For decades, the environmental cost of Nigeria’s oil and gas industry has been measured by oil spills that poison rivers and gas flares that light up the skies of the Niger Delta. Yet another pollutant, methane, largely invisible to the naked eye, is increasingly attracting the attention of scientists, regulators and public health experts.

Unlike crude oil, methane leaves no stain on water. Unlike gas flaring, it produces no towering flames. But scientists say it is among the most potent greenhouse gases, trapping far more heat than carbon dioxide over a 20-year period. Globally, reducing methane emissions has become one of the fastest ways to slow climate change.

For thousands of Nigerians living near oil wells, pipelines, compressor stations and gas processing facilities, however, the concern is more immediate.

Who is monitoring the air they breathe?

That question lies at the heart of an accountability gap that experts say has received far less attention than oil spills or gas flaring.

Although Nigeria has introduced stricter regulations requiring oil and gas operators to measure and report methane emissions, many host communities still lack continuous air-quality monitoring, long-term environmental health surveillance and public access to emissions data that could help them understand what they are exposed to.

Methane is released through leaking pipelines, ageing wellheads, storage facilities, compressor stations and other oil and gas infrastructure. Detecting these leaks often requires infrared cameras, specialised sensors or satellites because they cannot be seen with the naked eye.

To improve accountability, the Nigerian Upstream Petroleum Regulatory Commission (NUPRC) introduced Methane and Greenhouse Gas Emissions Guidelines in 2022 and strengthened them in 2026 by requiring upstream operators to adopt internationally recognised Measurement, Reporting and Verification (MRV) systems.

The Commission says the reforms are intended to improve emissions reporting, reduce waste and align Nigeria with international climate commitments.

However, field epidemiologist and PhD candidate in Health Services Research Studies at Old Dominion University, Virginia, Dr. Salam Samson Polycarp, says public discussions often oversimplify the issue.

“Every time gas flaring or a pipeline leak makes the news, people ask whether they should fear methane. My answer is that methane is both the wrong villain to fixate on and the right place to start,” he said.

According to him, methane itself is generally not highly toxic at the concentrations encountered outdoors.

“What should worry communities is what comes with it,” he explained.

Oil and gas leaks, he said, rarely consist of methane alone. They are frequently accompanied by hazardous pollutants such as benzene, toluene, xylene and hydrogen sulphide, chemicals known to affect human health, with some classified as carcinogens.

Methane also reacts with other pollutants under sunlight to form ground-level ozone, a recognised trigger of asthma while contributing significantly to climate change.

“The honest answer is that communities should worry about the mixture, not just the molecule,” Polycarp said.

The missing monitors

Across much of the Niger Delta, residents have long complained about emissions from nearby oil and gas facilities.

Yet, experts say there is little publicly available information showing how many host communities have continuous air-quality monitoring systems capable of measuring methane and associated pollutants.

Environmental scientists argue that without long-term monitoring, it is almost impossible to determine whether pollution levels are changing or whether industrial emissions are contributing to disease patterns.

Polycarp said the absence of continuous environmental monitoring remains one of Nigeria’s biggest scientific challenges.

“To establish a relationship between pollution and disease, you need to know what people actually breathed, at what concentration and for how long, then compare those exposures with health outcomes over several years,” he said.

“What we mostly have are isolated academic studies conducted over short periods. They are useful for identifying concerns but cannot replace continuous monitoring.”

He added that regulators should monitor not only methane but also benzene, hydrogen sulphide, sulphur dioxide, nitrogen oxides, ground-level ozone, fine particulate matter and heavy metals associated with industrial emissions.

Health questions remain unanswered

International studies have associated living near oil and gas facilities with higher rates of respiratory illnesses, asthma, cardiovascular diseases and adverse birth outcomes.

Polycarp cautioned that these studies demonstrate associations rather than direct proof that methane itself causes disease.

Nigeria’s evidence, he noted, remains limited.

Studies in parts of the Niger Delta have linked gas-flaring communities with higher rates of hypertension and documented eye and skin irritation, but data on cancers, birth defects and other chronic illnesses remain insufficient.

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“Nigeria needs robust, long-term epidemiological studies rather than isolated research projects if we are to understand the real health burden facing oil-producing communities,” he said.

He said his own research on vehicular emissions in Kano State found higher respiratory risks among households located close to major highways, demonstrating how environmental exposure studies can inform policy when supported by sustained monitoring.

Technology is improving accountability

Satellite technology is transforming methane detection worldwide.

Through the United Nations Environment Programme’s International Methane Emissions Observatory (IMEO) and its Methane Alert and Response System (MARS), governments and operators can now receive notifications when significant methane emissions are detected from space.

NUPRC says it is working with UNEP to improve methane monitoring and has already received satellite alerts identifying high-emission events requiring regulatory action.

But Polycarp said satellite technology alone cannot answer the questions communities are asking.

“Satellites can identify where emissions occur, but they cannot tell us who has been exposed, for how long or what illnesses may have resulted,” he said.

“That requires linking environmental monitoring with long-term public health surveillance.”

Industry and community perspectives

Oil and gas operators argue that reducing methane emissions has become both an environmental and economic priority because methane lost through leaks represents valuable natural gas that could otherwise be utilised.

Several companies have invested in leak detection systems, improved maintenance and gas recovery technologies while working with regulators to improve compliance.

Environmental advocates, however, say transparency must go beyond technical reporting.

Community leaders argue that residents are rarely informed when emissions are detected nearby or when regulatory investigations have been completed.

They want air-quality information made publicly available and communities included in environmental decision-making.

Polycarp believes stronger coordination among the NUPRC, NOSDRA, NESREA, the Federal Ministry of Environment and the Federal Ministry of Health and Social Welfare is essential.

Without an integrated environmental-health surveillance system, he said, the government cannot easily identify disease clusters, direct healthcare resources to affected communities or establish evidence capable of supporting regulatory enforcement.

The accountability gap

Nigeria has committed to reducing methane emissions through stronger regulation and international partnerships, including the Nigeria Methane Emissions Reduction Pilot Programme and broader climate commitments.

Experts say these initiatives could improve transparency, reduce greenhouse gas emissions and strengthen Nigeria’s position in global energy markets.

But for communities living beside oil and gas infrastructure, success will not be measured solely by international commitments.

It will be measured by whether the air around their homes is monitored, whether environmental data are publicly available, whether pollution-related illnesses are tracked and whether regulators and operators can demonstrate that communities are genuinely safer.

Polycarp believes achieving that goal requires independently verifying company-reported emissions with satellite and ground-based sensors, installing continuous air-quality monitoring stations across oil-producing communities, establishing a national environmental-health registry linking pollution exposure to health outcomes and funding long-term Nigerian epidemiological research.

“The gas we lose through leaks and flaring costs Nigeria twice,” he said.

“First, in lost economic value. Second, in the potential health burden borne by people living beside the infrastructure. Reducing methane emissions is therefore not only an environmental obligation but also an investment in public health.”

As Nigeria positions natural gas as a transition fuel for economic growth, experts say the country’s methane story should no longer be viewed only through the lens of climate change.

It is also a story of environmental justice, public health and accountability.

Until the gaps in monitoring, health surveillance and public transparency are closed, communities living above one of Africa’s largest gas reserves may continue to shoulder an environmental burden they cannot see, cannot measure and cannot independently verify.