Controls on Plastic Debris Capture in Urban Stormwater Drains of London, Canada: A Study Within the Great Lakes Watershed
Abstract
Land-based sources are the greatest contributors of plastic pollution in aquatic environments. Prior to this investigation, there were no available studies concerning the number and types of plastic debris items between 1 mm and 5 mm captured in urban stormwater drains. The present study examined macroplastic (>5 mm) and large microplastic (1-5 mm) debris that accumulated in LittaTrapTM devices at six drain sites over four seasonal periods in London, Ontario, Canada. Macroplastics (MaPs) and microplastics (MPs) were found in all 36 samples, and the totals ranged from 5-158 MaPs and 18-359 MPs per trap. Out of the 118 different MaPs found, the most common were cigarette butts, wrappers, and expanded polystyrene. The predominant MPs were fragments, foams, and fibres. Summer samples contained the highest average amounts of plastic. The main controls on plastic debris accumulation in stormwater drains of the London core are increased pedestrian traffic, driving, and seasonal variability.