Desenvolvimento de Amostrador Passivo para Óxidos de Nitrogênio (NOx) na Atmosfera

Resumo

Measurements of air constituents can be done automatically, actively and at a high cost or using passive samplers (PS), simple, easy to operate and low cost, presenting integrated concentrations in a given time. Among the various forms of nitrogen that pollute the air are nitrogen oxides (NOx = NO + NO₂). These play an important role in atmospheric reactions and also on the health of the population. This work developed an AP for NOx in the atmosphere, aiming to expand spatially and temporally the ability to measure these oxides. The performance of PS was evaluated as a function of the collection medium (filter impregnation solution) and exposure time, in addition to validation for accuracy and precision of the measurements, Limit of Quantification (LQ) and ability to sample NOx. The results showed that the PS is suitable for measurements in urban, industrial and remote areas, with an LQ of 0,07 µg m^-3 NOx. The application of PS for NOx in 14 districts of the city of Salvador revealed the range of NOx concentration in the atmosphere (11- 48 µg m^-3 NOx), showing NOx levels in places with more intense vehicular traffic exceeding the European Union recommendation.