Air Pollutants: Understanding Their Impact And Our Health

Pollutants can have a detrimental impact on the environment and human health. They can affect the air, water, and soil, as well as take the form of harmful noise or artificial light. Pollutants in the air can be toxic to plants and trees, while those in rainfall can damage habitats by depositing acid or excess nutrients. Water bodies such as rivers and lakes are also susceptible to the effects of air pollution. For example, pollutants such as sulfur can lead to excess levels of acid in lakes and streams, and damage trees and forest soils. Atmospheric nitrogen can reduce the biodiversity of plant communities and harm aquatic life.

Harmful gases and particles in the air

The transport sector, including cars, trucks, buses, planes, and trains, is a significant source of air pollution. These vehicles emit a range of harmful pollutants, such as particulate matter, nitrogen oxides, sulphur dioxide, carbon monoxide, and volatile organic compounds (VOCs). The burning of fossil fuels, such as natural gas, coal, or wood, in vehicles and power plants releases pollutants like nitrogen oxide, sulphur dioxide, and hydrocarbons, which react with sunlight to produce smog. Smog is a thick fog or haze that makes breathing difficult, especially for children and older adults.

Other human activities that contribute to air pollution include mass deforestation, industrial processes such as oil and gas development, and agricultural practices. Pesticides, for example, are chemical poisons used to kill weeds and insects that can seep into waterways and harm wildlife. Additionally, the burning of coal to create electricity releases pollutants into the air, affecting the air quality in surrounding areas.

Air pollution can have severe impacts on human health and the environment. It can cause respiratory problems, increase the risk of lung cancer, and lead to premature death. Additionally, air pollution can damage crops and other vegetation, impair their growth, and affect entire ecosystems and the planet's climate.

Water contamination

Causes of Water Contamination

Agricultural activities also contribute to water contamination. Pesticides, nitrogen fertilisers, and organic farm waste from agriculture contaminate water with nitrates, phosphorus, pesticides, soil sediments, salts, and pathogens. The agricultural sector is the biggest consumer of global freshwater resources, and it is also a serious water polluter.

Additionally, industrial sites and industries across the world are major contributors to water contamination. Many industrial sites produce toxic chemicals and pollutants as waste, and in rare cases, this waste is dumped into nearby freshwater systems without proper treatment.

Other causes of water contamination include sewage and wastewater, radioactive waste, and global warming, which causes water temperatures to rise and can kill water-dwelling animals.

Effects of Water Contamination

Furthermore, water contamination results in a lack of potable water, with billions of people worldwide lacking access to clean water for drinking and sanitation, particularly in rural areas. According to the World Health Organisation (WHO), contaminated water causes diseases such as diarrhoea, cholera, dysentery, typhoid, and poliomyelitis, killing more than 500,000 people worldwide annually.

Preventing Water Contamination

To prevent water contamination, it is crucial to reduce CO2 emissions to mitigate global warming and acidification of the oceans. Additionally, the use of chemical pesticides and nutrients on crops should be reduced, and wastewater should be reduced and safely treated for reuse in irrigation and energy production. Single-use plastics should also be restricted to prevent them from ending up in water bodies and breaking down into microplastics.

Soil contamination

• Industrial activity: Industrial processes such as manufacturing, mining, and waste disposal can release toxic chemicals into the soil.
• Agricultural chemicals: Excessive or improper use of pesticides, herbicides, and fertilizers can contaminate the soil.
• Improper waste disposal: Inadequate disposal of industrial, residential, and agricultural waste can lead to soil contamination.
• Atmospheric deposition: Contaminants from the atmosphere, including emissions from industry, transport, and agriculture, can be deposited onto the soil through dry or wet deposition.
• Sewage sludge: The use of sewage sludge as fertilizer can introduce contaminants into the soil.
• Accidental spills: Spills during industrial or agricultural activities can result in soil contamination.

The most common chemicals involved in soil contamination include petroleum hydrocarbons, polynuclear aromatic hydrocarbons (PAHs), solvents, pesticides, lead, and other heavy metals. These contaminants can have detrimental effects on human health, causing various health issues such as cardiovascular problems, nervous system damage, kidney damage, and an increased risk of cancer. They can also impact the ecosystem by reducing crop yields, disrupting food chains, and contaminating water sources.

To address soil contamination, various remediation techniques have been developed, including excavation and removal of contaminated soil, thermal remediation, bioremediation, and phytoremediation. It is important to assess and monitor contaminated sites to ensure the safety of human health and the environment.

Noise pollution

Impact on Humans

Impact on Wildlife

In the ocean, whales and dolphins are particularly affected by noise pollution as they rely on echolocation to survive. Excessive noise from ships, sonar devices, and seismic tests interfere with their ability to communicate, navigate, and find food. Research has linked naval sonar to mass strandings of whales and altered feeding behaviour in endangered blue whales.

Light pollution

Types of Light Pollution

There are four main types of light pollution:

• Skyglow: The collective light pollution found over big cities, creating an artificially bright arch in an urban area at night. Skyglow is caused by light being scattered by water droplets or particles in the air.
• Glare: Gratuitous, bright light causing discomfort or pain. This can be caused by unshielded lights, which can also lead to poor visibility and safety risks.
• Light trespass: When a light beams where it shouldn’t, such as a street light shining into a bedroom or a floodlight spilling light onto an adjacent property.
• Clutter: When too many sources of light are grouped together, causing confusion.

Causes of Light Pollution

The growth of light pollution is also driven by increased development, with more people installing and leaving outdoor lights on throughout the night. The mindset that 'dark is bad and light is good' and the belief that more light equals more safety also contribute to the problem.

Effects of Light Pollution

Impact on Human Health

Artificial light messes with our circadian rhythm, the instinctual beat humans follow to know when to wake up and go to sleep. Disruption of the circadian rhythm has been linked to various health issues, including sleep disorders, depression, hypertension, attention deficit disorder, obesity, diabetes, and heart disease.

Exposure to artificial light at night can also increase the risk of certain types of cancer, such as breast cancer. This is partly due to the disruption of melatonin production, a potent anti-oxidant and anti-carcinogen responsible for regulating metabolism and immune responses.

Environmental Impact

Migratory birds, for example, can be disoriented by artificial light, leading to collisions with buildings or exhaustion from veering off their migratory paths. Sea turtles are also impacted, as hatchlings instinctually move towards light sources, causing them to head away from the ocean and towards danger.

In addition, insects are drawn to artificial lights, reducing their numbers and affecting plant reproduction. Bats, nocturnal creatures, have their activities dramatically altered by artificial light, and researchers have blamed light pollution for declines in populations of North American moths.

Addressing Light Pollution

To reduce light pollution, it is important to turn off unnecessary lights and use fully shielded, light-efficient fixtures that prevent light from escaping and reduce sky glow. Educating oneself on the types of lights that avoid excessive cast or brightness and opting for those products can also help.

Regulatory measures and lighting regulations, such as those implemented in Tucson, Arizona, portions of Northern Italy, and Flagstaff, Arizona, have proven effective in curbing light pollution growth rates.

Frequently asked questions