Understanding Polluted Water: A Doctor's Perspective

Water pollution is the contamination of water bodies, including lakes, rivers, oceans, and groundwater, which results in a negative impact on their uses. It is predominantly caused by human activities, such as sewage discharges, industrial waste, and agricultural activities. Pollutants can be organic, inorganic, radioactive, or include heavy metals, plastics, and toxic substances such as oil, pesticides, and industrial solvents. These contaminants can have devastating effects on aquatic ecosystems and human health, with waterborne diseases such as cholera and gastrointestinal issues being common consequences. With over 80% of wastewater returning to ecosystems untreated, water pollution is a pressing issue that requires appropriate infrastructure, management, and legislation to address.

Characteristics of Polluted Water

Causes of water pollution

Water pollution is caused by a variety of factors, including human activities and natural processes. Here are some key causes of water pollution:

Agricultural Activities

The agricultural sector is a major contributor to water pollution. Farms and livestock operations use pesticides, fertilizers, and chemicals that can contaminate water sources. When it rains, these substances are washed into nearby waterways, leading to nutrient pollution. Animal waste from farms can also introduce bacteria and viruses, causing waterborne diseases such as cholera and typhoid. Additionally, uncontrolled spreading of slurries and manures, as well as ploughing, can contribute to water pollution.

Industrial Waste

Industrial sites often produce toxic chemicals and pollutants as waste. In some cases, improper waste management leads to the dumping of these hazardous substances into freshwater systems, making the water unsafe for human consumption and harmful to marine life. Industries such as manufacturing plants, mines, and agricultural sites are responsible for releasing pollutants into rivers, streams, and other bodies of water that eventually flow into the sea.

Oil Spills and Leaks

Large oil spills and leaks are significant causes of water pollution. These incidents can occur during oil drilling operations in the ocean or from ships transporting oil. Oil reduces the oxygen supply in water environments and destroys marine life and ecosystems. Even small leaks from land-based sources like factories, farms, and cities contribute significantly to marine oil pollution.

Sewage and Wastewater Treatment

Domestic sewage and wastewater treatment plants are primary sources of water pollution. Sewage can contain pathogens, bacteria, and viruses that pose a direct threat to public health. When released into water bodies, these contaminants can cause diseases such as cholera, hepatitis A, and typhoid. Additionally, the decomposition of organic matter in sewage depletes the oxygen content in the water, creating "dead zones" where aquatic life cannot survive.

Plastic and Marine Debris

Plastic pollution is a significant issue, with approximately 11 million metric tons of plastic entering the oceans each year. This pollution comes from various sources, including fishing boats, tankers, and cargo shipping, and storm drains. Plastic breaks down into microplastics, which are consumed by marine wildlife and can accumulate in humans through the food chain, particularly when seafood is consumed.

Climate Change and Rising Temperatures

The increasing global temperatures due to CO2 emissions have a direct impact on water pollution. Warmer water has reduced oxygen content, creating challenges for marine life. Additionally, the felling of forests to meet industrial demands can exhaust water resources and create breeding grounds for harmful bacteria.

Types of water pollution

Water pollution is the contamination of water bodies, which has a negative impact on their uses. Water pollution is usually a result of human activities, but it can also occur naturally. Water pollution can be categorised based on the source of the pollutant or the nature of the water body it affects.

Groundwater Pollution

Groundwater comes from below the Earth’s surface and is found in stores called aquifers. Groundwater pollution occurs when hazardous chemicals and particles applied on the surface by humans seep into the ground through rainwater. These contaminants then pollute underground water sources such as underground rivers and waterbeds. As a result, wells and boreholes may become contaminated. The most common causes of this type of pollution are pesticides and fertilisers from farms, landfill leachate, effluent from wastewater treatment plants, leaking sewers, petrol filling stations, hydraulic fracturing (fracking), and the over-application of fertilisers in agriculture.

Surface Water Pollution

Surface water includes water that is found naturally on the Earth's surface, such as lagoons, rivers, oceans, and lakes. Contamination of these water bodies happens when pollutants dissolve in or mix with the water. Point sources of surface water pollution include industrial effluents and improper wastewater management systems. Non-point sources include agricultural run-off, precipitation, and seepage.

Suspended Matter

Suspended matter pollution comes from soil erosion, runoff, discharges, stirred bottom sediments, and algae blooms. Suspended solids either settle at the bottom or float to the surface. When they settle, they damage underwater life and leach chemicals into the water supply.

Oil Spillages

Once oil enters the water, it quickly spreads over the surface, reducing the amount of oxygen and sunlight that can penetrate the water's surface, preventing plants from photosynthesising, and suffocating fish. Oil spillages also smother the feathers of seabirds, preventing them from flying, and expose them to oil ingestion when they catch fish.

Microbiological Pollution

Microbiological pollution is a type of naturally occurring water pollution. It is caused by microorganisms such as bacteria, viruses, and protozoa, which can cause waterborne diseases such as cholera. This type of water pollution is common in areas where people drink untreated water. Humans are very sensitive to this type of water pollution; therefore, adequate drinking water systems play an important role in eliminating it.

Chemical Water Pollution

Chemicals are the most common type of water contaminant, affecting both surface and underground water bodies. Industrial, commercial, and farming activities are the leading causes of this pollution. Solvents and metals used in industries can pollute rivers and lakes. On farms, pesticides used to control weeds, insects, and fungi contribute to soil contamination. Chemical contamination also occurs due to petroleum spills.

Effects of water pollution

Water pollution has a wide range of effects on the environment, human health, and the economy. Firstly, it destroys biodiversity by depleting aquatic ecosystems and triggering the uncontrolled proliferation of phytoplankton in lakes, a process known as eutrophication. Eutrophication, caused by chemical dumping, leads to the degradation of water quality and the destruction of aquatic life.

Secondly, water pollution contaminates the food chain. Fishing in polluted waters and using wastewater for farming and agriculture introduces toxins into food sources, which are harmful to human health. According to the World Health Organization (WHO), polluted water is water whose composition has changed to the extent that it is unusable and toxic. These toxins can cause various diseases, including cholera, hepatitis, skin diseases, malnutrition, cancer, and other waterborne illnesses. Children are especially vulnerable, with exposure to nitrates at an early age affecting their development and even proving fatal in some cases.

Furthermore, water pollution poses a significant threat to global economic growth. The World Bank President, David Malpass, has warned that "deteriorating water quality is stalling economic growth and exacerbating poverty in many countries." When the biological oxygen demand, an indicator of organic pollution, exceeds a certain threshold, the growth in the Gross Domestic Product (GDP) of the associated regions falls by a third.

The agricultural sector is the biggest consumer of freshwater resources, using about 70% of the Earth's surface water supplies. However, it is also a significant contributor to water pollution. Fertilizers, pesticides, and animal waste from farms wash into waterways during rainfall, leading to nutrient pollution. This excess nitrogen and phosphorus in water or air is the primary threat to water quality worldwide and results in harmful algal blooms.

Unsafe water kills more people each year than war and all other forms of violence combined, and it is estimated that more than 50 kinds of diseases are caused by poor drinking water quality. With increasing water consumption and deteriorating water quality, the challenges of water pollution will only intensify unless action is taken.

Water pollution prevention

Water pollution is a severe issue that poses a threat to the health of millions of people worldwide. It is caused by various factors, including agricultural activities, industrial waste, and sewage, which contaminate our rivers, reservoirs, lakes, and seas with chemicals, waste, plastic, and other pollutants. According to the World Health Organization (WHO), polluted water is water that has become toxic and unusable, causing diseases such as diarrhoea, cholera, and dysentery.

To prevent water pollution and conserve this precious resource, individuals can make several lifestyle changes. Firstly, it is essential to reduce water wastage. This can be achieved by adopting habits such as running washing machines and dishwashers only with full loads, using a bucket of soapy water instead of a running hose when washing cars, and installing water-efficient toilets or placing a brick in the toilet tank to reduce water usage per flush. Additionally, individuals can opt for more water-efficient cleaning methods, such as using a broom instead of a hose to clean driveways and sidewalks and hanging clothes to dry instead of using a dryer.

Another way to prevent water pollution is to minimize the use of harmful chemicals and properly dispose of those that are necessary. For instance, when cleaning or washing dishes, it is advisable to use the minimum amount of detergent or bleach required and to choose phosphate-free soaps and detergents. It is also crucial to avoid disposing of chemicals, motor oil, pesticides, herbicides, fertilizers, or other automotive fluids into sewer systems, as these can contaminate water sources and harm the environment.

Agricultural practices can also contribute to water pollution, so it is essential to promote sustainable farming methods. This includes reducing the use of pesticides, fertilizers, and animal waste, as these can wash into waterways during rainfall and cause nutrient pollution, leading to toxic algal blooms. Implementing drip-irrigation water systems and using drought-tolerant plants can help minimize water usage and reduce the impact of agriculture on water sources.

Finally, raising awareness and advocating for change at a larger scale is crucial. This can involve supporting organizations working towards practical solutions to the water crisis, such as those featured in the documentary "FLOW". Additionally, staying informed about the issues and impacts of water privatization, as explored in films like "Tapped" and "Blue Gold: World Water Wars", can empower individuals to make informed decisions and take collective action to prevent water pollution and protect this vital resource.

Water pollution solutions

Water pollution is a critical issue that poses a threat to human health and the environment. It is caused by various factors, including oil spills, industrial waste, agricultural runoff, and improper sewage disposal. To address this problem, several solutions can be implemented:

Wastewater Treatment

One of the most effective ways to reduce water pollution is by treating wastewater before it re-enters waterways. Wastewater treatment facilities employ biological, physical, and chemical processes to remove pollutants and reduce toxicity levels. Regular maintenance of equipment, such as water treatment sensors, is crucial to ensure the effective removal of contaminants.

Stormwater Management

Stormwater picks up pollutants as it flows along sidewalks, streets, and lawns, eventually carrying them into storm drains, streams, and rivers. By managing stormwater, we can reduce the amount of pollution that reaches these water bodies. This includes practices such as proper fertiliser management, reducing the use of pesticides, and preventing litter and trash from entering storm drains.

Water Conservation

With increasing global demand for freshwater, water conservation becomes essential. Individuals can play a role by reducing water waste, fixing leaky faucets, and practising responsible water usage.

Agricultural Practices

Agriculture is a significant contributor to water pollution, mainly through the use of pesticides, fertilisers, and animal waste. To mitigate this, farmers can adopt more sustainable practices, such as precision farming, integrated pest management, and the use of eco-friendly fertilisers. Planting trees and other vegetation near water bodies can also help prevent chemicals from being washed into waterways.

Public Awareness and Education

Raising public awareness about the causes and consequences of water pollution is vital. Educating communities about proper waste disposal, the dangers of polluting water sources, and the importance of water conservation can empower individuals to take action and make a difference.

Oil Spill Prevention and Response

Oil spills are a significant cause of water pollution, and it is crucial to implement measures to prevent them. This includes improving oil drilling operations, maintaining oil tankers, and enforcing strict regulations on land-based sources of oil pollution, such as factories and farms. When spills occur, rapid response and effective cleanup strategies are necessary to minimise their impact.

Frequently asked questions