Assessment of Microplastics Contamination in River Water, Bottled Water, Sachet Water and Branded Table Salt Samples in Kaduna Metropolis, Nigeria

Abstract

Microplastics (MPs) < 5 mm-sized are regarded as global environmental contaminants. This study analyzes MP concentrations in the Kaduna River (raw water), treated water from two conventional water treatment plants, brands of bottled water, and food-grade salts available in Kaduna Metropolis, Nigeria using standard methods. Data obtained show that levels of MPs ranged from 25 to 36 particles L-1 in treated water, and to 153 particles L-1 in raw water. While samples of bottled water contained 1.4 to 3.7 particles L-1 and samples of table salt contained 0.13 to 0.27 particles g-1. Water and salt samples contained five different types of polymers, including polyethylene, polypropylene, polyester, polyvinyl chloride and polyethylene terephthalate. Additionally, MPs were divided into three groups based on their physical characteristics. In both raw and treated water, fragments were clearly more prevalent; in samples of bottled water and table salt, fragments and fibers predominated. Microplastics in bottled water pose a medium pollution risk, according to pollution risk indices. The estimated daily intake was generally minimal, indicating little harm from daily consumption, but it also demonstrates that children have a larger intake of microplastics than adults. Leaching from the packing material was identified as the MPs' primary source. This study fills the knowledge gap in the area of emerging microplastic pollution of water sources, drinking water, and food-grade salt.