A comparison of risk factor investigation and experts' opinion elicitation analysis for identifying foot-and-mouth disease (FMD) high-risk areas within the FMD protection zone of South Africa (2007-2016).

Foot-and-mouth disease is a controlled disease in accordance with the South African Animal Diseases Act (Act 35 of 1984). The country was classified by the World Organisation for Animal Health (WOAH) as having a FMD free zone without vaccination in 1996. However, this status was suspended in 2019 due to a FMD outbreak outside the controlled zones. FMD control in South Africa includes animal movement restrictions placed on cloven-hoofed species and products, prophylactic vaccination of cattle, clinical surveillance of susceptible species, and disease control fencing to separate livestock from wildlife reservoirs. The objectives of this study were to evaluate differences in identifying high-risk areas for FMD using risk factor and expert opinion elicitation analysis. Differences in risk between FMD introduction and FMD spread within the FMD protection zone with vaccination (PZV) of South Africa (2007-2016) were also investigated. The study was conducted in the communal farming area of the FMD PZV, which is adjacent to wildlife reserves and characterised by individual faming units. Eleven risk factors that were considered important for FMD occurrence and spread were used to build a weighted linear combination (WLC) score based on risk factor data and expert opinion elicitation. A multivariable conditional logistic regression model was also used to calculate predicted probabilities of a FMD outbreak for all dip-tanks within the study area. Smoothed Bayesian kriged maps were generated for 11 individual risk factors, overall WLC scores for FMD occurrence and spread and for predicted probabilities of a FMD outbreak based on the conditional logistic regression model. Descriptively, vaccine matching was believed to have a great influence on both FMD occurrence and spread. Expert opinion suggested that FMD occurrence was influenced predominantly by proximity to game reserves and cattle density. Cattle populations and vaccination practices were considered most important for FMD spread. Highly effective cattle inspections were observed within areas that previously reported FMD outbreaks, indicating the importance of cattle inspection (surveillance) as a necessary element of FMD outbreak detection. The multivariable conditional logistic regression analysis, which was consistent with expert opinion elicitation; identified three factors including cattle population density (OR 3.87, 95% CI 1.47-10.21) and proximities to game reserve fences (OR 0.82, 95% CI 0.73-0.92) and rivers (OR 1.04, 95% CI 1.01-1.07) as significant factors for reported FMD outbreaks. Regaining and maintaining an FMD-free status without vaccination requires frequent monitoring of high-risk areas and designing targeted surveillance.

An evaluation of occupational health risk assessment methodologies from South African enterprises: noise risk assessment field study

Background: The South African occupational health and safety regulations, prescribing risk assessments be conducted by employers, are non-prescriptive with regard to the tools and techniques to be used. Consequently, companies freely adopt the numerous available tools and techniques from which risk management decisions are derived. Thus, risk management, ensuing from the results derived from these tools and techniques, is likely to vary from company to company. Objective: The objective of the study was to evaluate risk assessment processes and methodologies that are used and recorded in noise risk assessment reports, in four manufacturing companies. Methods: This was a case study, whereby risk assessment records were obtained from four South African companies with different operational units, from the manufacturing and utilities sectors. Results: There were inter- and intra-company variations in the processes related to the legal context in which the risk assessments were conducted, the risk assessment tools and techniques used, the risk criteria definitions, the statements about the effectiveness of controls in use, and the risk evaluation outcomes. Inter- and intra-company variations in risk rankings and risk prioritisation outcomes were also observed ­ a consequence of the risk perceptions of the assessors assigning a risk level to the noise hazard. In some instances, the adopted risk assessment tools and techniques categorised the risk from noise that was at or above regulated health and safety standards as 'insignificant', which those companies used as justification for taking no further measures to eliminate or reduce the risk. Conclusion: The use of different risk assessment processes, tools and techniques resulted in some facilities categorising noise as an insignificant hazard, which may contribute to high noise emissions and uncontrolled exposures.

Noise exposure abatement: a perspective from industry occupational health risk assessment reports

Background: Occupational health risk assessments are building blocks for occupational health programmes, allowing for the rating of identified risks and the continuous re-evaluation of the effectiveness of abatement measures. In South African industry, occupational health risk assessments are formally documented in reports, which can be presented as demonstration of legal compliance with legislation. Objective: To identify noise abatement measures recorded in noise risk assessment reports of four manufacturing companies and to rate their effectiveness. Methods: We analysed the occupational health risk assessment reports from 21 operational facilities in four South African companies from the manufacturing and utilities sectors to evaluate, through document analysis, the recorded noise abatement measures. Noise abatement measure effectiveness was rated using a preassigned effectiveness percentage scale. Results: Administrative controls and hearing protection devices were the most commonly used noise exposure abatement measures, but hearing conservation programmes were generally poorly formulated. There were inter- and intra-company differences in the qualitative risk assessment approaches used for rating or ranking the noise risk, which led to different risk conclusions and prioritisation outcomes. The calculated control effectiveness of the abatement measures showed that noise exposure remained largely unacceptable: 16 of the 21 operational units had unacceptable noise exposures, four had tolerable exposures, and one had broadly acceptable exposures. Conclusion: The four companies' common noise abatement measures, as elements of formalised hearing conservation programmes, which included administrative controls and hearing protection devices, were not effective in reducing noise exposure to the broadly acceptable level, reflective of limited use of engineering controls.