dc.description.abstract | Microplastic pollution has become a global concern due to its widespread presence in various ecological environments, including less populated areas. Microplastics have been detected in organisms, including humans, as well as in drinking water and food. The high surface area-to-volume ratio of microplastics enables them to adsorb environmental pollutants. Upon ingestion by organisms, these pollutants can desorb within their bodies, potentially posing health risks. Moreover, these organisms may eventually be ingested by humans again, causing a threat to human health.
Although rivers have been identified as major sources of microplastics in the oceans, research on microplastics in freshwater systems in Taiwan remains limited. Therefore, this study aims to investigate microplastics in Shihmen Reservoir and its inflowing rivers from July 2022 to May 2023. Sampling was carried out monthly, resulting in a total of ten sampling events. Water samples were pretreated using the Fenton method and oil separation technique. Microplastic identification was facilitated using the Nile Red staining method, followed by polymer identification using μ-Raman spectroscopy. This study investigated the composition, abundance, and spatiotemporal distribution of microplastics within both the reservoir and the inflowing rivers. Regarding statistical analysis, we have examined the interrelation between the abundance of microplastics and the percentage of land use types within the watersheds of the four inflowing rivers. Furthermore, we have explored the potential connections between microplastic abundance and variables like seasonality and rainfall.
The results revealed that the average microplastic abundance in Shihmen Reservoir was 6.00±0.44 items/L, whereas in the inflowing rivers, it was 7.66±3.53 items/L. Fragmented microplastics constituted over 90% of all samples collected in both the reservoir and inflowing rivers. The predominant size ranges were 37–100 μm and 100–300 μm, accounting for over 40% each. Seven polymer types were identified, with PE, PP, and PS being the predominant ones. Statistical analysis demonstrated a significant positive correlation (p < .05) between microplastic abundance in the reservoir and inflowing rivers and rainfall. Furthermore, microplastic abundance was higher during the wet season compared to the dry season in both the reservoir and inflowing rivers. However, no significant correlation (p > .05) was observed between microplastic abundance and different types of anthropogenic activities. | en_US |