Occupational Exposures to Organic Dust in Irish Bakeries and a Pizzeria Restaurant

Abstract

For decades, occupational exposure to flour dust has been linked to a range of respiratory diseases, including occupational asthma, thought to result from exposure to fungi present in the flour. Antifungal resistance is of increasing prevalence in clinical settings, and the role of occupational and environmental exposures, particularly for specific fungal species, is of concern. Occupational exposure to flour dust can occur in a range of occupational settings, however, few studies have focused on restaurant workers. The objective of this study was to measure occupational exposure to flour and microbial contamination, including azole resistance screening, in two small commercial bakeries and in a pizzeria. Personal full shift inhalable dust measurements were collected from workers, and were analyzed for inhalable dust and fungi, bacteria, azole resistance, and mycotoxins. Samples of settled dust were collected, and electrostatic dust cloths (EDC) were deployed and analyzed for microbial contamination, including azole resistance screening, and mycotoxins. Geometric mean exposures of 6.5 mg m−3 were calculated for inhalable dust, however, exposures of up to 18.30 mg m−3 were measured—70% of personal exposure measurements exceeded the occupational exposure limit for flour dust of 1.0 mg m−3. The air and EDC fungal counts were similar to those reported in previous studies for similar occupational environments. The fungi were dominated by Penicillium genera, however Aspergillus genera, including Fumigati and Flavi sections, were observed using culture-based methods, and the Fumigati section was also observed by molecular tools. Both Aspergillus sections were identified on the azole resistance screening. Mycotoxins were also detected in the settled dust samples, dominated by deoxynivalenol (DON). The role of environmental exposure in both the development of antimicrobial resistance and the total mycotoxin body burden is a growing concern; therefore, the presence of azole-resistant fungi and mycotoxin contamination, although low in magnitude, is of concern and warrants further investigation.

Occupational Exposure to Flour Dust. Exposure Assessment and Effectiveness of Control Measures

“…The results of environmental monitoring in all workplaces investigated showed personal occupational exposure to flour dust within the range 0.093–14.055 mg/m 3 with a mean value equal to 1.987 mg/m 3 (Phases 1 and 2). These values were comparable or lower than those found in other studies carried out in different countries in the last decade [ 25 , 26 , 27 , 28 ]. In the bakeries, as expected, the job tasks characterized by the higher exposure levels were the dough maker and the dough former.…”

Investigating Multi-Mycotoxin Exposure in Occupational Settings: A Biomonitoring and Airborne Measurement Approach

“…The limits of quantification in this study could not easily be compared to previously published data due to the discrepancy between method validation parameters when available, and due to the differences between the units used to express data [ 5 , 6 , 12 , 15 , 65 ]. For example, whereas the LOQs in this study were 0.06 ng m −3 for OTA, 8 ng m −3 for DON, and 1 ng m −3 for ZEN in the air, they ranged roughly from 0.01 µg/kg to 20 µg/kg, or were displayed as 0.002 ng in a review published by Viegas et al [ 66 ].…”

“…Occupational exposure may occur in workplaces due to the mycotoxins contained in organic matters, such as feed, food or waste. Studies have reported the prevalence of mycotoxins in airborne dust and settled dust samples in grain industries [ 4 , 5 , 6 , 7 , 8 ], food industries [ 4 , 9 , 10 , 11 , 12 , 13 ] and farming [ 14 , 15 ]. These findings point to the prevalence of an occupational exposure to mycotoxins through inhalation, skin contact and hand-to-mouth contact.…”

Culture Media and Sampling Collection Method for Aspergillus spp. Assessment: Tackling the Gap between Recommendations and the Scientific Evidence

“…The genus Aspergillus is known to be one of the most frequently airborne fungi found in indoor and outdoor environments worldwide [8][9][10][11][12][13][14][15][16]. More recently, due to molecular identification, the genus has been subdivided into 22 different sections, including the clinically relevant species Aspergilli, Fumigati, Circumdati, Terrei, Nidulantes, Ornati, Warcupi, Candidi, Restricti, Usti, and Flavi [12].…”