**1.3 Objectives**

Africa and Asia are the global source of the Desert's Dust Aerosols; therefore, the main target is to continue the research works which will alert the world and inhabitants about the updates in aerosols which can endanger the earth.

Considering the formation, correlation, health effects; assessing the on-site (in situ) versus remote sensing data collection, the in-field collected data is reliable for research related with physical, biological, and social sciences. However, studying aerosols and air pollution by targeting very big areas, remote sensing data is better than in situ data [13].

The research objectives are:


*An Analysis of Remote Sensing Data to Evaluate the Problem of Atmospheric Aerosol… DOI: http://dx.doi.org/10.5772/intechopen.99377*

• to discuss the inherent health hazards that link the existing research works with findings of this research.

#### **2. The research trends in aerosols as air pollutants**

Particulate matter (PM), a type of aerosol, is a complex mixture of molecules differing in chemical composition, shape and size; PM can come from natural sources such as the wind erosion of rocks and soil, sea sprays, volcanic dust, etc. PM also come from anthropogenic sources, noting the fossil fuels combustion, industrial processes, and traffic emission [12, 14, 15].

Airborne particles can change their size and composition by condensation of vapor species or by evaporation, by coagulation with other particles, by chemical reaction, or by activation in the presence of water super-saturation to become fog and cloud droplets. Particulates are eventually removed from the atmosphere by two mechanisms: deposition at the Earth's surface (dry deposition) and incorporation into cloud droplets (wet deposition) during the precipitation in the form of rain [16].

#### **2.1 Dust, particulate matter, black carbon**

Dust, particulate matter (PM) and Black Carbon aerosols have the common characteristics, especially when it comes to polluting the atmospheric breathable air.

The heavy contribution of the deserts' dust to the global airborne particulates as well as numerous other effects of dust aerosol are very well documentable [17–19]; the effects become very dangerous to human health when the dust is characterized to the PM size [19].

The smoke as a gaseous aerosol broadly links with ecosystem, to mean the living organisms and non-living entities like atmospheric air as well as cloud and climate.

The literature reiterates that the global air polluting particles come from both the discipline of aerosols and atmospheric chemistry; in this research, the selected aerosol particles are the dust's fine particulate matter (PM2.5), sulfates, as well as Black Carbon (BC). Cardiovascular problems and death caused by air pollution are globally reported, and air pollution kills more people than they die of viral diseases.

Due to the dust belt [17] as well as meningitis belt [20] which keep expanding, Africa is one of the best research areas, while targeting the source of different sized particulate matter, PM (PM1, PM2.5, PM10), which are classified under solid aerosols, and breathable air pollutants in particular [21].

#### **2.2 Sulfur dioxide**

The sulfur Dioxide (SO2) is produced from anthropogenic burning activities, and erupting volcanoes activities [22], and is recognized as a potential air pollutant; importantly, through chemical reaction, SO2 plays a considerable role in the formation of sulfate aerosols. The role that sulfate aerosols may play in ambient particulate matter (PM) chemistry is so meaningful that the possible effects might be the product of acidic component formed by sulfur dioxide [23, 24]. Acid rain, for example, is one of main reasons why atmospheric sulfur dioxide and nitrogen oxides can be of interesting focus among the air pollutants [25–27].

For instance, it was found that rain in northwestern Europe was measured with the most increased acidity; the tendency appeared linked with certain gaseous pollutants, like SO2, which chemically convert into strong acids in the atmosphere. Nonetheless, the trend seems to directly cause very little threat to human health.

Rather, the acidic rain can considerably damage some artificial architects, and seriously implicates to the ecosystem [25].
