Low tumor necrosis factor alpha levels and neutrophil counts in nasal lavage after mold exposure

Nasal lavage as analytical tool in assessment of exposure to particulate and microbial aerosols in wood pellet production facilities

Occupational exposure to wood dust and bioaerosols may lead to numerous respiratory tract diseases. We aimed to assess a degree of workplace contamination with dust, bacteria, fungi, endotoxins, and (1 → 3)-β-D-glucans released into the air during wood processing in pellet production facilities and to check against this background the usefulness of nasal lavage (NAL) as analytical tool for assessment of combined workers' exposure to airborne dust and microbiological contaminants. In 10 pellet plants, the particulate (wood dust) aerosol concentrations were determined by using Grimm aerosol spectrometer and CIS filter sampler. The collected CIS samples were subsequently used to evaluate endotoxin and (1 → 3)-β-D-glucan concentrations. Simultaneously with particulate aerosol, bioaerosol samples were collected by using 6-stage Andersen and single-stage MAS impactors. Bacterial and fungal aerosol concentrations were calculated and all isolated microorganisms were taxonomically identified. NAL fluid samples were collected from workers exposed to studied aerosols and the concentrations of proinflammatory mediators (IL-1β, IL-6, IL-8, and TNFα) and cytological image of nasal mucosa (expressed as cell counts) were established. The dynamics of production activities resulted in wide range of observed wood dust, microorganism, endotoxin and (1 → 3)-β-D-glucan concentrations reaching periodically extremely high values up to 65 mg m^-3, 19,320 CFU m^-3, 215 ng m^-3 and 1525 ng m^-3, respectively. Environmental stress caused by exposure to particulate and microbial aerosols stimulated immune response among workers of pellet production facilities. Correlation analysis revealed that interleukin levels and the number of cells in NAL were significantly affected by both wood dust and bioaerosol concentrations. As nasal mucosa serves as the primary barrier against inhaled pollutants, NAL seems a reliable analytical material to assess work-related adverse respiratory health outcomes derived from such exposure.

Markers of upper airway inflammation associated with microbial exposure and symptoms in occupants of a water-damaged building

BACKGROUND

Water damage in buildings has been associated with reports of upper airway inflammation among occupants.

METHODS

This survey included a questionnaire, allergen skin testing, nasal nitric oxide, and nasal lavage on 153 participants. We conducted exposure assessments of 297 workstations and analyzed collected dust for fungi, endotoxin, and (1 → 3)-β-D-glucan to create floor-specific averages.

RESULTS

Males had higher levels of nasal inflammatory markers, and females reported more symptoms. ECP, IL-8, and MPO were significantly associated with nasal symptoms, flu-like achiness, or chills. Fungi and glucan were positively associated with blowing out thick mucus. Endotoxin was significantly associated with ECP in overall models, and with ECP, IL-8, MPO, and neutrophils among non-atopic females.

CONCLUSIONS

In this study, we documented an association between endotoxin and nasal inflammatory markers among office workers. The results of our study suggest that a non-allergic response may contribute to symptoms occurring among occupants in this water-damaged building.

A dose-dependent relationship between the severity of visible mold growth and IgE levels of pre-school-aged resident children in Taiwan

To demonstrate a dose-dependent relationship between severity of indoor visible mold growth and serum total IgE levels of resident children. A total of 97 children (4-7 years old) identified from previously established birth-cohort, with information pertaining to indoor environmental conditions after child's birth, were successfully recruited while sera were concurrently collected for total IgE and specific IgE analysis during clinical visits. Severity of visible mold growth at homes was scaled into three levels accordingly. A statistically significant dose-dependent relationship was found between severity of indoor visible mold growth and total serum IgE levels. The trend sustains after the model was adjusted for resident child's age, gender, pet-keeping history, number of siblings, atopic history of parents, presence of incense burning, and environmental tobacco smoking (ETS) at home. Further analysis of specific IgE to commonly examined fungal allergens did not substantiate the correlation. Rather, resident child's specific IgE to mite allergens, although without statistical significance, seemed to better associate with the ranked severity of indoor mold growth in this study. An adjuvant role of fungal exposure to enhance sensitization in indoor environment is therefore suggested in Taiwanese population with high prevalence of building dampness.

PRACTICAL IMPLICATIONS

The presence of indoor visible mold growth, potentially resulting in fungal exposure, was not associated directly with changing biomarker levels of allergic response in resident children, rather playing an adjuvant role to enhance sensitization. On the other hand, other allergens, such as mite allergen examined in this study, appeared to support a more plausible etiology for directly triggering the ultimate allergic symptoms and diseases of interest. Evidence as such may derive different priority-setting when designing preventive measures for managing indoor air quality.