Health effects associated with emissions from household generators used for backup power in Africa: a scoping review

Abstract

Background

In many low- and middle-income countries, unreliable electricity supply has led to widespread reliance on petrol (gasoline) and diesel generators. The type of fuel influences both the quantity and composition of emissions, which contribute substantially to air pollution and pose significant health risks. Emissions from household generators, similar to diesel exhaust, contain volatile organic compounds and particulate matter linked to adverse outcomes, including cancer. This review synthesizes evidence on health impacts associated with domestic generator emissions in Africa and proposes mitigation recommendations.

Methods

We searched PubMed and Google Scholar for English-language studies using combinations of terms related to backup generators, emissions, air pollution, human health, and households. Studies were included if they explicitly examined household generator use as the exposure of interest in relation to health outcomes.

Results

Nine articles met the inclusion criteria. Generator emissions were found to contain harmful pollutants such as nitrogen oxides (NO_x), sulphur dioxide (SO₂), and fine particulate matter (PM₂.₅ and PM₁₀), all associated with well-established health risks. Exposure was linked to respiratory and cardiovascular diseases and increased mortality. However, epidemiological evidence was limited, with only 2% of screened studies addressing health outcomes directly. Overall, the included studies indicated high levels of pollution associated with generator use and suggest potential public health impacts, though measurement of exposures and outcomes remains insufficiently developed.

Conclusion

Evidence on the health effects of generator emissions in Africa is limited and methodologically inconsistent. While some studies indicate associations with respiratory symptoms, carbon monoxide poisoning, and possible long-term risks such as cancer and hypertension, these findings largely rely on indirect evidence, self-reports, or modelling approaches rather than robust epidemiological data. No studies established a direct causal relationship between generator-related air pollution and health outcomes. Strengthening the evidence base through well-designed epidemiological studies is essential to better understand and quantify the health burden associated with household generator use.

Introduction

Many low- and middle-income countries (LMICs) face unreliable and insufficient public electricity supply, forcing many end users of electricity, from households to commercial and industrial enterprises to provide their own power [1]. Backup generators are a major source of electricity access in many developing regions, providing as much as 40% of the electricity consumed in West Africa, 9% in Sub-Saharan Africa, and 2% in South Asia [2]. These generators can be a significant source of air pollution and poor air quality that often exceeds national and World Health Organization (WHO) guidelines is a major cause of premature deaths in LMICs, aside from other environmental issues [3]. Household backup generators are predominantly fuelled by petrol (gasoline) or diesel and fuel type is an important determinant of the quantity and composition of the pollutants emitted [4].

In Africa, seventeen countries such as Nigeria, Ghana and Kenya, have greater installed backup generator capacity than grid capacity [5]. Countries in West Africa have particularly high reliance on fossil fuel backup generators despite the health and economic burdens that accompany these energy sources [2]. In Nigeria, Africa's most populous nation, generators are ubiquitous and a way of life in households [6] due to the poorly performing electrical grid. The central electricity grid only meets at most 30% of consumer power usage, and most homes have access to grid electricity for only 6 h daily [7]. It has been reported that there are between 22 and 60 million small (domestic use) backup generators in Nigeria, reflecting widespread reliance on decentralized power in a large population [8]. Ghana has also been heavily reliant on alternative energy sources such as diesel generators, candles and kerosene lamps during power outages [9].

In contrast, South Africa and Angola, despite having smaller absolute numbers of generators, are among the LMICs with the largest generator fleets within southern Africa [2]. In Angola, the diesel price is so low that use of traditional diesel generators still dominates and is not easy to replace with photovoltaic solutions [10]. In South Africa, the national power utility, has implemented planned outages for many years now due to insufficient generation capacity [11]. Known colloquially as loadshedding, rolling blackouts have been in effect since 2007 but with substantial increased frequency since 2022 [12]. The worsening energy crisis over the years reached unprecedented levels when loadshedding was declared a national state of disaster in February 2023 [13]. Loadshedding has necessitated that households find alternative energy sources to have uninterrupted and reliable power supply. Using small, mobile generators is one form of backup power supply,other options to generate power include solar systems and inverters with batteries, but they are more expensive on the front-end than generators for the same capacity.

Past evidence suggests that, in 2019, South Africa had approximately 2.1 generators per 100 people, equivalent to about 1.25 million generator users. In the same year, diesel-powered generators contributed roughly 1% of the country’s total electricity supply [14]. Moreover, the diesel generator market is expected to grow by a compound annual growth rate of 2% between 2020–2025 (Mordor [15]. According to a consumer survey on the low- and middle-income market, middle-income South Africans would rather buy a generator than a car [16]. Between 40—50% of study respondents regardless of age or income level wanted to purchase backup power sources in the future [16].

Fuels used to power generators include petrol or diesel and during the combustion process, both petrol- and diesel-powered generators emit air pollutants including nitrogen oxides (NO_x), hydrocarbons and other organic compounds (also known as volatile organic compounds or VOCs), carbon monoxide (CO) and particulate matter (PM₁₀ and PM_2.5) [4]. Sulphur dioxide (SO₂) also appears in the exhaust emissions of generators and the concentration is directly related to the sulphur content of the fuel [4]. However, the relative amounts of these pollutants varies depending on the fuel type and engine efficiency [17]. A comparison between petrol and diesel generators shows that petrol-powered generators emit higher levels of CO [18], VOCs [19] and carbon dioxide (CO₂) [20] while diesel generators emit higher levels of NO_x [21] and particulate matter [18, 22]. In addition to differences in emissions, the two generator types differ in their operational characteristics. Small petrol generators are better suited for home use as they are more portable and quieter while diesel generators are heavier to move around, have higher initial purchase costs but are more fuel-efficient and durable in the long run when properly maintained [20].

A 2018 study conducted by the World Bank for the city of Lagos revealed that generators were the third largest contributor to air pollution, after road transport and industrial emissions [23]. The health cost of air pollution calculated in this study was estimated at 11 200 premature deaths annually, with children under five years of age being the most affected. The report also highlighted that the cost of mortality and morbidity due to air pollution amounted to $2.1 billion in losses within a single year [23]. Generator emissions at the household level are especially a cause for concern given that they are released in close proximity to people and at a height that is within their breathing zone, thus representing an increased health risk to humans and the environment [24].

To the best of our knowledge, no review of literature has been conducted that examines all probable health impacts of backup generator emissions in Africa. In this context, this review presents a synthesis of the research and provides evidence of the impact of emissions from generators at the household level on human health. Additionally, further scientific research, policies and practices needed to mitigate the health risks associated with exposure to emissions from generators are discussed.

Methods

The analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for scoping review (PRISMA-Scr) [25]. In line with scoping review guidelines, methodological quality and risk of bias of the studies were not assessed [26, 27]. The data were extracted from published manuscripts thus no research ethics board approval was necessary.

Inclusion/exclusion criteria

The research question used for the review was “What are the health effects of household generators’ emissions on air quality and health in Africa?” Starting from the research question, the inclusion/exclusion criteria were defined.

Studies were included if they met the following criteria:

• Health studies (toxicological, clinical, epidemiological or risk assessment) linking exposure to specific pollutants released from generators with health outcomes.

• Air quality assessments with integration into broader health studies.

• Qualitative and mixed methods studies that explored the public’s perception of generator exposure and associated health risks, serving as self-reported health data

• Conducted in varying locations, populations and health outcomes in Africa.

• Written in English and published from 2000 to 2025.

• Open access articles for which full text is available.

Studies were excluded based on the following criteria:

• Focused on generators used in the agricultural, industrial or business sectors only.

• Conducted in countries outside of Africa.

• Did not assess health effects (i.e. were solely evaluating air quality or emissions)

Databases and search strategy

The searches were conducted using PubMed and Google Scholar up until 31 December 2025, focusing on literature published in the past 20 years (2005–2025). PubMed was selected for its comprehensive evaluation of peer-reviewed biomedical and life science research, while Google Scholar was used to capture a wider range of sources, such as Grey Literature. The integration of both databases supported a more comprehensive review, enhancing both the precision and quality of the data collected.

The search strategy involved a combination of terms containing "backup generators" AND "emissions" AND “air pollution” AND "health" AND “household” AND ("developing" OR “low- and middle-income” OR “Africa”). The terms listed in the search strategy were searched for in the title, abstract and topic fields (for the databases that allow such delimiters). A wide range of studies were used for this scoping review including cross-sectional, case–control, observational, and mixed-methods studies, as well as case reports, autopsy studies, environmental monitoring studies and health risk assessments. This inclusive approach was used in order to comprehensively cover the available evidence given that there were limited epidemiological studies on the effects of generator emissions on health in Africa. The reference lists of included articles were searched for additional records to ensure no studies were omitted. Following the search strategy, scholarly articles retrieved from the selected databases were supplemented with relevant grey literature such as reports (i.e., government, consultancies, community-based), and newspaper articles to provide more context where relevant. We screened the articles to include only research published that explicitly mentioned both air pollutant exposure and health outcomes.

Results and discussion

Selection of studies

Following the PRISMA-guidelines, a total of 707 papers were identified. Out of these, nine articles were retrieved and included in the review since they met the eligibility criteria. The other 698 papers were excluded and major reasons for the exclusion were that the research related to energy rather than to health, the studies were air quality assessments only or they were not conducted in Africa. The results of the search, the article selection log, and the number of articles is reported in Fig. 1 and a summary of the nine articles included in this review is reported in Table 1. Furthermore, Table 2 summarises the acute and chronic health outcomes studied in each article.

Fig. 1.

PRISMA-ScR flow diagram for the study selection process

Table 1.

Summary of research articles on backup generator emissions, exposure and health effects

	Author and Year	Study population	Fuel type	Study focus	Study design	Exposure measures	Health outcome measures	Key findings
1	Afolayan et al. [28]	Nigeria	Petrol (gasoline)	Assessing cases reported on casualties following inhalation of carbon monoxide in fumes produced from generators	Case reports	Inhalation of CO from generators	Hospital admission cases Patient 1: 17-year-old female, breathlessness, restlessness and unconsciousness, convulsion, sphincteric incontinence, foaming in the mouth Patient 2: 78-year-old man, unconsciousness, breathlessness, death	Death in the case of the one patient was probably due to advanced age and delayed presentation at the hospital
2	Awofeso [7]	Nigeria	Diesel	To investigate adverse health and environmental effects of electricity generator use in Nigeria	Secondary data taken from other studies	Generator diesel exhaust	Lung cancer Asthma	Found association between incidences of asthma and diesel generator use in homes. Rise in asthma prevalence from 2003 to 2006 Rising incidence of lung cancer among urban-based nonsmokers less than 60 years old, most of whom use diesel generators daily
3	Ibhadode et al. [29]	Port Harcourt, Uyo & Calabar metropolitan cities in Nigeria	Unspecified	To investigate human experiences and perceptions of fossil fuel generators	Questionnaires administered to generator users and their neighbours; purposive sampling	Field surveys using questionnaires administered to users of generators and their neighbours	Health hazards; environmental hazards; psychosocial hazards	Health effects were largely sleep disruption, hearing loss and cognitive decline and ophthalmic problems Noise levels often exceeded the WHO acceptable levels of 70 dB(A) for normal discussions and 30 dB(A) for sleeping and resting and stood at 93 dB
4	Mbamali et al. [30]	Lagos and Kaduna, Nigeria	Diesel and petrol (gasoline)	To assess the perceived environmental, health and social hazards of fossil fuel generators	Questionnaire survey administered to generator users and their neighbours; purposive sampling	Non-specific air pollutant exposure (i.e. generator exposure)	Health hazards (also environmental and social hazards)	Hearing loss, sleeplessness, choking sensation, deafness, vertigo and impaired visibility were most prevalent (in descending order)
5	Oguntoke and Adeyemi [31]	Abeokuta city, Ogun state, Nigeria; urban environment; Generator operators and nearby residents exposed to emissions from electricity generators	Diesel and petrol (gasoline)	To evaluate the impact of emissions from diesel-powered generators on air quality and human health	Cross-sectional, observational study	Exposure level measured by portable samplers in proximity to diesel generators. Measured PM1, PM3, CO, CO2, SO2, NO, NO2, H2S, CH4	Outcomes identified by self-reported questionnaire Short-term effects: nasal congestion, cough, headache, fever	Pollutant concentrations were highest at generator sites Most reported health symptoms included nasal congestion (66%), cough (33%), headache (24%) and fever (12%)
6	Saka [32]	Kwara State, Nigeria Households and business owners	Not reported	To assess the impact of generator fumes on health hazards, environmental damage, and social hazards using households and business owners as the key units of analysis	Mixed methods to collect both empirical and descriptive data	Exposure to hazards	Outcomes identified by self-reported questionnaire Health symptoms impaired visibility, deafness, sleeplessness, choking sensation, dizziness noise pollution	Affected users reacted heterogeneously to the effects of fossil-fuels-electric-generator which releases generator fumes from its exhaust pipe
7	Seleye-Fubara et al. [33]	Port Harcourt metropolis, Rivers State, Nigeria	Not reported	To study and characterize deaths resulting from CO poisoning	Autopsy study of 75 cases	CO poisoning	Death	64% of the deaths were accidental carbon monoxide poisoning from petrol generators which were ignorantly placed in the sitting rooms and/or confined spaces for safety especially at night and rainy days
8	Sibanda and Makaza [34]	Zimbabwe	Diesel	Investigating case of a patient who presented to an A&E facility with asthma-like symptoms, where asthma and rhinitis were diagnosed and treatment commenced	Case report	Office located in proximity to a diesel-powered electricity generator	Asthma and rhinitis Asthma Control Test (ACT™) questionnaire, skin prick testing, lung function testing, laboratory tests	Recent onset of asthma in adult with no history of either atopy or sensitization to inhaled allergen sources triggered investigation into occupational hazards including exposure to generator exhaust smoke
9	Ugbede et al. [35]	Three suburban communities in Nigeria: Abule-Egba; Iyana Ipaja and Ugwogou	Unspecified	To explore existing studies on the relationship between the use of household generators and respiratory health	Mixed-methods cross-sectional design n = 420 survey participants	Generator fumes	Spirometry tests to assess lung function; qualitative interviews and focus group discussions	High exposure significantly associated with increased prevalence of chronic respiratory symptoms (chronic cough, shortness of breath and wheezing). Abnormal spirometry results indicating abnormal lung function

Table 2.

Summary of acute and chronic health effects identified in each of the included studies

	Article Reference	Health effects
1	Afolayan et al. [28]	Premature mortality (CO poisoning) Hospital admission (CO poisoning)
2	Awofeso [7]	Asthma Lung cancer
3	Ibhadode et al. [29]	Sleep disruption, hearing loss, difficulty in mental concentration and ophthalmic problems
4	Mbamali et al. [30]	Hearing loss, sleeplessness, choking sensation, deafness, vertigo and impaired visibility
5	Oguntoke and Adeyemi [31]	Nasal congestion, cough, headache, fever
6	Saka [32]	Impaired visibility, deafness, sleeplessness, choking sensation, dizziness
7	Seleye-Fubara et al. [33]	Premature mortality (CO poisoning)
8	Sibanda and Makaza [34]	Asthma onset and rhinitis
9	Ugbede et al. [35]	Chronic respiratory symptoms – chronic cough, shortness of breath, wheezing Abnormal lung function

Summary of article characteristics

We found nine studies conducted in Africa that quantified the health impacts of generator emissions in terms of morbidity, mortality or quality of life. Epidemiological studies linking exposure to air pollutants from generators with health outcomes may be difficult and costly to conduct in Africa. Among the nine studies that considered air quality and health, none described a specific association between exposure to generator-related pollutants and measured health outcomes. A broader limitation observed across several studies, including studies from Nigeria and other countries, was the lack of direct emissions or exposure data related to backup generators and their impacts on community health and air quality [2]. In addition, several studies relied on self-reported information as their source of health and generator exposure data, which may limit the strength of the evidence.

Results of the review

The health effects associated with fossil fuel-burning generators are both acute (short- term) and chronic (long-term). Specific health risks and their severity depend upon the concentrations of pollutants that individuals are exposed to, as well as the duration of the exposure.

Respiratory problems

From the literature reviewed, respiratory diseases were the most prevalent [31]. Asthma symptoms include wheezing, shortness of breath, chest tightness and coughing and exposure to generator emissions can exacerbate existing respiratory issues [34]. In an occupational setting, exposure to emissions emanating from a diesel-powered electricity generator resulted in an office worker experiencing asthma symptoms and rhinitis although there was no history of atopy or allergen-specific sensitization [34].

Mortality

Approximately 1 500 deaths per year were reported from inhaling generator smoke and carbon monoxide in Nigeria [29]. Carbon monoxide (CO) emissions from portable generators are caused by the incomplete combustion of the fuel. Petrol generators produce more CO compared to diesel generators [33] so majority of the casualties from CO poisoning occur with petrol generators which is common especially in developing countries because of the lower cost of petrol compared to diesel [28]. Lack of knowledge and awareness of CO poisoning also contributes to people often locating their generators located in poorly ventilated spaces including sitting rooms, kitchens, hallways and other enclosed places for safety especially at night. This has resulted in CO intoxications and increased hospital admissions, particularly in Port Harcourt, Nigeria, where accidental deaths from inhalation of generator fumes containing CO accounted for majority (64%) of cases of CO poisoning deaths highlighting the need for increased public awareness of the health risks associated with exposure to generator emissions [33].

Cancer risks

Long-term exposure to generator emissions has been linked to an increased risk of cancer. The rising incidence of lung cancer among urban-based non-smoking adults younger than 60 years old, most of whom were generator users, provides indirect evidence of the possible effects of long-term and chronic exposure to diesel generator exhaust. [7].

Noise-related health effects

Noise pollution from generators is considered a health hazard due to the high-stress factor and extreme noise exposure linked to its usage, which negatively affects quality of life and other facets of wellbeing. In Nigeria, generator noise pollution was reported by almost 50% of participants in one study [29].

Perceptions of generator-related health risks

Several studies [7, 28, 30–35] investigated generator users’ perceptions on the hazards through survey questionnaires. The most common health hazards reported were sleep disturbance, hearing loss, choking sensation and ophthalmic (eye) problems. Other symptoms frequently experienced by residents included nasal congestion, cough, headaches and fever which can often be mistaken for the flu.

Strengths and limitations

The literature search was conducted using only two databases which may limit the scoping review. PubMed provides a high coverage database on biomedical and life science research while Google Scholar was used to capture Grey Literature relevant for the study. Together, these databases provide broad coverage however, using only two sources increases the risk of selection bias and may result in an incomplete mapping of the available literature. In addition, the review did not assess the methodological quality of the included studies which could lead to an overemphasis on conclusions drawn from weaker studies. The reason for this is the study designs and measured outcomes varied, so we decided assessing the quality of the peer-reviewed studies would not add value to our review.

Conclusions

Current evidence on the health impacts of generator emissions in Africa remains limited, heterogeneous, and insufficient to establish causal relationships. Although existing studies suggest associations with respiratory symptoms, carbon monoxide poisoning, and potential long-term health outcomes, the evidence is largely based on indirect measures, self-reported exposures, or modelling rather than rigorous epidemiological investigations. High-quality, well-designed epidemiological studies with robust exposure assessment are urgently needed to quantify the health burden of household generator use, strengthen the evidence base, and inform effective public health interventions and energy policies.

Authors’ contributions

All authors contributed to the study conception and design. Data collection was conducted by T.L., analysis was performed by T.L. and C.W. The first draft of the manuscript was written by T.L. and all authors commented on subsequent versions of the manuscript. All authors read and approved the final manuscript.

Funding

This work was supported by the National Research Foundation of South Africa [grant number CSUR230524109441] and the South African Medical Research Council.

National Research Foundation,CSUR230524109441

Data availability

The authors declare that the data supporting the findings of this study are available within the paper and its Supplementary Information files. Should any raw data files be needed in another format they are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests to disclose.