**Alpha Version Data** (has undergone several rounds of internal review from the Moore Institute and is ready for external review) This dataset is part of the [Microplastics Data Portal](https://github.com/Moore-Institute-4-Plastic-Pollution-Res/Microplastic_Data_Portal). It was created by reviewing peer-reviewed studies on microplastics in drinking water for bottled water and tap water. This data is tidied in a way that we think it is most actionable but raw data is also available on [Github](https://github.com/Moore-Institute-4-Plastic-Pollution-Res/Microplastic_Data_Portal/tree/main/data/Raw_DrinkingWater_Data). Data was validated with the rules file provided in combination with the [Data Validation Portal](https://wincowger.shinyapps.io/validate/).

**Alpha Version Data** (has undergone several rounds of internal review from the Moore Institute and is ready for external review) This mock dataset is part of the [Microplastics Data Portal](https://github.com/Moore-Institute-4-Plastic-Pollution-Res/Microplastic_Data_Portal) and is intended to eventually serve as the data shared by state-accredited labs for microplastics in drinking water. It was created by discussions with domain experts. Data comes with a template with mock data entry and a rules file that can be used to validate the data using the [Data Validation Portal](https://wincowger.shinyapps.io/validate/).

AIMS, in collaboration with The Clean Ocean Foundation, has completed this proof-of-concept study to facilitate further sampling of microplastics in the Southern Ocean (a joint collaborative initiative involving the Australian Institute of Marine Science (AIMS), the Integrated Marine Observing System (IMOS) and solo yachtswoman Lisa Blair). In this project, AIMS trialled density flotation and chemical digestion separation methods to process subsurface seawater samples and retrieve environmental microplastics. This report presents findings from controlled spike recovery tests as well as opportunistic field sampling events of subsurface waters processed with both separation methods. Opportunistic samples were collected along the NSW coastline in December 2021. Given the location of the sampling transects, this report also provides the first spatial baseline information on microplastic contamination in NSW waters adjacent to estuary outflows and urban outfalls. After trialling both separation methods, microplastics retrieved from the NSW samples were physically and chemically characterized used stereomicroscopy and spectroscopy, respectively. No statistical analysis were performed due to the low number of replicates. Results showed repeated chemical digestion employing potassium hydroxide solutions was most effective at microplastic recovery. Microplastics were retrieved from each of the eight samples collected in NSW subsurface seawaters, with polyethylene and polyester fibres being the most prevalent polymer types detected. The highest numbers of microplastics were recorded adjcent to the estuary outflows and urban outfalls present within the sampling area. Overall, the sampling and processing protocols developed here are allowing for the extension of the spatial coverage of microplastic data in seawaters.

A review of peer-reviewed publications was undertaken, focusing on coastal and marine microplastics relevant to South Eastern Australia (South Australia, Victoria, and New South Wales), as well as from ongoing citizen science programmes from AUSMAP (https://www.ausmap.org/). This dataset summarises basic information about the microplastics studies: the location of the study; if the study focused on water, sediment or biota; the type of biota (for biotic studies); and the DOI of the publication. Although the primary focus of this study was restricted to southeastern Australia, studies collated from other regions have also been included in this dataset. The outcomes of the literature review for other regions (QLD, NT, SA, WA, Tas) should not be considered comprehensive.

These data were collected to characterize the quantity and quality of microplastic particles found in 17 streams in the northeastern United States, from New York to Virginia. USGS staff who represent the Urban Landscapes Capabilities Team (ULCT) within the North Atlantic-Appalachian Region designed the study and collected the water samples on which the data are based. Data were collected during 2017 and 2018 and included a baseflow and stormflow sample at each site. Additionally, the various microplastic particles in each sample were characterized by one of two different size-fraction categories (categories of 355-1000 micrometers and 1000-5600 micrometers), by type of particle (fiber/line, fiber clump, bead/pellet, film, foam/rubber, or fragment), and by the number of particles of each type per sample. Quality control data also are included.

These data were collected to characterize the quantity and quality of microplastic particles found in 17 streams in the northeastern United States, from New York to Virginia. USGS staff who represent the Urban Landscapes Capabilities Team (ULCT) within the North Atlantic-Appalachian Region designed the study and collected the water samples on which the data are based. Data were collected during 2017 and 2018 and included a baseflow and stormflow sample at each site. Additionally, the various microplastic particles in each sample were characterized by one of two different size-fraction categories (categories of 355-1000 micrometers and 1000-5600 micrometers), by type of particle (fiber/line, fiber clump, bead/pellet, film, foam/rubber, or fragment), and by the number of particles of each type per sample. Quality control data also are included.

The data set contains a summary of literature sources involving microplastics in urban watersheds. This This primarily deals with aqueous phase and sediments from freshwater systems, along with influent and effluent from wastewater treatment plants. This dataset is not publicly accessible because: There are no data associated with this review paper. It can be accessed through the following means: N/A. Format: This is a review article. There are no data associated with the entry. This dataset is associated with the following publication: Birch, Q.T., P.M. Potter, P.X. Pinto, D.D. Dionysiou, and S.R. Al-Abed. Sources, transport, measurement, and impact of nano and microplastics in urban watersheds. ENVIRONMENTAL POLLUTION. Elsevier Science Ltd, New York, NY, USA, 19: 275-336, (2020).