Concentrations of respirable crystalline silica and radon among tanzanite mining communities in Mererani, Tanzania

BACKGROUND

Globally, the number of small-scale miners (SSM) is estimated to be more than 25 million, but it supports the livelihoods of around 100 million individuals. In Tanzania, the number of SSM has increased from an estimated 150,000 in 1987 to ~1.5 million in 2017. The miners are at a high risk of occupational-related health challenges. The study aimed to assess the concentrations of respirable crystalline silica (RCS) and radon among the tanzanite mining communities in Simanjiro District, Tanzania.

METHODS

We carried out a cross-sectional study involving the Mererani mines in Tanzania. These are underground mines comprised of informally employed miners, i.e. SSM. Concentrations of RCS and radon gas were measured in 44 study units, i.e. 22 mining pits and within 22 houses in the general community, e.g. shops in the peri-mining community. A total of 132 respirable personal dust exposure samples (PDS), 3 from each of the study units were taken, but only 66 PDS from the mining pits were analysed, as this was the main interest of this study. Radon concentration was measured by continuous monitoring throughout the working shift (and overnight for residences) using AlphaGuard monitor. The medians and comparison to the reference values, OSHA USA PEL and WHO/IARC references, were done for RCS and radon, respectively, using SPSS Ver. 27.0.0).

RESULTS

The median time-weighted average (TWA) concentration of the RCS in the mining pits was 1.23 mg/m3. Of all 66 personal dust samples from the mining pits, 65 (98.5%) had concentrations of RCS above the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) of 0.05 mg/m3. Mining pits had a median radon concentration of 169.50 bq/m3, which is above the World Health Organization (WHO)/International Commission on Radiation Protection (ICRP) recommended reference of 100.00 bq/m3 but not above the upper reference of 300.00 bq/m3, while the community buildings had a median radon concentration of 88.00 bq/m3. Overall, 9 (20.5%) and 17 (38.6%) radon measurements were above 300.00 bq/m3 and between 100.00 and 300.00 bq/m3 references, respectively. Specifically, in the mining pits, 9 (40.9%) test results were above 300.00 bq/m3, while none of the test results in the community was above 300.00 bq/m3.

CONCLUSION

The tanzanite SSM in Mererani we highly exposed to RCS, which increases the risk of pulmonary diseases, including silicosis, tuberculosis, and pulmonary malignancies. Immediate action by OSHA Tanzania should be enforcement of wearing respirators by all miners throughout the working hours. Health education programmes to the SSM must be strengthened and OSHA Tanzania should adopt the 0.05 mg/m3 PEL, and enforce other occupational health and safety measures, including regular use of dust suppression mechanisms (water spray and wet drilling) and monitoring of RCS exposures among SSM. Monitoring of radon exposure both in the mining pits and community buildings should be conducted, and mitigation measures should be implemented in areas that exceed the reference level of 100.00 bq/m3.

Prevalence of chronic obstructive pulmonary disease and associated factors among small-holder fish vendors along coastal areas in Tanzania

BACKGROUND

In Tanzania little is known about how the respiratory system of small-holder fish vendors is affected by occupational exposure to biomass smoke and other associated factors. This study assessed the prevalence of lung obstruction and associated factors among small-holder fish vendors along coastal areas in Tanzania.

METHODS

A cross-sectional descriptive study was conducted in Bagamoyo and Kunduchi fish markets along coastal areas of Tanzania. Environmental air pollutant levels and composition were measured using a hand-held device. A standardized questionnaire was used to assess respiratory symptoms while EasyOne spirometer was used to test for lung function among small-holder fish vendors. Chronic Obstructive Pulmonary Disease (COPD) was defined as FEV1/FVC below the lower limit of normal. Data were analyzed using STATA Version 17. Descriptive statistics was performed and logistic regression analysis was used to determine factors that are associated with poor lung function presented as crude and adjusted odds ratio and their 95% confidence intervals.

RESULTS

A total of 103 participants were included in the study who were predominantly males 82 (79.6%). The participants' mean age was 35.47 (± 8.77 SD) years. The hourly average concentration levels of PM1, PM2.5, PM10, and CO exposure during fish frying were 653.6 (± 206.3 SD) μg/m3, 748.48 (± 200.6 SD) μg/m3, 798.66 (± 181.71 SD) μg/m3 and 62.6 (± 12.3 SD) ppm respectively which are higher than the WHO recommended limits. The prevalence of COPD was found to be 32.04% (95% CI 0.23-0.42). Most of the participants reported respiratory symptoms like coughing, wheezing, sputum production and breathlessness during performing their daily activities.

CONCLUSION

Findings suggest that three out of ten participants had COPD and the major environmental air pollutants (PMs and CO) concentration levels were too high, suggesting that occupational exposure to biomass smoke may be a risk factor. This calls for effective approaches to reduce exposure and prevent known acute and chronic respiratory diseases that are associated with such exposure to air pollutants. Also the study calls for follow up or cohort studies to be conducted in this area.

Work-Related Injuries Reported toWorkers Compensation Fund in Tanzania from 2016 to 2019

Quality data on the magnitude and determinants of work-related injuries is an important element in the development of appropriate preventative strategies. However, there have been many challenges in obtaining quality information on work-related injuries in the developing countries. This archival study based on the data from workers' compensation registry from the year 2016 to 2019 aimed at determining trends and factors associated with work-related injuries (WRI). Data from 4578 WRI claims reported to Workers Compensation Fund (WCF) in Tanzania were analyzed. As expected, this new workers' compensation system had increasing participation from inception in 2016 through 2019, resulting in increasing numbers of fatal and non-fatal work-related claims. Motor traffic accidents, machine faults and falls were the most reported causes of WRI. Males had more than 2-fold increased odds of sustaining fatal injuries compared to females. More than 6-fold increased odds of fatal injuries were observed for injuries occurring during conveyance. Explosions, motor traffic accidents, and falls were more likely to result into fatal injuries. Increased odds of fatal injuries were observed in workers from transportation and storage sector; information and technology; construction and building; and electricity, gas, and steam sectors, as well as among teachers, drivers, office workers, and security guards. The current study offers some insights regarding trends and associated factors that are vital in planning and implementation of appropriate preventative strategies for work-related injuries in Tanzania.

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.

Thermal Exposure and Heat Illness Symptoms among Workers in Mara Gold Mine, Tanzania

Background:

Working in a humid and hot environment creates challenges to occupational health and safety in tropical countries. Being in the region, Tanzania can experiences more than 30°C ambient temperature, which exposes miners to heat-related injury and illness.

Objectives:

This study was conducted to assess heat stress exposure and associated heat illness symptoms among gold mine workers in the Mara region.

Methods:

A cross-sectional study was conducted among 60 miners from four Similar Exposure Groups based on risk to extreme heat environment. The WBGT index was used to assess the heat load while the miners’ physiological condition explained the heat strain indicator. Data was analyzed using SPSS 20. Chi-square was used to differentiate proportion of miners with heat illness symptoms in different categories. Pearson correlation was used to determine association between environmental measures and change in physiological conditions of the miners. Independent t-test and ANOVA were used to assess differences between numerical data among groups. A p ≤ 0.05 at 95% confidence was considered to be statistically significant.

Findings:

The recorded average WBGT at the mining site was within the ACGIH TLV of 28.5°C, however, 78.4% of underground miners and 69.6% of open cut miners reported to have moderate heat illness. High body temperature and hot and dry skin were the most frequently reported heat illness symptoms. The mean core body temperatures of miners in open cut and underground were 38.4 ± 0.5°C and 37.3 ± 0.5°C respectively. Approximately 80% of miners in open cut indicated higher core body temperature above ISO 7933 threshold of 38.0°C for safety. The majority of workers under contract didn’t drink water prior to work shift commencement.

Conclusions:

The occupational setting at the mining area presents the potential exposure to a thermal condition that can contribute to heat illness symptoms. Effective strategies must be implemented to enhance workers’ safety.

Reduction in respiratory symptoms among cement workers: a follow-up study

BACKGROUND

Several studies have reported associations between cement dust exposure and adverse respiratory health effects, but there are few follow-up studies and no studies of respiratory health effects following dust control measures.

AIMS

To assess changes in respiratory health among cement workers and unexposed controls after 1 year in a factory implementing a health and safety campaign with the main aim to increase use of personal protective equipment. Earlier the factory had made technical improvements which had reduced dust levels.

METHODS

Respiratory questionnaire interviews and personal total dust exposure assessments were conducted in 2010 and 2011.

RESULTS

A total of 171 cement workers and 98 controls participated in the study in 2010. The prevalence of cough, cough with sputum, dyspnoea and wheeze among the 134 exposed workers assessed at follow-up in 2011 was significantly lower than in 2010, but not among 63 controls followed up in 2011. Total dust exposure levels among exposed workers did not differ between 2010 and 2011.

CONCLUSIONS

The prevalence of respiratory symptoms among cement workers was reduced after 1 year of follow-up following an intervention campaign to improve use of personal protective equipment.