Integration of Low-Cost Sensors in Understanding the Impacts of the Saharan Air Layer on Puerto Rico's Air Quality

The Saharan air layer (SAL) carries dry, dusty air from the Sahara Desert, which can travel thousands of miles across the Atlantic Ocean. PM₁₀ is most common in Saharan dust, leading to health concerns and reduced visibility. Due to its geographical location, Puerto Rico is particularly impacted by SAL during the months of June through September. Despite its vulnerability, the existing air quality monitoring network faces limitations, especially in the distribution of PM₁₀ sensors (e.g., lack of PM₁₀ sensors on the west coast) and availability of data. Nevertheless, low-cost sensors (LCS) can provide monitoring opportunities and information to communities about their local air quality. Here we analyze the impacts of the SAL on air quality as it moves across Puerto Rico. To address the observational gaps, we deployed five MODULAIR-PM sensors across the island to track the movement of SAL and its effects on air quality. Since the accuracy of sensor data can be of concern, we compared LCS data with information collected by the United States Environmental Protection Agency (EPA) to implement necessary corrections. Our initial findings reveal that hourly and daily PM₁₀ observations from LCS have higher values when compared to EPA data for the sensors located in Ponce, Puerto Rico. This suggests the need for potential corrections in the LCS data, accounting for relative humidity and additional factors, to ensure data accuracy. Ongoing research aims to refine these corrections and explore the influence of topography and meteorology on SAL in Puerto Rico. Overall, integrating LCS in assessing the impacts of the SAL on Puerto Rico’s air quality can empower communities to make informed decisions and anticipate conditions effectively.