A groundbreaking study is underway to investigate whether Rooibos could mitigate the harmful effects of petrochemical exposure among petrol attendants.
Scientists from the National Institute for Occupational Health (NIOH) developed the idea in response to the industry’s significant occupational hazards, aiming to determine whether Rooibos – a readily available and cost-effective health beverage – could offer meaningful protection for workers.
CAPTION (from left): Dr Kerry Wilson, Asanda Jekwa and Vusi Ntlebi – the dedicated fieldwork team behind the Rooibos occupational health study.
Dr Kerry Wilson, an epidemiologist from the NIOH points out that petrol attendants in South Africa work long hours at fuel stations, often inhaling hazardous petrochemical fumes, particularly benzene, toluene, ethylbenzene and xylene (BTEX). “These volatile organic compounds have been linked to severe respiratory issues, DNA damage and long-term health complications,” she says.
The study aims to assess petrol attendants’ exposure to BTEX chemicals in a busy city like Johannesburg, while exploring a cost-effective way to minimise their harmful effects.
“We were encouraged by findings from international studies, which highlighted the positive impact of antioxidants in tea, particularly in combating oxidative stress caused by BTEX exposure. Given Rooibos’ caffeine-free nature and its known ability to reduce oxidative stress, it emerged as a promising focus for further research.”
Long-term exposure to petrochemical pollutants has been linked to respiratory diseases, skin irritation, blood disorders and organ damage. High exposure levels can cause immediate symptoms like headaches, dizziness and airway irritation, while prolonged exposure may lead to more serious conditions, including haematological issues, such as blood poisoning and DNA damage. Dr Wilson also highlights reports of changes in liver and kidney function associated with excessive exposure.
“While South Africa has occupational health and safety regulations, enforcement and compliance remain inconsistent. Unlike some developed countries where self-service refuelling limits a worker’s exposure, South African petrol attendants face daily direct contact with fuel fumes.
“Petrol stations are owned by individual owners, but certain standards also need to be met by petrol suppliers. Exposures differ globally, with environmental conditions also playing a role in exposure levels,” she remarks.
Caption: Dr Kerry Wilson (centre) shares a cup of Rooibos with petrol attendants participating in the study on its potential health benefits against petrochemical exposure.
The study is evaluating biomarkers of oxidative stress and DNA damage in petrol attendants.
By measuring these biomarkers and using comet assays[1], researchers aim to determine whether Rooibos consumption improves antioxidant status and is able to mitigate some damage caused by petrochemical exposure.
Participants were recruited through quota sampling at selected petrol stations. Baseline health assessments were conducted in late 2023, followed by an intervention phase in 2024, with final evaluations set for March this year.
During the study, half of the participants consumed three 250 ml cups of Rooibos daily for six months. The control group didn’t receive Rooibos, but had access to illustrated occupational health guidelines for reducing exposure.
Rooibos (Aspalathus linearis) is rich in bioactive compounds with potential occupational health benefits, which include:
Aspalathin: A unique antioxidant that reduces oxidative stress.
Quercetin and luteolin: Anti-inflammatory flavonoids that support immune function.
Chrysoeriol: A bronchodilator beneficial for lung health.
Nothofagin: Protects against free radical damage.
Phenolic acids: Support neuroprotection and detoxification.
Tannins: While present in low levels, these provide mild antimicrobial properties.
Dr Wilson and her team believe that these compounds may help counteract oxidative stress, inflammation, respiratory irritation and cardiovascular strain associated with petrochemical exposure in the following way:
Reducing oxidative stress: Rooibos bioactives neutralise reactive oxygen species (ROS) that cause cellular damage.
Anti-inflammatory action: Flavonoids suppress inflammation triggered by prolonged chemical exposure.
Supporting detoxification: Aspalathin and nothofagin enhance glutathione production, aiding in petrochemical detoxification.
Cardiovascular benefits: Chrysoeriol promotes blood vessel relaxation, reducing hypertension risks.
Respiratory support: Rooibos compounds ease bronchial constriction, improving lung function.
Stress reduction: Aspalathin lowers cortisol, helping workers cope with occupational stress.
While the final study results are pending, Dr Wilson acknowledges that Rooibos could be a valuable addition to occupational health strategies. However, more extensive trials are needed to confirm long-term benefits and determine optimal dosing strategies.
Key areas for further investigation include:
Long-term clinical trials in high-risk occupational settings.
Comparative studies against other antioxidants, like Vitamin C, green tea.
Research on genetic and epigenetic impacts of Rooibos on workers.
Workplace feasibility studies on adherence and cost-effectiveness.
“Although Rooibos cannot replace exposure control measures, it offers a promising avenue for enhancing worker health. While we have yet to finalise our findings, the potential benefits of Rooibos merit further exploration.”
The findings will be published later this year.