# Portable Low-Cost Sensors for Environmental Monitoring in China: A Comprehensive Review of Application, Challenges, and Opportunities

## TL;DR

This review highlights the limited use of low-cost sensors in China for environmental monitoring, focusing mainly on air and noise pollution, and calls for broader applications and improved reliability.

## Contribution

The paper provides a comprehensive review of low-cost sensor applications in China, identifying key research gaps and offering a framework for future studies.

## Key findings

- Low-cost sensors in China are mostly used for air and noise pollution, with soil and biological contamination underexplored.
- Most studies are small-scale, short-term, and lack sufficient validation of sensor reliability.
- The review emphasizes the need for improved accuracy, portability, and data integrity for large-scale monitoring.

## Abstract

What are the main findings?
Field applications of low-cost sensors in China are heavily skewed towards air and noise pollution, leaving critical areas like soil and biological contamination largely unexplored.The current research is predominantly limited by small-scale studies, short durations, and insufficient validation of sensor reliability.

Field applications of low-cost sensors in China are heavily skewed towards air and noise pollution, leaving critical areas like soil and biological contamination largely unexplored.

The current research is predominantly limited by small-scale studies, short durations, and insufficient validation of sensor reliability.

What is the implication of the main finding?
The identified gaps underscore an urgent need to extend the application of low-cost sensors to under-investigated environmental domains, which is essential for comprehensive multi-pollutant exposure assessment.This review provides a critical framework for future research, highlighting that overcoming challenges in sensor accuracy, portability, and data integrity is fundamental to achieving large-scale, reliable monitoring.

The identified gaps underscore an urgent need to extend the application of low-cost sensors to under-investigated environmental domains, which is essential for comprehensive multi-pollutant exposure assessment.

This review provides a critical framework for future research, highlighting that overcoming challenges in sensor accuracy, portability, and data integrity is fundamental to achieving large-scale, reliable monitoring.

Accurate environmental monitoring in outdoor and indoor settings is critical for exposure assessment in environmental and public health research. Conventional methods, predominantly relying on high-end instruments or laboratory analyses, face limitations in real-world applications due to their high cost and inflexibility. Recent advances in low-cost sensor technologies have enabled more adaptable monitoring. This study systematically reviews research utilizing low-cost sensors for environmental monitoring in real-world settings across China. A literature search was performed using the Web of Science database, resulting in the inclusion of 43 eligible studies out of 31,003 initially identified records. These studies primarily investigated air pollution (17 studies), noise (14), light (7), and water pollution (5). Results reveal that air and noise pollution were the most extensively examined factors. Nevertheless, the reviewed studies exhibited notable shortcomings, including limited geographical/thematic coverage, inadequate reliability validation, small sample sizes (typically under 100 participants), and short durations (often under one month). This review discusses these challenges and suggests future research directions. By synthesizing current practices and identifying gaps, this work offers valuable insights to guide the design of future sensor-based environmental monitoring projects and inform the selection of suitable sensors.