Environmental Health Research in Africa: Important Progress and Promising Opportunities

Chronic kidney disease of unknown aetiology in Africa: A review of the literature

During the last two decades, an epidemic of a severe form of chronic kidney disease (CKD) unrelated to traditional risk factors (diabetes and hypertension) has been recognized in low- to middle-income countries. CKD of unknown aetiology (CKDu) mainly affects young working-age adults, and has become as an important and devastating public health issue. CKDu is a multifactorial disease with associated genetic and environmental risk factors. This review summarizes the current epidemiological evidence on the burden of CKDu and its probable environmental risk factors contributing to CKD in Africa. PubMed/Medline and the African Journals Online databases were searched to identify relevant population-based studies published in the last two decades. In the general population, the burden of CKD attributable to CKDu varied from 19.4% to 79%. Epidemiologic studies have established that environmental factors, including genetics, infectious agents, rural residence, low socioeconomic status, malnutrition, agricultural practise and exposure to agrochemicals, heavy metals, use of traditional herbs, and contaminated water sources or food contribute to the burden of CKD in the region. There is a great need for epidemiological studies exploring the true burden of CKDu and unique geographical distribution, and the role of environmental factors in the development of CKD/CKDu.

Identifying and evaluating environmental determinants of health in Hashtpar city, Iran

This paper aimed to identify and evaluate the environmental factors that influence human health in Hashtpar. The town locates in the coastal plain of northern Iran and has an area of 1378 ha and a population of about 53,000 people. Fourteen indicators were included in the dataset and the data was collected in 34 data collection points through the evaluation of at least 5 experienced people or by calculations using Geographical Information System (GIS) and related shape files. First, it is used a descriptive and qualitative method and statistical parameters to analyze each determinant of health, regardless of its spatial differences, then the data entered into GIS to produce zoning maps using the Kriging interpolation tool. Findings show that generally, healthy environment indicators are higher than average level and the indicators are in better condition in central parts of the town than in its outskirts.

The burden, prevention and care of infants and children with congenital anomalies in sub-Saharan Africa: A scoping review

The aim of this scoping review was to determine the scope, objectives and methodology of contemporary published research on congenital anomalies (CAs) in sub-Saharan Africa (SSA), to inform activities of the newly established sub-Saharan African Congenital Anomaly Network (sSCAN). MEDLINE was searched for CA-related articles published between January 2016 and June 2021. Articles were classified into four main areas (public health burden, surveillance, prevention, care) and their objectives and methodologies summarized. Of the 532 articles identified, 255 were included. The articles originated from 22 of the 49 SSA countries, with four countries contributing 60% of the articles: Nigeria (22.0%), Ethiopia (14.1%), Uganda (11.7%) and South Africa (11.7%). Only 5.5% of studies involved multiple countries within the region. Most articles included CA as their primary focus (85%), investigated a single CA (88%), focused on CA burden (56.9%) and care (54.1%), with less coverage of surveillance (3.5%) and prevention (13.3%). The most common study designs were case studies/case series (26.6%), followed by cross-sectional surveys (17.6%), retrospective record reviews (17.3%), and cohort studies (17.2%). Studies were mainly derived from single hospitals (60.4%), with only 9% being population-based studies. Most data were obtained from retrospective review of clinical records (56.1%) or via caregiver interviews (34.9%). Few papers included stillbirths (7.5%), prenatally diagnosed CAs (3.5%) or terminations of pregnancy for CA (2.4%).This first-of-a-kind-scoping review on CA in SSA demonstrated an increasing level of awareness and recognition among researchers in SSA of the contribution of CAs to under-5 mortality and morbidity in the region. The review also highlighted the need to address diagnosis, prevention, surveillance and care to meet Sustainable Development Goals 3.2 and 3.8. The SSA sub-region faces unique challenges, including fragmentation of efforts that we hope to surmount through sSCAN via a multidisciplinary and multi-stakeholder approach.

A SWOT analysis of contemporary gaps and a possible diagnostic tool for environmental health in an upper-middle income country: a case study of South Africa

This study evaluated the state of environmental health in the Republic of South Africa using the strengths, weaknesses, opportunities, and threats (SWOT) analysis framework. The internal and external factor evaluations were conducted by reviewing existing literature searched using a combination of keywords and boolean functions. The weighted score for the strengths and weaknesses was 0.79 and 1.04, respectively. The external factor evaluations findings revealed that environmental health has an equal amount of threats and opportunities, however, the threats outweigh the opportunities. The total weighted score for the internal and external factor evaluations was 1.83 and 2.25, respectively, which were below the average value of 2.5. The internal-external factors matrix indicated that environmental health in the Republic of South Africa needs to be refocused and re-aligned to public health protection. Failure to address the weaknesses and threats and optimise the strengths and opportunities may further weaken the provision of environmental health services.

What Remains Unsolved in Sub-African Environmental Exposure Information Disclosure: A Review

Background: Africa comprises the bulk of struggling economies. However, Sub-Saharan Africa is experiencing rapid industrialization and urbanization. Excessive resource use, pollution, and the absence of relevant environmental disclosure are factors that contribute to these human-made damages. Environmental pollution as a threat to sustainable development results from these damages. Although it has been established that Sub-Saharan Africa would benefit from resource-management development, sustainable environmental strategies, and a reduction in urbanization and persistent poverty, the information on these issues has not been made public. Objective: To provide a full account of the level of environmental-exposure disclosure in Sub-Saharan African countries, including the current level of progress, gaps, and prospects, we reviewed the literature on environmental exposure information research in African populations. Methodology: We searched PubMed and Google Scholar for peer-reviewed research articles, reviews, or books examining environmental exposure and information disclosure in human populations in Africa. Results: In total, 89 full-text articles were eligible for the inclusion criteria. A quality assessment of the retrieved articles using the PRISMA guidelines resulted in the exclusion of 40 articles; therefore, 49 studies were included in the final analysis. In Sub-Saharan Africa, the environmental exposure information on household injuries, the use of chemicals such as pesticides in farming, industry-linked vectors and diseases, laboratory chemical exposure, industrial exposure, and epigenetic factors are not well-disclosed to the population. Conclusion: Environmental information disclosure standards should be incorporated into central-government policy recommendations. Standards should identify polluting industries, and companies should refrain from the voluntary disclosure of environmental information to manage their reputation. Heavy-pollution industries should be made sufficiently transparent to lessen the company–media collusion on information disclosure.

Biobanking in East and Central Africa: A case of the Integrated Biorepository of H3Africa Uganda

Biorepositories are essential because they guarantee the proper storage and distribution of biospecimens and their associated data for current and future research. In Eastern and Central Africa, the Integrated Biorepository of H3Africa Uganda (IBRH3AU) at Makerere University in Uganda was the first of its kind. It is strategically located at Makerere University College of Health Sciences, which is home to some of Uganda's most relevant and impactful infectious and non-infectious disease research.  Since its inception as a pilot project in 2012, the IBRH3AU biorepository has grown into a state-of-the-art facility serving the H3Africa consortium and the rest of the scientific community. IBRH3AU has built a solid infrastructure over the past ten years with cutting-edge methods and technologies for the collection, processing, quality control, handling, management, storage and shipment of biospecimens. H3Africa researchers, local researchers, postgraduate and postdoctoral students, and the greater scientific community in Eastern and Central Africa and beyond have benefited from IBRH3AU's exceptional biobanking services.

Roadmap of environmental health research on emerging contaminants: Inspiration from the studies on engineered nanomaterials

Research on the environmental health of emerging contaminants is critical to understand their risks before causing severe harm. However, the low environmental concentrations, complex behaviors, and toxicology of emerging contaminants present enormous challenges for researchers. Here, we reviewed the research on the environmental health of engineered nanomaterials (ENMs), one of the typical emerging contaminants, to enlighten pathways for future research on emerging contaminants at their initial exploratory stage. To date, some developed pretreatment methods and detection technologies have been established for the determination of ENMs in natural environments. The mechanisms underlying the transfer and transformation of ENMs have been systematically explored in laboratory studies. The mechanisms of ENMs-induced toxicity have also been preliminarily clarified at genetic, cellular, individual, and short food chain levels, providing not only a theoretical basis for revealing the risk change and environmental health effects of ENMs in natural environments but also a methodological guidance for studying environmental health of other emerging contaminants. Nonetheless, due to the interaction of multiple environmental factors and the high diversity of organisms in natural environments, health effects observed in laboratory studies likely differ from those in natural environments. We propose a holistic approach and mesocosmic model ecosystems to systematically carry out environmental health research on emerging contaminants, obtaining data that determine the objectivity and accuracy of risk assessment.

Heavy metal blood concentrations in association with sociocultural characteristics, anthropometry and anemia among Kenyan adolescents

OBJECTIVES

To measure heavy metal concentrations among Kenyan youth and quantify associations with sociocultural, demographic, and health factors as well as anthropometry.

METHODS

Using data from a study of semi-nomadic pastoralists in Samburu County, Kenya, we measured blood concentrations of lead (Pb), mercury (Hg), and cadmium (Cd) in 161 adolescents. We identified sociocultural, demographic and health characteristics associated with each metal and quantified the association between metals and adolescent anthropometry.

RESULTS

Median blood concentrations of Pb, Cd, and Hg were 1.82 µg/dL, 0.24 µg/L and 0.16 µg/L, respectively. Place of residence (highlands vs lowlands) was a determinant of metal concentrations. Hg was inversely related to anemia, and metals were not associated with anthropometry.

CONCLUSIONS

In this population of Samburu adolescents, median Pb and Cd blood concentrations were higher than other North American or European biomonitoring studies. These findings motivate further investigation into the environmental sources of metals in this community.

Cancer in sub-Saharan Africa: a Lancet Oncology Commission

In sub-Saharan Africa (SSA), urgent action is needed to curb a growing crisis in cancer incidence and mortality. Without rapid interventions, data estimates show a major increase in cancer mortality from 520 348 in 2020 to about 1 million deaths per year by 2030. Here, we detail the state of cancer in SSA, recommend key actions on the basis of analysis, and highlight case studies and successful models that can be emulated, adapted, or improved across the region to reduce the growing cancer crises. Recommended actions begin with the need to develop or update national cancer control plans in each country. Plans must include childhood cancer plans, managing comorbidities such as HIV and malnutrition, a reliable and predictable supply of medication, and the provision of psychosocial, supportive, and palliative care. Plans should also engage traditional, complementary, and alternative medical practices employed by more than 80% of SSA populations and pathways to reduce missed diagnoses and late referrals. More substantial investment is needed in developing cancer registries and cancer diagnostics for core cancer tests. We show that investments in, and increased adoption of, some approaches used during the COVID-19 pandemic, such as hypofractionated radiotherapy and telehealth, can substantially increase access to cancer care in Africa, accelerate cancer prevention and control efforts, increase survival, and save billions of US dollars over the next decade. The involvement of African First Ladies in cancer prevention efforts represents one practical approach that should be amplified across SSA. Moreover, investments in workforce training are crucial to prevent millions of avoidable deaths by 2030. We present a framework that can be used to strategically plan cancer research enhancement in SSA, with investments in research that can produce a return on investment and help drive policy and effective collaborations. Expansion of universal health coverage to incorporate cancer into essential benefits packages is also vital. Implementation of the recommended actions in this Commission will be crucial for reducing the growing cancer crises in SSA and achieving political commitments to the UN Sustainable Development Goals to reduce premature mortality from non-communicable diseases by a third by 2030.

Consumer Perceptions of the Use of Nondegradable Plastic Packaging and Environmental Pollution: A Review of Theories and Empirical Literature

Studying people’s perceptions of their attitudes and behaviour toward the use and inappropriate disposal of plastics is necessary because it helps explain the meaning of sustainable environmental behaviour in the context of African countries. Formulating appropriate behavioural change interventions may lead to a shift in people’s behaviour in terms of plastic consumption if they become aware of the environmental risk of plastics. Using a qualitative review of literature, relevant materials for this paper were identified using a search strategy that involved keywords and databases. Previous empirical studies employed several theoretical frameworks. However, inconsistences in the use and definition of variables, make comparing the results of these studies difficult. Although the literature is growing, more empirical evidence is still needed to understand the drivers of people’s perceptions toward unsustainable environmental behaviour in the context of African countries and to formulate appropriate behavioural change interventions. A review of the literature determined four broad drivers of people’s perceptions toward unsustainable environmental behaviour. These include policy or institutional variables, product and market attributes, community variables, and individual characteristics. Additionally, we offer a consolidated conceptual framework for analysing consumer perception in relation to the use of nondegradable plastics and environmental pollution and identify the drivers of people’s perceptions. Policy implications for developing countries as well as future research directions are flagged.

Pesticide Importation in Sierra Leone, 2010–2021: Implications for Food Production and Antimicrobial Resistance

There are no previous studies reporting the type and quantity of pesticides for farming from Sierra Leone and the impact of Ebola or COVID-19 on importation. This study reviewed imported farming pesticides by the Sierra Leone, Ministry of Agriculture and Forestry (MAF), between 2010–2021. It was a descriptive study using routinely collected importation data. We found the MAF imported pesticides for farming only during 2010, 2014 and 2021, in response to growing food insecurity and associated with Ebola and COVID-19 outbreaks. Results showed insecticide importation increased from 6230 L in 2010 to 51,150 L in 2021, and importation of antimicrobial pesticides (including fungicides) increased from 150 kg in 2010 to 23,560 kg in 2021. The hazard class risk classification of imported pesticides decreased over time. Increasing amounts of imported fungicides could increase the risk of future fungal resistance among humans. We found that in responding to escalating food insecurity, the government dramatically increased the amount of pesticide importation to improve crop production. Further support is necessary to decrease the risk of worsening food shortages and the possible threat of emerging antimicrobial resistance. We recommend continued monitoring and surveillance, with further studies on the most appropriate response to these multiple challenges.

Heavy metals and neurodevelopment of children in low and middle-income countries: A systematic review

BACKGROUND

The presence of harmful environmental exposures, which disproportionately affects low-and-middle income countries (LMICs), contributes to >25% of deaths and diseases worldwide and detrimentally affects child neurodevelopment. Few resources succinctly summarize the existing literature on this topic. Our objective is to systematically review and characterize the evidence regarding the relationship between heavy metals and neurodevelopment of children in LMICs.

METHODS

We conducted a medical librarian-curated search on multiple online databases to identify articles that included individuals <18 years living in a LMIC, quantitatively measured exposure to a heavy metal (either prenatal or postnatal), and used a standardized measurement of neurodevelopment (i.e. cognitive, language, motor, and behavior). Reviews, editorials, or case studies were excluded. Results were analyzed qualitatively, and quality was assessed.

RESULTS

Of the 18,043 screened articles, 298 full-text articles were reviewed, and 100 articles met inclusion criteria. The included studies represented data from 19 LMICs, only one of which was classified as a low-income country. Ninety-four percent of postnatal lead and all postnatal manganese studies showed a negative association with metal exposure and neurodevelopment, which were the strongest relationships among the metals studied. Postnatal exposure of mercury was associated with poor neurodevelopment in only half of studies. Limited data on postnatal arsenic and cadmium suggests an association with worse neurodevelopment. Findings were mixed for prenatal arsenic and lead, although some evidence supports that the neurotoxicity of lead was amplified in the presence of manganese.

CONCLUSIONS AND POTENTIAL IMPACT

We found that lead and manganese appear to consistently have a detrimental effect on the neurodevelopment of children, and more evidence is needed for mercury, arsenic, and cadmium. Better characterization of these effects can motivate and inform prioritization of much needed international policies and programs to reduce heavy metal exposures for young children within LMICs.

Air Quality in Africa: Public Health Implications

This review highlights the importance of air quality in the African urban development process. We address connections between air pollution and (a) rapid urbanization, (b) social problems, (c) health impacts, (d) climate change, (e) policies, and (f) new innovations. We acknowledge that air pollution levels in Africa can be extremely high and a serious health threat. The toxic content of the pollution could relate to region-specific sources such as low standards for vehicles and fuels, cooking with solid fuels, and burning household waste. We implore the pursuit of interdisciplinary research to create new approaches with relevant stakeholders. Moreover, successful air pollution research must regard conflicts, tensions, and synergies inherent to development processes in African municipalities, regions, and countries. This includes global relationships regarding climate change, trade, urban planning, and transportation. Incorporating aspects of local political situations (e.g., democracy) can also enhance greater political accountability and awareness about air pollution.

A feasibility study to assess Imbrasia belina (mopane worm) sensitisation and related respiratory health outcomes in a rural community in Gwanda district, Zimbabwe

Background

Allergic diseases are considered to be some of the fastest growing chronic conditions in Africa. Of concern is the paucity of knowledge about the local environment and its role in allergic disease development. In response to this, we explored whether Imbrasia belina, a popular indigenous edible insect commonly known as mopane worm, is a potential allergen of clinical and public health significance in Zimbabwe. This study was intended to assess the plausibility and feasibility of this hypothesis with a view to evaluate the insect’s health impact in a larger study.

Methods

The study participants included male and female villagers aged 10 years and above in Gwanda district, Zimbabwe. Eligible participants who completed the household questionnaire were referred to the local clinic for skin prick tests and to measure lung function and allergic airway inflammation. Allergen sensitisation patterns were evaluated using 10 different inhalant allergen extracts including an in-house preparation of mopane worm. Lung function was measured with a Koko Legend spirometer, and fractional exhaled nitric oxide levels (FeNO) (NIOX VERO) were measured in participants with at least one abnormal spirometric parameter. Data was analysed using Stata version 13 software.

Results

Of the 46 eligible participants that completed the household questionnaire, 17 went to the clinic giving a response rate of 37%. The majority who completed the questionnaire were adults (91%) and the children (9%) were all female. The prevalence of sensitisation to Imbrasia belina was 50%, and the prevalence ranged from 22 to 72% for the other allergens including cockroach, mosquito and house dust mites. The data collection tools were safe and well tolerated by participants with no adverse events reported. Self-reported respiratory symptoms, abnormal lung function and elevated FeNO were recorded amongst participants sensitised to mopane worm.

Conclusion

Pre-defined feasibility criteria were met with the exception of a lower than expected response rate for clinic data collection in this pilot study. For the main study, modifying the sampling strategy and applying more consistent community engagement will improve the response rates.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00780-9.

Lung Health in Children in Sub-Saharan Africa: Addressing the Need for Cleaner Air

Air pollution is increasingly recognized as a global health emergency with its impacts being wide ranging, more so for low- and middle-income countries where both indoor and outdoor pollution levels are high. In Africa, more than 80% of children live in households which use unclean sources of energy. The effects of both indoor and outdoor pollution on lung health on children who are the most vulnerable to their effects range from acute lower respiratory tract infections to long-term chronic health effects. We reviewed the literature on the effects of air pollution in children in Sub-Saharan Africa from prenatal exposure, infancy and school-going children. Data from Sub-Saharan Africa on quantification of exposures both indoor and outdoor mainly utilizes modelling or self-reporting. Exposures to biomass not only increases the risk of acute respiratory tract infections in young children but also increases the risk of carriage of pathogenic bacteria in the upper respiratory tract. Although there is limited evidence of association between asthma and pollution in African children, airway hyper-responsiveness and lower lung function has been demonstrated in children with higher risk of exposure. Interventions at a policy level to both quantify the exposure levels at a population level are urgently needed to address the possible interventions to limit exposure and improve lung health in children in Sub-Saharan Africa.