Comparative analysis of South African BEIs with those of developed countries
Sekhula, Kamogelo Ruth
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The objective of biological monitoring (BM) is to evaluate workplace exposure to hazardous chemical substances (HCSs) by assessing the total systemic exposure of workers. Biological monitoring should be viewed as a complementary assessment tool to the more traditional measurement of airborne concentrations of HCSs in the work environment. It is also used to verify the effectiveness of existing control measures in the workplace used to manage HCS exposure. The intention of BM is to detect HCSs and/or their associated metabolites in the body before the occurrence of adverse health effects. For BM, a variety of techniques are used to measure bio-indicators usually found in urine, blood or exhaled air. The availability of biological guidance values (BGVs) make BM possible and useful to industry as they serve as concentration limit values for a particular HCS, its metabolites found in biological media or bio-indicators due the chemical’s effect. It is essential that BGVs are reviewed and kept scientifically relevant to achieve the utmost effectiveness in protecting workers from the development of adverse effects resulting from excessive exposure to HCSs. In South Africa, the Department of Employment and Labour is responsible for establishing these BGVs and because it is a regulatory body, BGVs are legally binding to all workplaces to which they may apply. It was noted that since the incorporation of BGVs into legislation in 1995, no attempts were made to revise them. In 2018, revised BGVs were drafted and released for public comment. This study, therefore, explored the suitability of the currently legislated South African biological exposure indices (BEIs) — term used in South Africa to refer to BGVs — by comparatively analysing them relative to those of developed countries. It further explored the newly proposed BEI’s and offers general commentary on these. It should be noted that for this mini-dissertation, “Biological Guidance Value (BGV)” is used as the term under which the various types of index values fall. This is done because individual developed countries/organisations designate different terms for these guidance values. The aim of this study was achieved by comparing BEIs legislated in the Hazardous Chemical Substances Regulations (HCSR) of the Occupational Health and Safety (OHS) Act of 85 of 1993 with those of organisations representing selected developed countries. These include the American Conference of Governmental Industrial Hygienists (ACGIH), Deutsche Forschungsgemeinschaft (German Research Foundation, DFG), Occupational Safety and Health Administration (OSHA), Health and Safety Authority (HSA), Scientific Committee on Occupational Exposure Limits (SCOEL) and the Japan Society of Occupational Health (JSOH). Countries of origin being: United States, Germany, United States, Ireland, Europe and Japan; respectively. Only HCSs appearing in both the HCSR and the lists of the organisation in question, as well as having similar metabolites, were considered. The overall level of the set concentrations of the BGV was completed using a geometric means (GM) and interval method. The results obtained from the comparison of the overall coverage of substances between the HCSR and the selected developed countries/organisations indicated noteworthy discrepancies. It appeared that HCSs for which the HCSR designates BEIs are also included in the BGV lists of most developed countries/organisations considered in this study. Only two organisations, SCOEL and JSOH, were found to have a ˂75% overlap in HCSs coverage with the HCSR. Although there seems to be a lot of similarity in the HCSs coverage, the developed countries/organisations have a greater number of HCSs with established BGVs when compared to those included in the HCSR. The most noticeable difference observed in the results was between the DFG and the HCSR. The DFG designates 85 BGV which are not included in the HCSR, having the highest number of unique HCSs, followed by the ACGIH and HSA; having a total of 21 and 22 unique HCSs compared to the HCSR, correspondingly. The GM and interval methods were used to compare the overall levels at which the South African BEIs are set relative to those established by developed countries/organisations. Both these methods indicated that the levels at which developed countries/organisations have set their BGVs are more stringent than the BEI levels found in South African legislation. The most stringent organisation was found to be the SCOEL, having a GM value of 0.37; followed by the DFG and ACGIH with GM values of 0.45 and 0.46 respectively. It may be concluded, based on the results of this study, that significant differences exist between the BEIs found in the HCSR and BGVs established by developed countries/organisations. These disparities are notable in both the levels at which the BEIs are set as well as the overall HCSs coverage. It may be said that the BEIs established by South African legislation does not reflect the most up to date data. The current review of BEIs is therefore warranted and should be concluded as a matter of urgency.
- Health Sciences