Microplastics Contamination in Commercial Green Mussels from Selected Wet Markets in Thailand.

Mussels have been identified as sentinel organisms (around the world) that indicate microplastic (MP) pollution. Since they are filter feeders, they easily uptake MPs. Mussels sold in commercial markets have been identified as an ideal way to directly quantify human exposure to MPs through seafood consumption. There are no studies reported on MP contamination of market-sold species in Thailand. This study investigates the level of MP contamination in market-sold green mussels, which is a popular seafood in Thailand. A total of 90 green mussels (Perna viridis) collected from three markets were analyzed for the number, polymer types, and morphology of the MPs. Fourier-Transform Infrared Micro-Spectroscopy (micro-FTIR) analysis was used for polymer identification. Nile Red (NR) tagging was used for the enumeration of MPs. MPs were widely discovered in green mussels from all three markets with 100% detection frequency. The average abundance of MPs in green mussels was quantified as 7.32 ± 8.33 items/mussel and 1.53 ± 2.04 items/g (wet weight). Ethylene/propylene copolymer followed by low-density polyethylene (PE-LD), polypropylene (PP), and polyethylene terephthalate (PET) were found. Fragments (75.4%) were the most common morphotype, followed by fibers (24.6%). Results indicate that the consumption of green mussels as a food can be one of the exposure pathways for the Thai population. Moreover, smaller size MPs were predominant, which are reported to cause higher impacts.

Unveiling the abundance and potential impacts of microplastic contamination in commercial organic fertilizers/compost produced from different solid waste.

This study comprehensively investigated the abundance, morphologies, and polymer types of plastics, larger (1-5 mm) and smaller (< 1 mm) microplastics (MPs), in organic fertilizers using spectroscopic and microscopic methods. MPs abundance varied depending on the type of waste employed. MPs were detected in 80% of the investigated compost samples, while macro/meso plastics were found in only four samples. Compost from mixed municipal solid waste exhibited the highest MPs contamination (23100 ± 3615 items/kg dry weight), whereas compost produced from canteen waste had the lowest contamination (100 ± 65 items/kg dry weight). Smaller MPs were dominant in all samples. The estimated loads of MPs introduced into agricultural soil exceeded the previous studies. Common morphologies observed were sheet, film, fragment, and fiber, while dominant polymer types were polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and polystyrene (PS). Heavy metals, including Cr, Cu, Ni, and Pb, were identified in association with MPs. Results indicate that the utilization of appropriate waste for composting and upgrading fertilizer regulations is crucial to protect the environment and human health from smaller MPs.