Environmental Influences On The Air Pollutants

Everything changes; the environment, the technology, the people, the industries, the processes, and activities. It´s difficult to think that something can remain constant, the same happens with the air, the composition and its contaminants change with time. 

In the center of any city, the air is contacted with constructions, industries, cars, and people; whereas in nature, the air is in contact with plants, there are few people and buildings, there are no cars. It is correct to think that the cleaner air is in nature unless you are in a desert and inhale all that sand; nature will have a hand for cleaner air. 

As the sources that emit pollutants are not found in nature and the plants purify some part of the air, there is no air pollution, well, there was none, since the progressive increase in worldwide pollution even the most distant places on earth are being affected by it. 

In the cities there is a different situation, through the seasons there are episodes of polluting haze; there are days when it is not noticeable, maybe the wind carry it to another city or to another place, but does not mean that the pollution is not there, increasing globally day after day, accumulating over the years.

Image 1: Sunlight can generate chemical reactions to create new pollutants.

The types of chemicals that are contained in air pollution have already been discussed before, but there is still a difficult question to solve, ¿what are the percentages of the polluting compounds contained in the air?. As I mentioned at the beginning of the text, the air is not the same between places, because some factors determine the amounts and types of pollutants.

I had previously discussed some of the influence of temperature on environmental pollution, thus, the most significant variation is found between the seasons of the year; although, regardless of the season we are, from winter to autumn, if the sources of pollutants increase the pollutants will increase too. 

Therefore, the climatic characteristics are of secondary concern, for example, if in any given year, my city finds there are more pollutants in summer than in winter, but my neighbor in another place of eath finds the opposite; it is obvious that there are discrepancies, not caused by the seasons but by the increase in the emission of pollutants. 

Polluting activities are so integrated into our daily life as humanity that is easier to transform and adapt than to eliminate them; activities such as construction, production, metallurgy, cars, among other processes must be corrected to remove the emission of pollutants. 

Also, the heating and cooling requirements change through the seasons of the year altering the emission of pollutants, so it should be noted that some of the activities are the needs of the people, so the solution cannot be expensive to make it easily accessible.

Image 2: The weather influences the speed to disperse pollutants.

The factors that influence the concentration of air pollutants. The hand-made and natural sources involve the process of emissions, the chemical reactions caused by sunlight and between chemical compounds in the air induce increased levels of pollutants; subsequently, the impacts of the environment and the topography influence the dispersion of high concentrations of pollutants that generate impacts on people and the environment.

Image 3: Factors that influence the concentration of air pollutants. Air pollution is produced by industries, cars, garbage dumps, industrial chemicals, buildings, agriculture, energy production, fuels, and others; these sources are found in different locations, therefore, the place where the air sample is taken for chemical analysis will have the chemical profile according to the majority activities and materials in the area. 

If the compounds are highly stable and have the ability to remain in the air for a long time, you could receive pollutants from another city or country, even continent. The amounts of pollutants found in the air are not the same between days, the levels may vary even on the same day. 

The meteorological factors are important determinants in the concentration of pollutants in the air, for example in areas where there is not a good wind current, the gases remain for longer, so there is a greater accumulation of pollutants. Scientific studies have been developed and they have identified the meteorological and environmental ideal-conditions where the air pollutants are easily removed; these conditions are: 

• Temperature < 10°C or > 21°C (less than 10°C and more than 21°C). 
• Precipitation > 1500 mm. 
• Atmospheric pressure < 900 hPa. 
• Wind speed > 3 m / s. 
• Relative humidity > 65%.

Other values for these factors could favor air pollution and its permanence in a place. Nevertheless, all these factors come into play for the contribution of air pollution, but the main causes of pollution are the activities that cause the emissions of pollutants, and until the processes are corrected the levels will not stop increasing.

References

• Zhang HH, Li Z, Liu Y, et al. Physical and chemical characteristics of PM2.5 and its toxicity to human bronchial cells BEAS-2B in the winter and summer. J Zhejiang Univ Sci B. 2018;19(4):317-326. doi:10.1631/jzus.B1700123

• Naser, TarekMohamed & Yoshimura, Yuji & Sekiguchi, Kazuhiko & Wang, Qingyue & Sakamoto, Kazuhiko. (2008). Chemical Composition of PM2.5 and PM10 and Associated Polycyclic Aromatic Hydrocarbons at a Roadside and an Urban Background Area in Saitama, Japan. Asian Journal of Atmospheric Environment. 2. 10.5572/ajae.2008.2.2.090. 

• Sarkawt M.L. Hama, Rebecca L. Cordell, Jeroen Staelens, Dennis Mooibroek, Paul S. Monks. Chemical composition and source identification of PM10 in five North Western European cities. Atmospheric Research. Volume 214, 2018, Pages 135-149. ISSN 0169-8095. https://doi.org/10.1016/j.atmosres.2018.07.014.

• Li, Xiaodong & Chen, Xuwu & Yuan, Xing-Zhong & Zeng, Guangming & León, Tomás & Liang, Jie & Chen, Gaojie & Yuan, Xinliang. (2017). Characteristics of Particulate Pollution (PM2.5 and PM10) and Their Spacescale-Dependent Relationships with Meteorological Elements in China. Sustainability. 9. 2330. 10.3390/su9122330.