Ground Ozone (Tropospheric)
Introduction
Ozone refers to a mass of colorless gas that comprises three atoms of oxygen (O3) occurring both at the upper atmosphere and the ground level of the earth. Ozone is not a direct emission into the air, but comes into existence through chemical reactions between man-made and natural emissions of volatile organic compounds and nitrogen oxides. Beneficial ozone, which is referred to as stratospheric ozone occurs in the upper atmospheres naturally, forming protective layer that shields living organisms on earth from the harmful ultraviolet rays of the sun. This paper focuses on Ground Ozone (Tropospheric Ozone), which is a harmful air pollutant because it has severe effects on people, animals, plants and the entire environment. Despite the fact that ground ozone is less concentrated compared to stratospheric ozone, it has adverse damages because of its harmful, irritant and negative effects on human beings, animals, plants and the entire environment.
Literature Review
Definition and Formation of Ground Ozone
According to McCrady and Andersen (468), Ground Ozone also known as Tropospheric Ozone is man-made. It is a product of air pollution from power plants and internal combustion engines. Industrial emissions and automobile exhaust release a contingent of volatile organic compound (VOC) as well as nitrogen oxide gas (NOx), which are by products of burning coal and gasoline. As a result, VOC and NOx combine chemically with oxygen during sunny periods that create late spring and early fall high temperature conditions to form ozone (Schlink et al., 3243). Ozone dissipates during cooler nights but high levels of ozone form in the afternoon and early evening heats. In addition, slow wind speeds, low humidity, large range between low and high temperatures and high peak temperatures are also weather conditions that accelerate formation of high ground ozone.
Effects of Ground Ozone on People, Animals, Plants and Environment
Guttorp, Meiring and Sampson (245) posit that studies have revealed adverse effects of high levels of tropospheric ozone on both animals and plants. Concerns regarding the adverse effects on the environment and human health have ignited the need to control emissions of various pollutants such as precursors of ozone. Further, Guttorp et al., maintain that both exposure time and levels of ozone have relationship with severity of its effects. On hot sunny days, ground Ozone presents more dangers on human health because studies show that high temperatures accelerate its production. People involved in outdoor activities, older adults, children and those asthmatic are most at risk. Moreover, certain generic characteristics and those with reduced intake of vitamin C and E also risk harmful effects associated with ozone exposure. Other adverse effects of ground ozone on people include difficulty in deep and vigorous breathing, shortness of breath, coughing and sore throat, damaging and inflammation of airways, aggravation of lung diseases such as chronic bronchitis and emphysema as well as increasing the asthmatic attack frequency ((The Royal Society 34).
Andersen (218) has also examined the role played by tropospheric ozone. He asserts that this ozone plays a significant role in altering plant development and growth. He emphasizes that it is fundamental to understanding how plants respond to ozone towards identifying dynamics occurring in the ground. In his findings, Anderson outlines that ground ozone has adverse effects because it alters stomatal conductance thereby affecting carbon assimilation by plants. Consequently, concentration of ribulose experiences, decreased activity and reduced leaf longevity occur (Thompson 10-7). In addition, tropospheric ozone also causes stress that contributes to reduction in plant carbon acquisition. As a result, the stress causes choking of carbon allocation to the plant roots.
Conclusion and Recommendations
Despite the efforts and measures laid down by industrialized countries to reduce its emission, ground level O3 remains a challenge as a global air pollution problem. There is need to emulate the reduction efforts taken by both North America and Europe in order to mitigate its harmful effects on people and environment. Focus should shift to the urban set ups where emission of NOx and VOC is relatively high compared to rural environments. In addition, countries should also consider limiting emissions of VOC as an effective method of reducing ground ozone and its effects (The Royal Society 85). It is therefore necessary to include NOx and VOC emission control measures in urban and regional air quality strategies.
Works Cited
Andersen, Christian P. “Source–sink balance and carbon allocation below ground in plants exposed to ozone.” New Phytologist 157.2 (2013): 213-228.
Guttorp, Peter, Wendy Meiring, and Paul D. Sampson. “A space‐time analysis of ground‐level ozone data.” Environmetrics 5.3 (2014): 241-254.
McCrady, J. K., and C. P. Andersen. “The effect of ozone on below-ground carbon allocation in wheat.” Environmental Pollution 107.3 (2010): 465-472.
Schlink, Uwe, et al. “A rigorous inter-comparison of ground-level ozone predictions.” Atmospheric Environment 37.23 (2013): 3237-3253.
The Royal Society. Ground-level ozone in the 21st century: future trends, impacts and policy implications. Science Policy Report, 2018. Accessed at https://royalsociety.org/~/media/Royal_Society_Content/policy/publications/2008/7925.pdf on April 19, 2020.
Thompson, Anne M., et al. “Southern Hemisphere Additional Ozonesondes (SHADOZ) 1998–2000 tropical ozone climatology 1. Comparison with Total Ozone Mapping Spectrometer (TOMS) and ground‐based measurements.” Journal of Geophysical Research: Atmospheres 108.D2 (2013).