Characterization, sources, and risk assessment of PAHs in borehole water from the vicinity of an unlined dumpsite in Awka, Nigeria

Heavy Metals and Associated Risks of Wild Edible Mushrooms Consumption: Transfer Factor, Carcinogenic Risk, and Health Risk Index

This research aims to investigate the heavy metals (i.e., Cd, Cr, Cu, Ni, and Pb) in the fruiting bodies of six indigenous wild edible mushrooms including Agaricus bisporus, Agaricus campestris, Armillaria mellea, Boletus edulis, Macrolepiota excoriate, and Macrolepiota procera, correlated with various factors, such as the growth substrate, the sampling site, the species and the morphological part (i.e., cap and stipe), and their possible toxicological implications. Heavy metal concentrations in mushroom (228 samples) and soil (114 samples) were determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). In the first part of the study, the soil contamination (index of geo-accumulation, contamination factor, and pollution loading index) and associated risks (chronic daily dose for three exposure pathways-ingestion, dermal, and inhalation; hazard quotient of non-cancer risks and the carcinogenic risks) were calculated, while the phytoremediation capacity of the mushrooms was determined. At the end of these investigations, it was concluded that M. procera accumulates more Cd and Cr (32.528% and 57.906%, respectively), M. excoriata accumulates Cu (24.802%), B. edulis accumulates Ni (22.694%), and A. mellea accumulates Pb (18.574%), in relation to the underlying soils. There were statistically significant differences between the stipe and cap (i.e., in the cap subsamples of M. procera, the accumulation factor for Cd was five times higher than in the stipe subsamples). The daily intake of toxic metals related to the consumption of these mushrooms with negative consequences on human health, especially for children (1.5 times higher than for adults), was determined as well.

Polycyclic aromatic hydrocarbons content of food, water and vegetables and associated cancer risk assessment in Southern Nigeria

The polycyclic aromatic hydrocarbon content of water (four surface water, six underground water (borehole water), seven sachet water), barbecued food and their fresh equivalents (barbecued beef, fish, plantain, pork, yam, chicken, chevon, potato, corn), oil (three palm oil, nine vegetable oil), and fresh vegetable samples (water leaf, bitter leaf, cabbage, carrot, cucumber, pumpkin, garlic, ginger, green leaf, Gnetum Africana, onion, pepper) were determined by GC-MS analysis. The current study also determined the estimated lifetime cancer risk from ingesting polycyclic aromatic hydrocarbon-contaminated food. The polycyclic aromatic hydrocarbon content of water, oil, vegetable, and food samples were within the United States Environmental Protection Agency/World Health Organization safe limits. The naphthalene, benzo(b)fluoranthene, and benzo(k)fluoranthene levels in surface water were significantly higher than in borehole samples (P = 0.000, 0.047, 0.047). Vegetable oils had higher anthracene and chrysene compared to palm oil (P = 0.023 and 0.032). Significant variations were observed in levels of naphthalene, acenaphthylene, phenanthrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, and dibenzo(a,h)anthracene among the barbecued and fresh food samples (P <0.05). Barbecued pork, potato, and corn had significantly higher naphthalene compared to their fresh equivalents (P = 0.002, 0.017, and <0.001). Consumption of barbecued food and surface water may be associated with higher exposure risk to polycyclic aromatic hydrocarbons which may predispose to increased cancer health risk. The current work explores in depth the concentration of polycyclic aromatic hydrocarbons in different dietary categories that pose direct risk to humans via direct consumption. These findings add knowledge to support future considerations for human health.

Kinetic properties of glucose 6-phosphate dehydrogenase and inhibition effects of several metal ions on enzymatic activity in vitro and cells

Due to the non-degradable and persistent nature of metal ions in the environment, they are released into water bodies, where they accumulate in fish. In order to assess pollution in fish, the enzyme, glucose 6-phosphate dehydrogenase (G6PD), has been employed as a biomarker due to sensitivity to various ions. This study investigates the kinetic properties of the G6PD enzyme in yellow catfish (Pelteobagrus fulvidraco), and analyzes the effects of these metal ions on the G6PD enzyme activity in the ovarian cell line (CCO) of channel catfish (Ictalurus punctatus). IC50 values and inhibition types of G6PD were determined in the metal ions Cu2+, Al3+, Zn2+, and Cd2+. While, the inhibition types of Cu2+ and Al3+ were the competitive inhibition, Zn2+ and Cd2+ were the linear mixed noncompetitive and linear mixed competitive, respectively. In vitro experiments revealed an inverse correlation between G6PD activity and metal ion concentration, mRNA levels and enzyme activity of G6PD increased at the lower metal ion concentration and decreased at the higher concentration. Our findings suggest that metal ions pose a significant threat to G6PD activity even at low concentrations, potentially playing a crucial role in the toxicity mechanism of metal ion pollution. This information contributes to the development of a biomonitoring tool for assessing metal ion contamination in aquatic species.

Environmental effects from petroleum product transportation spillage in Nigeria: a critical review

Nigeria has struggled to meet sustainable development goals (SDGs) on environmental sustainability, transportation, and petroleum product distribution for decades, endangering human and ecological health. Petroleum product spills contaminate soil, water, and air, harming humans, aquatic life, and biodiversity. The oil and gas industry contributes to environmental sustainability and scientific and technological advancement through its supply chain activities in the transport and logistics sectors. This paper reviewed the effects of petroleum product transportation at three accident hotspots on Nigeria highway, where traffic and accident records are alarming due to the road axis connecting the southern and northern regions of the country. The preliminary data was statistically analysed to optimise the review process and reduce risk factors through ongoing data monitoring. Studies on Nigeria's petroleum product transportation spills and environmental impacts between the years 2013 and 2023 were critically analysed to generate updated information. The searches include Scopus, PubMed, and Google Scholar. Five hundred and forty peer-reviewed studies were analysed, and recommendations were established through the conclusions. The findings show that petroleum product transport causes heavy metal deposition in the environment as heavy metals damage aquatic life and build up in the food chain, posing a health risk to humans. The study revealed that petroleum product spills have far-reaching environmental repercussions and, therefore, recommended that petroleum product spills must be mitigated immediately. Furthermore, the study revealed that better spill response and stricter legislation are needed to reduce spills, while remediation is necessary to lessen the effects of spills on environmental and human health.