About The Water Map

The Water Map enables citizen science-powered microplastic detection in drinking water through Nile Red fluorescence staining, a peer-reviewed method published in the Journal of Hazardous Materials Letters. Developed by the UCLA Ozcan Lab, the project combines affordably-priced test kits with a public database mapping microplastic contamination across Los Angeles neighborhoods. Every sample result is published without paywall or signup requirement.

The analytical workflow uses Nile Red dye to stain microplastic particles in water samples, which glow bright pink under 365 nm UV light (blue LED). Users photograph the filter under illumination; image analysis software counts particle density and assigns a severity rating. The method detects microplastics across multiple size fractions and polymer types without requiring laboratory instrumentation. Results feed directly into a real-time open dataset viewable on an interactive map.

Key Features of The Water Map

• Also includes two test replicates per kit, enabling direct comparison between tap and filtered water sources.
• Furthermore, the dataset currently covers 50+ samples from 21 Los Angeles neighborhoods, with median particle count of 9 microplastics per liter.
• In addition, 73% of tested samples showed detectable microplastic contamination.
• Additionally, the method is rapid, requiring less than one hour from sample preparation to result generation.

Development and Validation

The Water Map was developed by the UCLA Ozcan Lab and is based on Leonard et al., 2022, Journal of Hazardous Materials Letters. The Nile Red fluorescence staining method has been peer-reviewed and validated for microplastic identification in aqueous matrices. The project emphasizes community participation in water quality monitoring, shifting microplastic detection from centralized laboratory infrastructure to distributed, citizen-led sampling.

Access and Data Availability

The Water Map is fully open and free to access. View the interactive map and all sample results at thewatermap.com without signup or paywall. All raw photographs, particle counts, and fluorescence images are publicly available.

Test kits are available for purchase at thewatertest.com for $50 per kit. Each kit contains materials for two independent tests, staining reagent, UV light source, and photographic guidance for submission to the dataset. The dataset updates in real time as new samples are added. The test kit works in a similar way to nile red kits published in the literature.

Community and Support

The Water Map actively invites community participation. Users can order a test kit, conduct analysis at home, photograph results, and submit them to expand the public dataset. This crowdsourced approach has generated sample coverage across 21 Los Angeles neighborhoods and continues to recruit additional households. The project prioritizes transparent, utility-independent water quality data at the community scale.

This resource complements standardized methods such as infrared spectroscopy protocols, and citizen science sampling guidance by providing a low-cost, community-accessible entry point for microplastic detection in drinking water.