Learning Material

 

THE IMPACT OF AIR POLLUTION ON HUMAN HEALTH

Rose Mary Jose

St. Joseph College of Teacher Education for Women, Ernakulam

 

 

Abstract

Air pollution is a major concern of new civilized world, which has a serious toxicological impact on human health and the environment. It has a number of different emission sources, but motor vehicles and industrial processes contribute the major part of air pollution. According to the World Health Organization, six major air pollutants include particle pollution, ground-level ozone, carbon monoxide, sulphur oxides, nitrogen oxides, and lead. Long and short term exposure to air suspended toxicants has a different toxicological impact on human including respiratory and cardiovascular diseases, neuropsychiatric complications, the eyes irritation, skin diseases, and long-term chronic diseases such as cancer. In this review article, we aimed to discuss the impact of air pollution on human health.

Key terms

Air pollution, cardiovascular diseases, morbidity, mortality, particulate matter

 

Introduction

Pollution of the air have been known since the early man discovered fire and started to use biomass for heating and preparing food. However, many people consider that ambient air pollution is a modern phenomenon linked to industrial development, although health problems related to air pollution have been known before the industrial age. The sources of pollution vary from small unit of cigarettes and natural sources such as volcanic activities to large volume of emission from motor engines of automobiles and industrial activities. Long-term effects of air pollution on the onset of diseases such as respiratory infections and inflammations, cardiovascular dysfunctions, and cancer is widely accepted; hence, air pollution is linked with millions of death globally each year.

A recent study has revealed the association between male infertility and air pollution. Several reports have revealed the direct association between exposure to the poor air quality and increasing rate of morbidity and mortality mostly due to cardiovascular and respiratory diseases. Air pollution

is considered as the major environmental risk factor in the incidence and progression of some diseases such as asthma, lung cancer, Alzheimer's and Parkinson's diseases, psychological complications, autism, fetal growth, and low birth weight.

Air pollution has now emerged in developing countries as a result of industrial activities and also increase the quantity of emission sources such as inappropriate vehicles. About 4.3 million people die from household air pollution and 3.7 million from ambient air pollution.

Exposure to air pollution

In general, combustion is the chief process responsible for pollutant emissions. The chemical composition of air pollution is very complex and consist of gases, e.g. nitrogen oxides, sulphur dioxide, ozone, carbon monoxide, carbondioxide and particles. Combustion processes are mainly responsible for the pollutant present in ambient air. However, incomplete combustion and spill,

e.g. gasoline, may also contribute to ambient air pollution, e.g. benzene. Focus has mostly been on combustion of fossil fuel in connection with energy production and transportation. However, combustion of garbage and biomass, e.g. forest fires will also contribute to the air pollution. Combustion of garbage is especially a problem in poorer areas and villages; as the combustion temperature and technology is not sufficient, many unwanted products are formed.

Urbane airborne particulate matter is a variable mixture of numerous classes and subclasses of contaminants. Particle properties and their associated health effects differ by size. The size and associated composition of particles determine their behaviour in the respiratory system, i.e., penetration, deposition and clearance. The particle size is one of the most important parameters in determining the residence and spatial distribution of particles in ambient air. Ultrafine particles have a very short life, but will rapidly accumulate to form larger particles, that can be transported thousands of kilometers and remains in the atmosphere from days to weeks.

Particles consist of a core to which numerous other compounds, organic as well as inorganic are associated, e.g. nitrogen oxide reacts to form nitrate and sulphur dioxides to form sulphates. These secondary particles do have diverging toxicity from the original particle. Polycyclic aromatic hydrocarbons are principal pollutants formed by incomplete combustion and are associated with particulate matters. Polycyclic aromatic hydrocarbons are products of incomplete combustion and are commonly found in diesel exhaust. Pollutants in diesel exhausts exist as particles and gas phase

compounds. Exposure to diesel exhaust has been associated with an increased risk of bladder cancer in workers occupationally exposed to high level of diesel exhaust.

Sulphur dioxide (SO2) is a gaseous by-product of the combustion of fossil fuels that contains sulphur, e.g. certain coals, liquid fuels and natural gas. Exposure to SO2, even at low level is linked to increased bronchoconstriction in people with asthma, and reduction in lung function has been observed at higher concentrations. Long-term exposure to SO2 has been associated with decreased pulmonary function and increased mortality.

Nitrogen dioxide (NO2) is a gaseous by-product of the combustion of fossil fuels. In many urban areas mobile source emissions are the major source of NO2. NO2 may also react as an oxidant and exposure even at low levels induces inflammatory response. Short-term exposure is associated with increased mortality and hospital admissions.

Adverse health effects

Outdoor air pollution contributes to various adverse health effects. Whereas some effects may be related to short-term exposure, others have to be related to long-term exposure. Although the biological mechanisms are not fully elucidated, epidemiological studies suggest a link between air pollution and various health outcomes, e.g. respiratory symptoms, mortality, cancer.

Mortality

 

A large body of epidemiological evidence suggests an association between ambient air pollution and cardiovascular mortality and morbidity. The major risks have been linked to SO2 and PM. Sulphur dioxide is associated with increased daily mortality from both respiratory and cardiovascular disease even at the low levels. Long term exposure to ambient PM contributes to systemic inflammatory pathways, which are relevant aspects of atherogenesis resulting in atherosclerosis and ultimately cardiovascular death.

Respiratory disorders

 

Exposure to traffic related air pollution has been implicated in impairment of respiratory health in children. Truck traffic and air pollutants associated with truck traffic were associated with chronic respiratory symptoms in children living close to motorways, whereas there was no association with car traffic. Furthermore, there was no association with bronchial hyper responsiveness in these

children, however sensitization to outdoor allergen was increased in the group exposed to high level of air pollution. The increased sensitivity to outdoor allergen may be a consequence of the fact that diesel exhaust particles modifies the allergen and enhances the immunologic response of the allergen and increase the inflammatory responses. Air pollution has not been found to induce asthmatic conditions in children, but will exuberate an already existing condition.

Cancer

 

Epidemiological studies have indicated that in Western countries the relative risk of developing lung cancer is 1.5-fold higher in urban that in rural areas after adjusting for cigarette smoking. Air pollution, e.g. vehicles, industry, power plants, has been reported to increase the risk of lung cancer. The risk of lung cancer death has been suggested to increase by 8% for every 10 micrograms of fine particles/m³ of inhaled air.

Significance and Importance

 

Addressing air pollution is crucial for creating a healthier and sustainable environment. Efforts to reduce pollution not only improve public health but also contribute to the overall well-being of ecosystems and future generations. Improving air quality will improve the quality of life and have important impact on economic development. Mobile sources are the major contributor to ambient air pollution in developed countries. Thus, stringent standards for new sources of air pollution (especially motor vehicles) will significantly improve air quality. However, the increasing economic welfare will result in an increasing number of vehicles and longer commuting distances, so the net benefits of these standards may be negligible. As the level of the pollution depends on the engine type and condition, fuel type, traffic congestions, driving habits and load of vehicles stricter control and introduction of cleaner technologies, e.g. hybrid cars. Furthermore, improved city planning to minimize traffic congestions and development of public transportation may help in minimize the air pollution in the megacities and improve the quality of life.

 

Clean air contributes to a better quality of life by providing a safer and healthier environment. People in areas with lower air pollution levels generally experience improved mental well-being and a higher overall quality of life. Prevention of air pollution is essential for addressing environmental justice concerns. Vulnerable and marginalized communities often bear a

disproportionate burden of pollution, and preventing it can contribute to a more equitable distribution of environmental impacts. Air pollution knows no borders, and preventing it requires global cooperation. International efforts to reduce emissions and limit pollution contribute to a healthier planet for all.

Preventing air pollution is essential for safeguarding human health, preserving ecosystems, mitigating climate change, and promoting sustainable development. It is a multifaceted challenge that requires coordinated efforts at local, national, and global levels.

Conclusion

 

In conclusion, the impact of air pollution on human health is a grave and multifaceted challenge that demands urgent attention and comprehensive action. The detrimental effects of breathing polluted air reach far beyond mere inconvenience, manifesting as a significant threat to public health on a global scale. From respiratory and cardiovascular diseases to increased mortality rates, the consequences are both widespread and severe.

Children, in particular, bear a heavy burden, facing impaired lung development and heightened vulnerability to various health issues. Moreover, emerging research hints at the insidious neurological effects of air pollution, underscoring the need for a holistic understanding of its impact on human well-being.

The ramifications extend beyond individual health, permeating societal and economic realms. The economic costs associated with healthcare expenses and loss of productivity are substantial, emphasizing that the battle against air pollution is not only a public health imperative but an economic one as well.

Crucially, the issue of air pollution is not confined by borders. It is a global concern with transboundary effects, necessitating collaborative efforts on an international scale. Environmental justice considerations highlight the importance of addressing the disproportionate impact on vulnerable communities, emphasizing the need for equitable solutions.

In the face of these challenges, the imperative to prevent air pollution becomes evident. Implementing stringent environmental regulations, adopting sustainable practices, and promoting

clean energy sources are critical steps toward safeguarding human health. The importance of public awareness, education, and advocacy cannot be overstated in fostering a collective responsibility to protect the air we breathe.

Ultimately, recognizing the significance of the impact of air pollution on human health is the first step towards creating a healthier and more sustainable future. Through concerted efforts at the individual, community, and global levels, we can mitigate the adverse effects of air pollution, ensuring cleaner air for current and future generations. The pursuit of cleaner air is not just a matter of environmental stewardship; it is an investment in the well-being of humanity and the planet we call home.

 

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