Air Pollution: Health Effects

Air pollution occurs when hazardous or excessive amounts of substances such as gases, particles, and organic atoms enter the Earth’s climate. Objective: This review article defines air pollution, describes the types of pollutants, lists the various causes, describes the effects on human health, and preventive measures to reduce the effects of air pollution on human health. Methods: A comprehensive review of the literature was conducted and the effects of air pollution on human health were described. Results and Conclusion: Air pollution has significant impact on human health in the form of respiratory diseases, asthma and lung cancer, cardiovascular disorders, malignant tumors etc. Associations have been found between male infertility and air pollution, and between air pollution and higher risk of immune deficiency, neuroinflammation, neurogenic hyperactivity, crime, age-inappropriate behavior, Alzheimer’s disease, and Parkinson’s disease. Traffic-related air pollutants affect skin aging and cause facial pigmentation. There is an association between air pollution and the risk of eye irritation, dry eyes, retinopathy, and adverse eye outcomes. Chronic exposure to air pollutants during pregnancy has adverse effects on fetal development, leading to low birth weight and stillbirth. Air pollution is considered a significant contributing factor to the increased prevalence of allergic diseases in children.

Introduction

Air pollution is the presence of chemicals or compounds in the air that are not normally present, which degrade air quality or negatively affect the quality of life, such as: B. Ozone layer damage or global warming. Air pollution occurs when hazardous or excessive amounts of substances such as gases, particles, and organic atoms invade the Earth’s climate. Both human activities and natural phenomena can cause air pollution.

Target

This review article defines air pollution, describes the types of pollutants, enumerates the various causes, identifies the effects on human health, and suggests preventive measures to reduce the effects of air pollution on human health.

Methods

The literature has been extensively surveyed and describes the effects of air pollution on human health. Databases were searched through Google Scholar to identify research studies and interventions examining the health effects of air pollution. The keywords entered into the database were air pollution, health effects and papers were searched from 1979 to 2014.

Results

Air pollution is caused by various types of solid and various types of liquid particles and certain gases suspended in the air. These particles and gases are regularly produced from vehicle and truck exhaust, industries, dust, volcanoes, and forest fires. Solid and liquid particles suspended in air are called aerosols.

Types

Primary Pollutants: There are many types of primary pollutants like carbon oxide, nitrogen oxide, sulfur oxide, particulate matter, lead, volatile organic compounds etc.

Secondary pollutants: Secondary pollutants result from chemical reactions that occur when pollutants are exposed to sunlight. The most important air pollutants include particulate matter, nitrogen dioxide, carbon monoxide, and sulfur dioxide.

Causes

Sources of pollution can range from simple causes such as small amounts of tobacco and volcanic eruptions to large amounts of emissions from automobile engines and mechanical activities. The main sources are emissions from vehicles, burning of petroleum products, pollution from air conditioning, pollution from dust and soil, household pollution, volcanic eruptions, pollution from natural phenomena like deforestation and pollution from industrial facilities which release harmful gases like carbon monoxide and nitrogen oxides.

Emit

Fog caused by air pollution Fog is a type of cloud that touches the ground. Fog occurs when the air near the ground becomes so cold that water vapor turns into liquid water or ice. Fog is becoming common in urban areas, which may be caused by increasing air pollution from various sources. Increasing levels of pollution can trigger atmospheric reactions that lead to the formation of secondary pollutants, which in turn can increase the concentrations of pollutants in the air.

Mist

Fog or mist is caused by water droplets in the air and varies only in the extent to which it can be seen. Haze is the reflection of sunlight caused by air pollution, while smog occurs when pollution causes ozone depletion at the ground. Both mist and fog are formed when water droplets are present in the air.

Smoke

Smog is a type of air pollution originally named for the mixture of smoke and fog in the air. Classic smog is caused by the burning of large amounts of coal in an area, resulting in a mixture of smoke and sulfur dioxide. Smog is a problem in many cities and continues to have adverse effects on human health.

Health Effects

The long-term effects of air pollution on the development of diseases such as respiratory diseases, inflammation, cardiovascular disorders and cancer are well known. A study conducted by Zhou et al found an association between male infertility and air pollution. Wheezing, cough, dry mouth and limited activity due to breathing problems are the most common clinical symptoms of respiratory diseases caused by air pollution. Air pollution is also considered to be the most important risk factor for some respiratory diseases such as asthma and lung cancer. Epidemiological studies have demonstrated a direct link between emissions of air pollutants and cardiovascular disease.

Neuropsychiatric Symptoms

Studies have shown links between air pollution and nervous system hyperactivity, crime and age-appropriate behavior. Studies have also found a link between air pollution and a higher risk of nerve inflammation, Alzheimer’s disease, and Parkinson’s disease. Some studies have shown that aggression and stress are closely related to higher levels of air pollution in big cities.

Skin Changes

Studies have shown that traffic-related air pollution affects skin aging and causes age spots on the face.

Defence System

Poor air quality can cause serious immune system complications, including: Abnormal increase in serum immunoglobulin (IG) levels. IgA, IgM and complement element C3 in humans, as well as chronic inflammatory diseases of the airways. Exposure to these immunotoxins can lead to various stages of immune deficiency, which may underlie the increased risk of many diseases such as neuroinflammation.

Effects On Eyes

Chronic exposure to air pollutants increases the risk of retinopathy and other adverse eye effects. Additionally, there is now evidence of a link between air pollution and eye inflammation, dry eyes and some of the leading causes of blindness.

Pregnancy

Recent studies have shown that maternal exposure to air pollution can affect fetal development, leading to premature birth, low birth weight, dwarfism, and potentially adverse cardiovascular and respiratory effects. Several epidemiological and clinical studies conducted in low-income countries have found an association between exposure to indoor air pollution during pregnancy and low birth weight and stillbirth.

Allergy

Air pollution is considered to be the main reason for the increase in the prevalence of allergies in children.

Preventive Measures

To reduce air pollution, proper cooking stoves can be used instead of wood stoves. A randomized trial with well-ventilated wood cooking stoves in rural Mexico showed that use of proper cooking stoves reduced the longitudinal decline in forced expiratory volume in 1 second and respiration compared to open fire. Related symptoms improved. It also found that use of improved cooking stoves halved carbon monoxide exposure and reduced the rate of pneumonia diagnoses.

Governments have a huge responsibility to control air pollution and must approve measures to control climate change, including strict laws to reduce carbon dioxide emissions. Urban forests and green roofs should be proposed as strategies to reduce pollution in urban areas. Plants remove pollutants in several ways, including absorbing gaseous pollutants, trapping particles through their leaves, and breaking down organic compounds such as polycyclic aromatic hydrocarbons.

Improving residential ventilation by using biomass fuels reduces the health effects of air pollution.

Encouraging walking and cycling instead of using cars and bicycles for short distance travel can help reduce air pollution.

Conclusion

Air pollution is caused by solid and liquid particles and some airborne gases that come from exhausts of automobiles and trucks, factories, dust, volcanoes, forest fires, etc. Air pollution has a significant impact on human health in the form of respiratory illnesses and diseases such as asthma, lung cancer, cardiovascular disorders and malignant tumors. Links have been found between male infertility and air pollution. Associations have been found between air pollution and higher risk of immune deficiency, neuroinflammation, nervous system overactivity, crime, age-appropriate behavior, Alzheimer’s disease, and Parkinson’s disease. Traffic-related air pollutants affect skin aging and cause facial pigmentation.

There is evidence of associations between air pollution and risk of eye inflammation, dry eye, retinopathy and adverse eye outcomes. Chronic exposure to air pollutants during pregnancy can have adverse effects on the developing fetus, resulting in low birth weight and stillbirth. Air pollution is considered a major factor for the increased prevalence of allergic diseases in children.

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