Persistent organic pollutants and heavy metals in Ghanaian environment: a systematic review of food safety implications.

Advances in industrial and technological innovations have led to significant socio-economic benefits, but with overwhelming negative impacts on the environment. These impacts include the infiltration of organic contaminants into soil, water, and air, posing a threat to the environment and public health. Polybrominated diphenyl ethers (PBDEs), heavy metals, and polycyclic aromatic hydrocarbons (PAHs) are increasingly released as waste, endangering the environment. In countries like Ghana, where regulations are weakly enforced, industrial waste is released uncontrollably, posing threats to public health, environmental integrity, and food systems. This study systematically evaluated existing literature on PBDEs, heavy metals, PAHs, and organic contaminant exposure in Ghana and proposes a roadmap for achieving food safety and protecting the environment and human health. The research identified high mobility of specific heavy metals and risks associated with PBDEs and PAHs in sediments, dumpsites, and various food items. Unregulated dumping of electronic waste with PBDEs raised environmental concerns. An integrated approach is needed to address the multifaceted impact of organic pollutants on public health and ecosystems. Urgent implementation of effective environmental management strategies and regulatory measures is crucial. The study proposed short- to mid-term priorities emphasising the need to foster collaboration and implementing global measures. The mid- to long-term strategy includes a national information surveillance system, local monitoring capacity development, and integrating land contamination controls with food safety legislation. These measures would mitigate risks, ensure sustainable practices, and improve overall food safety management in Ghana, serving as a model for regions facing similar challenges with diverse pollutants.

Impact of black soot emissions on public health in Niger Delta, Nigeria: understanding the severity of the problem.

Rivers State, Niger Delta, Nigeria often referred to as the 'treasure bed of the nation' is the seat of crude oil production activities with the accompanying environmental degradation. The severity of the environmental pollution and contaminated air quality took a new turn for the worse in November 2016, when the residents of Port Harcourt city, Rivers State, a major oil producing State experienced for the first time, aerosol deposition of plumes of black soot. This systematic review paper is aimed at quantifying the severity of this public health challenge. Using appropriate search words, the following databases SCOPUS, PUBMED, Google Scholar, and AJOL were searched from 1990 to 2022 to enable comparative analyses of data before and after the emergence of black soot deposition. Air-related morbidities and mortalities such as cerebrospinal meningitis (CSM), chronic bronchitis, measles, pertussis, hemoptysis, cough, pulmonary tuberculosis, pneumonia, and upper respiratory tract infection (URTI), pneumonia, eye irritation, conjunctivitis, traumatic skin outgrowth, cancers, cardiovascular diseases, and child deformities were compared with levels of air pollutants and particulate matter. The results showed that Port Harcourt city's ambient air quality data were above the standard National Ambient Air Quality data and that of other regulatory agencies having higher levels of both inorganic and organic pollutants. There were significant relationships between air pollutants concentration with morbidities. These correlations were significant in the period covering 2016-2022. Consequently, it is concluded that the black soot emissions in Port Harcourt city, Nigeria has worsened the public health situation in the city.

Polycyclic aromatic hydrocarbons in fish (fresh and dried) and public health in Nigeria: a systematic review.

In Nigeria, environmental pollution linked with PAHs has been increasing, and PAHs in fish pose a threat to all, especially those that rely upon fish. This systematic review aimed at evaluating human health effect of PAHs concentration in dried and fresh fish in Nigeria. A systematic literature search was carried out on PubMed, MedLine, Web of Science and Science Direct, etc. From the total of 31 articles reviewed, 19 studies reported on fresh fish and 9 on dried fish. 54.8% of the selected research reported on high-level PAH accumulation in fresh fish. PAH contamination was mainly from petrogenic and pyrogenic sources. The major health outcomes from this study were cancer and non-carcinogenic risks, skin irritations, gastrointestinal, child deformities, respiratory disorders, emotional distresses, neurological and haematological effects. It is recommended that regulations be made to abate and monitor the environmental exposure of humans to PAHs to ameliorate the public health effects.

Cadmium exposure and the risk of prostate cancer among Nigerian men: Effect modification by zinc status.

BACKGROUND: Prostate cancer (PCa) may result from an interplay between many factors including exposure to trace elements. This study examined the association between cadmium exposure and PCa among Nigerian men and evaluated possible modification of this effect by zinc status. METHODS: This case-control study involved men with histologically confirmed PCa (n = 82), benign prostatic hyperplasia (BPH; n = 93) and controls (n = 98), aged between 40 and 80 years. Study participants were recruited from the main teaching hospital that draws clients from the entire Anambra State in South-Eastern Nigeria. Blood and urine samples were collected from these participants and were analyzed for trace elements using ICP-MS. Statistical models were used to assess the exposure risk for cadmium exposure as well as the mediating effect of zinc status. RESULTS: Among men with prostatic disorders (case-case analysis), every 10-fold increase in urinary cadmium was associated with increased risk of PCa (adjusted odds ratios: 2.526; 95% CI: 1.096-5.821). Men in the highest blood zinc quartile had lower odds of PCa compared to the lowest quartile (AOR: 0.19; 95% CI, 0.06-0.54; p-for trend = 0.001). Zinc-specific effect was observed in this group: every 10-fold increase in urinary cadmium was associated with increased risk of PCa among men with creatinine-adjusted urinary zinc levels below the median value (AOR: 8.46; 95% CI: 1.97 -36.39) but not in those above the median value (AOR: 1.55; 95% CI: 0.45 - 5.39). CONCLUSION: Higher exposure to cadmium may be associated with increased risk of PCa in Nigeria and probably other countries with high prevalence of Zn deficiency. These results point to the need to consider co-occurring trace metals in any effort to mitigate the toxicity of Cd in the environment.

Pervasiveness, bioaccumulation and subduing environmental health challenges posed by polycyclic aromatic hydrocarbons (PAHs): A systematic review to settle a one health strategy in Niger Delta, Nigeria.

The crude oil-rich Niger Delta region of Nigeria is under threat due to anthropogenic activities that include mainly PAH contamination. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), multiple online searches were conducted using several databases (e.g. Cochrane Library, Scopus, Embase, National Library of Medicine, PubMed etc.) between October and November 2022 to collect evidence on pervasiveness, bioaccumulation and health challenges posed by PAH in Nigeria Niger Delta. Included studies were appraised for quality using the Standard for Quality Improvement Reporting Excellence (SQUIRE 2.0) framework and the Joanna Briggs (JB) checklist and retrieved data were analysed using the narrative synthesis method. With the indiscriminate exposure of the local inhabitants to PAH and a lack of public health policies that efficiently prevent exposure-associated adverse health events, there is a need for a collaborative and multi-disciplinary approach, cutting across boundaries of animal, human, and environmental health to undertake risk assessments, develop plans for response and control in an attempt to protect public health. The complex and wide distribution of PAHs within the Niger Delta region would benefit of the One Health strategy. Such systemic approach would help managing the harmful effects of PAHs on ecosystems, from environmental remedial approaches to measures to mitigate exposure-associated risks. One health, including environmental health and food safety, would help risk assessors and risk managers in prioritising actions for the prevention and mitigation of PAHs pollution and its spread and accumulation.

Heavy metals and metalloids exposure and in vitro fertilization: Critical concerns in human reproductive medicine.

Exposures to heavy metals and metalloids have been associated with decreased fecundity and fertility in couples conceiving via assisted reproduction. Heavy metals and metalloids can alter the homeostasis of critical hormones controlling sexual maturation by binding to critical hormones and receptors. This may disrupt the time course of sexual maturation directly or indirectly affecting reproductive competence in males and females. The present review aims to provide a summarized overview of associations between heavy metal exposure, reproductive concerns, and IVF outcomes. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) in Google Scholar, Scopus, EMBASE and PubMed databases. Initial search produced 1,351 articles from which 30 articles were eligible to be included in the systematic review. From our results, 16 articles reported associations between selected heavy metals and IVF outcomes, while 14 articles summarized the role of heavy metals in reproductive concerns. For the studies on IVF outcomes, different human samples were examined for heavy metals. Heavy metals and metalloids (Pb, Hg, Cd, Cr, Mn, As) correlated negatively with oocyte fertilization/pregnancy rates in hair, follicular fluid, serum, urine and seminal plasma samples, while Cd and Hg in whole blood samples showed no associations. For the studies on reproductive concerns, high levels of heavy metals/metalloids were implicated in the following conditions: infertility (Cd, Pb, Ba, U), spontaneous abortion/miscarriage (Pb, Cd, Sb), congenital heart disease (Al, Mg, Cd), PCOS (As, Cd, Hg, Pb), endometriosis (Pb) and uterine leiomyomata (Hg). Taken together, the results of our study suggest that the impact of heavy metals and metalloids exposure on reproductive health may contribute to the failure rates of in vitro fertilization.

Multi-organ protective effect of Costus afer on low concentration toxic metal mixture in albino rats.

Heavy metal mixture can induce multiple organ damage through oxidative stress and inflammatory processes. Dietary intervention using natural antidotes in resource poor countries where classical metal chelators are either not affordable or available can be explored as an alternative means of management of public health effects of chronic heavy metal exposure. The search for natural antidote against the deleterious effects of heavy metals gives the thrust for this study. Thus, the study investigated the effect of aqueous leaf extract of Costus afer on liver, kidney, brain and testis induced by low dose heavy metal mixture (LDHMM) of PbCl2, CdCl2 and HgCl2 of concentrations of 20 mg/kg, 1.61 mg/kg and 0.40 mg/kg, respectively. Five groups of seven rats each (weight-matched) were used. First and second groups received deionized water and heavy metal mixture and served as normal and toxic controls, respectively. Groups 3, 4 and 5 received through oral gavage 750, 1500, 2250 mg/kg of the Costus afer extract respectively, with the metal mixture concurrently. All treatments were four times a week for 90 days (4/week/90 days). Hepatorenal, hormonal, oxidative stress markers, cytokines (interleukin-6 and interleukin-10), and heavy metals (Pb, Cd and Hg) concentrations were assayed. The one-way analysis of variance, agglomerative hierarchical clustering, parallel coordinates plot, principal component analysis and Bray Curtis dissimilarity were used to statistically analyze the data. LDHMM caused significant changes in these organs and however, the plant extract provided a protective effect against these pathological changes. The statistical analysis revealed that the kidney was the most affected organ, followed by the liver, then brain and testis, respectively. Costus afer may be an important nutraceutical in multi-organ deleterious effects of LDHMM following its regulation of oxidative stress markers, inflammatory cytokines and biometal chelation.

Immunomodulatory and Mechanistic Considerations of Hibiscus sabdariffa (HS) in Dysfunctional Immune Responses: A Systematic Review.

Hibiscus sabdariffa calyx (HS) water decoction extract is a commonly consumed beverage with various pharmacological properties. This systematic review examines the possible effect of HS intake on immune mediators. The Scopus and PUBMED databases were searched for all human and animal studies that investigated the effect of HS administration on immune related biomarkers. For each of the immune biomarkers, the mean, standard deviation and number of subjects were extracted for both the HS treated and untreated group. These values were used in the computation of standardized mean difference (SMD). Statistical analysis and forest plot were done with R statistical software (version 3.6.1). Twenty seven (27) studies met the eligibility criteria. Twenty two (22) of the studies were used for the meta-analysis which included a total of 1211 subjects. The meta-analysis showed that HS administration significantly lowered the levels of TNF-α (n=10; pooled SMD: -1.55; 95% CI: -2.43, -0.67; P < 0.01), IL-6 (n=11; pooled SMD:-1.09; 95% CI: -1.77, -0.40; P < 0.01), IL-1ß (n=7; pooled SMD:-0.62; 95% CI: -1.25, 0.00; P = 0.05), Edema formation (n=4; pooled SMD: -2.29; 95% CI: -4.47, -0.11; P = 0.04), Monocyte Chemoattractant Protein -1 (n=4; pooled SMD: -1.17; 95% CI: -1.78, -0.57; P < 0.01) and Angiotensin converting enzyme cascade (n=6; pooled SMD: -0.91; 95% CI: -1.57, -0.25; P < 0.01). The levels of IL-10 (n=4; pooled SMD: -0.38; 95% CI: -1.67, 0.91; P = 0.56), Interleukin 8 (n=2; pooled SMD:-0.12; 95% CI: -0.76, 0.51; P = 0.71), iNOS (n=2; pooled SMD:-0.69; 95% CI: -1.60, 0.23 P = 0.14) and C- Reactive Protein (n=4; pooled SMD: 0.05; 95% CI: -0.26, 0.36; P = 0.75), were not significantly changed by HS administration. Some of the results had high statistical heterogeneity. HS may be promising in the management of disorders involving hyperactive immune system or chronic inflammation.

Plant-Derived Food Grade Substances (PDFGS) Active Against Respiratory Viruses: A Systematic Review of Non-clinical Studies.

Human diet comprises several classes of phytochemicals some of which are potentially active against human pathogenic viruses. This study examined available evidence that identifies existing food plants or constituents of edible foods that have been reported to inhibit viral pathogenesis of the human respiratory tract. SCOPUS and PUBMED databases were searched with keywords designed to retrieve articles that investigated the effect of plant-derived food grade substances (PDFGS) on the activities of human pathogenic viruses. Eligible studies for this review were those done on viruses that infect the human respiratory tract. Forty six (46) studies met the specified inclusion criteria from the initial 5,734 hits. The selected studies investigated the effects of different PDFGS on the infectivity, proliferation and cytotoxicity of different respiratory viruses including influenza A virus (IAV), influenza B virus (IBV), Respiratory syncytial virus (RSV), human parainfluenza virus (hPIV), Human coronavirus NL63 (HCoV-NL63), and rhinovirus (RV) in cell lines and mouse models. This review reveals that PDFGS inhibits different stages of the pathological pathways of respiratory viruses including cell entry, replication, viral release and viral-induced dysregulation of cellular homeostasis and functions. These alterations eventually lead to the reduction of virus titer, viral-induced cellular damages and improved survival of host cells. Major food constituents active against respiratory viruses include flavonoids, phenolic acids, tannins, lectins, vitamin D, curcumin, and plant glycosides such as glycyrrhizin, acteoside, geniposide, and iridoid glycosides. Herbal teas such as guava tea, green and black tea, adlay tea, cistanche tea, kuding tea, licorice extracts, and edible bird nest extracts were also effective against respiratory viruses in vitro. The authors of this review recommend an increased consumption of foods rich in these PDFGS including legumes, fruits (e.g berries, citrus), tea, fatty fish and curcumin amongst human populations with high prevalence of respiratory viral infections in order to prevent, manage and/or reduce the severity of respiratory virus infections.

Crude oil and public health issues in Niger Delta, Nigeria: Much ado about the inevitable.

The importance of crude oil has come at a great cost. In many developing economies of the world, it can be described as the bitter-sweet crude for its double-edged impacts on the welfare, wellness and wellness of the people. Agitations and restiveness remain characteristic features of Niger Delta following claims of exploitation and neglect of the local population by the multinationals. Literature on the environmental and public health impacts of crude oil was searched from relevant databases such as google scholar, Science Direct, Scopus and PubMed. This paper is a translational scientific and toxicological insight on what should be done by the major players rather than casting unending aspersions. Since living near oil spills and crude oil production sites is an environmental stressor occasioned by exposure to both chemical pollutants and physical menace that are all detrimental to health, cumulative risk assessment CRA is proposed as a viable approach for a comprehensive understanding of the size of this problem. Multinational oil companies should support development of Environmental Medicine Research which will in turn generate data on both how to harness the natural resources to combat the public health issues associated with oil exploration and the mitigation and remediation of the environment. This endeavor will create a waste-to-wealth program that will pacify the restiveness in oil exploring communities. It will be interesting to know that in the same environment that breeds the elephant-in-the-parlor lies the natural antidotes to check-mate the public health malady.

Lead and cadmium in infant milk and cereal based formulae marketed in Nigeria: a probabilistic non-carcinogenic human health risk assessment.

BACKGROUND: There has been concern on the likelihood of contamination of infant formulae and consequent health risk in children. OBJECTIVE: This study has assessed and compared the lead and cadmium levels in infant formulae commonly consumed in Nigeria with international regulatory limits. It has also compared the estimated daily intake with Joint FAO/WHO Expert Committee on Food Additives (JECFA) and Proposition 65 Provisional Tolerable Daily Intake. MATERIAL AND METHODS: Lead and cadmium levels in 26 different brands of infant formulae purchased from stores in Port-Harcourt, Rivers state, Nigeria in January 2018 were assayed by Atomic Absorption Spectrophotometry. RESULTS: The lead and cadmium levels in milk based infant formulae ranged from 0.61-3.50 mg/kg and 0.01-0.55 mg/kg respectively whereas the range of the lead and cadmium levels in the cereal and cereal mix based were 0.29-1.95 mg/kg and 0.02-0.37 mg/kg, and 0.47-2.34 mg/kg and 0.001-0.46 mg/kg respectively. The mean lead level in the milk-based formulae (1.49 0.89 mg/kg) was slightly higher than other groups of formulae but the difference was not significant (p<0.05). The mean level of cadmium (0.17 mg/kg) in milk-based infant formulae was higher than levels in cereal and cereal mix but there was no significant statistical difference (p<0.05) between the samples. The lead and cadmium level in milk, cereal and cereal mixed based infant formulae were above the food safe limits. CONCLUSIONS: The consumption of infant formulae may add to the body burden of cadmium and lead of children with attendant public health implication. Regular monitoring and safety assessment of metals contamination of these infant formulae is advised.

Current mechanistic perspectives on male reproductive toxicity induced by heavy metals.

Environmental and occupational exposures to heavy metals have led to various deleterious damages to the biological system of which infertility is one of them. Infertility is a global public health concern, affecting 15% of all couples of reproductive age. Out of the 100% cases of reported infertility among couples, 40% of the cases are related to male factors; including decreased semen quality. This review focuses on the recent mechanistic perspectives of heavy metal-induced male reproductive toxicity. The associated toxic metal-mediated mechanisms of male reproductive toxicity include ion mimicry, disruption of cell signaling pathways, oxidative stress, altered gene expression, epigenetic regulation of gene expression, apoptosis, disruption of testis/blood barrier, inflammation and endocrine disruption. The current literature suggests that non-coding RNAs (ncRNAs) mediate paternal intergenerational epigenetic inheritance and thus has a direct functional importance, as well as possess novel biomarker potential, for male reproductive toxicity. To identify the specific ncRNAs with the most profound impacts on heavy metal-induced male reproductive toxicity should be thrust of further research.

Cadmium and lead in geophagic clay consumed in Southern Nigeria: health risk from such traditional nutraceutical.

Geophagy is a cultural behavior, based on the recurrent intentional eating of clay soil, that is raising increasing concern as it implies multidimensional (space, time) potential risk of serious adverse health effects. This study investigated the level of toxic metals (Cd and Pb) in 20 Nigerian geophagic clays intended for both local consumption and distribution to the West Africa market. After sampling in 4 open markets in southern Nigeria (Akwa Ibom, Abia, Rivers, Imo), samples were subjected to digestion, ashing and analysis. The Pb levels in all samples exceeded the WHO/FAO maximum permissible limit of 0.1 mg kg-1 whereas 16% exceeded the Cd limit of 0.3 mg kg-1. The estimated daily intake of Pb for all samples ranged from 0.0032-0.0286 mg kgbw-1 day-1 to 0.0024-0.0215 mg kgbw-1 day-1 for children and adults, respectively. The estimated daily intakes for Cd ranged from bdl (below detection limit)-0.0010 mg kgbw-1 day-1 to bdl-0.0028 mg kgbw-1 day-1 for children and adults, respectively. In both cases, the WHO/FAO provisional Tolerable Weekly Intake is exceeded through the ingestion of these soils. Our results confirm health risks related to the geophagic practices, its role in exceeding health guidelines when considering aggregate exposure in the Nigerian scenario and body burden in developing organisms, young women, women at fertile age, and pregnant women. We discuss how geophagists consider clays as traditional nutraceuticals and how clarifying the nutraceutical role of geophagy could facilitate risk communication. Geophagic products are implicitly or explicitly marketed as dietary supplements, and as such they should be regulated (1) by labeling, and prohibition of scientifically unfounded health claims and (2) by safety standards before marketing. This is particularly critical when clays originate from countries living rapid, unplanned and uncontrolled development and dumped, like Nigeria.

Sentinel species for biomonitoring and biosurveillance of environmental heavy metals in Nigeria.

Nigeria receives copious annual precipitation to nourish its forests and agriculture, it has an extensive river drainage system, and it possesses valuable mineral deposits that stimulate both commercial and artisan mining activities. The combination of these features complicates Nigeria's efforts to produce adequate amounts of healthy foods to support its population. Toxic heavy metals like lead, cadmium, and mercury, and toxic metalloids such as arsenic, are also present in its mineral deposits and they migrate gradually into the soil and water of Nigeria by natural means. However, mining activities can liberate higher levels of toxic metals, which adversely affect Nigerian ecosystems and its food chains. Thus, environmental pollution due to anthropogenic activities is a major public health concern in Nigeria. This review covers the importance of native Nigerian and African wild and cultivated plants along with livestock and wild animals as sentinel species to evaluate heavy metals as environmental stressors and the use of sentinel species for food safety monitoring and for predicting potential risks to human health.

Management of Iron Overload in Resource Poor Nations: A Systematic Review of Phlebotomy and Natural Chelators.

Iron is an essential element and the most abundant trace metal in the body involved in oxygen transport and oxygen sensing, electron transfer, energy metabolism, and DNA synthesis. Excess labile and unchelated iron can catalyze the formation of tissue-damaging radicals and induce oxidative stress. English abstracts were identified in PubMed and Google Scholar using multiple and various search terms based on defined inclusion and exclusion criteria. Full-length articles were selected for systematic review, and secondary and tertiary references were developed. Although bloodletting or phlebotomy remains the gold standard in the management of iron overload, this systematic review is an updated account of the pitfalls of phlebotomy and classical synthetic chelators with scientific justification for the use of natural iron chelators of dietary origin in resource-poor nations.

Nigerian foods of probiotics relevance and chronic metal exposure: a systematic review.

Probiotics are functional foods with a wide armamentarium of health benefits in man including metal chelation. Given the unacceptable blood lead levels and the near ignorance or negligence of heavy metals in both diagnoses and management of diseases in Nigeria, it is feared that these metals are involved in the aetiogenesis of several ailments from preeclampsia, metabolic syndrome, cancer, etc. This is an insight on Nigerian fermented foods and their possible role as metal chelators in the management of the chronic heavy metal exposure in Nigeria. One hundred and five articles fulfilled the inclusion criteria. Google scholar, PubMed and SCOPUS were searched for articles reporting fermented foods and probiotics in Nigeria. Only studies published in English Language were included, but there was no limitation in year of study. One hundred and five articles fulfilled the inclusion criteria. Studies from some African countries suggest that fermented foods of probiotics relevance have effectively shown metal chelation properties. Consumption of Nigerian fermented foods may hold a promise in checking the high body burden of heavy metals in Nigeria. Graphic abstract.

Safety of honey consumed in Enugu State, Nigeria: a public health risk assessment of lead and polycyclic aromatic hydrocarbons

Background: Information about lead (Pb) and polycyclic aromatic hydrocarbons (PAHs) concentrations in honey and their dietary intake is very important in human health risk assessment. Currently, there are paucity of data on the risk assessment and concentrations of lead and PAHs in honey in Nigeria. Objective: This study has determined the potential human health risk of lead and PAHs associated with the consumption of honey in Enugu state, Nigeria. Materials and methods: Lead and US EPA 16 priority PAHs in honey harvested from rural and urban communities in March 2016 were determined using Atomic Absorption Spectrometer and Gas Chromatograph respectively. Carcinogenic and non-carcinogenic risk assessments were carried. Results: The mean concentration of Pb in honey ranged from 0.005 mg/kg ­ 0.08 mg/kg. The mean concentrations of 16 PAHs in honey ranged from 4.71E-03 ­ 2.72 mg/kg. The dietary intake of the PAHs for adults and children ranged from 0.0021 ­ 0.0259 mg/kg/day and 0.0011 ­ 0.0129 mg/kg/day respectively. The levels of BaPeq and their margin of exposure MOE suggest non-significant health risk. The incremental life cancer risk ILCR of Pb were within safe range of <1E-04. Conclusion: Consumption of honey from Enugu State, Nigeria may not pose a significant health risk_

Exposure to Wood Smoke and Associated Health Effects in Sub-Saharan Africa: A Systematic Review.

Background: Observational studies suggest that exposure to wood smoke is associated with a variety of adverse health effects in humans. Objective: We aimed to summarise evidence from sub-Saharan Africa on levels of exposure to pollutants in wood smoke and the association between such exposures and adverse health outcomes. Methods: PubMed and Google scholar databases were searched for original articles reporting personal exposure levels to pollutants or health outcomes associated with wood smoke exposure in Sub-Saharan African population. Results: Mean personal PM2.5 and carbon monoxide levels in the studies ranged from 26.3 ± 1.48 µg/m3 to 1574 ± 287µg/m3 and from 0.64 ± 2.12 ppm to 22 ± 2.4 ppm, respectively. All the reported personal PM2.5 exposure levels were higher than the World Health Organization's Air Quality Guideline (AQG) for 24-hour mean exposure. Use of wood fuels in domestic cooking is the major source of wood smoke exposure in this population. Occupational exposure to wood smoke included the use of wood fuels in bakery, fish drying, cassava processing and charcoal production. Females were exposed to higher levels of these pollutants than males of the same age range. Major determinants for higher exposure to wood smoke in SSA included use of unprocessed firewood, female gender and occupational exposure. We recorded strong and consistent associations between exposure to wood smoke and respiratory diseases including acute respiratory illness and impaired lung function. Positive associations were reported for increased blood pressure, low birth weight, oesophageal cancer, sick building syndrome, non-syndromic cleft lip and/or cleft palate and under-five mortality. Conclusion: There is high level of exposure to wood smoke in SSA and this exposure is associated with a number of adverse health effects. There is urgent need for aggressive programs to reduce wood smoke exposure in this population.

Dietary supplementation of Pleurotus tuber regium in rat feed ameliorates metabolic and hematotoxicity induced by carbon tetrachloride.

Pleurotus tuber regium, a wild edible mushroom can reduce free radical-mediated injury and oxidative stress induced by carbon tetrachloride (CCl4) via improvement of antioxidant capacity. This work evaluates the protective effects of this mushroom against the metabolic and hematological toxicity induced by CCl4. Sixty male Sprague Dawley rats were divided into six groups (n = 10). Group I received olive oil (3 mL/kg) i.p. twice weekly for 13 weeks, while maintaining free access to food and water ad libitum (negative control). Group II received 3 mL/kg (30% CCl4 in olive oil) injected i.p. twice weekly, while Groups III, IV, and V received 100, 200, and 500 mg wild edible P. tuber regium (33.3% in feed) daily in addition to 3 mL/kg CCl4 in olive oil injected twice weekly i.p. Group VI received olive oil (3 mL/kg) i.p. twice weekly for 13 weeks in addition to 500 mg P. tuber regium (33.3% in feed) daily. The body weight (b.w.), feed intake (FI), and water intake (WI) were obtained weekly, while the hematological indices and oxidative stress parameters were carried out shortly after necropsy on days 30, 60, and 90. Treatment with CCl4 significantly (p < 0.05) decreased the b.w., FI and WI, feed efficiency, ascorbic acid, α-tocopherol, and antioxidant enzymes, superoxide dismutase, catalase, total glutathione, and peroxidase, while increasing the oxidative stress as measured by malondialdehyde in CCl4 only group when compared with control. Supplementation of feed with P. tuber regium reversed the effects of CCl4. Pleurotus tuber regium ameliorated the CCl4-induced metabolic and hematotoxicity by improving the antioxidant capacity.

Public Health Burden of E-waste in Africa.

BACKGROUND: Environmental impacts from informal e-waste recycling are increasing in Africa. E-waste handling and disposal exposes people to highly toxic cocktails of heavy metals, brominated flame retardants, non-dioxin-like polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAH), polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PBDF) and dioxin-like polychlorinated biphenyls (DL-PCB). Most of these compounds are endocrine disrupters, and most are neuro- and immune-toxic as well. OBJECTIVES: Informal e-waste recycling in African countries is a serious public health threat. The present paper reviews the extent of e-waste exposure in Africa and related impacts on people, animals and the environment. METHODS: Four electronic databases (PubMed, Science Direct, Scopus, Google Scholar) were searched for publications related to e-waste and human health in Africa. Search terms included 'e-waste in Africa', 'e-waste in developing nations', 'public health and e-waste', 'environment and e-waste', and 'e-waste and health'. DISCUSSION: Elevated levels of e-waste pollutants in water, air, soil, dust, fish, vegetable, and human matrices (blood, urine, breast milk) indicate that not only are e-waste workers at risk from exposure to e-waste, but the general population and future generations as well. Headache, cough and chest pain, stomach discomfort, miscarriage, abnormal thyroid and reproductive function, reduction of gonadal hormone, and cancer are common complaints of those involved with the processing of e-waste. CONCLUSIONS: The evidence presented from the reviewed studies illustrates the extent of the human health and environmental risks posed by e-waste in Africa. There is a need for a regulatory framework including specific legislation, infrastructure and protocols to safely recycle and dispose of e-waste in sub-Saharan African countries. COMPETING INTERESTS: The authors declare no competing financial interests.