Heavy metals such as Zn, Pb, Fe, and Cu are abundant in the environment and contribute largely to the sustainability and equilibrium of ecosystem processes. However, because of their bioaccumulation, nondegradability, and the excessive amounts in which they exist, these metals contaminate the food chain and subsequently become a source of toxicity to human beings and the entire ecological function. This is a major issue of concern within the study of environmental science and geochemistry. Although there is a global significance to the issue, it seems more immediate for the developing countries (DCs) such as Nigeria, where the pressure of the teeming population escalates the exigency for human sustainability, food security, and total eradication of hunger. Within the Nigerian context, many studies have examined this all-important issue, but most of these studies are fragmented and limited within the purview of mostly individual states and localities within the country. Taken on a wider geographical scale, the discussions and perspectives of these studies on heavy metal contamination of the food chain offer insufficient insight and expose merely a snapshot of the actual situation. As a result of this, a country-wide knowledge base of the implications of heavy metals on the food chain is lacking. Thus, the present study synthesises existing literature and their findings to create a knowledge base on the vulnerability of the food chain in Nigeria. Aquatic foods, fruits, vegetables, and major staple food such as tubers are the major host of carcinogenic and mutagenic components of heavy metals in Nigeria. This study motivates the Standard Organisation of Nigeria (SON), along with other food and agricultural agencies, to intensify their efforts in monitoring and analysing food components, and we advise consumers to eat with certain degrees of caveat.

PurposeDuring the coronavirus (COVID-19) pandemic lockdowns, stay at home or work from home, many have argued that the westernised non-pharmaceutical interventions (NPI) do not provide remedial in low-income countries like Nigeria, where informal job seekers, street traders, informal labourers and artisans depend mainly on the informal economy. By applying social solidarity (SS) and community-based approach (CBA), the authors evaluate individual acts (trust, altruism and reciprocity) during the lockdown and how these practices evolve from individual approaches to collective actions.Design/methodology/approachThis study reflects on pragmatism research paradigm that enables researchers to maintain both subjectivity in their reflections and objectivity in data collection and analysis. The authors adopt a qualitative method through purposeful and convenience sampling procedure. Data were analysed thematically to identify elements of SS, individual acts, collective or community actions and perceptions.FindingsThe findings reveal that COVID-19 had a disproportionate impact (lack of food and a fall in daily income) on workers, informal job seekers, informal businesses operators and the poor households. As such, the study developed a reflective model of solidarity exhibited by individual acts and collective acts (practices of resource pooling, information sharing, women empowerment, distribution of palliatives and donations) within trusted circles that helped people cope with the lockdown experiences.Practical implicationsSolidarity represents beliefs, practices of values and norms. The SS exhibited by people through NPI would have implications on planning and monitoring the effectiveness of public health programmes during a pandemic in the future.Social implicationsThe findings of citizens and community actions have implications related to the process of building communities – coming together – and solidarity that enhances social development with implications on community health policy agenda during disasters, emergencies and health pandemic.Originality/valueThis is one of the first studies to analyse the relationship between trust, altruism, reciprocity, SS and CBA during the COVID-19 pandemic. Also, it seems reasonable to clarify the concept of SS given the lack of clarity about the definitions from previous studies.

Mining activities have long been recognized as a major source of environmental contamination associated with heavy metals and metalloids. This study evaluated the relationship between the occurrence and mining of lead-zinc sulphide ores at Ishiagu, Nigeria, and heavy metal and metalloid contamination. A comparative study of two zones in the area, with and without mining activities was also made Water, soil, stream sediment and ore samples were analyzed, after acid digestion, using atomic absorption spectrophotometer (AAS).  The concentration levels of seven heavy metals and a metalloid namely Pb, Cu, Ni, Zn, Mn, Co, Cd and as were evaluated. While the highest concentration levels of As, Co and Pb (5.20 mg/l, 0.54 mg/l and 3.40 mg/l respectively) were found in water, those of Ni and Mn (2.26 mg/l and 5.48 mg/l respectively) occurred in soil.  For Cu and Zn, highest levels of concentration (2.80 mg/l and 0.41 mg/l respectively) occurred in stream sediments. The variations in the concentration levels of these elements in varying geologic media (soil, water and sediment) indicate influence of rock types, human activities and media physiochemical characteristics. Geostatistical analyses using QQPlot, semivariogram and kriging showed normal distribution of these elements. Distribution and dispersion patterns of the heavy metals indicated increase in concentration levels in the local stream flow direction. Pb, Cu, As, Cd, Mn, and Ni concentrations had reached pollutant levels in water based on WHO standards, while Zn level is below. Since the local people use untreated surface water and groundwater for drinking and other domestic purposes, soil for farming and lead for cosmetics, long term exposure poses significant health risk for humans, animals and plants.