Low-level Eexposure to lead dust in unusual work schedules and hematologic, renal, and hepatic parameters.

BACKGROUND: Many workers are exposed to lead dust in lead-­zinc mines. Exposure to this heavy toxic metal and its compounds can cause irreversible adverse health effects. OBJECTIVE: To assess possible hematotoxic, nephrotoxic, and hepatotoxic potentials of low levels of lead in a group of mine workers exposed to this heavy metal in an unusual work schedule. METHODS: A total of 73 exposed and 70 non-exposed employees were interviewed. Demographic data, and occupational and medical history of the employees were obtained by questionnaires. Air monitoring was performed to determine the workers' time-weighted average (TWA) exposure to lead dust. The threshold limit value (TLV) for lead was adjusted for unusual work schedules according to the model developed by the University of Montreal and the Institute de Recherche en Sante et en Securite du Travail (IRSST). Blood samples were collected for complete blood count, liver and kidney function tests. Data were analyzed using version 21.0 of the SPSS software. RESULTS: The TWA exposure of workers was 24 µg/m3. On average, the worker's exposure to lead dust did not exceed the 8-h OSHA and ACGIH TLV-TWA of 50 µg/m3. Significant associations were found only between exposure to lead and platelet count, red cell distribution width, total protein, and albumin. CONCLUSIONS: Exposure to low levels of lead dust in unusual work schedules was not associated with overt hematotoxicity, hepatotoxicity or nephrotoxicity. However, mild, sub-clinical, pre-pathologic significant changes were noted in some blood parameters of the exposed employees as compared with their referent counterparts.

Multibiomarker approach to assess the magnitude of occupational exposure and effects induced by a mixture of metals.

Metals and metalloids including lead (Pb), arsenic (As) and manganese (Mn) can occur as mixtures in occupational contexts, such as mines. These chemicals are all known to be neurotoxic and provoke changes in heme metabolism also known to induce neurotoxicity. The objective of this work was to propose a multi-biomarker (BM) methodology to screen subjects exposed to the mixture of Pb, As and Mn and assess the severity of their exposure/effects, in an individual basis. The urinary levels of the metals, dela-aminolevulinic acid (ALA) and porphyrins were determined in Portuguese miners and in a control group. The combination of Pb and As urinary levels had the highest capability to identify subjects occupationally exposed to this mixture in mines, as evaluated through Receiver Operating Characteristic (ROC) (A = 98.2%; p < 0.05), allowing that 94.2% of 86 studied subjects were properly identified and the generation of an equation indicating the odd of a subject be considered as exposed to the metal mixture. The combination of urinary ALA and porphyrins revealed to be best one to be applied in the assessment of subjects with high, intermediate, and low magnitudes of exposure/effects, with 95.7% of 46 miners classified correctly according to their severity sub-group and allowing to generate equations, which can be applied in new subjects. The proposed methodology showed a satisfactory performance, evaluating in an integrated manner the magnitude of exposure/effects of the exposed workers, may contributing to improve the control of their health.

[Analysis on the monitoring results of occupational health of workers who leaving their posts from small-sized coal mines].

Objective: To explore the health status of the workers who were leaving their posts from small-scaled coal mines, and to provide evidence for coal workers' pneumoconiosis prevention and safeguard measures. Methods: In 2017, 1008 workers from the coal mine in a town were monitored for occupational health, and the effects of working type, age were analyzed and evaluated. Results: The health monitoring of the mine workers in this town showed high rate of the abnormal detection of respiratory system and cardiovascular system, the incidence rate of pneumoconiosis was up to 34.82%. The incidence of pneumoconiosis in different types of work was not the same (P<0.05) , and the incidence of tunneling workers' pneumoconiosis was the highest. Pneumoconiosis detection rate increased with age (P<0.05) . The difference of pneumoconiosis detection rate among workers of different ages was statistically significant (P<0.05) , among which the pneumoconiosis detection rate was the highest in the group of 40 years old. Conclusion: The pneumoconiosis is serious in small coal mines in this town. It should strengthen the prevention of diseases such as respiratory system and cardiovascular system of coal mine workers, and pay attention to their health management and prolong the life of patients with pneumoconiosis.

Micronucleus frequency in copper-mine workers exposed to arsenic is modulated by the AS3MT Met287Thr polymorphism.

Arsenic(III)methyltransferase (AS3MT) has been demonstrated to be the key enzyme in the metabolism of arsenic as it catalyses the methylation of arsenite and monomethylarsonic acid (MMA) to form methylated arsenic species, which have higher toxic and genotoxic potential than the parent compounds. The aim of this study is to evaluate if genetic variation in the AS3MT gene influences arsenic-induced cytogenetic damage, measured by the micronucleus (MN) assay. AS3MT Met287Thr allele frequencies and MN values were determined for 207 subjects working in the copper-mine industry, who were exposed to variable levels of arsenic. The urinary arsenic profile was used as individual biomarker of arsenic exposure. Results indicate that the MN frequencies found in peripheral blood lymphocytes of the exposed population poorly correlate with the levels of total arsenic content in urine. Nevertheless, when workers were classified according to their AS3MT Met287Thr genotypes, significantly higher MN values were observed for those carrying the variant allele [odds ratio (OR), 3.4 (1.6-5.2); P=0.0003)]. To our knowledge, these results are the first to show that genetic variation in AS3MT, especially the Met287Thr polymorphism, may play a role in modulating the levels of arsenic-induced cytogenetic damage among individuals chronically exposed to arsenic.

Is There a Difference in Brain Functional Connectivity between Chinese Coal Mine Workers Who Have Engaged in Unsafe Behavior and Those Who Have Not?

(1) Background: As a world-recognized high-risk occupation, coal mine workers need various cognitive functions to process the surrounding information to cope with a large number of perceived hazards or risks. Therefore, it is necessary to explore the connection between coal mine workers' neural activity and unsafe behavior from the perspective of cognitive neuroscience. This study explored the functional brain connectivity of coal mine workers who have engaged in unsafe behaviors (EUB) and those who have not (NUB). (2) Methods: Based on functional near-infrared spectroscopy (fNIRS), a total of 106 workers from the Hongliulin coal mine of Shaanxi North Mining Group, one of the largest modern coal mines in China, completed the test. Pearson's Correlation Coefficient (COR) analysis, brain network analysis, and two-sample t-test were used to investigate the difference in brain functional connectivity between the two groups. (3) Results: The results showed that there were significant differences in functional brain connectivity between EUB and NUB among the frontopolar area (p = 0.002325), orbitofrontal area (p = 0.02102), and pars triangularis Broca's area (p = 0.02888). Small-world properties existed in the brain networks of both groups, and the dorsolateral prefrontal cortex had significant differences in clustering coefficient (p = 0.0004), nodal efficiency (p = 0.0384), and nodal local efficiency (p = 0.0004). (4) Conclusions: This study is the first application of fNIRS to the field of coal mine safety. The fNIRS brain functional connectivity analysis is a feasible method to investigate the neuropsychological mechanism of unsafe behavior in coal mine workers in the view of brain science.

Effect of Shift Work on Cognitive Function in Chinese Coal Mine Workers: A Resting-State fNIRS Study.

AIM: Pilot study to examine the impact of shift work on cognitive function in Chinese coal mine workers. BACKGROUND: Shift work is commonly used in modern industries such as the coal industry, and there is growing concern over the impact that shift work has on miners' work performance and personal well-being. METHOD: A total of 54 miners working three shifts (17 in morning shift, 18 in afternoon, and 19 in night shift) participated in this exploratory study. A resting-state fNIRS functional connectivity method was conducted to assess the cognitive ability before and after the work shift. RESULTS: Results showed significant differences in cognitive ability between before and after the work shifts among the three-shift workers. The brain functional connectivity was reduced ranking as the night, afternoon, and morning shifts. Decreased brain functional connectivity at the end of the working shift was found compared with before in the morning and afternoon shifts. Opposite results were obtained during the night shift. The resting-state functional brain networks in the prefrontal cortex of all groups exhibited small-world properties. Significant differences in betweenness centrality and nodal local efficiency were found in the prefrontal cortex in the morning and night shifts. CONCLUSIONS: The current findings provide new insights regarding the effect of shift work on the cognitive ability of Chinese coal mine workers from the view of brain science.

A Predictive Model for Abnormal Bone Density in Male Underground Coal Mine Workers.

The dark and humid environment of underground coal mines had a detrimental effect on workers' skeletal health. Optimal risk prediction models can protect the skeletal health of coal miners by identifying those at risk of abnormal bone density as early as possible. A total of 3695 male underground workers who attended occupational health physical examination in a coal mine in Hebei, China, from July to August 2018 were included in this study. The predictor variables were identified through single-factor analysis and literature review. Three prediction models, Logistic Regression, CNN and XG Boost, were developed to evaluate the prediction performance. The training set results showed that the sensitivity of Logistic Regression, XG Boost and CNN models was 74.687, 82.058, 70.620, the specificity was 80.986, 89.448, 91.866, the F1 scores was 0.618, 0.919, 0.740, the Brier scores was 0.153, 0.040, 0.156, and the Calibration-in-the-large was 0.104, 0.020, 0.076, respectively, XG Boost outperformed the other two models. Similar results were obtained for the test set and validation set. A two-by-two comparison of the area under the ROC curve (AUC) of the three models showed that the XG Boost model had the best prediction performance. The XG Boost model had a high application value and outperformed the CNN and Logistic regression models in prediction.

Morbidity patterns among current and ex-mine workers in Karauli district of Rajasthan, India.

Background: The mining industry has many hazards to which workers are exposed. Despite that, study on health hazards among mine workers are limited in India. Also, there are negligible studies on ex-miners in India. Thus, the present study tried to explore the current levels of self-reported morbidity among mine workers and ex-mine workers in the Karauli district of Rajasthan, India. Methods: This study was a comparative cross-sectional study conducted in the Karauli district of Rajasthan, India. A total of 218 mine workers, 137 ex-mine workers, and 203 non-mine workers were interviewed. An interview-led questionnaire recording the presence of self-reported health problems and demographic information was administered. Self-reported symptoms were classified according to the categories defined in the operational definitions. Results: Ex-mine workers moved away from mining due to respiratory problems (31%), weakness (24%), and TB (20%). Mine workers and ex-miners have significantly increased prevalence of respiratory-related symptoms and injury at the workplace, vision, and oral health problems than the non-mine workers. The adjusted odds of morbidity conditions such as cough up with blood, shortness of breath, and wheezing were significantly higher among ex-miners than current miners. Conclusion: This study identified respiratory symptoms, injury, vision loss, hearing loss, and poor oral health for both mine and ex-mine workers. The higher self-reported health problems for symptoms like cough up with blood, shortness of breath, and wheezing were found among ex-miners than current mine workers.

Silicosis, progressive massive fibrosis and silico-tuberculosis among workers with occupational exposure to silica dusts in sandstone mines of Rajasthan state: An urgent need for initiating national silicosis control programme in India.

CONTEXT: Silicosis is a progressive, irreversible and incurable respiratory morbidity and often becomes a cause for pre-mature mortality among occupationally silica dust-exposed workers in India and similar countries. It has a dual problem of associated silico-tuberculosis as a co-morbidity. The present study was done to assess the respiratory morbidity caused by silicosis in sandstone mine of Rajasthan, India. METHODS: The chest X-rays of 529 subjects having history of employment in stone mines with respiratory morbidity were subjected for this study and evaluated in accordance with ILO Classification 2000. The X-rays were classified into various categories of silicosis and progressive massive fibrosis (PMF) in relation to years of work in stone mines. RESULTS: Out of 529 chest radiographs evaluated, 275 (52%) showed radiological evidence of silicosis. Of them, 40 (7.5%) subjects showed large opacities suggestive of progressive massive fibrosis. Both silicosis and progressive massive fibrosis were associated with increasing duration of work in stone mines. Sixty-one (12.4%) subjects with silicosis also had associated pulmonary tuberculosis, termed as silico-tuberculosis. CONCLUSION: The present study showed a high prevalence of silicosis, progressive massive fibrosis and silico-tuberculosis among stone mine workers. It appears that that unless silicosis is controlled, elimination of tuberculosis is far from reality in the country. Hence, states and central authorities must work together towards control of both silicosis as well as silico-tuberculosis. Similarly, there is an urgent need of initiation of national silicosis control programme, similar to existing national tuberculosis control programme, considering the huge burden of silicosis in India.

The evaluation of the smoking cessation behaviors of coal miners according to the health belief model: A cross-sectional study.

The aim of this descriptive and cross-sectional study was to evaluate smoking characteristics and smoking cessation behaviors among smoking coal miners according to the Health Belief Model (HBM). The population of this cross sectional study consisted of 582 coal miners, while the sample consisted of 473 miners who agreed to participate in the study. The miners working above ground obtained significantly higher scores compared to those who worked underground (p = 0.027). There was a significant positive correlation between smoking costs and perceived susceptibility (p < 0.001; r = 0.249) sub dimension scores, while smoking costs also had a weak positive correlation with perceived severity (p < 0.050; r = 0.179). In addition, many sub dimensions of the HBM-SCS were found to be correlated (p < 0.001). This finding shows that workers who have smoking costs may have made smoking cessation a strategic goal. Smoking habits are widespread among coal miners, and it was thought that further efforts should be made to explain to those coal miners the health hazards of smoking.

Edgar Leigh Collis: Industrial lung disease and ergonomics.

Edgar Collis was appointed as the second Medical Inspector of Factories in 1908, holding the post until the outbreak of the First World War when he became Medical Director of the Ministry of Munitions. After the war, he was appointed to the chair in public health in the University of Wales. He held this post while living in Lossiemouth in Scotland, some 570 miles distant. His research interests were in industrial lung disease, industrial hygiene, and the health of coal miners. He made important contributions to the first and third subjects, but was a less significant figure in the field of industrial hygiene. Among his achievements were the recognition of the relationship between silicosis and tuberculosis, the harmful effects of non-silicaceous coal dust, and the need to fit the worker to the job, and the job to the worker.

Oral hygiene habits amongst chromium mine workers-A cross sectional study.

BACKGROUND: Oral health means much more than just having healthy teeth. Various oral diseases have significant side effects on general health; also systemic diseases can show a reciprocal effect on oral health. So oral health needs to be regarded by multi-professional approaches and should be combined into comprehensive health-promotion strategies and actions. The present study aimed to determine oral hygiene habits amongst chromium mine workers. MATERIALS AND METHODS: The present observational, cross-sectional study was conducted for a period of 4 months from April to October 2017. The present study evaluated the oral hygiene habits amongst the chromium mine workers of Odisha. A total of 1140 males were enrolled in the study. The study was conducted after the institutional ethical board clearance and informed written consent for participation in the study and written consent was obtained from all in their vernacular language. Data were entered using MS-EXCEL 2016 and the statistical analysis was done using SPSS software. RESULTS: There were 91.9% of subjects who brushed once a day, 6.9% brushed twice a day and 1.1% brushed after every meal. The results of the study showed that 75.9% and 8.1% of subjects used tooth paste and tooth powder respectively for brushing there teeth regularly.the results of this study also showed that 11.9% of study participants used indigenous means (other means) as an aid to tooth brushing. CONCLUSION: There is a lack of awareness and education about oral hygiene practices amongst mine workers due to which they do not resort to good oral hygiene practices.

Pulmonary Tuberculosis among Stone Miners of India vis-à-vis Silica Exposure.

BACKGROUND: Tuberculosis is one of the biggest public health concerns in India with a prevalence of 195 cases per 100000. Silica is cytotoxic to macrophage which is primary defense mechanism to tubercular bacilli and, hence, exposure to silica dust increases risk for TB. Silica exposed persons are at 2.8 to 39 times greater risk of affected by pulmonary tuberculosis in comparison to healthy subjects. METHODOLOGY: A cross-sectional epidemiological study was conducted among 935 workers in sandstone mining. Full-size posteroanterior view (PA) chest X-ray in full inspiration was evaluated and evidence of tuberculosis was noted. Fourier transform infrared spectrophotometer was used for determining the free silica in 23 dust samples. RESULTS: 6.4% X-rays showed evidence of TB and silica dust concentration was 0.11 to 0.16 mg/m3. The TB cases significantly increased from 2% to 6% to 12.7% as the work exposure increased from <10 years to 11-20 years to >20 years respectively. 8.5% of the TB cases were seen among the workers having more than 10 years of work exposure. The odds ratio (95% CI) for work exposure more than 10 years to less than 10 years was 4.53 (1.92-10.65). CONCLUSION: Reduction of silica particles from work environment can significantly reduce the number of TB cases and hence wet drilling should be practiced and personal protective equipment should be regularly used.

Rehabilitation of Silicosis Victims of District Karauli, Rajasthan, India.

BACKGROUND: This study was carried out to assess the reach of medico-social and economic programs to the silicosis victims in Karauli. The district is infamous for large-scale unregulated sandstone mining, a pulmonary hazard, causing silicosis, a debilitating occupational disease compensable under Indian laws. METHODOLOGY: A sample of 250 silicosis cases from 38 villages were randomly recruited and interviewed from four different sites. RESULTS: The study reports that 99% of sandstone miners came from marginalized poor communities, had large families, and lived in mud houses. Victims' linkage to their entitlements and welfare programs was poor (51%). Victims (43%) continue to work as casual laborers including in mining sector due to economic compulsions. Greater than 68% of the laborers were wrongly treated for tuberculosis (TB) prior to their diagnosis, >50% go out of the state or cities for better treatment, and 60% of cases had not received their compensation from the government. Among those who received compensation, only 4% spent money for productive purposes and 44% victims were not in a position to work due to health difficulties. CONCLUSIONS: Silicosis has affected the poorest of the poor; victims are wrongly diagnosed and treated for TB. The district is not equipped to deal with the health problems of the victims, forcing them to seek treatment in other states and cities. In conclusion, the impact of rehabilitation programs in the district is ineffective and inadequate and has limited reach. Findings of the study will have far-reaching implications for informed policymaking on the rehabilitation of silicosis victims in the state.

Influencing Factors of High-Risk Human Papillomavirus Infection and DNA Load According to the Severity of Cervical Lesions in Female Coal Mine Workers of China.

High-risk human papillomavirus (HR-HPV) plays an aetiological role in the progression of cervical cancer and precancerous lesions. Determining the risk factors of HR-HPV infection is useful for HR-HPV infection surveillance and control. We aimed to explore the influencing factors of HR-HPV infection in female coal mine workers, and to evaluate the associations between HR-HPV DNA load and cytological and histological changes of cervix. In total 6,325 participants completed standard questionnaire on potential influencing factors of HR-HPV infection and underwent gynecological examinations, HPV test as well as Thinprep cytology test (TCT). 1,512 women with positive results of HPV and/or TCT were referred to colposcopy with biopsy and histological examination. HR-HPV DNA load was evaluated by Digene second generation hybrid capture (HC2) assay. Multiple unconditional logistic regression analysis was used to determine the influencing factors for HR-HPV infection. Of 6,325 study participants, 1,405 (22.2%) were HR-HPV positive. HR-HPV infection rate was higher in women aged 30-50 years, with lower education level, working inside the mines and engaging in shift work. Risk factors for HR-HPV infection in female coal mine workers included contraception (OR=1.395, 95%CI=1.102-1.458), previous artificial abortion (OR=1.603, 95%CI=1.202-1.856), working inside the mines (OR=1.230, 95%CI=1.056-1.528) and history of gynecological diseases (OR=1.198, 95%CI=1.001-1.462), while menopause was a protective factor (OR=0.402, 95%CI=0.306-0.507). The HR-HPV DNA load significantly increased with the severity of cervical cytological (χ 2 trend=177.372, p<0.001) and histological (χ 2 trend=194.501, p<0.001) changes. The results indicated that HR-HPV infection is highly prevalent in female coal mine workers in China. Contraception, artificial abortion, working inside the mines and gynecological diseases could increase the risk of HR-HPV infection in these women. HR-HPV DNA load might predict risks of cervical precancerous lesions and cancer. Our findings could provide scientific basis for reducing the risk of HR-HPV infection and cervical cancer in this vulnerable population.

Metabolic syndrome in different sub occupations among mine workers.

INTRODUCTION: Metabolic syndrome (MS) is a condition described by the group of risk factors associated with obesity that raise the risk of cardiovascular disease and type 2 diabetes. MS has an increasing trend in developing countries with change of diet and lifestyle. Many studies in India have reported high prevalence of MS among general population however there is little information available about the same in working population. MATERIAL AND METHODS: The present study was conducted among 281 mine employees from an organized mining company from Southern India. The workers were classified into different sub occupational groups according to ISCO-88. WHO Criteria was used for the diagnosis of MS. RESULTS: The overall prevalence of MS in mine employees was about 17%. Among different sub occupations, the highest was observed in professional group of 52.9% and lowest in elementary occupations of 9.4%. In other sub occupational groups it was 23.3% in clerical, 18.9% in trade workers, 17.5% in technicians and 15.5% in machine operators. Occurrence of MS when compared in different sub occupations was statistically significant (P = <0.001). Further MS was found to be 6.4% in the 18-30 years of age group which significantly increased to 40.3% in the 51-60 years age group suggesting direct relation of MS with increase in age. DISCUSSION: Mining being physical demanding occupation prevalence of MS is assumed to be lower than the general population; however it was observed that the prevalence is in similar line to that of general population with the prevalence ranging from 9.4% to 52.9% among different sub occupations. Hence it is concluded that there is need of health education and promotion among the mine workers.

The Research on the Impact of Management Level's Charismatic Leadership Style on Miners' Unsafe Behavior.

The aim of this study is research the impact of management level's charismatic leadership style on miners' unsafe behavior by using the questionnaires on charismatic leadership style, safety attitude and the miners' unsafe behavior measurement to investigate 200 employees in Shen Dong Company. The research results suggest that management level's charismatic leadership style have very important influence on miners' unsafe behavior and the influence is affected by the safety attitude which is the intermediary function. In the end, this study propose advice on how to improve the coal mine enterprise managers charismatic leadership style in the coal mine enterprise's safety management work, including attach great importance to a variety of incentive methods, set up safety moral models, practice of inductive leadership concept, create a good atmosphere of safety, etc for reference for coal mining enterprises.

Periodic breathing and oxygen supplementation in Chilean miners at high altitude (4200m).

Our objective was to determine the nocturnal ventilatory pattern and characterize the effect of oxygen enrichment on nocturnal ventilatory pattern and sleep quality in miners exposed to intermittent hypobaric hypoxia at 4200m. A total of 16 acclimatized miners were studied. Nocturnal ventilatory pattern (plethysmographic inductance), arterial oxygen saturation and heart rate (pulse oximetry) were performed in 9/16 subjects. Sleep quality at high altitude was assessed by self-questionnaires in 16/16 subjects. All measurements were performed during at least 7h of sleep. Subjects were studied while sleeping at high altitude without (control, C) and with oxygen supplementation (FiO2=0.25, treated, T). Periodic breathing (%) C: 25±18 vs T: 6.6±5.6 (p<0.05), apneas index (no./h) C: 34.9±24.1 vs T: 8.5±6.8 (p<0.05); and sleep quality C: 17.8±3.4 vs T: 12.1±2.2 (p<0.0001) were evaluated. In conclusion, periodic breathing with apneas was present in miners exposed to high altitude for 1 to 4 years and was reduced by treatment with supplementary oxygen.

Occupational injuries and fatalities in a tanzanite mine: Need to improve workers safety in Tanzania.

INTRODUCTION: Work related injuries are common, and the mining industry accounts for a significant proportion of these injuries. Tanzania is among the countries with high rates of mining injuries, nevertheless pre-hospital care is almost non existant and health care service deliveries are poor. This study sought to identify factors associated with injuries and fatalities among miners in Mererani, Tanzania. METHODS: A Cross - Sectional study of miners who sustained injuries and seen at Mererani health centre between January 2009 and May 2012. RESULTS: In the selected period 248 injury patients were seen. All were males, and 54% were between 18 - 30 years age-group. Almost all (98.7%) didn't use protective gears at work, and worked for more than 12 hours daily. Falling rocks were the leading cause of injury (18.2%), and majority sustained multiple injuries (33%). Of the patients seen, 41.3% died. The following were more likely to die than others; Primary education (p = 0.04), Less than 5 years work experience (p = 0.000), unintentional injuries (p = 0.000), fall injuries (p = 0.000) and sustaining multiple injuries (p = 0.000). CONCLUSION: The burden of injuries and fatalities demonstrated in this study, point to the need for implementation and monitoring of the use of safety equipment and operating procedures of the mines by government and other regulatory authorities. Initiation of pre hospital care at the mines and improved emergency medical service delivery at health centers in Tanzania.

Factors associated with severe occupational injuries at mining company in Zimbabwe, 2010: a cross-sectional study.

INTRODUCTION: Injury rate among mining workers in Zimbabwe was 789/1000 workers in 2008. The proportion of severe occupational injuries increased from 18% in 2008 to 37% in 2009. We investigated factors associated with severe injuries at the mine. METHODS: An unmatched 1:1 case-control study was carried out at the mine, a case was any worker who suffered severe occupational injury at the mine and was treated at the mine or district hospital from January 2008 to April 2010, a control was any worker who did not suffer occupational injury during same period. We randomly selected 156 cases and 156 controls and used interviewer administered questionnaires to collect data from participants. RESULTS: Majority of cases, 155(99.4%) and of controls 142(91%) were male, 127(81.4%) of cases and 48(30.8%) of controls worked underground. Majority (73.1%) of severe occupational injuries occurred during night shift. Underground temperatures reached 500C. Factors independently associated with getting severe occupational injuries included working underground (AOR=10.55; CI 5.97-18.65), having targets per shift (AOR=12.60; CI 3.46-45.84), inadequate PPE (AOR=3.65 CI 1.34-9.89) and working more than 8 hours per shift (AOR=8.65 CI 2.99-25.02). CONCLUSION: Having targets exerts pressure to perform on workers. Prolonged working periods decrease workers' attention and concentration resulting in increased risk to severe injuries as workers become exhausted, lose focus and alertness. Underground work environment had environmental hazards so managers to install adequate ventilation and provide adequate PPE. Management agreed to standardize shifts to eight hours and workers in some departments have been supplied with adequate PPE.