The impacts of climate change on eroding coastal historic landfills

Impacts of climate change – sea level rise, more frequent storms and coastal flooding will exacerbate coastal erosion, resulting in the erosion of coastal historic landfills. These historic landfills are particularly vulnerable to such erosion as they typically have no lining or leachate management, limited information of the proportion and/or types of waste mixtures they contain and inaccurate records of their location and waste volumes. There are over 1200 coastal historic landfills in England alone, and over 10,000 such sites are at risk of release both solid waste and soluble contaminants across Europe. The contaminated matrix and solid wastes make landfills a major sink and source of microplastics and heavy metal, posing a threat to the coastal and marine environment.

We investigated heavy metal and microplastic pollution on the beach and foreshore in three coastal historic eroding landfills, East Tilbury (n = 32 samples), Lynemouth (n = 33 samples), Northam Burrows Tilbury (n = 33 samples), UK. Samples were collected every 50 meters along the shoreline, with 100g of surface soil from the landfill edge, and 1kg of beach and intertidal sediment collected from each transect. The metal concertation was measured with handheld X-ray Fluorescence (XRF). Microplastics were density separated with a zinc chloride solution (1.5 g cm⁻³), after the samples were dried and digested with hydrogen peroxide. The extracted microplastics were recorded under stereomicroscope at 50× magnification with a digital camera, and characterized with Fourier-transformed infrared (ATR-FTIR) spectroscopy.

This study is one of the first few to investigate the impacts of eroding historic landfill. Our preliminary findings suggest that eroding landfill are releasing significant amounts of microplastics and heavy metal pollution. These findings will be crucial to assess the impacts of eroding landfills, identify solutions and raise public attention to this environmental problem.