The widespread occurrence of microplastic has invaded the environment to an extent that it appears to be present throughout the globe. This review investigated the global abundance and distribution of microplastics in marine and freshwater ecosystems. Furthermore, the issues and challenges have been addressed for better findings in microplastics studies. Findings revealed that the accumulation of microplastics varies geographically, with locations, hydrodynamic conditions, environmental pressure, and time. From this review, it is crucial that proper regulations are proposed and implemented in order to reduce the occurrence of microplastics in the aquatic environment. Without appropriate law and regulations, microplastic pollution will eventually threaten human livelihood.

The activity concentrations of naturally occurring radionuclides²²⁶Ra,²³²Th, and⁴⁰K were determined in 30 agricultural and virgin soil samples randomly collected from Kedah, north of Malaysia, at a fertile soil depth of 0–30 cm. Gamma-ray spectrometry was applied using high-purity germanium (HPGe) gamma-ray detector and a PC-based MCA. The mean radioactivity concentrations of²²⁶Ra,²³²Th, and⁴⁰K were found to be 102.08 ± 3.96, 133.96 ± 2.92, and 325.87 ± 9.83 Bq kg⁻¹, respectively, in agricultural soils and 65.24 ± 2.00, 83.39 ± 2.27, and 136.98 ± 9.76 Bq kg⁻¹, respectively, in virgin soils. The radioactivity concentrations in agricultural soils are higher than those in virgin soils and compared with those reported in other countries. The mean values of radium equivalent activity (Raeq), absorbed dose ratesD(nGy h⁻¹), annual effective dose equivalent, and external hazard index (Hex) are 458.785 Bq kg⁻¹, 141.62 nGy h⁻¹, and 0.169 mSv y⁻¹, respectively, in agricultural soils and 214.293 Bq kg⁻¹, 87.47 nGy h⁻¹, and 0.106 mSv y⁻¹, respectively, in virgin soils, with averageHexof 0.525. Results were discussed and compared with those reported in similar studies and with internationally recommended values.

Studies on marine debris have gained worldwide attention since many types of debris have found their way into the food chain of higher organisms. Thus, it is crucial that more focus is given to this area in order to curb contaminations in sea food. This study was conducted to quantify plastic debris buried in sand at selected beaches in Malaysia. Marine debris was identified according to size range and distribution, and this information was related to preventive actions to improve marine waste issues. For the purpose of this study, comparison of plastic waste abundance between a recreational beach and fish-landing beaches was also carried out, since the different beach types represent different activities that produce debris. Six beaches along the Malaysian coastline were selected for this study. The plastic types in this study were related to the functions of the beach. While recreational beaches have abundant quantities of plastic film, foamed plastic including polystyrene, and plastic fragment, fish-landing beaches accumulated line and foamed plastic. A total of 2542 pieces (265.30 g m^-2) of small plastic debris were collected from all six beaches, with the highest number from Kuala Terengganu, at 879 items m^-2 on Seberang Takir Beach, followed by Batu Burok Beach with 780 items m^-2. Findings from studies of Malaysian beaches have provided a clearer understanding of the distribution of plastic debris. This demonstrates that commitments and actions, such as practices of the ‘reduce, reuse, recycle’ (3R) approach, supporting public awareness programmes and beach clean-up activities, are essential in order to reduce and prevent plastic debris pollution.