Baseline Assessment of Microplastic Pollution at Eleko Beach, Lagos, Nigeria: Implications for Citizen-Science-Based Coastal Monitoring National Ocean Microplastics Monitoring Initiative (NOMMI)

Plastic has become a permanent fixture of the modern world, but once it enters the ocean, it does not stay whole. Sunlight and waves break large items down into tiny fragments, eventually creating particles so small they are invisible to the naked eye. Scientists call these microplastics, defined as any piece of plastic smaller than five millimeters. These particles do not just float on the surface; they sink into the sand, drift through the water, and enter the food chain. The concern is not merely that they are there, but that they act as sponges for other harmful chemicals and can be eaten by marine life, potentially moving up to the humans who rely on the sea for food. For decades, researchers have mapped these pollutants in Europe and North America, but vast stretches of the African coastline have remained a mystery, leaving a huge gap in our understanding of how this crisis affects the world's most populous continent.

In May 2026, a group of researchers and community volunteers set out to fill that gap at Eleko Beach, a stretch of sand on the Lekki Peninsula in Lagos, Nigeria. This location sits at the edge of a rapidly growing city where millions of people live, work, and generate waste daily. The team, part of an initiative called the National Ocean Microplastics Monitoring Initiative, or NOMMI, wanted to see what was hiding in the sand and water of this specific beach. They were not just looking for trash; they were testing a new way to study pollution that relies on ordinary citizens rather than expensive, high-tech laboratories. Their goal was to prove that regular people, trained with simple tools, could collect data that is accurate enough to help scientists understand the scale of the problem.

The team arrived on a calm day and began collecting samples from two places: the top layer of the ocean water and the dry sand near the tide line. To ensure their results were trustworthy, they followed a strict set of rules designed to catch any mistakes before they happened. One of the most important steps involved a "field blank." Before collecting any real samples, a volunteer opened a clean jar and left it sitting in the air for fifteen minutes, just long enough to gather the same amount of dust and fibers that would settle during the actual sampling. This jar was then sealed and taken to the lab alongside the real samples. This step was crucial because the air in a busy city is full of tiny fibers from clothes and construction, and without this control, the researchers might have mistaken airborne dust for pollution coming from the ocean.

Once the samples reached the laboratory, the team processed them quickly, within two days, to prevent the plastic from breaking down further or being eaten by tiny organisms. They filtered the water and washed the sand with a salty solution to make the plastic float to the top, separating it from the heavy sand grains. Under a microscope, they counted every tiny piece they found. The results showed that microplastics were indeed present. In the water, they found a small number of particles, but when they subtracted the dust that had fallen into the open jar during the field blank, the true amount of pollution in the water was even lower, though still measurable. In the sand, the numbers were higher. After removing the background dust, the team calculated that there were twenty-six particles of plastic for every kilogram of dry sand.

The type of plastic found told a clear story about where it came from. The vast majority of the particles were tiny fibers, resembling threads from clothing. This dominance of fibers points directly to two likely sources: the washing of synthetic clothes, which releases thousands of fibers with every cycle, and the wind carrying these fibers from the city onto the beach. The researchers also found small pieces of foam and rigid plastic fragments, which likely came from food containers, fishing gear, and larger plastic items that had been left on the beach and broken down by the sun and waves. The presence of foam is particularly notable because expanded polystyrene, a common material for food packaging in the region, breaks apart very easily in the tropical sun.

These findings confirm that Eleko Beach is not free from plastic contamination, despite being a popular recreational spot. The levels of pollution found in the sand are comparable to, and in some cases higher than, levels reported in other busy coastal cities around the world. This suggests that the problem is not unique to this one beach but is part of a larger pattern driven by rapid urbanization and the lack of effective waste management systems. The study also proved that the method used was successful. By using a simple field blank and a strict timeline for processing, the team showed that citizen scientists can generate reliable data without needing a fully equipped university laboratory.

The report emphasizes that this was just the first step. Because the sampling happened on a single day, it cannot show how the pollution changes with the seasons or the tides. The researchers noted that the sample was taken at the start of the rainy season, a time when heavy rains might wash more waste from the city into the ocean, potentially making the numbers higher than they would be in the dry months. They also acknowledged that without advanced chemical testing, they could not be certain of the exact type of plastic for every single fiber, though the visual evidence was strong. Despite these limitations, the study provides a solid starting point. It proves that microplastics are present in the water and sand of Lagos and offers a working model for how to monitor them in the future.

The ultimate goal of this work is to expand the network of monitoring across the entire Nigerian coast. If more communities can be trained to collect this data, policymakers will have the evidence they need to make better decisions about waste management and environmental protection. The study concludes that the contamination observed is not an anomaly but a reflection of the daily reality of a megacity. By understanding exactly what is in the water and sand, and where it comes from, communities can begin to address the sources of the pollution, protecting both the marine life that depends on these waters and the people who rely on them for their livelihoods.