Exposure assessment to dust and free silica for workers of Sangan iron ore mine in Khaf, Iran

Occupational Respirable Mine Dust and Diesel Particulate Matter Hazard Assessment in an Underground Gold Mine in Ghana

BACKGROUND

Underground miners can experience occupational health diseases due to exposure to particulate matter hazards.

OBJECTIVES

The aim of the present study was to examine occupational exposures of underground miners to dust and diesel particulate matter and to identify exposure groups with high potential to develop associated health effects due to the presence of dust and diesel particulate matter (DPM) hazards in an underground gold mine in Ghana.

METHODS

Purposive sampling was employed using gravimetric air samplers over an 8-hour time weighted average period. The National Institute for Occupational Safety and Health (NIOSH) analytical Chapter Q and 5040 were used in determining crystalline silica dust and diesel particulate matter fractions, respectively. Structured questionnaires were administered to gather data on workers' level of awareness to dust and DPM exposures.

RESULTS

It was found that 41% of the sampled groups were exposed to higher crystalline silica levels above the (NIOSH) permissible exposure limit (PEL) level of 0.05 mg/m³. For DPM, 49% of these groups had exposures above the Mine Safety and Health Administration (MSHA) PEL level of 160 μg/m³. Among the 94 mine workers who responded to this study, 62% were found to be aware of the presence and hazardous nature of silica dust, 28% had minimal knowledge and the remaining were found to be unaware.

CONCLUSIONS

There are varying levels of dust and DPM due to the presence of silica-bearing rocks, the production of diesel fumes and inefficiencies of available mitigation measures. Research carried out over the past decades has found confirmed cases of silicosis and lung cancer due to high dust exposure levels. Rock drillers, blast men and shotcrete operators were found to be exposed to higher levels of dust and diesel particulate matter and are at greater risk of silicosis.

PARTICIPANT CONSENT

Obtained.

ETHICS APPROVAL

This study was approved by the Ethics Committee of the Kwame Nkrumah University of Science and Technology, Ghana and carried out under full consent of the mining company under study.

COMPETING INTERESTS

The authors declare no competing financial interests.

Determination of crystalline silica in respirable dust upon occupational exposure for Egyptian workers

Crystalline free silica is considered as a lung carcinogen and the occupational exposure to its dust is a health hazard to workers employed in industries that involve ores of mineral dust. In Egypt, thousands of people work under conditions of silica dust exposure exceeding the occupational exposure limit, as a result the monitoring of this occupational exposure to crystalline silica dust is required by government legislation. The assessment of the later is a multi-phase process, depend on workplace measurements, quantitative analyses of samples, and comparison of results with the permissible limits. This study aims to investigate occupational exposure to crystalline silica dust at 22 factories in Egypt with different industrial activities like stone cutting, glass making, ceramic, and sand blasting. Dust samples were collected from work sites at the breathing zone using a personal sampling pump and a size-selective cyclone and analyzed using FTIR. The sampling period was 60-120 min. The results show that the exposure at each of the industrial sectors is very much higher than the current national and international limits, and that lead to a great risk of lung cancer and mortality to workers.