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the intervention resources where the immediate need is most conspicuous, but there is a danger of stigmatization, and it comes relatively late (secondary prevention) In contrast, a population approach targets everyone irrespectively of risk profile in what can be perceived more as primary prevention, but the fundamental root causes are not addressed.

Irrespective of the public health issue in question, implicit or explicit choices are made regarding the target population for appropriate interventions. For instance, screening programs are based on the rationale of focusing on populations at risk defined by various biomedical markers; and health promotion interventions will emphasize various solutions with consequential age group, gender and potentially place implications. But there are other ways of defining who should benefit from a given intervention, i.e., which population segment should be targeted.

This paper explores the various criteria based on which target populations for public health interventions are chosen and suggests a conceptual framework based on four criteria biomedical, social, spatial, and temporal The researchers contend that this may guide strategic choices within public health planning and research

In 1974, the Canadian Lalonde report recommended a focus on “populations at risk” characterized by either risk behavior or biomarkers Nine years later in 1985, Geoffrey Rose introduced the alternative “whole population approach” and interposed these two approaches to public health interventions According to Rose the overall sum of the impact on the “whole population” is larger than the total impact on the group of “individuals at risk ” There are pros and cons of both approaches A focus on individuals at risk concentrates

Notwithstanding Rose’s insights, there have been critical voices Based on the notion of “fundamental causes”, Frohlich and Potvin point out that a whole population approach does not address the underlying determinants, and that it is likely to increase health inequalities due to uneven distribution of risk factors as well as disparate ability to benefit from interventions

For the past decades, biomedical research has highlighted the importance of the life-course perspective Building on epidemiological and epigenetic research, the life-course concept describes how positive and negative exposures affect individuals’ cumulative risk profiles throughout the life-course with consequences for a wide range of diseases and socioeconomic and educational achievements However, risk of disease accumulates not only throughout an individual’s life from the fetal stage onwards but is also passed on from one generation to the next Consequently, one can visualize the notion of life-course as a circle incorporating each stage of life: fetal life, infancy, early childhood, school age, adolescence, and fertile age (including the preconception period)

It is a key element of public health interventions to address either individual, behavioral change (“lifestyle”) or structural, environmental living conditions or a combination thereof This paper contends that a deliberate selection of intervention population segments will entail the best possible return of investment, which is essential within often resourcescarce health care systems in most parts of the world

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Asthma is a major public health problem worldwide, which generates significant healthcare costs and has high morbidity and mortality rates. The World Health Organization (WHO) estimated that between 100 and 150 million people worldwide suffer from asthma, and over 180 000 deaths occur annually The Republic of South Africa (RSA), with 8.1% prevalence over all ages, ranked 25th worldwide, and the asthma case fatality rate in the country is reported as being the fourth highest in the world, with 1 5% deaths annually

Recently, it has been documented that South Africa has the highest prevalence of asthma in Africa. Adeloye et al. conducted a systematic review to ascertain an estimate prevalence of asthma in Africa in which they included 45 studies covering most parts of Africa (RSA: 11 studies, Nigeria: 8 studies, Ethiopia: 6 studies, Kenya: 5 studies, and 4 studies in each in Algeria, Morocco and Tunisia) Asthma morbidity and mortality are potentially preventable with optimal control of chronic asthma and appropriate management of asthma exacerbation.

Many triggers have been reported to cause patients with a poor asthma control status to increasingly frequent emergency departments (EDs)

This was a prospective, cross-sectional study in a district hospital in Johannesburg, South Africa Data of consecutive samples of 239 adult patients aged ≥ 18 years with asthma exacerbation seen in the ED at Bertha Gxowa District Hospital (BGDH) between February 2015 and April 2015, collected through a survey questionnaire, were analysed. The chi-square test or Fisher's exact test was used to test the associations between variables and acute asthma severity Bivariate logistic regression was used to ascertain triggers associated with acute asthma attack. P-values < 0.05 were considered statistically significant

Overall, 239 patients were enrolled (139 males, 100 females, and median age 31 years). The majority of them had moderate acute asthma attack (52 7%) Active cigarette smoking (p < 0 001) and/or passive cigarette smoking (p = 0.004) were identified to be potential associated triggers for acute asthma attack. There was no significant association between acute asthma attack severity and acute respiratory infection (p = 0 818), and use of medication-related asthma triggers (p = 0.942).

The study shows that the majority of patients present with moderate acute asthma attack in an ED Active and/or passive cigarette smoking is a potential associated trigger for asthma exacerbation.

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diffusion samplers Therefore, comparisons of the central tendency of VOC exposure concentrations of a SAE nail technician group with a group of nail technicians for which exposures were measured under the conventional controlled assessment of exposure (CAE) regime

Wits researchers involved: Derk Brouwer, Goitsemang

Keretetse, Gill Nelson

Participatory research, including self-assessment of exposure (SAE), can engage study participants and reduce costs. The objective of this study was to investigate the feasibility and reliability of a SAE regime among nail technicians.

Introduction

Citizen science, i e , a voluntary collaboration among scientists and non-specialists to achieve both scientific and societal goals, is an emerging form of scientific inquiry that is growing in popularity in the environmental sciences However, education and engagement of the public with scientific discoveries are other important objectives. Introducing citizen science into occupational health is considered a potentially innovative and economical approach, especially since resource constraints challenge this field From a measurement strategy perspective, daily monitoring of workers’ exposure is the optimum approach. However, currently, the selection of an appropriate measurement strategy is a compromise between statistical efficacy, i e , minimizing the variance of an unbiased estimate of the target exposure variable, and associated costs. Quantitative self-assessment of inhalation exposure relied mainly on passive sampling of volatile organic compounds (VOCs) and gases

To investigate the reliability of SAE, especially in the informal service sector, This study report on the results of a self-assessment study in which nail technicians in both formal and informal nail salons measured inhalation exposure to VOCs using passive

This comparative study had a cross-sectional design and was nested in a larger study in nail salons in the City of Johannesburg, hereafter referred to as the controlled assessment of exposure (CAE) study The formal nail salons were franchises of one of the largest local beauty therapy companies in South Africa, which permitted them to approach the salons in the northern suburbs of Johannesburg The informal nail salons comprised unregistered nail salons in the central Johannesburg Braamfontein area, some of which operated inside hairdressing salons.

If a nail technician agreed to participate in the study, i e , to self-assess their personal exposure on three consecutive workdays, oral instructions were given on how to open, attach, close, and store the passive samplers (diffusion tubes), as well as how to complete the worksheets The worksheets facilitated the participant to record information, such as the time the passive sampler was opened and donned, the number and types of nail applications performed, and the duration of the nail applications The researcher checked and noted the sampling tubes’ status and the worksheets’ completeness

Self-assessment of exposure in occupational settings, including informal workplaces, seems to be a feasible and economical method to contribute to the expansion of exposure data, which enables a more reliable interpretation of exposure variation In principle, SAE can be a citizen science tool in occupational health; however, passive sampling, requiring analytical costs and experts’ feedback, is not the ideal method to assess exposure. However, exposure science approaches and expertise to identify the exposure pathway and determinants of exposure are still needed to develop effective exposure control strategies

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