Fumonisins, a class of mycotoxins predominantly produced by Fusarium species, represent a major threat to food safety and public health due to their widespread occurrence in staple crops including peanuts, wine, rice, sorghum, and mainly in maize and maize-based food and feed products. Although fumonisins occur in different groups, the fumonisin B series, particularly fumonisin B1 (FB1) and fumonisin B2 (FB2), are the most prevalent and toxic in this group of mycotoxins and are of public health significance due to the many debilitating human and animal diseases and mycotoxicosis they cause and their classification as by the International Agency for Research on Cancer (IARC) as a class 2B carcinogen (probable human carcinogen). This has made them one of the most regulated mycotoxins, with stringent regulatory limits on their levels in food and feeds destined for human and animal consumption, especially maize and maize-based products. Numerous countries have regulations on levels of fumonisins in foods and feeds that are intended to protect human and animal health. However, there are still gaps in knowledge, especially with regards to the molecular mechanisms underlying fumonisin-induced toxicity and their full impact on human health. Detection of fumonisins has been advanced through various methods, with immunological approaches such as Enzyme-Linked Immuno-Sorbent Assay (ELISA) and lateral flow immunoassays being widely used for their simplicity and adaptability. However, these methods face challenges such as cross-reactivity and matrix interference, necessitating the need for continued development of more sensitive and specific detection techniques. Chromatographic methods, including HPLC-FLD, are also employed in fumonisin analysis but require meticulous sample preparation and derivitization due to the low UV absorbance of fumonisins. This review provides a comprehensive overview of the fumonisin family, focusing on their biosynthesis, occurrence, toxicological effects, and levels of contamination found in foods and the factors affecting their presence. It also critically evaluates the current methods for fumonisin detection and quantification, including chromatographic techniques and immunological approaches such as ELISA and lateral flow immunoassays, highlighting the challenges associated with fumonisin detection in complex food matrices and emphasizing the need for more sensitive, rapid, and cost-effective detection methods.

Heavy metals (HMs) contamination raises the expression of antibiotic resistance (AR) in bacteria through co-selection. Biochar application in composting improves the effectiveness of composting and the quality of compost. This improvement includes the elimination and reduction of antibiotic resistant genes (ARGs). The use of biochar in contaminated soils reduces the bioaccessibility and bioavailability of the contaminants hence reducing the biological and environmental toxicity. This decrease in contaminant bioavailability reduces contaminants induced co-selection pressure. Conditions which favour reduction in HMs bioavailable fraction (BF) appear to favour reduction in ARGs in compost and soil. Biochar can prevent horizontal gene transfer (HGT) and can eliminate ARGs carried by mobile genetic elements (MGEs). This effect reduces maintenance and propagation of ARGs. Firmicutes, Proteobacteria, and Actinobacteria are the major bacteria phyla identified to be responsible for dissipation, maintenance, and propagation of ARGs. Biochar application rate at 2–10% is the best for the elimination of ARGs. This review provides insight into the usefulness of biochar in the prevention of co-selection and reduction of AR, including challenges of biochar application and future research prospects.

Composting influences heavy metal (HM) speciation by transforming the exchangeable and reducible forms of HMs to oxidisable and residual forms, promoting the redistribution of HMs to a more stable form thereby reducing their mobility, leachability, and bioavailability. This enhances HM passivation hence reducing environmental contamination and possible HM-related toxicity. In this review, we explored the impact of additives/ameliorants on HM passivation during composting and the reduction in HM bioavailability in compost. Using additives in composting improved the passivation of HMs and reduced the bioavailability through several mechanisms. Additives may not reduce total HM concentration but reduce the bioavailable concentration, which is of importance in risk assessment. However, vermicomposting is exceptional, as it reduces total HM concentration. Improving humification and microbial activity is at the heart of HM passivation in composting. Overall, conditions and substances that promote humification, thermophilic phase, and improve microbial community structure enhance HM passivation in compost. Combining suitable composting additives depending on HMs of interest and vermicomposting the final compost is most likely to yield the best result in reducing HM bioavailability cum total concentration to achieve a safe final product.

The rising global temperatures due to climate change have a profound impact on global health. Heat is associated with many physical and mental health conditions. The impact of heat on health could be exacerbated in polluted areas due to the combined impact of pollutants and heat stress. Polycyclic aromatic hydrocarbons (PAHs) are among environmental pollutants of public health significance. Exposure to PAHs has adverse effects on physical and mental health and these effects could be worse in oil-impacted communities due to increased PAH exposure and environmental degradation. Heat increases the volatilisation of PAHs, mobility and availability of PAHs, formation of toxic PAH derivatives, and possible wildfire incidents which introduce more PAHs into the environment. This increases human exposure to PAHs through various pathways, in addition to heat stress, thereby worsening mental health challenges. The anticipated decrease in PAH levels due to reduced emissions is offset by the impact of rising temperatures, which promote the mobilisation and volatilisation of existing PAHs. Therefore, this review highlighted the combined risks of heat and PAHs amid rising global temperatures, especially in oil-impacted communities. The various mechanisms through which heat could increase PAH risks were also highlighted. Possible pollution prevention, exposure mitigation, and environmental and public health intervention approaches were suggested. Rapid oil spill response, environmental remediation, ecosystem restoration, biomonitoring, environmental, and agro products monitoring could help mitigate exposure. Additionally, the introduction of green education, mental health impact assessment for every project, and investment in sustainable green technologies by the oil companies. Overall, this review creates awareness of the neglected impact of heat on PAH risks and draws the attention of researchers, funders, policymakers, and society to approaches to mitigate PAH risks as we navigate the challenges of climate change. Graphical Abstract

Biochar is widely applied in soils to improve environmental quality. However, reported biochar effects remain highly variable and often contradictory, even under similar experimental conditions. This inconsistency is commonly attributed to differences in feedstock, pyrolysis conditions, and soil properties. A fundamental limitation persists as biochar is usually applied on a mass basis, despite large variability in the functional properties that govern its environmental performance. Equal masses of different biochar do not deliver equivalent functional capacity. This perspective introduces the Principle of Functional Delivery (PoFuD), which reframes biochar application from a mass-based to a function-based. PoFuD proposes that biochar effects are determined by the type and quantity of functional capacity delivered rather than by the applied mass. This article outlines a functional standardisation approach in which biochar application is normalised to a target property (or process-relevant function), while all co-delivered properties are measured transparently and treated as contextual background. Adopting PoFuD would clarify dose-response relationships, improve comparability across studies, and strengthen mechanistic interpretation. This conceptual shift has broad implications for soil remediation, biogeochemistry, greenhouse gas mitigation, and policy-relevant biochar research, and provides a foundation for more robust experimental design and standardisation in environmental applications.