Pedestrian traffic is the main driver of macro- and large microplastic debris deposition in urban stormwater drains
By Kozikowski N and Corcoran PL (2024), Department of Earth Sciences, The University of Western Ontario, London, ON, Canada
This study examines macroplastic (>5 mm) and large microplastic (1–5 mm) pollution in urban stormwater drains in London, Ontario, using LittaTrap™ devices equipped with standard 5 mm and finer 1 mm mesh liners. Over four seasons, six drains in areas with varying pedestrian activity were monitored to assess debris types, sources, and seasonal patterns. Results revealed that cigarette butts, food and beverage packaging, and expanded polystyrene were the most common macroplastics, while microplastics were dominated by polyethylene and polypropylene fragments, foams, and fibres. Pedestrian traffic was identified as the primary driver of plastic accumulation, with the highest levels observed in busy urban areas, particularly during spring and summer when outdoor activities and snowmelt increase debris mobility.
The study demonstrated the effectiveness of the 1 mm mesh in capturing up to 9.8 times more microplastics compared to the 5 mm mesh, without causing drainage issues. Seasonal weather factors like precipitation and wind speed had limited influence on debris patterns, highlighting the dominant role of human activity.
Findings emphasise the need for targeted public awareness campaigns, improved urban waste management, and enhanced stormwater filtration systems to mitigate plastic pollution. Future research is recommended to expand the study area, include water sampling at stormwater outlets, and monitor debris over longer periods to better understand the interplay of environmental and anthropogenic factors in plastic waste accumulation.
Read 'Pedestrian traffic is the main driver of macro- and large microplastic debris deposition in urban stormwater drains' HERE.
