Water Pollution: Sources And Causes

Water pollution is a pressing issue that poses significant risks to human health, the environment, and the economy. It occurs when harmful substances contaminate water bodies, degrading water quality and rendering it toxic or unfit for human use. The main sources of water pollution include sewage and wastewater treatment, agricultural activities, industrial waste, oil spills, and marine dumping. These sources introduce contaminants such as toxic chemicals, pathogens, and microorganisms into water systems, leading to a range of negative consequences.

Sewage and wastewater

Sources of Sewage and Wastewater

Treatment and Disposal of Sewage and Wastewater

The treatment and disposal of sewage and wastewater are crucial aspects of water pollution control. Wastewater treatment plants employ physical, biological, and chemical processes to remove impurities before the water is released into natural bodies of water or aquifers. However, it is important to note that more than 80% of the world's wastewater flows back into the environment without proper treatment or reuse, according to the United Nations. This untreated wastewater can contain harmful pollutants such as pathogens, phosphorus, nitrogen, heavy metals, and toxic chemicals.

Health and Environmental Risks of Sewage and Wastewater Pollution

Mitigation and Management of Sewage and Wastewater Pollution

To address the issues associated with sewage and wastewater pollution, it is essential to prioritize proper sewage management and treatment. This includes investing in wastewater treatment infrastructure and ensuring that sewage is treated before being released back into water bodies. Innovative solutions, such as waste-free toilets and resource recovery for fuel and drinking water production, also show promise in mitigating sewage pollution.

Industrial waste

Hazardous waste may result from manufacturing or other industrial processes, and it can be toxic, ignitable, corrosive, or reactive. Certain commercial products, such as cleaning fluids, paints, or pesticides, can also be defined as hazardous waste if they are discarded by commercial establishments or individuals.

The production of industrial goods generates wastewater contaminated with toxic substances. This wastewater often contains specific and readily identifiable chemical compounds, such as heavy metals, oils and greases, industrial salts, nitrogen, benzene, and lead.

In the United States, the Environmental Protection Agency (EPA) regulates 94 chemicals in drinking water sources, but there are many other chemicals that are potentially dangerous and unregulated. A 2017 analysis by News21 found that the drinking water of more than 244 million people contains contaminants linked to industrial practices that are not currently regulated.

In addition, industrial waste can have economic impacts, as communities may need to bear the costs of additional treatment to ensure polluted public water is safe to drink.

Oil leaks and spills

Oil spills occur when liquid petroleum hydrocarbons are released into the environment due to human activities or natural disasters. The most common sources of oil spills are tanker accidents, offshore platforms, drilling rigs, and wells. In addition, spills of refined petroleum products, such as gasoline and diesel fuel, as well as heavier fuels used by large ships, contribute to the problem. Oil spills can also result from operational discharges, human error, equipment failure, or deliberate acts.

Oil spills in water have catastrophic consequences for local marine wildlife, including fish, birds, and sea otters. Oil forms a thick sludge in water, as it cannot dissolve, and this suffocates fish, impairs the flight of birds, and blocks light from reaching photosynthetic aquatic plants. The insulating ability of the fur and feathers of marine mammals and birds is reduced, making them more vulnerable to temperature changes and decreasing their buoyancy in the water. Oil spills can also contaminate drinking water supplies, as seen in incidents in Miri, Malaysia, and Coca, Ecuador, affecting hundreds of thousands of people.

The cleanup and recovery process after an oil spill is challenging and time-consuming, depending on factors such as the type of oil, water temperature, and shoreline characteristics. Physical cleanups are expensive, and chemical remediation methods are often employed. Bioremediation, using microorganisms to break down oil, is a promising technology for the future.

Oil spills have far-reaching impacts on tourism, fishing, and port activity, leading to significant economic losses. Tourism industries suffer due to declines in recreational activities and negative media attention. Fishing bans and disruptions to fishing routes are necessary to protect human health from contaminated seafood, resulting in financial hardship for fishermen and related industries. Ports bear the brunt of managing and mitigating oil spills to prevent further spread and ensure the safety of ships and cargo.

Oil spills are a significant environmental concern, and preventing them is crucial to protect aquatic ecosystems and human health. The Oil Pollution Act of 1990 holds responsible parties accountable for cleanup and restoration costs, and regulations such as double hulls in oil tankers have helped reduce the number and severity of spills. However, the ongoing challenge of oil pollution in water demands continued attention and innovative solutions.

Radioactive waste

Another way radioactive waste can enter water sources is through groundwater contamination. Radioactive materials can percolate from soil sediments into aquifers, which are a major source of freshwater. This is particularly common in areas with radioactive elements in the rocks, such as uranium and thorium. Nuclear reactors and nuclear warhead experiments are key sources of human-induced radionuclide discharge, releasing radioactive isotopes that can contaminate groundwater.

The impact of radioactive waste on water sources is long-lasting and harmful. Radioactive waste can persist in the environment for thousands of years, making it difficult and costly to remediate. It poses a significant threat to human health, causing various disorders such as cancer, leukaemia, genetic mutations, osteonecrosis, cataracts, and chromosomal disruption. The ingestion of radioactive water can lead to acute radiation syndrome or cutaneous radiation injury.

To address the issue of radioactive waste in water sources, proper analysis, monitoring, and prevention measures are necessary. Various treatment methods, such as aeration, reverse osmosis, ion exchange, and granule carbon adsorption, can be used to remediate contaminated water. Regulatory organizations also play a crucial role in controlling and managing radioactive waste to minimize its impact on the public and the environment.

Solid waste and plastics

Plastics are produced from fossil fuels, and their lightweight, durable nature has led to their widespread use in a variety of applications, from transportation to medicine. However, the convenience of plastics has fostered a throw-away culture, with single-use plastics accounting for 40% of the plastic produced annually. These single-use items, such as plastic bags and food wrappers, have a very short lifespan but can persist in the environment for hundreds of years. As a result, plastic waste has become ubiquitous, prompting efforts to create a global treaty to address the issue.

The primary sources of plastic pollution are land-based, including urban and stormwater runoff, littering, industrial activities, tyre abrasion, construction, and agriculture. Rivers are a significant pathway for plastic to enter oceans, acting as conveyor belts that pick up trash as they flow downstream. Once in the sea, plastic waste can remain in coastal waters or be transported by ocean currents around the world.

Plastic pollution has severe ecological, social, and economic impacts. It alters habitats and natural processes, reducing ecosystems' ability to adapt to climate change and affecting the livelihoods, food production, and social well-being of millions of people. Marine wildlife, such as fish, turtles, seals, and crustaceans, are among the most directly affected by plastic pollution, suffering from entanglement, ingestion, and internal injuries.

Microplastics, formed from the breakdown of larger plastic pieces, have been found in drinking water systems, the air, and even human blood, lungs, and faeces. While the long-term health effects of microplastics are still being studied, their presence in the environment and human bodies is a cause for concern.

To combat plastic pollution, several strategies can be employed:

• Improve waste management systems and recycling capabilities, particularly in middle- and low-income countries.
• Reduce the manufacturing of unnecessary single-use plastics and encourage the design of plastic products that are more easily reusable or recyclable.
• Implement policies that reduce the demand for certain plastic products and promote circular economy solutions.
• Increase international cooperation and develop global agreements to address plastic pollution, such as the resolution adopted by the United Nations Environmental Assembly (UNEA) in March 2022.

Frequently asked questions