Background. The informal settlement of Owino Uhuru near an abandoned lead smelter attracted international attention due to an apparent lead poisoning event. Despite this attention, the environmental data collected to date do not indicate high levels of residual contamination. Objectives. To further confirm previous findings and determine any necessary risk mitigation measures, an assessment of surface soil lead concentrations was conducted in the community. Methods. Investigators carried out an assessment of the soil in a ~12,000 m2 section of the Owino Uhuru neighborhood over the course of a single day in June 2017 with the assistance of community leaders. Fifty-nine in situ soil measurements were taken using an Innov-X tube-based (40 kV) alpha X-ray fluorescence instrument (pXRF). Results. The assessment found that mean surface soil lead concentrations in areas conducive to exposure were 110 mg/kg (95% CI: 54–168); below United States Environmental Protection Agency and the Environment Canada screening levels of 400 mg/kg and 140 mg/kg, respectively. Conclusions. There is likely no current need for risk mitigation activities in the community. These results could inform discussions on the allocation of public health spending. Competing Interests. The authors declare no competing financial interests. BE, VOO, CN and JSF are employees of Pure Earth. MPT sits on the Editorial Board of the Journal of Health and Pollution.

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.

Background. Groundwater quality can be poor in Nigeria due to indiscriminate refuse dumping. Exposed dumps serve as point source pollution that discharge potentially toxic heavy metals into the environment. Objectives. The present research aimed to assess the impact of metal pollution on groundwater quality in hand-dug wells around an active dumpsite and to evaluate the long-term human health effects of this pollution. Methods. Water samples from hand-dug wells used for drinking, irrigation and domestic purposes were collected around the dumpsite. Two samples were collected at each location for cation and anion analyses. Samples for cation analysis were acidified with concentrated hydrochloric acid to preserve the elements in the samples, while those for anion analysis were not acidified. Collected samples were analyzed using inductively coupled plasma mass spectrometry and atomic absorption spectroscopy. Results. Mean concentrations of metals and physical parameters were compared with the World Health Organization's standards (2012). All samples were found to be within permissible limits, except for arsenic (As) (0.13 mg/L), potassium (K) (29.94 mg/L), lead (Pb) (0.38 mg/L), cadmium (Cd) (0.003 mg/L) and average temperature (31.93°C) as a result of corroded service pipes containing Pb in the dumpsites and the reaction of leachates with various materials such as used battery, tins, and electronic wastes which later leaked into the groundwater. The geoaccumulation index revealed Pb to be moderately to highly contaminated in groundwater. Conclusions. Heavy metal pollution can cause deleterious health effects that can lead to short- and long-term diseases such as keratosis (skin hardening), lung cancer, bladder cancer and ultimately death if proactive steps are not taken. Disposal bags should be provided to all houses in the area, as well as guaranteed waste disposal trucks and dispose of waste at approved sites. In addition, enforcement agents should ensure compliance with rules and regulations. A centralized, deep, double-cased well should be constructed in a clean environment in the study area for drinking and domestic use. Competing Interests. The authors declare no competing financial interests.

Background. Soil contamination resulting from the use and handling of petrochemicals and other petroleum products during power generation activities is an increasing global concern due to its adverse impact on the ecosystem. Objectives. The present study was carried out to determine the concentrations and speciation of potentially toxic metals in oil-contaminated soils around transformer installation areas in Ile-Ife, Nigeria, and to confirm soil pollution levels with hazard quotient and hazard index analysis. Methods. Soils from the transformer oil-contaminated and uncontaminated (control) areas were collected at 0–15 cm and 15–30 cm depths and analyzed for heavy metal concentrations using atomic absorption spectrometry. The metals were fractionated and their hazard evaluated to confirm the pollution level of the contaminated soils. Results. The concentrations of cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn) in the two sets of oil-impacted soils were higher than in the control soils. The metals also had relatively moderate bioavailability and mobility potential with more of the proportion retained in the residual fraction. Chronic daily intake (CDI) of the metals increased in the order of: Cd < Cr < Pb < Ni < Mn < Cu < Zn < Fe, while chronic daily intake risk exposure pathway followed the order of: CDIinhalation < CDIdermal < CDIingestion. Conclusions. The study concluded that the concentrations of the metals were within permissible limits, but the chronic daily dosage was significant and may pose a health hazard to humans with long term exposure to these heavy metal contaminants. Competing Interests. The authors declare no competing financial interests.

Background. The use of solid fuels in household cooking contributes to indoor air pollution and is the cause of more than 4 million deaths around the world annually. Solid fuel use varies with the level of development and ranges from 0% in high-income countries to more than 80% in low- and middle-income countries. Three billion people (more than 40% of the global population) are still dependent on solid fuels like firewood, dung cakes, coal, wood and agricultural residues in these countries. Objectives. The present study aims to analyze the association of certain respiratory diseases (tuberculosis (TB), acute upper respiratory infections (AURI), chronic obstructive pulmonary diseases (COPD), and bronchial asthma) with the use of solid fuels for cooking across sociodemographic groups in India. Methods. The 71st round of the National Sample Survey, conducted in 2014, was used. In total, 54,985 inpatients who received medical treatment from any medical institution during the last 365 days preceding the survey and who reported various diseases, such as infections, cancers, blood diseases, cardiovascular diseases, and respiratory diseases were included in the analysis. Of these inpatients, 2513 participants who reported TB, AURI, COPD and bronchial asthma were considered the dependent variables in the study. The main variable was exposure to different types of fuels used as a primary source of energy for cooking. Multinomial logistic regression was used to explain associations. Results. The results reveal a significant association between solid fuel use and respiratory diseases in India. Overall, more than 60% of the population uses firewood and cow dung as their primary source of energy for cooking and are at a higher risk of TB, COPD and bronchial asthma. In rural areas there is a high dependence on solid fuels (80.5%) and a higher risk of respiratory diseases compared to those residing in urban areas where people are less dependent on solid fuels (22%). Among different socio-demographic groups, the dependence on solid fuels is highest among Scheduled Tribes (87.42%), followed by Scheduled Castes (74.78%) and Other Backward Classes (OBCs) (a term used by the Indian government to categorize castes that face social or educational challenges) (64.47%). Scheduled Tribes have the highest risk of TB, followed by Scheduled Castes and OBCs, respectively. Conclusions. Exposure to solid fuels for cooking increases the potential risk of TB, COPD and bronchial asthma. Access to clean and efficient fuels for cooking is essential to reduce the burden of respiratory disease. Measures are needed to increase the availability of clean fuels for households, especially among socially disadvantaged and marginalized groups, to reduce the burden of respiratory diseases in India. Competing Interests. The authors declare no competing financial interests

Background. Port Harcourt is an oil-rich city in Nigeria's Niger delta region. For over two years, Port Harcourt experienced black soot deposition in the environment. In November 2016, residents woke up to black soot covering cars, clothes, houses, plants, etc. Soot concentrations continued to increase until the first quarter of 2017. After public outcry, the frequency and concentration of soot deposition began to decline. Objective. The present study was carried out to determine the presence and levels of heavy metals in soot along with a cancer risk assessment of heavy metals exposure in Port Harcourt, Nigeria. Method. Three residential locations were sampled: Aba road, Woji and Iwofe. Sampling was performed from 6:00 am to 6:00 pm, to simulate the estimated duration that most residents who do not work in offices are exposed to soot in places such as the open market and business areas. Five heavy metals (iron (Fe), nickel (Ni), chromium (Cr), cadmium (Cd) and lead (Pb)) were investigated. The data obtained were subjected to Pearson correlation and one-way analysis of variance using SPSS software to test the correlation and significant differences between metals concentrations. Results. Lead was found to have a significant correlation with Cd (0.808), indicating that both metals originated from the same source. Concentrations of heavy metals were higher than control values and the World Health Organization's specifications for ambient air. Chromium concentrations were the lowest. The order of concentration of heavy metals was Fe > Pb > Cd > Ni > Cr. Conclusions. Non-carcinogenic and carcinogenic health risks of these heavy metals were evaluated using the target hazard quotient (THQ) and the incremental lifetime cancer risk (ILCR). Obtained ILCR values were within the acceptable limits for cancer risks. However, the total ILCR values for Cd and Pb for children were 3 times higher than those for adults. This is a source of concern as their prevalence in ambient air puts children and residents in Port Harcourt metropolis at risk of various types of cancers. Competing Interests. The authors declare no competing financial interests.

Background. The generation and management of solid waste pose potential adverse impacts on human health and the environment. Objective. The present study examines the operational performance of municipal solid waste (MSW) disposal in the Wa Municipality, Ghana. Methods. The study applied both qualitative and quantitative research methods and modelled the Wa Municipality's MSW disposal system using the municipal solid waste decision support tool (MSW DST). Acid gases (sulphur oxides and nitrogen oxides) and total particulate matter that have a direct impact on human health were set as the objective functions for modelling five MSW disposal scenarios. The modelled scenarios were: 1) landfill disposal only; 2) composting and landfill disposal; 3) composting, incineration, refuse derived fuels (RDF) and landfill disposal; 4) separation, composting, incineration, RDF and landfill disposal; and 5) separation, transfer, material recovery, composting, incineration, RDF and landfill disposal. The pollutants chosen as indicators for substance flow analysis included lead, cadmium, arsenic, mercury, copper, chromium, and zinc. Results. Scenarios 4 and 5 produced the least engineering cost of 1 150 000 US $/year for the entire MSW disposal system, whereas scenario 2 produced the highest cost of 1 340 000 US $/year. Scenario 5 produced the least average health impacts of −5.812E-04 lbs/year, while scenario 2 generated the highest engineering cost and produced the highest average health impact of 9.358E-05 lbs/year. Scenarios 5 and 4, which included waste-to-energy conversion in the systems, produced the lowest average health impacts (−5.812E-04 lbs/year and −5.611E-04 lbs/year, respectively). Conclusions. The adoption of an integrated solid waste management concept, including waste-to-energy technologies, will not only help to lessen MSW disposal hazards, but also to produce alternative sources of energy for Ghana and other developing countries. Competing Interests. The authors declare no competing financial interests

Background. Ologe Lagoon is an important water body that receives effluents from neighboring industries. These effluents may increase the levels of anthropogenic contaminants in the lagoon, thereby creating stressors for aquatic organisms. Objectives. To assess the occurrence of polycyclic aromatic hydrocarbons (PAHs) in Ologe Lagoon, along with the histopathological, biochemical and genotoxic effects of the most prevalent PAH compound. Methods. An initial field study was performed to determine the concentrations of PAHs in Ologe Lagoon, followed by a chronic toxicity test to assess the effects of the most prevalent PAH compound in a fish model (Clarias gariepinus). Results. High molecular weight PAHs were more predominant than low molecular weight PAHs in the lagoon, with B[b]F being the most predominant. The formation of micronuclei and binuclei was induced by a 10-fold increase over the present environmental concentration of B[b]F in Ologe Lagoon. Histopathological studies showed that epithelial necrosis, fused lamellae, shortened lamellae, and desquamation were the major histological anomalies induced by ERCs of B[b]F. Results from the biochemical assay indicated that ERCs of B[b] F increased aspartate aminotransferase and alanine transaminase levels in fish. Glutathione-S-transferase, superoxide dismutase and catalase were inhibited in the exposed fish, whereas malondialdehyde was significantly increased. Conclusions. Concentrations of fluoranthene, pyrene, benzo[a]anthracene, and benzo[a] pyrene in the surface water of Ologe Lagoon were above the Canadian Council of Ministers of the Environment's (CCME) safe limits, suggesting that the water may not be safe for domestic uses, and the present concentration of B[b]F in Ologe Lagoon may be chronically toxic to aquatic organisms, in terms of oxidative stress and hepatotoxicity. Competing Interests. The authors declare no competing financial interests.