This introductory chapter gives relevant historical information about nanoparticles and the attempts to define the nanoparticle size (1-1,000 nm), as well as their most important general properties, which vary with size: surface area, optical properties, uniformity, fictionalisation, quantum confinement and other fractal-type characteristics.

This chapter deals with anthropogenic sources of nanoparticles in atmosphere. The stationary and diffuse sources are described first: mining and extraction of fossil fuels, ferrous and non-ferrous ores and other mineral resources. Brief references are then made to secondary stationary sources of particulate matter which originate in thermal energy and power generation, ferrous and non-ferrous metallurgy, chemical industry and construction materials (cement, lime) production technologies. A separate section is dedicated to particulate matter resulted from municipal, toxic and hazardous waste incineration and its effect on the environment and human health. The authors also speak about emissions from point sources of nanoparticles, such as the residential heating sector that makes a major contribution to the total amount of nanoparticles produced by anthropogenic activities. Mobile nanoparticle sources include engines that are most frequently used in the present: plane engines, rocket engines, engines for road and water transport. Particulate matter emissions can be reduced by using alternative fuels or other forms of propulsion energy.

This chapter deals with the major natural sources of nanoparticles in the atmosphere: volcanic eruptions, desert surfaces, dust from cosmic sources located in the solar system or outside it. Details are given about the composition of very fine particles according to their type, the successive or parallel chemical transformations that can occur among them or when they meet the major components of the atmosphere (nitrogen, oxygen, carbon dioxide). The authors specify possible ways of evolution from the mineral kingdom to organic substances through nanoparticles originating from cosmic dust, based on suppositions that are provided in the literature of the field and accepted based on physical and chemical computational models.

This paper presents the zone maps resulted from the statistical processing of NOx and SOx emissions varying with the weather conditions. This study uses data from the nitrogen and sulphur oxides emissions monitoring collected in 2013-2016 from the on-line gas analyser with the incineration plant evacuation system, as well as hourly weather records for four parameters (atmospheric pressure, temperature, rainfalls, wind speed and direction) recorded at our own weather station in the same period. The statistical calculation and zone map drawing software was performed by our team members.

Several relevant models of nanoparticle formation and reformation in the atmosphere are underlined: the mechanism of forming fine ash particles in coalfired thermal power plants; carbon particulates formed either directly or through partial oxidation intermediates; acid rain, bases, ammonia, saline or oxide particulates formation mechanism. For solid or liquid particulate matter of organic nature present in the atmosphere, the phases of the partial oxidation of organic compounds and the dioxin and furan generation in various combustion systems are presented.