Microplastic pollution in interdune lagoons of two brazilian national parks

Abstract

Microplastics (MP) are particles ranging in size from 1 μm to 5 mm. They are currently considered ubiquitous, as they have been found in a wide variety of environmental compartments. Intermittent interdune lagoons are an intrinsic part of the landscape of northeastern Brazil, constantly attracting visitors who may contribute to MP pollution. Thus, this study seeks to assess and understand the extent of MP pollution in intermittent coastal lagoons in coastal preservation areas that are areas of tourist interest. Therefore, surface water samples were collected in 1L aluminum bottles from 16 visited and unvisited lagoons in the Jericoacoara National Park (JNP) and Lençois Maranhenses National Park (LMNP), which have essential links to tourism. A total of 1,558 MPs were identified, with an average density of 24.34 ± 21.97 MPs L−1. JNP had a higher average density of 31.59 ± 24.46 MPs L−1, while LMNP had an average density of 17.1 ± 16.55 MPs L−1. In terms of shape, fragments and fibers were the most abundant, accounting for 58.2% and 34.5% of the total, respectively. Among colors, blue was the most abundant at 53.9%, followed by red at 21.3%. Finally, there was no significant variation in the size of microplastics, with most being less than 1 mm in size. There was no significant difference between the density and composition of PMs between visited and unvisited lagoons. However, there was a significant difference between parks. This result indicates that visitation is not directly the most important factor for the contamination of these lake environments. Thus, other factors such as winds, geomorphological factors, and proximity to urban centers may have a greater influence on the distribution of PM in lagoons. Further studies are needed to understand the relationships between human activities and environmental factors that contribute to MP pollution in coastal preservation areas.