Avaliação de sensores de material particulado PM2.5 E PM10 em monitores automáticos de qualidade do ar

Abstract

Air pollution affects the entire planet, especially developing countries, at a rapid pace, largely caused by human action. Pollutants are any particles present in the air, with concentrations capable of making it inappropriate, harmful or offensive to health, causing damage to property, fauna and flora. Numerous studies link polluted air as the main risk factor for respiratory, cardiovascular, autoimmune diseases, cancer and damage to cognitive functions. The damage caused affects natural and anthropogenic ecosystems, the climate, the economy and society as a whole. Based on the guidelines established by the World Health Organization (WHO), a group of pollutants was adopted worldwide as air quality indicators, due to their frequency of occurrence and their adverse effects. Among them are particulate matter: PM2.5 and PM10. Using data established as reference methods, this work aimed to investigate the feasibility of integrating optical sensors of particulate matter, PM2.5 and PM10, in microcontrolled platforms, forming particle monitors. These sensors are relatively inexpensive and have compact sizes, working in conjunction with microcontrollers, can perform size and concentration measurements in real time, and send them over wireless networks, which enables communication with mobile devices. The monitors described in this work use the PMS7003 and SPS30 sensors, both low cost sensors, which are based on the principle of optical scattering. The sensor has a LASER light source, which emits light focused on the point of passage of the particles; and a photodiode, which receives the light scattered by the particles, and through signal conversion and processing, it is possible to estimate the amount of particles present in the air per cubic meter, as well as to differentiate the sizes of the particles. The R² values were greater than 0.9 in the correlation between the PMS7003 sensors and the SPS30 sensor, defined as the reference sensor. This equipment allows obtaining knowledge about the space-time concentration of the highlighted pollutants, in real time, in fixed locations and also in vehicles, demonstrating the versatility in applications. Therefore, the optical monitors developed in this work provide measurement in places where a conventional station could hardly be used, and can be developed with items available on the market.