%, and analyte precision ranged from 0.38% to 8.78%. The intra-day and inter-day reproducibility showed coefficients of variation ≤11% and ≤8%, respectively. Accurate and precise quantification of MVOCs is necessary for detecting and quantifying harmful human exposures in environments with active microbial growth. The method is well suited for high-throughput analysis to aid investigations of unhealthy exposures to microbial emissions.

Health, work performance, and risk of infection in office-like environments: The role of indoor temperature, air humidity, and ventilation

Epidemiological and experimental studies have revealed the effects of the room temperature, indoor air humidity, and ventilation on human health, work and cognitive performance, and risk of infection. In this overview, we integrate the influence of these important microclimatic parameters and assess their influence in offices based on literature searches. The dose-effect curves of the temperature describe a concave shape. Low temperature increases the risk of cardiovascular and respiratory diseases and elevated temperature increases the risk of acute non-specific symptoms, e.g., dry eyes, and respiratory symptoms. Cognitive and work performance is optimal between 22 °C and 24 °C for regions with temperate or cold climate, but both higher and lower temperatures may deteriorate the performances and learning efficiency. Low temperature may favor virus viability, however, depending on the status of the physiological tissue in the airways. Low indoor air humidity causes vulnerable eyes and airways from desiccation and less efficient mucociliary clearance. This causes elevation of the most common mucous membrane-related symptoms, like dry and tired eyes, which deteriorates the work performance. Epidemiological, experimental, and clinical studies support that intervention of dry indoor air conditions by humidification alleviates symptoms of dry eyes and airways, fatigue symptoms, less complaints about perceived dry air, and less compromised work performance. Intervention of dry air conditions by elevation of the indoor air humidity may be a non-pharmaceutical treatment of the risk of infection by reduced viability and transport of influenza virus. Relative humidity between 40 and 60% appears optimal for health, work performance, and lower risk of infection. Ventilation can reduce both acute and chronic health outcomes and improve work performance, because the exposure is reduced by the dilution of the indoor air pollutants (including pathogens, e.g., as virus droplets), and in addition to general emission source control strategies. Personal control of ventilation appears an important factor that influences the satisfaction of the thermal comfort due to its physical and positive psychological impact. However, natural ventilation or mechanical ventilation can become sources of air pollutants, allergens, and pathogens of outdoor or indoor origin and cause an increase in exposure. The "health-based ventilation rate" in a building should meet WHO's air quality guidelines and dilute human bio-effluent emissions to reach an acceptable perceived indoor air quality. Ventilation is a modifying factor that should be integrated with both the indoor air humidity and the room temperature in a strategic joint control to satisfy the perceived indoor air quality, health, working performance, and minimize the risk of infection.

Impact of negative pressure system on microbiological air quality in a Central Sterile Supply Department

OBJECTIVE

Guidelines recommend that the cleaning area in a Central Sterile Supply Department (CSSD) maintain a negative pressure of the environmental air, but how much this system can impact the contamination of the air by bioaerosols in the area is not known. The objective of this study was to assess the impact of negative pressure on CSSD by evaluating the microbiological air quality of this sector.

METHODS

Microbiological air samples were collected in two CSSD in the same hospital: one with and one without a negative air pressure system. Outdoor air samples were collected as a comparative control. Andersen six-stage air sampler was used to obtain the microbiological air samples.

RESULTS

The concentration of bioaerosols in the CSSD without negative pressure was 273.15 and 206.71 CFU/m3 , while in the CSSD with negative pressure the concentration of bioaerosols was 116.96 CFU/m3 and 131.10 CFU/m3 . The number of isolated colonies in the negative pressure CSSD was significantly lower (P = .01541).

CONCLUSION

The findings showed that the negative pressure system in the CSSD cleaning area contributed to the quantitative reduction in bioaerosols. However, the concentration of bioaerosols was lower than that established in the guideline for indoor air quality of many countries. Therefore, it cannot be concluded that CSSDs which do not have a negative pressure system in their cleaning area offer occupational risk.

Bioreactivity, Guttation and Agents Influencing Surface Tension of Water Emitted by Actively Growing Indoor Mould Isolates

The secretion of metabolites in guttation droplets by indoor moulds is not well documented. This study demonstrates the guttation of metabolites by actively growing common indoor moulds. Old and fresh biomasses of indoor isolates of Aspergillus versicolor, Chaetomium globosum, Penicillium expansum, Trichoderma atroviride, T. trixiae, Rhizopus sp. and Stachybotrys sp. were compared. Metabolic activity indicated by viability staining and guttation of liquid droplets detected in young (<3 weeks old) biomass were absent in old (>6 months old) cultures consisting of dehydrated hyphae and dormant conidia. Fresh (<3 weeks old) biomasses were toxic more than 10 times towards mammalian cell lines (PK-15 and MNA) compared to the old dormant, dry biomasses, when calculated per biomass wet weight and per conidial particle. Surfactant activity was emitted in exudates from fresh biomass of T. atroviride, Rhizopus sp. and Stachybotrys sp. Surfactant activity was also provoked by fresh conidia from T. atroviride and Stachybotrys sp. strains. Water repealing substances were emitted by cultures of P. expansum, T. atroviride and C. globosum strains. The metabolic state of the indoor fungal growth may influence emission of liquid soluble bioreactive metabolites into the indoor air.

Influence of indoor chemistry on the emission of mVOCs from Aspergillus niger molds

People spend 80% of their time indoors exposed to poor air quality due to mold growth in humid air as well as human activities (painting, cooking, cleaning, smoking…). To better understand the impact of molds on indoor air quality, we studied the emission of microbial Volatile Organic Compounds (mVOCs) from Aspergillus niger, cultivated on malt agar extract, using a high-resolution proton transfer reaction- time of flight- mass spectrometer (PTR-TOF-MS). These emissions were studied for different cultivation time and indoor relative humidities. Our results show that the concentration of the known C₄-C₉ mVOCs tracers of the microbial activity (like 1-octen-3-ol, 3-methylfuran, 2-pentanone, dimethyl sulfide, dimethyl disulfide, nitromethane, 1,3-octadiene…) was the highest in the early stage of growth. However, these emissions decreased substantially after a cultivation time of 10-14 days and were highly affected by the relative humidity. In addition, the emissions of certain mVOCs were sensitive to indoor light, suggesting an impact of photochemistry on the relative amounts of indoor mVOCs. Based on this study, an estimation of the mVOC concentration for a standard living room was established at different air exchange rates and their indoor lifetimes toward hydroxyl radicals and ozone were also estimated. These findings give insights on possible mVOCs levels in moisture-damaged buildings for an early detection of microbial activity and new evidences about the effect of indoor light on their emission.

High prevalence of neurological sequelae and multiple chemical sensitivity among occupants of a Finnish police station damaged by dampness microbiota

Objectives: The aim of the study was to estimate the risks of different symptoms after the exposure to indoor air dampness microbiota (DM).Methods: This cross-sectional retrospective cohort-based study compared morbidity risks in DM exposed (n = 116) vs. unexposed cohort (n = 45). Gender-adjusted log-binomial regression models were used to calculate risk ratios (RR). The analysis of indoor dust toxicity was based on the inhibition of the motion of boar spermatozoa in vitro. Conventional microbiological work-up was performed in an accredited laboratory.Results: Compared to the unexposed cohort, the study cohort had statistically significant (p < 0.05) risks to develop symptoms of the central nervous system RR = 2.85 (95% CI 1.19-6.85), fatigue RR = 2.82 (1.55-5.11), Multiple Chemical Sensitivity (MCS) RR = 2.81 (1.06-7.46), cardiac arrhythmia RR = 9.58 (1.33-68.81) and respiratory symptoms RR = 2.66 (1.58-4.48).Conclusions: The results of this study corroborate our earlier findings that toxic indoor air may cause a plethora of neurological symptoms. Higher than in the control group the prevalence of MCS associated with the exposure to DM. Bad indoor air is therefore not only a risk for respiratory problems and asthma but should be viewed broader as a systemic biotoxicosis. Therefore, psychologization of this disorder without mentioning the underlying insulting mechanisms should be discouraged.

Normal background levels of air and surface mould reserve in English residential building stock: a preliminary study towards benchmarks based on NAHA measurements

This paper reports results obtained from a surface (both visually clean and dirty/dusty surfaces) and active (aggressive or activated) air testing scheme on 140 residential rooms in England, without visible water damage or mould growth, along with a few rooms with visible mould growth/water damage tested for comparison purposes. The aim was to establish normal background levels of mould in non-water-damaged interiors to benchmark a 'normal' indoor environment, and in turn when there is a need for further investigation, and, possibly, remediation. Air and surface mould was quantified based on the activity of β-N-acetylhexosaminidase (EC 3.2.1.52; NAHA). The obtained readings showed a log-normal distribution. Ninety-eight percent of the samples obtained from visually clean surfaces were equal to or less than 25 relative fluorescence units (RFU), which is suggested to be the higher bound for the range which can be used as a success criterion for surface cleaning/remediation. Of samples obtained from visually dirty/dusty surfaces, around 98% were below 450 RFU, which is suggested to define the lower-bound for abnormally high levels of mould, rare even on dirty/dusty surfaces. Similarly, around 98% of the air samples were found to have 1700 RFU or below. Values above 1700 RFU are therefore deemed unlikely in a non-problem indoor environment and can be indicative of a possible problem inducing mould growth. The samples with values below 1700 were further divided into three proposed sub-categories. Finally, the obtained RFU values and the suggested benchmarks were compared to those obtained from 17 non-residential indoor environments tested previously in Copenhagen, and the benchmarks that are currently used in Danish national standards, and they were both found to be highly congruent, suggesting that local climate regimes and room functions might not be as influential on indoor mould levels as commonly thought, or that the nuances between England and Denmark in terms of these factors are not strong enough to lead to sizable changes in the typical indoor mould levels in these countries' building stocks.

Relationships between Exposure to Bioaerosols, Moldy Surface and Symptoms in French Mold-Damaged Homes

Air quality in homes is a major concern in Europe, where people spend most of their time indoors. According to the World Health Organization, numerous houses are subject to dampness that can lead to mold growth, with associated health and economic consequences. Our goal was to characterize the human exposure to bioaerosols in French mold-damaged houses but also to study the effects of these bioaerosols as suffered by the inhabitants of these houses. A global approach including both field study and laboratory experimentation was used to investigate 48 mold-damaged homes. Among a wide fungal diversity, 101 viable species, Aspergillus versicolor, Penicillium chrysogenum and P. crustosum were observed as recurrent species and could be used as microbial indicators of indoor air quality. Statistical analyses highlighted a relationship between the concentrations of these recurrent molds and the levels of surface contamination by molds in homes. Fever, cough, dyspnea, flu-like symptoms were observed with several fungal strains (A. versicolor, P. chrysogenum and P. crustosum) or in relation to moldy odor. Relationships between particles of 2 to 15 µm diameter and headaches and dizziness were also observed. In our study, we identified a cutaneous effect (itching) in relationship to the airborne concentration of A. versicolor.

The Pathogenesis of Fungal-Related Diseases and Allergies in the African Population: The State of the Evidence and Knowledge Gaps

The prevalence of allergic diseases in the African continent has received limited attention with the allergic diseases due to fungal allergens being among the least studied. This lead to the opinion being that the prevalence of allergic disease is low in Africa. Recent reports from different African countries indicate that this is not the case as allergic conditions are common and some; particularly those due to fungal allergens are increasing in prevalence. Thus, there is need to understand both the aetiology and pathogenies of these diseases, particularly the neglected fungal allergic diseases. This review addresses currently available knowledge of fungal-induced allergy, disease pathogenesis comparing findings from human versus experimental mouse studies of fungal allergy. The review discusses the potential role of the gut mycobiome and the extent to which this is relevant to fungal allergy, diagnosis and human health.

Indoor exposure to Streptomyces albus and Aspergillus versicolor elevates the levels of spore-specific IgG, IgG1 and IgG3 serum antibodies in building users - A new ELISA-based assay for exposure assessment

Moisture-indicative microbes in buildings are associated with a variety of symptoms, ranging from mild irritation to severe clinical illnesses. These symptoms are caused principally by dried, dormant and dead microbe material like spores, mycelium and microbe metabolites, leading to the activation of the immune system and formation of the antigen-specific immunoglobulins. This activation presumably takes place through the respiratory track and is a normal immune reaction against pathogenic invaders. During continuous exposure, a prolonged state of inflammation will follow, and this forms a considerable health risk for a building's occupant. A new ELISA system utilizing spores from two species Streptomyces albus and Aspergillus versicolor as an antigen was developed to reveal the related immunological processes. In 159 persons, microbial exposure was observed to increase the levels of spore-specific IgG, IgG1 and IgG3 serum antibody levels of individuals residing in microbe-dense buildings compared with the control reference buildings. No differences were detected in the levels of S. albus- and A. versicolor-specific serum IgA or IgM levels.

Penicillium expansum strain isolated from indoor building material was able to grow on gypsum board and emitted guttation droplets containing chaetoglobosins and communesins A, B and D

Aims

Emission of toxic metabolites in guttation droplets of common indoor fungi is not well documented. The aims of this study were (i) to compare mycotoxins in biomass and guttation droplets from indoor fungi from a building following health complaints among occupants, (ii) to identify the most toxic strain and to test if mycotoxins in guttation liquids migrated trough air and (iii) to test if toxigenic Penicillium expansum strains grew on gypsum board.

Methods and Results

Biomass suspensions and guttation droplets from individual fungal colonies representing Aspergillus, Chaetomium, Penicillium, Stachybotrys and Paecilomyces were screened toxic to mammalian cells. The most toxic strain, RcP61 (CBS 145620), was identified as Pen. expansum Link by sequence analysis of the ITS region and a calmodulin gene fragment, and confirmed by the Westerdijk Institute based on ITS and beta‐tubulin sequences. The strain was isolated from a cork liner, was able to grow on gypsum board and to produce toxic substances in biomass extracts and guttation droplets inhibiting proliferation of somatic cells (PK‐15, MNA, FL) in up to 20 000‐fold dilutions. Toxic compounds in biomass extracts and/or guttation droplets were determined by HPLC and LC‐MS. Strain RcP61 produced communesins A, B and D, and chaetoglobosins in guttation droplets (the liquid emitted from them) and biomass extracts. The toxins of the guttation droplets migrated c. 1 cm through air and condensed on a cool surface.

Conclusions

The mycotoxin‐containing guttation liquids emitted by Pen. expansum grown on laboratory medium exhibited airborne migration and were >100 times more toxic in bioassays than guttation droplets produced by indoor isolates of the genera Aspergillus, Chaetomium, Stachybotrys and Paecilomyces.

Significance and Impact of the Study

Toxic exudates produced by Pen. expansum containing communesins A, B and D, and chaetoglobosins were transferable by air. This may represent a novel mechanism of mycotoxin dispersal in indoor environment.

Observational cross-sectional study on Symptoms Associated to Moisture DAmage at Workplace: the SAMDAW study protocol

INTRODUCTION

Moisture damage (MD) exposure at work has been shown to increase the risk of new onset asthma and exacerbation of asthma. However, most of the studies in this field have been questionnaire studies. A small proportion of MD-exposed workers are diagnosed with asthma. Many patients with MD exposure at work referred to secondary healthcare report intermittent hoarseness, loss of voice or difficulty to inhale, referring to functional or organic problems of the larynx. For accurate treatment, proper differential diagnostics is paramount. We present an ongoing observational study in which we describe the prevalence of respiratory, voice and other symptoms related to MD at work in patients referred to secondary healthcare. Case-control setting will be used to evaluate the frequencies of the background factors, bronchial hyperreactivity and laryngeal findings.

METHODS AND ANALYSIS

The study sample consists of patients with workplace MD exposure and associated respiratory tract and/or voice symptoms referred to Tampere University Hospital. The clinical tests conducted to the study patients included comprehensive lung function tests, laboratory and skin prick tests, imaging and clinical evaluation by specialists of respiratory medicine, oto-rhino-laryngology and phoniatrics. The exposure assessment was performed by an occupational physician. The study patients filled out a questionnaire on previous illnesses and other background factors, which for comparison was also sent to 1500 Finnish-speaking people in the same hospital district randomly selected by the Finnish Population Information System. To explore how common laryngeal disorders and voice symptoms are in general, a part of the tests will be conducted to 50 asymptomatic volunteers.

ETHICS AND DISSEMINATION

The regional ethics committee of Tampere University Hospital approved the study. All study subjects gave their written informed consent, which is required also from the controls. The results will be communicated locally and internationally as conference papers and journal articles.

Assessment of Indoor Air Quality Problems in Office-Like Environments: Role of Occupational Health Services

There is an increasing concern about indoor air quality (IAQ) and its impact on health, comfort, and work-performance in office-like environments and their workers, which account for most of the labor force. The Scientific Committee on Indoor Air Quality and Health of the ICOH (Int. Comm. Occup. Health) has discussed the assessment and management of IAQ problems and proposed a stepwise approach to be conducted by a multidisciplinary team. It is recommended to integrate the building assessment, inspection by walk-through of the office workplace, questionnaire survey, and environmental measurements, in that order. The survey should cover perceived IAQ, symptoms, and psychosocial working aspects. The outcome can be used for mapping the IAQ and to prioritize the order in which problems should be dealt with. Individual health surveillance in relation to IAQ is proposed only when periodical health surveillance is already performed for other risks (e.g., video display units) or when specific clinical examination of workers is required due to the occurrence of diseases that may be linked to IAQ (e.g., Legionnaire’s disease), recurrent inflammation, infections of eyes, respiratory airway effects, and sensorial disturbances. Environmental and personal risk factors should also be compiled and assessed. Workplace health promotion should include programs for smoking cessation and stress and IAQ management.

Addressing Molecular Diagnosis of Occupational Allergies

PURPOSE OF REVIEW

Numerous clinically relevant allergenic molecules enhance the performance of specific (s) IgE tests and improve the specificity of allergy diagnosis. This review aimed to summarize our current knowledge of the high-molecular-weight allergens involved in the development of occupational asthma and rhinitis and to critically analyze the contribution of component-resolved diagnosis in the management of these conditions.

RECENT FINDINGS

There is a lack of standardization and validation for most available extracts of occupational agents, and assessment of sIgE reactivity to occupational allergen components has been poorly investigated, with the notable exception of natural rubber latex (NRL) and wheat flour. In the case of NRL, the application of recombinant single allergens and amplification of natural extracts with stable recombinant allergens improved the test sensitivity. IgE-sensitization profile in patients with baker's asthma showed great interindividual variation, and extract-based diagnostic is still recommended. For other occupational allergens, it remains necessary to evaluate the relevance of single allergen molecules for the sensitization induced by occupational exposure. Progress has been made to characterize occupational allergens especially NRL and wheat, although there is still an unmet need to increase the knowledge of occupational allergens, to include standardized tools into routine diagnostic, and to evaluate their usefulness in clinical practice.

Indoor mould testing in a historic building: Blickling Hall

Indoor mould growth is a growing concern for all stakeholders of built environment, including residents, builders, insurance and building remediation industry as well as custodians of heritage buildings. The National Trust has reported this problem in a number of buildings under their ownership, and developed solutions and fine-tuned their maintenance programme so as to minimise indoor and surface mould growth risk. This paper reports findings from an extensive mould-testing scheme in Blickling Hall, a National Trust property in Norfolk, England, for an appraisal of airborne and surface mould levels within a total of eight rooms, including the famous Long Gallery. The testing protocol used combines active (aggressive) air sampling and surface sampling, analysis of the β-N-acetylhexosaminidase (NAHA) activity to quantify mould levels and particle counting. The results show that the airborne mould levels are quite low in all spaces, due to satisfactory maintenance of indoor hygrothermal conditions by conservation heating. On the other hand, while the National Trust's developed solutions and maintenance programme have proved effective to avoid surface mould growth in those locations that historically suffered from microbial activity (such as behind book presses, picture frames and tapestries), the results show that the surface cleaning around windows should be improved to tackle surface water due to condensation, which is considered to be the main driver behind high surface NAHA activity obtained in these areas.