| Summary: | A research report submitted to the Faculty of Health Science, University of the Witwatersrand,
In partial fulfillment of the requirements for the degree: Master of Public Health.
Johannesburg, March 2017 === Introduction
Exposure to respirable crystalline silica (commonly known as quartz) is primarily from dust containing quartz which occurs in a variety of occupational settings. The occupational setting in which dust containing quartz occurs includes: quarry and mining, mineral processing, foundry, construction, ceramic, and brick and tile industries.
The International Agency for Research on Cancer (IARC) classified quartz as a human carcinogen. Occupational exposure to respirable quartz is a well-established hazard in mining, sandblasting, foundry work, agriculture, and construction, but not in power station processes. The coal handling process at power station involves activities such as coal stock piling, coal conveying and coal pulverising which generate coal dust. It is during these activities where occupational exposure to coal dust may occur among workers.
Objectives
The overall objective of this study was to determine if workers at coal fired power stations in Mpumalanga province are exposed to respirable coal dust and quartz at levels above the Department of Labour’s Occupational Exposure Limit (DoL OEL) 2mg/m3 for respirable coal dust and 0.1mg/m3 for quartz, Occupational Safety and Health Administration Permissible Exposure Limit (OSHA PEL) 2.4mg/m3 for respirable coal dust and 0.05mg/m3 for quartz and American Conference of Governmental Industrial Hygienists Threshold Limit Value (ACGIH TLV) 0.025mg/m3 for quartz.
4
Methods
The study used a retrospective record review of respirable dust and quartz data collected from seven coal fired power stations during a 4-year period (2012 to 2015). The study analysed this secondary occupational hygiene data collected by the occupational hygiene officers working in the selected power stations.
Results
One site (PS6) had the highest mean respirable quartz concentration (0.036) and a median value of 0.03mg/m3 which exceeded the TLV of 0.025mg/m3 but was within the OSHA PEL of 0.05mg/m3 and DoL OEL of 0.1mg/m3. The site PS1 had the lowest mean respirable quartz concentration of 0.017mg/m3 and a median value of 0.01mg/m3.
Out of all occupations 7.31% (n=55) were exposed to quartz concentrations equal to or exceeding the DoL OEL of 0.1mg/m3 and 29.39% (n=221) of all occupations exceeded the ACGIH TLV of 0.025mg/m3 but were below the DoL OEL 0.1mg/m3. Only 4.63% (n=35) of all occupations were exposed to respirable dust concentrations equal to or exceeding the DoL OEL of 2mg/m3. Majority of all occupations 95.37% (n=721) were below the DoL OEL. === MT2017
|
|---|
