# First Lidar Campaign in the Industrial Sites of Volta Redonda-RJ and Lorena-SP, Brazil
## 1 Introduction  
Atmospheric composition plays an important role in the Earth's radiation budget and the understanding of its physical, chemical and optical properties is important to address the effects on climate, weather conditions and air quality [1; 2; 3]. The determination of atmospheric composition is becoming increasingly important for large urban centers and megacities where the impact of air pollution is extremely worrying. In these locations, serious problems are faced, such as overpopulation, disorderly growth, large vehicle fleet, poor quality of the collective transportation system and others [4; 5; 6; 7]. In recent years, several studies have been focused on the monitoring of emission sources and analysis of primary and secondary formation of pollutants of large urban centers in Brazil [7; 8]. In 2012 [PERSON] et al. [9] and [PERSON] et al. [8] conducted two similar studies to quantify \(PM_{2.5}\) and black carbon concentrations in six large Brazilian urban centers and to correlate them with harmful health effects and the increased mortalityrisk. Ref. [PERSON] et al. [10] used mobility data and emission models to investigate the relation of air quality and short-lived climate pollutant impacts related to on-road transportation in the Metropolitan Area of Sao Paulo (MASP). Several other studies in different regions of Brazil were conducted in order to investigate the composition of organic matters present in the aerosols and the effects of inorganic chemical composition on the aerosol hygroscopicity of urban polluted areas [11; 12]. Concerning the large fleet of light and heavy-duty vehicles in the large urban areas of Brazil, several efforts have been made to understand the correlation between secondary inorganic and organic particle formation, particle number concentrations, ozone and fine particles with the vehicle emissions [13; 14; 15]. In addition, atmospheric pollution and aerosols are recognized as risk factors for health, associated with several diseases and premature deaths. The emission of particulates, especially with diameter smaller than 10 \(\upmu\)m, is correlated with respiratory problems that increase mortality and cancer in some urban areas [16; 17; 18; 19; 20]. Other studies developed an approach based on the atmospheric model employing specific arrangements of the physical and chemical processes to study the effects and impacts of air pollution in the large cities and their neighborhood, focusing on the pollution episodes [21], air quality forecasting [22; 23], and regional and long-distance pollution transport [24; 25; 26]. In this context, to enhance the accuracy and the air quality predictions based on these forecasting and pollution transport models it is necessary to improve the inventories database and increase the coverage area for atmospheric monitoring. Brazil has a historical deficiency in atmospheric monitoring in almost all its territory and the Paraiba valley is one of the regions where there is a lack of monitoring data. The Paraiba valley is a geographic region formed by the hydrographic basin of the Paraiba do Sul river and it is located among three different Brazilian states, Rio de Janeiro, Sao Paulo and Minas Gerais. Important natural reserves are located in this region, such as Mantiqueira mountains, Sea Ridge (Serra do Mar) and important reserves of the original Atlantic rain forest, despite being an urbanized and industrialized region with more than 3 million people living in their cities. Moreover, connecting the cities of Sao Paulo and Rio de Janeiro, and crossing all the Paraiba valley, there is one of the longest and important Brazilian highways, the Presidente Dutra Highway (PDH) or BR-116, a longitudinal highway that begins in the northeastern region of Brazil and goes to the extreme south Brazilian region, crossing a total of 10 states, with a total of 4486 km of extension with an intense flux of heavy and light-duty vehicles. Recently, in an attempt to cover the lack of monitoring in these large populated regions, [PERSON] et al.