Endotoxin, dust and exhaled nitrogen oxide among hand pickers of coffee; a cross-sectional study

Microbial Contamination in the Coffee Industry: An Occupational Menace besides a Food Safety Concern?

Respiratory abnormalities among workers at coffee roasting and packaging facilities have already been reported; however, little is known about microbiological contamination inside coffee production facilities. This study intends to assess the microbial contamination (fungi and bacteria) in two coffee industries from Brazil with a multi-approach protocol for sampling and for subsequent analyses using four main sources of samples: filtering respiratory protection devices (FRPD) used by workers, settled dust, electrostatic dust cloths (EDC) and coffee beans. The fungal contamination in the assessed industries was also characterized through the molecular detection of toxigenic species and antifungal resistance. Total bacteria contamination presented the highest values in FRPD collected from both industries (7.45 × 104 CFU·m^-2; 1.09 × 104 CFU·m^-2). Aspergillus genera was widespread in all the environmental samples collected and sections with clinical relevance (Fumigati) and with toxigenic potential (Nigri and Circumdati) were recovered from FRPD. Circumdati section was observed in 4 mg/mL itraconazole. Sections Circumdati (EDC, coffee beans and settled dust) and Nidulantes (EDC, coffee beans and FRPD) were detected by qPCR. Some of the targeted Aspergillus sections that have been identified microscopically were not detected by qPCR and vice-versa. Overall, this study revealed that microbial contamination is a potential occupational risk in the milling stage and should be tackled when assessing exposure and performing risk assessment. In addition, a multi-sampling campaign should be the approach to follow when assessing microbial contamination and FRPD should be included in this campaign. Occupational exposure to mycotoxins should be considered due to high fungal diversity and contamination. A One Health approach should address these issues in order to prevent consumption of coffee crops and beans infected by fungi and, more specifically, to avoid widespread azole resistance.

Dust Exposure and Respiratory Health Among Workers in Primary Coffee Processing Factories in Tanzania and Ethiopia

Introduction: In primary coffee factories the coffee beans are cleaned and sorted. Studies from the 80- and 90-ties indicated respiratory health effects among the workers, but these results may not represent the present status. Our aim was to review recent studies on dust exposure and respiratory health among coffee factory workers in Tanzania and Ethiopia, two major coffee producing countries in Africa.

Methods: This study merged data from cross-sectional studies from 2010 to 2019 in 4 and 12 factories in Tanzania and Ethiopia, respectively. Personal samples of “total” dust and endotoxin were taken in the breathing zone. Chronic respiratory symptoms were assessed using the American Thoracic Society (ATS) questionnaire. Lung function was measured by a spirometer in accordance with ATS guidelines.

Results: Dust exposure among male production workers was higher in Ethiopia (GM 12 mg/m³; range 1.1–81) than in Tanzania (2.5; 0.24–36). Exposure to endotoxins was high (3,500; 42–75,083) compared to the Dutch OEL of 90 EU/m³. The male workers had higher prevalence of respiratory symptoms than controls. The highest symptom prevalence and odds ratio were found for cough (48.4%; OR = 11.3), while for breathlessness and wheezing the odds ratios were 3.2 and 2.4, respectively. There was a significant difference between the male coffee workers and controls in the adjusted FEV1 (0.26 l/s) and FVC (0.21 l) and in the prevalence of airflow limitation (FEV1/FVC < 0.7) (6.3 vs. 0.9%). Among the male coffee workers, there was a significant association between cumulative dust exposure and the lung function variables FEV1 and FVC, respectively.

Conclusions: The results suggest that coffee production workers are at risk of developing chronic respiratory symptoms and reduced lung function, and that the findings are related to high dust levels. Measures to reduce dust exposure should be targeted to factors identified as significant determinants of exposure.

Respiratory Health Among Hand Pickers in Primary Coffee-Processing Factories of Ethiopia

OBJECTIVE

The aim of this study was to assess chronic respiratory symptoms and lung function among female hand pickers.

METHODS

A total of 374 hand pickers exposed to coffee dust and 175 female controls from water bottling factories were included. The symptoms were assessed using a standardized questionnaire. Personal total dust exposure and lung function tests were performed.

RESULTS

Hand pickers experienced a higher dust exposure, displayed a higher prevalence ratio for cough [prevalence ratio (PR) = 3.0, 95% confidence interval (95% CI): 1.4 to 6.2] and work-related shortness of breath (PR = 2.5, 95% CI: 1.1 to 5.6), and had a lower FEF25-75 than controls. Hand pickers without tables had a significantly higher prevalence ratio of cough with sputum (PR = 3.9, 95% CI: 1.6 to 9.5) and lower forced vital capacity, forced expiratory volume in 1 second, and mean forced expiratory flow between 25% and 75% of the FVC than hand pickers with tables.

CONCLUSION

Hand pickers show a range of adverse symptoms and lung function impairments that warrant efforts to improve working conditions.

Exposure to field vs. storage wheat dust: different consequences on respiratory symptoms and immune response among grain workers

PURPOSE

The aim of this study was to understand the differential acute effects of two distinct wheat-related dusts, such as field or stored wheat dust handling, on workers' health and how those effects evolved at 6 month intervals.

METHODS

Exposure, work-related symptoms, changes in lung function, and blood samples of 81 workers handling wheat and 61 controls were collected during the high exposure season and 6 months after. Specific IgG, IgE, and precipitins against 12 fungi isolated from wheat dust were titrated by enzyme-linked immunosorbent assay, dissociation-enhanced lanthanide fluorescence immunoassay, and electrosyneresis. The level of fungi was determined in the workers' environment. Levels of exhaled fraction of nitrogen monoxide (F_ENO) and total IgE were obtained. Exposure response associations were investigated by mixed logistic and linear regression models.

RESULTS

The recent exposure to field wheat dust was associated with a higher prevalence for five of six self-reported airway symptoms and with a lower F_ENO than those in the control population. Exposure to stored wheat dust was only associated with cough. No acute impact of exposure on respiratory function was observed. Exposure to field wheat dust led to workers' sensitization against the three field fungi Aureobasidum, Cryptococcus, and Phoma, although exposure to storage wheat dust was associated with tolerance. The level of Ig remained stable 6 months after exposure.

CONCLUSION

The clinical picture of workers exposed to field or storage wheat dust differed. The systematic characterization of the aerosol microbial profile may help to understand the reasons for those differences.