The implications of chemical contamination in food: a surveillance and probabilistic human health risk assessment of heavy metal accumulation in food

Abstract

Food safety risks remain paramount in designing effective detection and surveillance systems. The globalisation of trade and environmental factors play a significant role in safeguarding against emerging and existing food safety risks from the food production chain to the consumer level. Targeted and routine human health risk assessments are critical in measuring exposure amongst populations. The study of chemical toxicity in the food industry is fundamental and needs to be supported by rigorous toxicological studies. This will improve the quality of food products offered by the food industry and ultimately benefit consumers. Contaminants such as heavy metals can cause adverse human health effects and thus need regulation through adequate legislative interventions and proper monitoring standards supported by curated scientific data. The study aimed to review the key drivers of chemical pollutants influencing contamination in food and their applicable surveillance methods. Then, measure the heavy metal contamination in the Bloemfontein fresh-produce markets. In this study, the first step in the research process included the extensive review of literature which aimed at establishing foundational information based on existing research. This was achieved through a rigorous literature review which framed the research questions and objectives. This study applied an experimental research strategy and encompassed a quantitative research method. Trace metal assessment was carried out in eighteen vegetable samples of six different vegetable types namely: Spinacia oleracea, Beta vulgaris, Daucus carota, Allium, Brassica oleracea, and Solanum Lycopersicum. The Inductively Coupled Plasma Optical Emissions Spectrometer (ICP-OES) was used to determine the concentration of heavy metals in selected vegetables, then measured against the Codex Alimentarius standards for metals in foodstuffs. In addition, probabilistic human health risk assessments were conducted to determine the hazard quotient and hazard index for the non-carcinogenic effects of the selected vegetables. Literature enquiry revealed that the food industry has been gravitating towards using mechanised systems with intelligent algorithms to meet the demand for safe food more cost-effectively. Therefore, the adoption of intelligent systems has shown significant benefits in controlling potential contaminants, thus reducing the burden of disease and economic loss. Findings further revealed that bioremediation studies should be intensified to cover a broad spectrum of contaminants such as heavy metals, pesticides, fertilizers, antibiotics, and microbial contaminants. As such, it should also consider the remediation of biological contaminants at the points of food production, processing, and supply chain. The concentration of cadmium in spinach, tomato, cabbage, and onion was reported to exceed the maximum permissible limits set by the Codex Alimentarius for metals in foodstuffs. However, the estimated daily intake and hazard quotients were less than a unit. Moreover, the hazard index shows that none of the studied metals (As, Cu, Pb, Cd) had values greater than 1. This demonstrated that there are no anticipated adverse health effects. The Target Hazard Quotient (THQ) in order of exposure for all vegetable types was ranked as follows: As > Cd > Cu > Pb. Based on the findings of this study, precautions should be taken to control the accumulation of cadmium in spinach, tomato, cabbage, and onions due to potentially adverse effects. Most developing nations rely on agricultural produce; therefore, there must be investments in sustainable technologies and research to understand and predict the leading food contaminants. Future studies will incorporate more essential and nonessential metals in the analysis. Additionally, vegetable samples will be collected directly from agricultural land which is the beginning of the food production chain. Toxicological studies are known to be sensitive and difficult due to timelines. This creates a challenge regarding the correlation between chemicals and human health outcomes through epidemiological investigations to assess the risks. To date, no significant study apart from laboratory-controlled research yields any substantial results concerning human exposure and health outcomes. Therefore, there are still gaps regarding the types of chemical toxicants and their subsequent human health effects. This calls for rapid policy adoption on persistent pollutants due to the lack of immediate results of human health deterioration.