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.