Algorithm to assess the presence of Aspergillus fumigatus resistant strains: The case of Norwegian sawmills

Association between selection pressure caused by the use of azole fungicides in sawmills and the development of fungal resistance has been described. The aim of this study was to implement an algorithm to assess the presence of Aspergillus section Fumigati resistant strains in sawmills.Eighty-six full-shift inhalable dust samples were collected from eleven industrial sawmills in Norway. Different culture media were used and molecular identification to species level in Aspergillus section Fumigati was done by calmodulin sequencing and TR₃₄/L98H and TR₄₆/Y121F/T289A mutations were screened by real-time PCR assay and confirmed by cyp51A sequencing. Six Fumigati isolates were identified as A. fumigatus sensu stricto and two of these grew on azole-supplemented media and were further analyzed by real-time PCR. One was confirmed to be a TR₃₄/L98H mutant.The obtained results reinforce the need to assess the presence of A. fumigatus sensu stricto resistant isolates at other workplaces with fungicide pressure.

Exposure Determinants of Wood Dust, Microbial Components, Resin Acids and Terpenes in the Saw- and Planer Mill Industry

Objectives

Sawmill workers have an increased risk of adverse respiratory outcomes, but knowledge about exposure–response relationships is incomplete. The objective of this study was to assess exposure determinants of dust, microbial components, resin acids, and terpenes in sawmills processing pine and spruce, to guide the development of department and task-based exposure prediction models.

Methods

2474 full-shift repeated personal airborne measurements of dust, resin acids, fungal spores and fragments, endotoxins, mono-, and sesquiterpenes were conducted in 10 departments of 11 saw- and planer mills in Norway in 2013–2016. Department and task-based exposure determinants were identified and geometric mean ratios (GMRs) estimated using mixed model regression. The effects of season and wood type were also studied.

Results

The exposure ratio of individual components was similar in many of the departments. Nonetheless, the highest microbial and monoterpene exposure (expressed per hour) were estimated in the green part of the sawmills: endotoxins [GMR (95% confidence interval) 1.2 (1.0–1.3)], fungal spores [1.1 (1.0–1.2)], and monoterpenes [1.3 (1.1–1.4)]. The highest resin acid GMR was estimated in the dry part of the sawmills [1.4 (1.2–1.5)]. Season and wood type had a large effect on the estimated exposure. In particular, summer and spruce were strong determinants of increased exposure to endotoxin (GMRs [4.6 (3.5–6.2)] and [2.0 (1.4–3.0)], respectively) and fungal spores (GMRs [2.2 (1.7–2.8)] and [1.5 (1.0–2.1)], respectively). Pine was a strong determinant for increased exposure to both resin acid and monoterpenes. Work as a boilerman was associated with moderate to relatively high exposure to all components [1.0–1.4 (0.8–2.0)], although the estimates were based on 13–15 samples only. Cleaning in the saw, planer, and sorting of dry timber departments was associated with high exposure estimates for several components, whereas work with transportation and stock/finished goods were associated with low exposure estimates for all components. The department-based models explained 21–61% of the total exposure variances, 0–90% of the between worker (BW) variance, and 1–36% of the within worker (WW) variances. The task-based models explained 22–62% of the total variance, 0–91% of the BW variance, and 0–33% of the WW variance.

Conclusions

Exposure determinants in sawmills including department, task, season, and wood type differed for individual components, and explained a relatively large proportion of the total variances. Application of department/task-based exposure prediction models for specific exposures will therefore likely improve the assessment of exposure–response associations.

Exposure to Wood Dust, Microbial Components, and Terpenes in the Norwegian Sawmill Industry

Sawmill workers are exposed to wood dust (a well-known carcinogen), microorganisms, endotoxins, resin acids (diterpenes), and vapours containing terpenes, which may cause skin irritation, allergy, and respiratory symptoms including asthma. The health effects of most of these exposures are poorly understood as most studies measure only wood dust. The present study assessed these exposures in the Norwegian sawmill industry, which processes predominantly spruce and pine. Personal exposures of wood dust, resin acids, endotoxin, fungal spores and fragments, mono-, and sesquiterpenes were measured in 10 departments in 11 saw and planer mills. The geometric mean (GM) and geometric standard deviation (GSD) thoracic exposures were: 0.09 mg m-3 dust (GSD 2.6), 3.0 endotoxin units (EU) m-3 (GSD 4.9), 0.4 × 105 fungal spores m-3 (GSD 4.2), 2 × 105 fungal fragments m-3 (GSD 3.2), and 1560 ng m-3 of resin acids (GSD 5.5). The GM (GSD) inhalable exposures were: 0.72 mg m-3 dust (2.6), 17 EU m-3 (4.3), 0.4 × 105 fungal spores m-3 (3.8), and 7508 ng m-3 (4.4) of resin acids. The overall correlation between the thoracic and inhalable exposure was strong for resin acid (rp = 0.84), but moderate for all other components (rp = 0.34-0.64). The GM (GSD) exposure to monoterpenes and sesquiterpenes were 1105 µg m-3 (7.8) and 40 µg m-3 (3.9), respectively. Although mean exposures were relatively low, the variance was large, with exposures regularly exceeding the recommended occupational exposure limits. The exposures to spores and endotoxins were relatively high in the dry timber departments, but exposures to microbial components and mono-and sesquiterpenes were generally highest in areas where green (undried) timber was handled. Dust and resin acid exposure were highest in the dry areas of the sawmills. Low to moderate correlation between components (rp ranging from 0.02 to 0.65) suggests that investigations of exposure-response associations for these components (both individually and combined) are feasible in future epidemiological studies.

[Prevalence of skin disorders associated with the use of bleaching cosmetics by Lome women]

The purpose of this study was to evaluate the occurrence of cutaneous complications among women who used bleaching cosmetics in Lomé, Togo. Of 536 women who used these cosmetics, 371 (69.2%) had at least one dermatological complication. The bleaching agents used were mercury derivatives (30.9%), hydroquinones (24%), topical corticosteroids (18.5%) and products of unknown composition (25.6%). The main dermatological side-effects were hypochromia (62.8%), hyperchromia (2.7%), melanoleucoderma (8.1%), acne (11.6%), and skin trophic disorders (14.8%). The occurrence of these complications was associated with the length of time for which the chemicals were used and the simultaneous use of different classes of these cosmetics. This study shows that dermatological complications are common in women using skin-bleaching cosmetics.