Work Environment and Respiratory Health among Sisal Processors in Tanzania : Studies in six sisal factories

Background: Very little is known about work and health in the sisal industry. Previous studies on sisal are old and mainly focused on sisal fibre textiles and rope factories. Stationary dust concentration rather than personal exposures has been measured in a few studies but not bio-aerosols content of sisal dust. Globally, Tanzania occupies a third place in annual sisal export. Production methods in Tanzanian sisal factories are still labour intensive, implying that many workers are currently employed in the country’s 82 sisal estates. Yet very little is known about work-related health risks among sisal workers in Tanzania. Methods: Six sisal processing factories were selected for the study. Walkthrough surveys were conducted in the decortication and brushing departments and all 165 sisal processing workers (exposed) in these departments (including 93 decorticators, 72 brushing) and 32 randomly selected security guards (low exposed) were invited to participate in the study. Daily interviews on acute respiratory symptoms arising during or after work, and assessment of peak expiratory flow rates before and after work shifts were performed from Monday to Friday. All sisal workers and security guards were also interviewed for chronic respiratory symptoms. Thirty-eight randomly selected sisal workers were involved to collect personal dust samples using 30 cellulose acetate and 48 polycarbonate filters for gravimetric dust analysis and for bacteria and fungi spore counting, respectively. Furthermore, 138 out of 165 sisal processing workers and 78 conveniently sampled urban-based control participants were skin prick tested with dry and fresh sisal extracts. Serum samples from a subset of 43 skin pricked participants were tested for total and sisal specific IgE, PhadiatopTM, and ELISA. A fresh sisal extract was examined by SDS PAGE (electrophoresis method) to look for sisal allergen proteins. Results: Walkthrough surveys indicated generally poor working conditions in five of the six sisal factories, with workplaces characterized by wet floors, visible dust emissions, long stressful work shifts, monotonous tasks at awkward postures and heavy manual lifting. Use of personal protective equipment and other general occupational health and safety services was almost absent. Old brushing and decortication machinery from as early as the 1890s was still in use. The arithmetic mean exposure of all sisal processors was 1.18 mg thoracic dust/m3, 43x106 bacteria /m3, and 2.35 x 106 fungal spores/m3 . The highest mean thoracic dust (2.06 mg/m3), bacteria spores (230 x 106/m3) as well as fungal spores (15.10 x 106/m3) were measured when cleaning corona drums at the decortication. Personal exposure measurements showed significant differences in thoracic dust levels and bacteria exposures between work departments and workers tasks. Positive correlations were found between fungal and bacteria counts (r = 0.47; p = 0.01; n = 32), but no significant differences were detected among the study groups for fungal exposure. Mixed effect models including the brushing and decortication departments explained 64.7% of the thoracic dust exposure variance between workers. The models also showed that working in the brushing department was a significant exposure determinant (p = 0.04) After the first day of work (Monday), and when compared to security guards, odds ratios for sisal processing workers were for sneezing 4.2 (95%CI; 1.6–11.1) and for dry cough 2.9 (95%CI; 1.3–5.4) after adjusting for age, smoking and past respiratory illnesses. Compared to decortication workers, brushing workers had significantly higher odds ratio for sneezing; 3.2 (95%CI; 1.6–6.2) and stuffy nose 3.1 (95%CI; 1.4–7.0). With the exception of shortness of breath and wheezing, brushing workers had significantly higher prevalence for all acute respiratory symptoms than decortication workers. During the five days of follow-up, brushing workers showed significantly higher severity scores and prevalences for most acute respiratory symptom than security guards and decorticators. Compared to security guards, workers in decortication had significantly higher prevalence of shortness of breath. A significantly decreasing trend across the week was found for the prevalence of shortness of breath among brushing workers (from 39% to 20%: P 100kU/L) IgE levels. Analysis of the sisal extract showed two IgE binding protein bands at 45 kDa. Discussion and conclusion: The combined effect of poor working conditions, use of old machinery and lack of protective clothing implies increased health risks due to possible exposures to sisal dust and bio-aerosols among sisal processing workers. Sisal processing workers had significantly higher severity scores and prevalence of respiratory symptoms, and were more sensitized to sisal than controls, indicating a possible association with exposure arising within the sisal fibre processing areas. Dust and bio-aerosol exposure levels appear to be higher for some tasks, emphasizing the need to consider differences in workers tasks when assessing workplace exposures and when planning control measures. Preventive action and more studies are recommended in this industry

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

Background Primary coffee processing takes place in countries where coffee is grown, and may include hand picking of coffee to remove low quality beans. Hand picking is mostly performed by women. No previous studies on dust and respiratory health have been performed in this occupational group, although studies indicate respiratory problems among other coffee production workers. Findings Our aim was to assess dust and endotoxin exposure among hand pickers in a coffee factory and compare the levels with limit values. In addition we wanted to examine the fraction of exhaled nitric oxide (FeNO) as a possible inflammatory marker in the airways among the hand pickers and evaluate the association between FeNO and years of hand picking. All hand pickers in a factory were examined during 1 week. The response was 100 %; 69 participated. FeNO was measured using an electrochemistry-based NIOX MINO device. Nine out of 69 workers (13 %) had levels of FeNO above 25 ppb, indicating presence of respiratory inflammation. A significant positive association was found between increasing FeNO and years of hand picking. Nine personal samples of total dust and endotoxin were taken. None of the dust samples exceeded the occupational limit value for total organic dust of 5 mg/m3. Three samples of endotoxin (33 %) were above the recommended value of 90 EU/m3. Conclusions Levels of endotoxin were higher than recommended standards among hand pickers, and there was a positive association between the level of exhaled nitrogen oxide and years of work with hand picking coffee

Respiratory Inflammation Among Workers Exposed to Airborne Dust With Endotoxins in a Coffee Curing Factory.

OBJECTIVE: To study dust exposure and inflammatory reactions in the respiratory tract among coffee curing workers in Tanzania. METHODS: A cross-sectional study was conducted in a Tanzanian coffee curing factory. Coffee workers (n = 15) were compared with unexposed controls (n = 18); all workers were nonsmokers. Exhaled nitric oxide was examined using an electrochemistry-based NIOX MINO device. Personal air samples were analyzed for total dust and endotoxins, using gravimetric analysis and the chromogenic Limulus amebocyte lysate endpoint assay, respectively. RESULTS: Total dust levels ranged from 0.2 to 27.9 mg/m, and endotoxin levels ranged from 42 to 75,083 endotoxin units/m. Concentrations of exhaled nitric oxide, analyzed by linear regression and adjusted for age (β = 0.57; 95% confidence interval, 0.08 to 1.06; P = 0.02), was higher among coffee workers than among the control group. CONCLUSION: The results indicate a relationship between the coffee dust and signs of respiratory inflammation