Historically, chemicals exceeding maximum allowable exposure levels have been disastrous to underdeveloped countries. The global food industry is primarily affected by toxic chemical substances because of natural and anthropogenic factors. Food safety is therefore threatened due to contamination by chemicals throughout the various stages of food production. Persistent Organic Pollutants (POPs) in the form of pesticides and other chemical substances such as Polychlorinated Biphenyls (PCBs) have a widely documented negative impact due to their long-lasting effect on the environment. This present review focuses on the chemical contamination pathways along the various stages of food production until the food reaches the consumer. The contamination of food can stem from various sources such as the agricultural sector and pollution from industrialized regions through the air, water, and soil. Therefore, it is imperative to control the application of chemicals during food packaging, the application of pesticides, and antibiotics in the food industry to prevent undesired residues on foodstuffs. Ultimately, the protection of consumers from food-related chemical toxicity depends on stringent efforts from regulatory authorities both in developed and underdeveloped nations.

Recently, the development of a unique class of layered silicate nanomaterials has attracted considerable interest for treatment of wastewater. Clean water is an essential commodity for healthier life, agriculture and a safe environment at large. Layered double hydroxides (LDHs) and other clay hybrids are emerging as potential nanostructured adsorbents for water purification. These LDH hybrids are referred to as hydrotalcite-based materials or anionic clays and promising multifunctional two-dimensional (2D) nanomaterials. They are used in many applications including photocatalysis, energy storage, nanocomposites, adsorption, diffusion and water purification. The adsorption and diffusion capacities of various toxic contaminants heavy metal ions and dyes on different unmodified and modified LDH-samples are discussed comparatively with other types of nanoclays acting as adsorbents. This review focuses on the preparation methods, comparison of adsorption and diffusion capacities of LDH-hybrids and other nanoclay materials for the treatment of various contaminants such as heavy metal ions and dyes.

Clean water is very important for the good health of society. In South Africa, it is estimated that people need 20 to 50 litres of safe water daily for basic hygiene, drinking, and cooking. In recent times, water bodies have harboured harmful pollutants, including oil, heavy metal ions, and dyes. As a result, this has become a major global concern. Societies with limited clean water are often forced to utilise contaminated water or buy filtered water, which might be a problem for poor residents. The health consequences that are related to contaminated water include Guinea worm disease, dysentery, cholera, etc. The side effects associated with the utilisation of unclean water are gastrointestinal diseases such as cramps, vomiting, and diarrhoea. The wastewater disposed of by chemical industries contains toxic elements such as arsenic. Wastewater that is released directly without treatment causes serious damage to the environment. Chronic arsenic poisoning can lead to keratinisation of the skin and even cancer. Cellulose biomass materials have the potential to become the greatest bio-based materials used in wastewater treatment applications. There are two major reasons that validate this statement: firstly, cellulose is a low-cost material that is abundant in nature, and, secondly, cellulose is an environmentally friendly material. However, these are not the only reasons that validate cellulose as a good candidate for wastewater treatment applications. Cellulose has a unique structure a large surface area, good mechanical properties and is degradable, renewable, and biocompatible. Cellulose also has an abundance of hydroxyl groups on its surface. These hydroxyl functional groups allow cellulose to be chemically modified in various ways, which results in the fabrication of nanocomposites with tunable characteristics. Since arsenic pollution has become a serious global concern, this review uniquely provides a broad discussion of the work that has been accomplished recently on the fabrication of functionalised cellulose-based materials designed specifically for the removal of arsenic heavy metal species from wastewater treatment facilities. Furthermore, the functionalised cellulose materials’ arsenic adsorption capacities are also discussed. These adsorption capacities can reach up to a maximum of 350 mg/g, depending on the system used. Factors such as pH and temperature are discussed in relation to the adsorption of arsenic in wastewater. The removal of As(V) was found to be effective in the pH range of 3.0–8.8, with a removal efficiency of 95%. Moreover, the removal efficiency of As(III) was reported to be effective in the pH range of 6–9. However, the effective pH range also depends on the system used. The selective extraction of cellulose from various sources is also discussed in order to verify the percentage of cellulose in each source. Future work should be focused on how the chemical modification of cellulose affects the toxicity, efficiency, selectivity, and mechanical stability of cellulose materials. The use of cheaper and environmentally friendly chemicals during cellulose functionalisation should be considered.

Purpose: This paper aims to report on the bibliometric research trends on the application of machine learning/intelligent systems in the prediction of food contamination and the surveillance of foodborne diseases.Design/methodology/approach: In this study, Web of Science (WoS) core collection database was used to retrieve publications from the year 1996–2021. Document types were classified according to country of origin, journals, citation and key research areas. The bibliometric parameters were analyzed using VOSviewer version 1.6.15 to visualize the international collaboration networks, citation density and link strength.Findings: A total of 516 articles across 6 document types were extracted with an average h-index of 51 from 10,570 citations. The leading journal in publications was Science of the Total Environment (3.6%) by Elsevier and the International Journal of Food Microbiology (2.5%). The United States of America (USA) (24%) followed by the People's Republic of China (17.2%) were the most influential countries in terms of publications. The top-cited articles in this study focused on themes such as contamination from packaging materials and on the strategies for preventing chemical contaminants in the food chain.Originality/value: This report is significant because the public health field requires innovative strategies in forecasting foodborne disease outbreaks to advance effective interventions. Therefore, more collaboration need to be fostered, especially in developing nations regarding food safety research.