Effects of the combined exposure to chemicals and unusual working hours.

OBJECTIVE: Both exposure to occupational chemicals and to unusual working hours have well documented effects on health. Determination of occupational exposure limits is, however, usually based on chemical-only exposure and assumes an 8-h workday, 5 days/week and a 40-h work week. A significant proportion of the workforce is exposed to chemicals while working in other work schedules. This review thus aimed to synthesize and evaluate the scientific support for a combined effect of unusual working hours and chemical exposure and, if possible, give recommendations for OEL adjustments to account for unusual working hours. METHODS: The search for articles was made as part of the preparation of a report for the Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals. In this report, unusual working hours were categorized as shift work or extended (>8 h) working hours. Inclusion criteria were observational studies in the English language published up to November 2021 in peer-reviewed journals, with explicit metrics of exposure (chemicals and unusual working hours) and of health outcome, and which explicitly tested the association between exposure and outcome. Search engines of seven databases were used. RESULTS: Of the initially 15 400 identified papers, 9 studies published between 1985 and 2021 met the inclusion criteria, 7 of which showed significant associations. Results from a few of the studies, i.e. regarding effects of dust and endotoxin on lung function, effects of acetone on sleep quality and tiredness, effects of carbon disulphide on coronary artery disease and effects of chemicals on spontaneous abortion, suggested more pronounced effects during night shifts compared to during day shifts. DISCUSSION: The reviewed data is considered insufficient to conclude on recommendations for OEL adjustment for shift work. Suggested areas of future studies are mentioned. CONCLUSION: Further studies about the effects of the combined exposure to unusual working hours and chemical exposure are essential for risk assessment, and for recommendation of potential OEL adjustments. What is important about this paper? Effects of chemical agents at the workplace may depend not only on exposure level and duration but also on the time of exposure in relation to the circadian rhythm. This study reviewed the scientific support for a combined effect of unusual working hours and chemical exposure and revealed an obvious need for additional studies regarding the complex interplay of the two different exposures with respect to adverse health effects.

Bacterial contamination of coffee and personal exposure to inhalable dust and endotoxin in primary coffee processing factories in Ethiopia.

INTRODUCTION AND OBJECTIVE: Endotoxins from gram-negative bacteria might be released when the coffee cherries are processed and may cause respiratory health problems among workers in the coffee industry. The relationship between bacterial contamination and occupational exposure to endotoxin levels has not been thoroughly explored previously in primary coffee processing factories in Ethiopia, or elsewhere. The aim of this study was to characterize the level of personal endotoxin exposure and its relations with bacterial contamination of coffee cherries in such factories in Ethiopia. MATERIAL AND METHODS: A cross-sectional study was conducted from March 2020 - February 2021 in 9 primary coffee processing factories in 3 regions in Ethiopia. A total of 180 personal air samples were collected to analyze workers' exposure to inhalable dust and endotoxin. Correlation tests were performed to assess the relationship between total bacteria and endotoxin levels and between inhalable dust and endotoxin levels. RESULTS: The geometric mean (GM) of personal inhalable dust exposure among machine room workers and hand pickers were 9.58 mg/m3 and 2.56 mg/m3, respectively. The overall GM of endotoxin exposure among machine room workers and hand pickers were 10,198 EU/m3 and 780 EU/m3, respectively. Gram-negative bacteria were found in all 54 coffee samples. The correlation between inhalable dust and endotoxin exposure was significant (r=0.80; P <0.01). CONCLUSIONS: About 92% of the samples from hand pickers and all samples from machine room workers exceeded the occupational exposure limit of 90 EU/m3 recommended by the Dutch Expert Committee on Occupational Standards. Prevention and control of bacterial contamination of the coffee in primary coffee processing are suggested to reduce endotoxin exposure that might cause respiratory health problems among coffee workers.

Benzene exposure and risk of lung cancer in the Norwegian Offshore Petroleum Worker cohort: a prospective case-cohort study.

OBJECTIVE: The objective of our study was to examine whether occupational exposure to benzene is associated with lung cancer among males in the Norwegian Offshore Petroleum Workers cohort. METHODS: Among 25 347 male offshore workers employed during 1965-1998, we conducted a case-cohort study with 399 lung cancer cases diagnosed between 1999 and 2021, and 2035 non-cases sampled randomly by 5-year birth cohorts. Individual work histories were coupled to study-specific job-exposure matrices for benzene and other known lung carcinogens. Weighted Cox regression was used to estimate HRs and 95% CIs for the associations between benzene exposure and lung cancer, by major histological subtypes, adjusted for age, smoking and occupational exposure to welding fumes, asbestos and crystalline silica. Missing data were imputed. RESULTS: For lung cancer (all subtypes combined), HRs (95% CIs) for the highest quartiles of benzene exposure versus unexposed were 1.15 (0.61 to 2.35) for cumulative exposure, 1.43 (0.76 to 2.69) for duration, and 1.22 (0.68 to 2.18) for average intensity (0.280≤P-trend≤0.741). For 152 adenocarcinoma cases, a positive trend was observed for exposure duration (P-trend=0.044). CONCLUSIONS: In this cohort of offshore petroleum workers generally exposed to low average levels of benzene, we did not find an overall clear support for an association with lung cancer (all subtypes combined), although an association was suggested for duration of benzene exposure and adenocarcinoma. The limited evidence might be due to restricted statistical power.

Validation of a full-shift benzene exposure empirical model developed for work on offshore petroleum installations on the Norwegian continental shelf.

Workers on offshore petroleum installations might be exposed to benzene, a carcinogenic agent. Recently, a full-shift benzene exposure model was developed based on personal measurements. This study aimed to validate this exposure model by using datasets not included in the model. The exposure model was validated against an internal dataset of measurements from offshore installations owned by the same company that provided data for the model, and an external dataset from installations owned by another company. We used Tobit regression to estimate GM (geometric mean) benzene exposure overall and for individual job groups. Bias, relative bias, precision, and correlation were estimated to evaluate the agreement between measured exposures and the levels predicted by the model. Overall, the model overestimated exposure when compared to the predicted exposure level to the internal dataset with a factor of 1.7, a relative bias of 73%, a precision of 0.6, a correlation coefficient of 0.72 (p = 0.019), while the Lin's Concordance Correlation Coefficient (CCC) was 0.53. The model underestimated exposure when compared to the external dataset with a factor of about 2, with a relative bias of -45%, a precision of 1.2, a correlation coefficient of 0.31 (p = 0.544), and a Lin's CCC of 0.25. The exposure model overestimated benzene exposure in the internal validation dataset, while the precision and the correlation between the measured and predicted exposure levels were high. Differences in measurement strategies could be one of the reasons for the discrepancy. The exposure model agreed less with the external dataset.

Exposure to benzene and other hydrocarbons and risk of bladder cancer among male offshore petroleum workers.

BACKGROUND: Occupational exposures constitute the second leading cause of urinary bladder cancer after tobacco smoking. Increased risks have been found in the petroleum industry, but high-quality exposure data are needed to explain these observations. METHODS: Using a prospective case-cohort design, we analysed 189 bladder cancer cases (1999-2017) and 2065 randomly drawn non-cases from the Norwegian Offshore Petroleum Workers cohort. Cases were identified in the Cancer Registry of Norway, while work histories (1965-1998) and lifestyle factors were recorded by questionnaire at baseline (1998). Occupational petroleum-related hydrocarbon exposures were assessed by expert-developed job-exposure matrices. Hazard ratios were estimated by weighted Cox-regressions, adjusted for age, tobacco smoking, education, and year of first employment, and with lagged exposures. RESULTS: Increased risks were found in benzene-exposed workers, either long-term exposure (≥18.8 years, HR = 1.89, 95% CI: 1.14-3.13; p-trend = 0.044) or high-level cumulative benzene exposure (HR = 1.60, 95% CI: 0.97-2.63; p-trend = 0.065), compared with the unexposed. Associations persisted with 20-year exposure lag. No associations were found with skin or inhalation exposure to crude oil, mineral oil (lubrication, hydraulics, turbines, drilling), or diesel exhaust. CONCLUSIONS: The results suggest that exposures in the benzene fraction of the petroleum stream may be associated with increased bladder cancer risk.

Esophageal and Head and Neck Cancer Patients Attending Ocean Road Cancer Institute in Tanzania from 2019 to 2021: An Observational Study.

BACKGROUND: Cancer in Africa is an emerging public health problem that needs urgent preventive measures, particularly in workplaces where exposure to carcinogens may occur. In Tanzania, the incidence rate of cancer and mortality rates due to cancers are increasing, with approximately 50,000 new cases each year. This is estimated to double by 2030. METHODS: Our hospital-based cross-sectional study describes the characteristics of newly diagnosed patients with head and neck or esophageal cancer from the Ocean Road Cancer Institute (ORCI), Tanzania. We used an ORCI electronic system to extract secondary data for these patients. RESULTS: According to the cancer registration, there were 611 head and neck and 975 esophageal cancers recorded in 2019-2021. Two-thirds of these cancer patients were male. About 25% of the cancer patients used tobacco and alcohol, and over 50% were involved in agriculture. CONCLUSION: Descriptions of 1586 head and neck cancer patients and esophageal cancer patients enrolled in a cancer hospital in Tanzania are given. The information may be important for designing future studies of these cancers and may be of value in the development of cancer prevention measures.

Benzene Exposure From Selected Work Tasks on Offshore Petroleum Installations on the Norwegian Continental Shelf, 2002-2018.

OBJECTIVES: Work on offshore petroleum installations may cause exposure to benzene. Benzene is a carcinogenic agent, and exposure among workers should be as low as reasonably practicable. We aimed to assess short-term (less than 60 min) benzene exposure from the most frequent work tasks on offshore installations on the Norwegian continental shelf and identify determinants of exposure. In addition, we aimed to assess the time trend in task-based benzene measurements from 2002 to 2018. METHODS: The study included 763 task-based measurements with a sampling duration of less than 60 min, collected on 28 offshore installations from 2002 to 2018. The measurements were categorized into 10 different tasks. Multilevel mixed-effect Tobit regression models were developed for two tasks: sampling and disassembling/assembling equipment. Benzene source, season, indoors or outdoors, design of process area, year of production start, sampling method, and work operation were considered as potential determinants for benzene exposure in the models. RESULTS: The overall geometric mean (GM) benzene exposure was 0.02 ppm (95% confidence intervals 95%(CI: 0.01-0.04). The pipeline inspection gauge (PIG) operation task was associated with the highest exposure, with a GM of 0.33 ppm, followed by work on flotation cells, disassembling/assembling, and sampling, with GMs of 0.16, 0.04, and 0.01 ppm, respectively. Significant determinants for the disassembling/assembling task were work operation (changing or recertifying valves, changing or cleaning filters, and breaking pipes) and benzene source. For sampling, the benzene source was a significant determinant. Overall, the task-based benzene exposure declined annually by 10.2% (CI 95%: -17.4 to -2.4%) from 2002 to 2018. CONCLUSIONS: The PIG operation task was associated with the highest exposure out of the ten tasks, followed by work on flotation cells and when performing disassembling/assembling of equipment. The exposure was associated with the type of benzene source that was worked on. Despite the decline in task-based exposure in 2002-2018, technical measures should still be considered in order to reduce the exposure.

Respiratory Health among Pesticide Sprayers at Flower Farms in Ethiopia.

BACKGROUND: Pesticide use in Ethiopia has become a common practice in which large-scale flower farms are the main consumers. Workers on flower farms might be exposed to pesticides while spraying or while performing other tasks related to pesticide use and management. It is unclear whether working as a flower farm sprayer is associated with respiratory health problems. OBJECTIVE: The objective of this study was to compare respiratory symptoms and lung function indices between pesticide sprayers and non-spraying workers. METHOD: A cross-sectional study was conducted on 15 flower farms, involving all-male sprayers as the pesticide-exposed group and all other male workers as a control group. Data were collected using a standard questionnaire for respiratory symptoms developed by the British Medical Research Council and the American Thoracic Society. Lung function tests were performed to determine forced vital capacity (FVC), forced expiratory volume at one second (FEV1), mid 50 expiratory flow, and the ratio of FEV1 to FVC. Chi-squared tests and Poisson regression analyses were used to compare respiratory symptoms between the two working groups. General linear regression models were used to compare lung function test indices between spraying and non-spraying working groups. The significance level was set to 0.05. RESULTS: A total of 285 male workers participated (152 sprayers and 133 non-spraying workers). The mean age of the workers was 25 years for sprayers and 24 years for non-sprayers. The proportions of cough, cough with sputum, breathlessness, and wheezing were similar in the two groups, while chest tightness was significantly high in the non-spraying group. Sprayers had significantly higher FVC and FEV1 than the non-spraying group. CONCLUSIONS: Respiratory symptoms were not different between the sprayers and non-spraying workers except that the non-spraying workers had increased chest tightness. FVC and FEV1 were significantly higher among sprayers relative to non-sprayers. The results must be interpreted with caution, as the sprayers used respiratory protective equipment, which probably reduced their exposure to the pesticides. Also, the workers were young, and a healthy worker effect might be present among the sprayers.

Occupational Benzene Exposure in the Norwegian Offshore Petroleum Industry, 2002-2018.

PURPOSE: Workers on offshore petroleum installations are at risk of being exposed to benzene which is carcinogenic to humans. The present study aimed to assess the time trend of full-shift benzene exposure from 2002 to 2018 in order to characterize benzene exposure among laboratory technicians, mechanics, process operators, and industrial cleaners, and to examine the possible determinants of benzene exposure. METHODS: A total of 924 measurements of benzene exposure from the Norwegian petroleum offshore industry were included. The median sampling duration was 680 min, ranging from 60 to 940 min. The overall geometric mean (GM) and 95% confidence interval, time trends, and determinants of exposure were estimated using multilevel mixed-effects tobit regression analyses. Time trends were estimated for sampling duration below and above 8 h, both overall and for job groups. The variability of exposure between installation and workers was investigated in a subset of data containing worker identification. RESULTS: The overall GM of benzene exposure was 0.004 ppm. When adjusting for job group, design of process area, season, wind speed, and sampling duration, industrial cleaners had the highest exposure (GM = 0.012). Laboratory technicians, mechanics, and process operators had a GM exposure of 0.004, 0.003, and 0.004 ppm, respectively. Overall, the measured benzene exposure increased by 7.6% per year from 2002 to 2018. Mechanics had an annual increase of 8.6% and laboratory technicians had an annual decrease of 12.6% when including all measurements. When including only measurements above 8 h, mechanics had an increase of 16.8%. No statistically significant time trend was found for process operators. Open process area, high wind speed, and wintertime were associated with reduced exposure level. CONCLUSIONS: An overall increase in measured exposure was observed from 2002 to 2018. The increase may reflect changes in measurement strategy from mainly measuring on random days to days with expected exposure. However, the time trend varied between job groups and was different for sampling duration above or below 8 h. Industrial cleaners had the highest exposure of the four job groups while no differences in exposure were observed between laboratory technicians, mechanics, and process operators. The design of the process area, job group, wind speed, and season were all significant determinants of benzene exposure.

Occupational exposure to air pollutants emitted from in situ burning of offshore oil spills: a large-scale field study.

BACKGROUND: In-situ burning (ISB) could be an effective cleanup method during spills. This study aims to study occupational exposure to pollutants emitted from offshore, large-scale ISB-experiments among personnel on vessels involved in ISB. MATERIALS AND METHODS: Six experimental ISBs after release of 4.2-6 m3 crude or refined oils were performed. Air measurements on three vessels were taken of particulate matter (PM) of different size fractions, polycyclic aromatic hydrocarbons (PAH) and volatile organic compounds (VOC). RESULTS: One vessel was located upwind (about 80-140 m) from the burning oil while two work boats were positioned 200-400 m downwind. One of the work boats moved back and forth transverse to the smoke plume while the other followed the edge of the smoke plume downwind. During the burn period (28-63 min) the range of mean concentrations of PM2.5 particles in the closest work boat downwind from the burn (0.068-0.616 mg/m3) was considerably higher than in the upwind vessel (0.0198-0.029 mg/m3) and in the work boat moving downwind at the edge of the visible smoke (0.007-0.078 mg/m3). The particles were mainly in the PM<1 fraction. In the work boat closest to the burn the mean concentration of particulate PAH and VOC was 0.046-0.070 ng/m3 and < limit of detection -17.1 ppm, respectively. CONCLUSIONS: The mean PM2.5 levels in the closest vessel varied between 4 and 41 times higher than the 24-hour Norwegian Air Quality Criteria for the general population, indicating that the particulate exposure may impose a health risk for personnel up to 400 m downwind from an ISB. Exposure to VOC and PAH among crew on board vessels both upwind and downwind from the burning was low during these conditions. However, it is recommended that crew on vessels close to and downwind of smoke plumes from oil fires should use half-masks with P3 filters.

Night shift work, chemical coexposures and risk of female breast cancer in the Norwegian Offshore Petroleum Workers (NOPW) cohort: a prospectively recruited case-cohort study.

OBJECTIVES: This study examined the association between night shift work and risk of breast cancer, overall and by hormone receptor subtype, among females in the Norwegian Offshore Petroleum Workers (NOPW) cohort. We also examined the association of coexposure (chlorinated degreasers and benzene) and breast cancer risk, and possible interaction with work schedule. DESIGN: Prospectively recruited case-cohort study within the NOPW cohort. SETTING: Female offshore petroleum workers active on the Norwegian continental shelf. PARTICIPANTS: 600 female workers (86 cases and 514 non-cases) were included in the study. We excluded workers that died or emigrated before start of follow-up, had missing work history, were diagnosed with breast cancer or other prior malignancy (except non-melanoma skin cancer) before start of follow-up. RESULTS: No overall association was found between breast cancer risk and work schedule (HR 0.87, 95% CI 0.52 to 1.46 for work schedule involving night shift vs day shift only). There was no significant association between work schedule and risk of any breast cancer subtype. No significant interactions were found between work schedule and chemical coexposures (breast cancer overall Pinteraction chlorinated degreasers=0.725 and Pinteraction benzene=0.175). CONCLUSIONS: Our results did not provide supporting evidence that work schedule involving night shift affects breast cancer risk in female offshore petroleum workers, but should be considered cautiously due to few cases. Further studies with larger sample sizes are warranted.

Offshore field experiments with in-situ burning of oil: Emissions and burn efficiency.

In situ burning (ISB) is an oil spill response technique including ignition and burning to remove oil on the water surface. The technique rapidly and effectively removes large portions of the oil. However, the combustion process causes a large smoke plume and leaves a viscous residue in the water. During six large-scale experimental burns in the North Sea in 2018 and 2019, the smoke plume, released oil and contained residues were analysed. The objectives were to document the content of particles and gases in the smoke plume, properties of both the released oils and residues, and the effectiveness of the burns. Oseberg crude oil, Ultra Low Sulphur Fuel Oil (ULSFO), Intermediate Fuel Oil (IFO180) and Marine Gas Oil (MGO) were released into a fire-boom and ignited. Particles and gases in the smoke plume were monitored using drones with several sensors. Soot particle monitoring indicated that more than 90% of the particles produced during the burns were <1 µm. Soot fallout was mainly limited to visible smoke, and the particle concentration was highest directly under the smoke plume and declined with distance from the burn. Gas monitoring in the smoke indicated low concentrations of SO2 and NOX (<2 ppm), and the concentrations of CO2 and CO were within air quality standards. Black Carbon produced relative to the amount of oil burned was 10-18%. The burn efficiency varied and were estimated to 80-91% for Oseberg, >90% for MGO, and <60% for both ULSFO and IFO180. The present paper addresses the results of the smoke plume monitoring, properties of the ISB residues and the burn efficiency.

Poor Provision of Sanitary Facilities in Markets of Lusaka District Zambia.

Background: Although provision of sanitary facilities in workplaces is an important issue, very few studies have been undertaken in this regard. Objective: This study assessed the provision of sanitary facilities for market traders and their perceptions of the provided facilities in Lusaka district Zambia. Methods: A cross-sectional study of workplace observations in 12 randomly selected markets and interviews with 386 traders, conducted in Lusaka district. Findings: The study revealed that eleven of the twelve markets provided toilets, hand-washing and drying facilities, water, urinals, soap, and toilet paper. However, most of the markets did not comply with the Zambian laws in terms of the adequacy and privacy of facilities. One market did not have any of the listed facilities. Most traders perceived facilities to be unsatisfactory and used them only because of the lack of alternatives. Poor provision of sanitary facilities was observed at markets thus predisposing its workforce and trading population to multiple public health hazards. Conclusions: The findings of this study call for urgent investments in sanitary structures and surveillance systems to guarantee the safety of the population and to promote the health of market traders as well as the community at large.

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.

Registered health problems and demographic profile of integrated textile factory workers in Ethiopia: a cross-sectional study.

BACKGROUND: Textile and garment factories are growing in low and middle-income countries as worldwide demand for inexpensive clothing increases each year. These integrated textile and garment production factories are often built-in areas with few workplaces and environmental regulations, and employees can be regularly exposed to workplace hazards with little regulatory oversight. Consequently, workers' health may be significantly affected due to long term exposure to hazards. This study describes registered health problems and their association to work-related and personal factors among workers in integrated textile factories in Ethiopia. METHODS: Institution-based cross-sectional study design was employed for this analysis. A one-year recording of worker's clinical diagnoses (between March 2016 and February 2017) was gathered from the factory clinics of three integrated textile factories. Clinical diagnosis data was obtained as factory workers visited the clinics if feeling unwell. Sociodemographic characteristics and work-related information were obtained from the factory's human resource departments. The sociodemographic and clinical diagnosis statuses of 7992 workers were analyzed. The association between the registered diagnoses and workplace factors (work in textile production, garment production and support process) and personal factors (age, sex and educational status) were studied using logistic regression analysis. RESULTS: The average employee age and years of service were 40 years and 11 years respectively. 60% of workers were females, comprising of 4778 women. 66% of all workers (5276) had 27,320 clinical diagnoses. In total, this caused 16,993 absent working days due to sick leave. Respiratory diseases (34%) and musculoskeletal disorders (29%) were the most prevalent diagnoses, while bodily injuries were the cause of most work absences. Work department, sex and educational status are variables that were most significantly associated with higher prevalence of disease groups. CONCLUSIONS: About two-thirds of the integrated textile factory workers were diagnosed with different types of disease. The textile and garment production department workers were affected at a greater rate than the support process workers, indicating that some diseases may be related to workplace exposure. Further study should investigate rare chronic diseases such as cancer, heart diseases, renal diseases and diabetes.

Hand-Arm Vibration Exposure in Rock Drill Workers: A Comparison between Measurements with Hand-Attached and Tool-Attached Accelerometers.

OBJECTIVES: To assess the hazard of tool vibrations, we need valid exposure measurements. The use of hand-attached accelerometers (vibration sensors) to measure hand-arm vibrations (HAVs) has become a popular approach. However, according to International Standard ISO 5349-2, the preferred attachment of accelerometers is at the tool handle. We compared measures of HAV between hand- and tool-attached accelerometers in rock drilling. METHODS: We measured HAV in five rock drillers using jackleg drills in normal working operations with simultaneous measures of both hand-attached and tool-attached accelerometers. Five to seven measurement cycles of 15 s were executed on each worker, resulting in a total of 29 measurement cycles. To identify possible differences in working technique, we recorded videos of tool handle handgrips during drilling. RESULTS: There was a significant difference (9.5 m s-2; P ≤ 0.05) in vibration magnitudes measured by the tool-attached accelerometers compared with the hand-attached accelerometers. The hand-attached accelerometer showed a lower vibration magnitude for all workers (range of difference: 2.3-14.6). The variation between the two accelerometer attachments was larger between workers than within workers (ICC = 0.68). CONCLUSIONS: For measurements of HAV from jackleg drills, the use of hand-attached accelerometers may cause a lower recorded vibration level compared with tool-attached accelerometers. This difference is likely to vary depending on how workers grip the tool handle, and a misclassification of exposure will occur if workers grip the tool handle in a way that makes the accelerometer lose contact with the vibrating surface. Individual differences in how workers grip the tool handles should be considered when assessing HAV.

Temporary Threshold Shifts among Iron and Steel Factory Workers in Tanzania: A Pre-Interventional Study.

Background: Workers in iron and steel factories in Tanzania are exposed to noise levels above recommended limit values, without using hearing protection devices. Exposure to noise levels above 85 dB(A) is associated with temporary threshold shifts (TTS) of human hearing. Nevertheless, there are few studies of noise and hearing from African countries. Objective: To determine whether the normal hearing workers in Tanzania experiences TTS after full-shift occupational noise exposure of 85 dB(A) and above. Methods: A total of 55 workers were included. Full-shift personal noise measurements were conducted. Pre- and post-shifts pure-tone audiometry were conducted for each worker. TTS was defined as a 10 dB or greater change at 1000, 2000, 3000 or 4000 Hz in either ear. Results: We found that 85.5% of the workers developed TTS across the work shift. There was significant increase in mean hearing thresholds across shift at 1000, 2000, 3000 and 4000 Hz among the workers exposed to an average personal noise exposure (LAeq,8h) of 90.4 dB(A) (SD = 2.7). The difference in mean hearing thresholds was higher at 4000 Hz [Arithmetic Mean (AM) = 10 dB SD = 4 dB] compared to that of 1000 Hz (AM = 4 dB SD = 3 dB), 2000 Hz (AM = 4 dB SD = 4 dB), and 3000 Hz (AM = 9 dB SD = 6 dB), respectively. Conclusions: Interventions to reduce occupational personal noise exposure are warranted to reduce the high risk of developing a permanent threshold shift with persistent high noise exposure. An intervention study is planned for this group of workers.

Reduced Cross-Shift Lung Function and Respiratory Symptoms among Integrated Textile Factory Workers in Ethiopia.

Chronic respiratory symptoms and reduction in lung function has been described as a common health problem among textile workers in low- and middle-income countries. The objective of this study was to measure lung function and respiratory symptoms among workers from an integrated textile factory. A comparative cross-sectional study design with a cross-shift lung function measurement was performed in 306 cotton dust exposed workers from an integrated textile factory and 156 control workers from a water bottling factory. An integrated textile factory typically has four main production departments (spinning, weaving, finishing, and garment) that process raw cotton and manufacture clothes or fabrics. Respiratory symptoms were assessed by adopting the standard American Thoracic Society questionnaire. Descriptive statistics and logistic and linear regression analysis were used. The prevalence of respiratory symptoms was significantly higher among textile workers (54%) than in controls (28%). Chronic cough, chest tightness, and breathlessness were significantly higher among textile workers (23%, 33%, and 37%, respectively) than in the control group (5%, 17% and 6%, respectively). Breathlessness was the most prevalent chronic respiratory symptom with highest adjusted odds ratio 9.4 (95% CI 4.4-20.3). A significantly higher cross-shift lung function reduction was observed among textile workers (123 mL for FEV1 and 129 mL for FVC) compared with the control group (14 mL for FEV1 and 12 mL for FVC). Thus, workers' respiratory health protection programs should be strengthened in textile factories.

Personal inhalable dust and endotoxin exposure among workers in an integrated textile factory.

The aim of this study was to determine personal exposure to inhalable dust and endotoxin levels among workers in an integrated cotton-processing textile factory and exposure variability across the different work sections. Full shift measurements were carried out using inhalable conical samplers with 37 mm glass-fiber filters. Personal inhalable dust was determined gravimetrically, and endotoxin levels were analyzed by kinetic chromogenic Limulus Amebocytes Lysate assay. The geometric means of personal dust and endotoxin concentrations were 0.75 mg·m-3 and 831 EU·m-3, respectively. The highest dust and endotoxin concentrations were observed in carding section (1.34 mg·m-3 and 6,381 EU·m-3, respectively). Altogether, 11% of dust and 89% of endotoxin samples exceeded workplace exposure limits. This study showed a moderate correlation between inhalable dust and endotoxin (r = 0.450, p < 0.001). Our findings indicate that low dust exposure does not guarantee a low exposure to endotoxin.