Water is part of daily life—used for drinking, cooking, cleaning, recreation, agriculture, and industry. Yet many people only think about water quality when something looks unusual, smells strange, or appears in the news. In reality, water quality is shaped by many physical, chemical, and biological factors, some visible and some invisible. Learning a few basic concepts can help people better understand their local water sources and participate in citizen science projects lik

This paper is also available at: https://doi.org/10.5281/zenodo.19490782 This field validation study evaluated the robustness and real-world deployability of a portable smartphone based zero-shear optical interaction assay for detection of microplastics and nanoplastics (MP–NP) in coastal water at Crissy Field East Beach, San Francisco Bay — a representative estuarine environment with elevated salinity and known microplastic presence.   Samples were collected directly from

Abstract: On April 2, 2026, the U.S. Environmental Protection Agency (EPA) and Department of Health and Human Services announced the prioritization of microplastics, pharmaceuticals, PFAS, and disinfection byproducts as candidate groups on the draft Sixth Contaminant Candidate List (CCL 6). This marks the first time microplastics have been designated at the group level for drinking water consideration. While this represents a significant policy milestone, reliable detection

Abstract  Turbidity, a measure of water clarity influenced by suspended particles, serves as a widely used proxy for water quality in environmental and industrial systems. Traditional nephelometric sensors and laboratory instruments, while quantitative, limit scalability and spatial coverage. This paper proposes an image-based framework for turbidity analysis using ubiquitous smartphone cameras. By extracting visual features such as clarity, light scattering, edge definition,

Abstract:  Detection of dispersed particles in water systems, including microplastics and nanoplastics, is strongly influenced by stochastic sampling effects at low concentrations. When particle concentrations are sparse, the probability of detection in small sample volumes follows Poisson statistics, resulting in high variability and frequent false-negative results. This paper examines the implications of Poisson sampling variance for environmental monitoring and demonstrate

Abstract Conventional laboratory workflows for microplastic and nanoplastic analysis rely on multi-step processes involving filtration, chemical digestion, transfer, and extensive contact with plastic laboratory materials . These steps introduce potential contamination pathways that can confound environmental measurements, even when samples are collected from water intended for human consumption or recreational use. In contrast, the EcoExposure platform employs an intentional

Microplastics and nanoplastics (MNPs) are increasingly recognized as environmental and potential human health concerns, with emerging evidence of widespread exposure through water sources. However, assessment of MNP burden remains challenging, particularly when samples appear visually indistinguishable. In this report, tap water, filtered water, and double-filtered water were evaluated using top-down optical imaging at standardized timepoints. Across all conditions, samples a

Environmental monitoring often relies on collecting small samples that are later analyzed in laboratories. These methods can provide highl y precise measurements, but the size of the sample itself can sometimes limit what researchers are able to observe. Many contaminants found in water—such as microplastics, sediments, and other suspended particles—are not evenly distributed throughout a water body. Instead, particles may occur in clusters, aggregates, or irregular concentra

When people think about water testing, they often picture freshwater systems such as drinking water supplies, rivers, or lakes. These environments are critically important to monitor, but they represent only a small fraction of the water on our planet. In fact, approximately 97% of Earth’s water is saltwater , contained in oceans and coastal environments. These vast systems play a central role in global ecosystems, fisheries, transportation, and climate regulation. As awaren

Many environmental testing methods rely on collecting samples that are later analyzed in specialized laboratories. This approach allows for highly precise measurements, but it also introduces delays and logistical challenges. Samples must be transported, preserved, and processed usin g complex instruments before results become available. For certain types of environmental observations, however, valuable information can be obtained by examining samples directly in the field. D

In recent years, smartphones have evolved into powerful computing platforms equipped with high-resolution cameras, advanced processors, and sophisticated software capabilities. While these devices are typically associated with communication and photography, researchers are increasingly exploring how smartphones can function as scientific instruments. Environmental sensing is one area where this transformation is particularly promising. Modern smartphones contain cameras capab

For decades, environmental science has relied on laboratory analysis to understand water quality and contamination. Laboratory instruments can measure extremely small concentrations of chemicals, metals, and particles with high precision. These tools have played an essential role in identifying pollutants and establishing environmental standards. However, traditional laboratory testing also has important limitations. Most environmental samples must be collected in the field a

Water systems around the world are facing a growing challenge: an increasing number of contaminants are being detected in rivers, lakes, coastal environments, and even drinking water supplies. Advances in environmental science have made it possible to identify pollutants that were previously diffic ult to observe, revealing a complex mixture of materials moving through natural and human-built water systems. Among the most widely discussed contaminants are microplastics , tiny

Water is one of the most fundamental resources on Earth, yet understanding what is actually present in the water around us is often surprisingly difficult. Traditional environmental testing typically relies on laboratory equipment, specialized instruments, and complex analytical workflows. While these approaches are powerful, they are also expensive and infrequent, leaving large gaps in environmental monitoring. ecotera home was created to help close that gap. Our goal is sim