**1. Introduction**

#### **1.1 Understanding aerosols and their sources**

Aerosols, sometimes referred to as the dust clouds, if not the airborne tiny particles, are hazardously toxic to health: human, animals and plants, especially if uncontrolled.

The dust storm (dust and sand carried away by the wind from the very dry grounds) has too many effects. For example, anthropogenic dust storm, as illustrated in **Figure 1**, directly pollutes the breathable air, food and water. If the storm is naturally caused by the desert's dust, it causes the drought [1].

As presented in **Figure 1(a)**, most of sub-Saharan inhabitants unavoidably live with anthropogenic aerosols; the most remarkable are the dust and smoke aerosols, and sometimes do not worry about the associated dangers. **Figure 1(b)** shows the smoke of the accidentally burnt house, its equipment and furniture. Hazards caused by the smoke from biomass burning's fire, volcanic eruptions, home and industrial chimneys, road vehicles exhausts, etc., is very dangerous to both health and climate uncertainties, and that's where most constituents of the fine particulate matter (PM2.5) come from.

In **Figure 2**, the primary sources of particulate matter as aerosols are deserts, erupting volcanoes and of course some human (anthropogenic) activities, it's a matter of the dust and many other aerosol particles that are windblown over either the sea, ocean or earth surface. The aerosol particles such as Soot, fly ash, black carbon (BC) and smoke are primarily produced during different combustion activities.

The secondary sources can otherwise be generically referred to as atmospheric chemistry source where gas-phase species can chemically transform before they condense, and they are technically referred to as aerosol precursor gases [2].

Aerosol science, however, is a sub-branch of physics or physical-chemistry which, until 1980s, has been so neglected that most people did not worry about aerosols dangers to the human breathing and blood circulation. The industrial revolution in the 19th century brought high-speed machinery; dust exposure increased dramatically, for instance dust from mines, which caused more cases of lung diseases. Thus, since then onwards, it's a very hot research topic to study the physicochemical properties of aerosol: how to sample (clustering), to control and avoid them. For instance, aerosols can play a role of polluting gases removal from the atmosphere, either by absorbing them on existing ones or launching new particles. The study of aerosols, however, is not easy because airborne particles behave very differently than the air in which they are suspended and also behave very differently among themselves depending on their sizes, shape and composition [3].

The atmosphere is such a complex dynamic natural system that sustaining life on earth is very essential as the atmospheric air interacts with water and land. Acidic rain is a result of air pollution. Therefore, it's very important for an air quality engineer to understand water pollution: air normally contains water vapor (varying from one to four per cent at surface), dust pollen, sea spray, volcanic ash and various industrial pollutants [3, 4].

#### **1.2 Significance: direct and indirect aerosols effects on health**

The aerosols transported by wind over a long distance directly pollute the quality of breathable air. For instance, the windblown dust from deserts entrains particulates which are hazardous to human health [5–7]. Particularly, the diseases such as pneumonia are attributed to that type of aerosol [8, 9].

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

**Figure 1.**

*Anthropogenic Aerosols (a) dust storm in the inhabited village's road (source: Original photos taken on the road under construction in June 2020); (b) smoke due to the burning (source: Original photo of the building that was accidentally burnt on 06 September, 2020).*

It has been ascertained that the dust endangers the respiratory, cardiovascular and nervous systems [10].

Referring to Pope et al., as cited by Dianat et al. ([11], p. 5155), "the prolonged health exposure to PM2.5 was most strongly associated with mortality attributable to cardiac dysrhythmias, ischemic heart diseases, cardiac arrest, and heart failure."

**Figure 2.** *Primary and secondary sources of particulate matter (PM).*

Besides, an aerosol is collectively known as solid, gaseous or/and liquid particles suspended in the atmosphere, except all the hydrometeors which include the cloud droplets, ice crystals, raindrops, snowflakes, and the alike particles [12]; smoke is the famously known gaseous aerosol. Therefore, apart from the direct health effects (learned from erstwhile works in the same research field), the aerosol in general can also change the clouds properties: thus, they indirectly affect the lives on earth in causing drought, acidic rain, etc.

A research question: "how can results from the remote sensing data analysis instruct the community about the tropospheric aerosols hazards?"
