Respiratory symptoms related to flour dust exposure are significantly high among small and medium scale flour mill workers in Ethiopia: a comparative cross-sectional survey

Background International Labour Organization (ILO) report indicates more than 2.4 million workers die from work-related diseases and accidents each year. Work-related respiratory ailments related to airborne particulate matter such as flour dust are responsible for about 386,000 deaths and 6.6 million illness-adjusted life years. Even though exposure to flour dust together with the extreme expansions of flour mill sectors is a priority health concern, extent of the problem is little investigated in Ethiopia. The aim of this study was to evaluate the magnitude and risk factors of work-related respiratory symptoms among flour mill workers in Bahir Dar City, Ethiopia. Methods This study employed a comparative cross-sectional survey of 560 samples (280 exposed group from flour mill workers and 280 unexposed group from office workers) with a stratified random sampling technique. The study was conducted from March to April 2019 in Bahir Dar City, Northwest Ethiopia. We used the British Medical Research Council (BMRC) questionnaire to assess work-related respiratory symptoms. The questionnaire was pretested and interview administered to collect data. Binary logistic regression analysis was fitted to evaluate significant factors of respiratory symptoms at a < 0.05 p value. Adjusted odds ratio (AOR) with a confidence interval (CI) of 95% was calculated to determine a strength of association. Results All the sampled participants had fully responded to the interview. The median age of exposed and unexposed groups was 28.5 interquartile range (IQR, 20) and 31 (IQR, 15) years, respectively. The prevalence of work-related respiratory symptoms among flour mill workers was substantially higher than that of among controls, 63.9% and 20.7%, respectively (Χ2 = 107.11; p < 0.0001). Chest illness among flour mill workers was higher, 43.6% (N = 122) compared to that of among control group, 7.9% (N = 22) followed by dyspnea, 33.6% (N = 94) versus 2.5% (N = 7) among flour mill workers and control group, respectively. Age > 35 years [AOR, 2.03; 95% CI (1.34, 5.48), having no education [AOR, 1.54; 95% CI (1.28, 3.06)], work set up with inadequate ventilation [AOR, 2.05; 95% CI (1.18, 3.56)], work experience > 5 years [AOR, 1.89; 95% CI (1.23, 4.67)] and having no training in safety [AOR, 2.45; 95% CI (1.45, 4.76)] significantly affected the experience of respiratory symptoms among flour mill workers whereas age [AOR, 1.79; 95% CI (1.06, 3.04)], monthly salary [AOR, 1.98; 95% CI (1.04, 3.78)] and exposure status [AOR, 5.18; 95% CI (3.34, 8.04)] were detected to be significant factors of respiratory symptoms in the exposed and the unexposed combined model. Conclusion Respiratory symptoms emanating from exposure to various flour dusts were significantly higher among flour mill workers than among the control group. Therefore, we recommend the need to effectively implement health and safety programs that account for the reduction of dust at a source, use of engineering controls (e.g., provision of adequate ventilation systems), use of administrative measures (e.g., training program and health surveillance) and provision of a suitable personal protective equipment (PPE). Furthermore, it is vital to integrate workplace health and safety programs to the wider public health policies and strategies to effectively mitigate the burden of work-related respiratory conditions. We also encourage future studies to evaluate concentration of flour dusts combined with physical examinations to establish plausible associations of respiratory symptoms with dusts of flour mill-related origin.

Molecular identification and DNA barcode screening of Acaroid mites in ground flour dust

Molecular identification of acaroid mites is difficult because of the scarcity of molecular data in GenBank. Here, acaroid mites collected from ground flour dust in Xi'an China were preliminarily morphologically classified/grouped. Universal primers were then designed to amplify and screen suitable DNA barcodes for identifying these mites. Sixty mite samples were morphologically classified into six groups. Groups 1–2 were identified to Dermatophagoides farinae, and Tyrophagus putrescentiae; while Groups 3–6 were not identified to the species level. ITS2 exhibited higher efficiency in molecular identification in comparison with COI, 12S, and 16S. Groups 1–6 were identified as D. farinae, T. putrescentiae, Suidasia nesbitti, Chortoglyphus arcuatus, Lepidoglyphus destructor, and Gohieria sp., respectively. The phylogenetic results were consistent with the morphological classification. Group 6 was further identified as G. fusca according to the morphology of reproductive foramen. We conclude that the use of ITS2 and the availability of universal primers provides an ideal DNA barcode for molecular identification of acaroid mites. The use of multiple target genetic markers in conjunction with morphological approaches will improve the accuracy of Acaridida identification. Key words: acaroid mites, Taxonomy, universal primers, molecular identification, DNA barcode.

Upper and Lower Respiratory Signs and Symptoms in Workers Occupationally Exposed to Flour Dust

A group of 142 bakers was studied in order to investigate the relationship between higher/lower respiratory signs/symptoms and inflammation biomarkers and occupational exposure to flour dust. A complete upper and lower respiratory tract evaluation was performed. Seven percent of bakers complained of lower respiratory symptoms, while 22% of them complained of upper respiratory symptoms. Fifty five percent of the bakers were allergic, and 37.1% showed sensitization to occupational allergens. Abnormal spirometries were found in 15% of bakers, while fractional exhaled nitric oxide (FeNO) was above the normal reference in 24.5% of them. Moreover, 23.8% of bakers were found to be hyposmic. Population mean peak nasal inspiratory flow (PNIF) was in the normal range even if almost all the workers suffered from neutrophilic rhinitis at nasal cytology with the number of nasal neutrophils increasing with the increase of the duration of exposure to flour dust (p = 0.03). PNIF and FEV1 (forced expiratory volume in the 1st second) showed a positive correlation (p = 0.03; r = 0.19). The Tiffeneau index decreased with the increase of dust (p = 0.017). A similar result was obtained once we divided our population into smokers and non-smokers (p = 0.021). Long-term exposure to bakery dusts can lead to a status of minimal nasal inflammation and allergy.

Airborne Particulate Matter Density in Traditional Bakeries of Saveh, Central of Iran, in 2020

Introduction: High concentration of inhalable airborne particles can increase the risk of lung disease in exposed people. This study aimed to determine the respirable particulate matter (PM5) concentration in traditional bakeries of Saveh in 2020. Materials and Methods: This cross-sectional descriptive study was conducted among 25 bakeries where the samples were collected by cyclone and teflon filter equipped by air sampling pump. Later, the respirable particulate matter concentration was measured using gravimetric method. The collected PM5 was scanned using a FTIR (Fourier-transform infrared spectroscopy) with regard to flour dust. In addition, size and shape of the collected PM5 were analyzed using a scanning electron microscope (SEM). Results: Findings showed that the Lavash bakery had the highest PM5 concentration (9.15 mg/m3) in comparison with two other bakeries (Sangak and Barbari). However, an inverse relationship was observed between RH and particle concentration. In addition, the results demonstrated that increasing RH decreased the particle concentration, but the relationship was not significant (P = 0.052, Spearman's rho = -0.393). Furthermore, Lavash bakery had the lowest average size of PM5 (0.63 ± 0.32 μm). However, the FTIR scans confirmed that the flour dust had the predominant amount of PM5. Conclusion: Based on the findings, the density of respirable PM5 has a high level in Saveh bakeries and workers are exposed to high levels of PM.

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

The adverse effects associated with exposure to flour dust have been known since the 1700s. The aim of the study was to assess the occupational exposure to flour dust in Italian facilities, identify the activities characterized by the highest exposure, and provide information to reduce workers’ exposure. The study was performed in different facilities such as flourmills (n = 2), confectioneries (n = 2), bakeries (n = 24), and pizzerias (n = 2). Inhalable flour dust was assessed by personal and area samplings (n = 250) using IOM (Institute of Occupational Medicine) samplers. The results showed personal occupational exposure to flour dust over the American Conference of Governmental Industrial Hygiene (ACGIH) and the Scientific Committee on Occupational Exposure Limit (SCOEL) occupational limits (mean 1.987 mg/m3; range 0.093–14.055 mg/m3). The levels were significantly higher for dough makers in comparison to the dough formers and packaging area subjects. In four bakeries the industrial hygiene surveys were re-performed after some control measures, such as installation of a sleeve to the end of pipeline, a lid on the mixer tub or local exhaust ventilation system, were installed. The exposure levels were significantly lower than those measured before the introduction of control measures. The exposure level reduction was observed not only in the dough making area but also in all bakeries locals.

Screening of flour mill workers for respiratory morbidities: a cross-sectional study in rural Bangalore

Background: Flour mill workers are highly exposed to organic wheat flour dust with a large diversity of antigenic/allergic component leading to respiratory morbidity and skin allergies. This work environment may affect workers health and safety if the effects are unchecked periodically.Methods: A cross-sectional study was conducted among 194 workers of 4 flour mills in Bangalore Rural district. Prior permission (factory) and informed consent *(workers) were obtained. Pre-structured interview-schedule was administered. Peak expiratory flow rate (PEFR) readings were measured by using wrights flow meter and best of 3 readings recorded. Respiratory morbidity was assessed on PEFR classification - based on American lung association (ALA) colour coding - red, yellow and green zones. Respiratory morbidity was compared with years of experience, type of work, smoking habits and usage of appropriate PPEs. Data was analyzed using Epi-info 08.Results: Among 194 workers studied, 188 were males, 6 were females. They were in the age group of 15-50 years. 143 (73.7%) were engaged in work with direct dust exposure. 84 (43%) were working for more than 3 years, 50 (25%) between 1-3 years and 60 (30%) for less than a year. 7.2% regularly smoked. According to ALA classification, PEFRs of 71 (36%) of the workers were classified into RED, 91 (46%) to yellow and 32 (16%) to green zones respectively. Usage of PPEs was only among 126 (64%).Conclusions: Respiratory morbidity among flour mill workers was high. Adequate use of PPEs was low. Half of the workers fell into yellow zone that had a potential to fall into red zone if external factors were not considered.

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

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.