Microplastics (MPs) have become pollutants of concern due to their unknown human health effect and negative impact on terrestrial and aquatic ecosystems. There is increasing number of experimental research on MPs globally with its effects not fully understood; recent animal studies explore its effects on the intestines, yet on other vital organs. Javanese medaka fish was exposed to polystyrene microplastics (PS-MPs) beads for a period of 21 days. Histological alterations, intestinal oxidative stress, permeability and neurotoxicity were evaluated. Significant inflammatory changes and tissue damage were observed in the intestine, liver and kidney. Intestinal oxidative stress and permeability were found to be significantly increased. In the brain, neurotoxicity characterised by a significant induction of oxidative stress, lipid peroxidation and the inhibition of acetylcholinesterase enzyme were elucidated. This study provided an insight into the multiple organ effect of microplastics exposure, necessitating further exploration and identification of biomarkers to be utilised for biomonitoring population at risk in the future.
The first report on the emergence of microplastic in Malaysian marine waters was documented in this study. Water samples were collected from two regions, namely Kuala Nerus and Kuantan port, as the representatives of different anthropogenic activities. Identification of microplastic was performed based on physical characteristics (colour, shape, density) and chemical characterisation (ATR-FTIR analysis) for a functional group of polymers. Fragment type, black or grey colour and high density (>1.02 g cm-3) of microplastic were the most prevalent characteristics found in both areas. Two principal components (density and colour) rendered explained about 95.3% (Kuantan) and 95.6% (Kuala Nerus) of the total variance. Six possible polymer materials were identified, namely polyester, polystyrene, polyamide, polyvinyl chloride, polypropylene, and polyethylene. The findings of the study provided good baseline information on marine debris issue in Malaysia.