International Atomic Energy Agency’s Efforts towards Marine Plastic Pollution: Where we are with reference to Asia Pacific

The International Atomic Energy Agency (IAEA) has launched the “NUTEC Plastics” flagship project addressing plastic pollution both upstream (irradiation and recycling) and downstream (assessment of scale and effects in marine areas). The UN SDG 14.1.1b addresses floating plastic debris density, including microplastics. The IAEA has initiated regional projects in addition to an International project to harmonize methodologies for microplastic assessment. The efforts have led to several notable outcomes including a harmonized methodology for the assessment of microplastics in 300 – 5000 µm size in beach sand and surface water. Over 99 countries have been trained and have adopted these methods. This exercise will enable countries to report comparable microplastic data for SDG 14.1.1B Level 3. A substantial amount of research has led to the development of a standard reference material for microplastics in beach sediment and an effervescence tablet for sea/freshwater that further enables assessing the efficacy of the method and operators' accuracy. In addition, The IAEA launched coordinated research projects on various aspects of microplastic research some of the significant observations include the presence of microplastics in dated sediment cores, which are consistent with the era of plastic production started, evidence has come from Kuwait and Mexico. The research showed the omnipresence of microplastics across environmental matrixes with MPs reported in bottom sediments, water column, in marine organisms. One of the biggest contributors of microplastic is the wastewater treatment plants with estimates suggesting the global annual contribution of 1.45 × 10¹⁵ MP from treated and 3.85 × 10¹⁶ from untreated wastewater streams. A significant range of MP presence is reported in marine organisms with values ranging from 0 – 5000 MPs/kg of tissue. Other experiments conducted under the IAEA coordinated projects in calanoid copepods suggest ingested MPs were defecated in 180 minutes with 100% recovery raising questions on its toxicity and translocation.

Efforts are being put towards the improvement of methods and assessing the limitations of the methodologies followed. Significant efforts have been made towards the use of Laser Direct Infrared Chemical Imaging System, with excellent recoveries for particles up to 50 µm size. The current findings have also highlighted the presence of MPs (2 – 61 per litre) in Millipore water, highlighting the pathways of sample contamination. Current efforts are on radiolabeling the MPs with gamma emitters to understand the penetration and translocation of MPs in various experiments. The regional baselines and data inconsistencies are assessed. The effectiveness of pyrolysis gas chromatography has been tested and questions are raised on its limitation as we don’t get any size, shape and number information rendering the data generated incomparable with other techniques such as FTIR, micro-RAMAN, LDIR and SEM. We believe it's a long way to understand the comprehensive effect of MP pollution on ecosystem functioning and seafood safety but the steps taken by the NUTEC initiative and achievements are in the right direction.