Occurrence, identification and characterization of plastic pollution from an open solid waste dumpsite in Calabar, Southern Nigeria

Abstract

Landfills and dumpsites are the final point of solid waste deposition and management in developing countries due to lack of recycling methods. Herein, we have investigated the occurrence, polymer composition and characterization of plastic pollution at the Lemna solid waste dumpsite, Calabar Nigeria. A total of 21 plastics were sampled and categorized into 10 representative plastic types for effective identification and characterization. The plastic categories were PET bottles, LDPE, PP, HDPE, PS tray, PVC fiber and PVC others. PET bottles were the most abundant (28.5%), followed by PP > LDPE > HDPE, while PS trays, PVC fiber and PVC others were the least prevalent plastics at the dumpsite. FT-IR analysis showed that only 5 different plastics polymers (PP, PET, PE, PVC, and PS) were identified and characterized, out of the 10 plastics categories collected. However, PP and PET were the most abundant plastic polymers at the dumpsite consisting of 33.3- and 28.6%, respectively, and reflecting their widespread application in domestic and household packaging products. PS was the least abundant plastic (4.8%) polymer. We used the density gradient separation techniques and recovered only three (3) plastic polymer types from soil at the dumpsite, namely - PET, PS, and PP with sizes >5mm in diameter and indicating macroplastics. Given that plastics are vectors of contaminants of legacy and emerging concern, their continuous deposition at dumpsites represent a significant environmental, human and wildlife health issue of concern.