Pollution's Impact On Clean Water And Sanitation

Access to clean water is a basic human need, and yet, billions of people are still unable to access it. In 2022, 2.2 billion people lacked safely managed drinking water, and 3.5 billion people lacked safely managed sanitation.

Water pollution is a significant contributor to this issue. Water pollution occurs when harmful substances, often chemicals or microorganisms, contaminate a body of water, degrading water quality and rendering it toxic to humans or the environment.

Agricultural pollution is the leading cause of water degradation worldwide. In the United States, agricultural pollution is the top source of contamination in rivers and streams, the second-biggest source in wetlands, and a major contributor to contamination in estuaries and groundwater. Sewage and wastewater, oil pollution, radioactive substances, and marine debris are also major sources of water pollution.

The effects of water pollution are devastating. In 2015, water pollution caused 1.8 million deaths worldwide. Contaminated water can transmit diseases such as cholera, diarrhoea, dysentery, typhoid, and polio, and it is estimated to cause approximately 505,000 diarrhoeal deaths each year.

Unsafe water is one of the world's largest health and environmental problems, particularly for the poorest people. It is a leading risk factor for infectious diseases and exacerbates malnutrition, especially in children.

To address this issue, it is crucial to understand the sources of pollution and the types of water bodies affected. Point source pollution comes from a single source, such as a manufacturer or refinery, while nonpoint source pollution comes from diffuse sources like agricultural or stormwater runoff. Groundwater, surface water, and ocean water are all vulnerable to pollution, with ocean water pollution often originating on land and being carried out to sea by streams and rivers.

To ensure access to clean water for all, it is necessary to implement measures such as improving water supply and sanitation, better managing water resources, and investing in infrastructure and sanitation facilities.

Water pollution and its effects on human health

Water pollution is a severe issue that jeopardizes human health. Unsafe water is responsible for more deaths each year than war and all other forms of violence combined. In 2015, water pollution caused 1.8 million deaths, with contaminated water causing about 1 billion cases of illness annually.

Sources of Water Pollution

Water pollution occurs when harmful substances contaminate water bodies, rendering them toxic to humans and the environment. Point source pollution comes from a single source, like wastewater discharge from a manufacturer, while nonpoint source pollution comes from diffuse sources like agricultural runoff. Transboundary pollution occurs when contaminated water from one country spills into another's waters.

The agricultural sector is the biggest consumer of global freshwater resources and a serious water polluter. In the US, agricultural pollution is the top source of contamination in rivers and streams, the second-biggest in wetlands, and the third in lakes. Sewage and wastewater, including stormwater runoff, are also major sources of water pollution. More than 80% of the world's wastewater is released into the environment without treatment or reuse.

Oil pollution is another significant issue, with consumers accounting for the vast majority of oil pollution in seas, and nearly half of the estimated 1 million tons of oil reaching marine environments each year coming from land-based sources. Radioactive waste, generated by uranium mining, nuclear power plants, and military weapons, is another dangerous contaminant that can persist in the environment for thousands of years.

Effects of Water Pollution on Human Health

Microbiologically contaminated drinking water can transmit diseases such as cholera, dysentery, typhoid, and polio, causing approximately 505,000 diarrhoeal deaths each year. Waterborne pathogens from human and animal waste are a leading cause of illness from contaminated drinking water, with Legionnaires' disease also sickening thousands in the US annually.

Chemical and industrial pollutants in water, such as heavy metals (e.g., arsenic, mercury), pesticides, and nitrate fertilizers, pose serious health risks, especially to children and pregnant women. These toxins can cause cancer, hormone disruption, and altered brain function.

Unsafe water also exacerbates malnutrition and childhood stunting. Diarrhoea, caused by contaminated water, is the most widely known waterborne disease, but other hazards include schistosomiasis, an acute and chronic disease caused by parasitic worms contracted through infested water, and dengue fever transmitted by insects breeding in water.

Addressing Water Pollution

Safe and readily available water is essential for public health and can boost countries' economic growth and poverty reduction. Sustainable Development Goal 6.1 aims for universal and equitable access to safe and affordable drinking water. In 2022, 73% of the global population used safely managed drinking water services, but 2.2 billion people still lacked access.

To address water pollution, it's crucial to understand its sources and the type of water body affected. Groundwater pollution occurs when contaminants like pesticides and fertilizers reach aquifers, while surface water pollution fills our oceans, lakes, and rivers with toxins. Ocean water pollution, often originating on land, includes chemical, nutrient, and heavy metal contaminants, as well as marine debris, mainly plastic.

To prevent water pollution, individuals can reduce plastic consumption, properly dispose of chemicals and non-biodegradable items, maintain vehicles to prevent leaks, and practice responsible landscaping. Supporting policies and regulations that protect water sources and investing in infrastructure, like wastewater treatment and lead-pipe removal, are also vital.

Agricultural pollution

Agriculture is the biggest consumer of global freshwater resources, with farming and livestock production using about 70% of the earth's surface water supplies. It is also a serious water polluter. Globally, agriculture is the leading cause of water degradation. In the United States, agricultural pollution is the top source of contamination in rivers and streams, the second-biggest source in wetlands, and the third main source in lakes. It is also a major contributor to contamination in estuaries and groundwater.

Every time it rains, fertilizers, pesticides, and animal waste from farms and livestock operations wash nutrients and pathogens into waterways. Nutrient pollution, caused by an excess of nitrogen and phosphorus in water or air, is the number-one threat to water quality worldwide. It can cause algal blooms, a toxic soup of blue-green algae that can be harmful to people and wildlife.

Livestock and poultry in the United States produce nearly 1.4 billion tons of manure annually, which is almost five times the waste of the entire US population. This waste is often spread on the land untreated, leading to runoff into water sources. Before being applied to land, the manure usually sits in vast manure lagoons that can grow to the size of a football field. These lagoons contain a toxic mix of antibiotic residue, chemicals, and bacteria that can overflow, leak, and spill, causing the contents to leach into the soil and groundwater.

Pesticides are another major contributor to agricultural pollution. They are routinely detected in 88% of streams and rivers in the US and are present in the bodies of more than 90% of Americans. They can cause many chronic diseases, such as endocrine, neurological, and hormonal disorders, as well as cancer.

Antibiotics are also increasingly being used in livestock farming, with nearly two-thirds of antibiotics important to human medicine in the US being sold for use in livestock. This widespread use is contributing to the public health crisis of antibiotic resistance. Bacteria can develop resistance to these drugs and then spread from farms through air and water, including water used to irrigate crops.

Sewage and wastewater

According to GESAMP (2001), sewage contamination in coastal marine environments leads to a significant increase in infectious diseases linked to bathing and swimming in the sea and the consumption of seafood. Human exposure to toxins associated with algae blooms also imposes significant risks. Most illnesses are caused by pathogens, which are biological/infectious agents that cause diseases. They cause a wide range of acute illnesses, including diarrhoea, cholera, dysentery, typhoid and hepatitis A. Furthermore, sewage can contain industrial chemicals, nutrients such as nitrates and phosphates, pharmaceuticals, medical waste, oils and greases, which result in additional threats to human health.

The release of untreated sewage into water bodies has severe ecological consequences. Excess nutrients from sewage, fertilisers from agriculture and nitrogen oxides from burning fossil fuels contribute to eutrophication, leading to excessive growth of marine plant life and decay. This process limits sunlight availability and causes a lack of oxygen in the water, known as eutrophication, which can suffocate and kill marine animals, coral reefs, seagrass beds and other vital habitats. Some algal blooms produced by eutrophication are toxic and can harm or kill marine mammals, causing hundreds of millions of dollars' worth of damage to commercial fisheries.

The impact of sewage and wastewater on water pollution is a global issue. According to the United Nations, more than 80% of the world's wastewater flows back into the environment without proper treatment or reuse, and this figure rises to over 95% in some least-developed countries. This lack of adequate wastewater treatment infrastructure has severe consequences for human health, the environment and economic activities such as fisheries and tourism.

To address the issue of sewage and wastewater pollution, it is crucial to invest in improving wastewater treatment infrastructure and promoting sustainable practices. This includes separating stormwater and household sewage, treating wastewater before discharge, and adopting circular economy principles to reduce contamination of ecosystems. Additionally, natural solutions such as constructed wetlands, neighbourhood green spaces and permeable pavements can help absorb and treat stormwater, reducing the burden on sewage systems.

Oil pollution

Oil spills can occur in various ways, but the most significant incidents generally involve ocean-going vessels, such as tankers, or offshore drilling platforms. Other sources of oil pollution include routine maintenance and operations on ships, such as bilge pumping, which, while small in volume, can collectively contribute significantly to oil pollution in oceans. Additionally, natural sources of oil, such as underwater seeps and eroding sedimentary rocks, also contribute to oil pollution.

The impacts of oil spills are wide-ranging and often catastrophic. Oil spills can spread quickly over the water surface, with lighter oils, like gasoline, dispersing faster than heavy crude oils. This rapid spread makes containing oil spills extremely challenging. Oil can also sink and settle at the bottom of water bodies, affecting aquatic life and ecosystems below the surface. The density of oil varies, and while most oils are less dense than seawater, some heavy oils can sink in freshwater rivers.

Oil spills have devastating effects on marine life, including birds, mammals, fish, shellfish, and corals. Oil destroys the insulating ability of fur-bearing mammals, such as sea otters, and the water repellency of birds' feathers, leaving them vulnerable to hypothermia. Juvenile sea turtles can become trapped in oil and mistake it for food. Dolphins and whales may inhale oil, affecting their lungs, immune function, and reproduction. Additionally, many birds and animals ingest oil when they attempt to clean themselves, leading to poisoning.

The clean-up of oil spills is a complex and challenging process. Natural methods, such as bioremediation, utilize microorganisms to break down oil, while chemical dispersants are applied to speed up the natural breakdown process. Other methods include the use of booms to contain oil spills, skimmers to remove oil from the water surface, and burning the oil. However, each method has its limitations and potential environmental trade-offs.

The release of oil into water sources and the subsequent pollution have severe consequences for human communities as well. Oil pollution can contaminate drinking water sources, leading to the transmission of diseases such as cholera, diarrhoea, dysentery, hepatitis A, typhoid, and polio. It can also disrupt food production, recreational activities, and economic activities, affecting livelihoods and well-being.

To address the challenges posed by oil pollution, regulations such as the Oil Pollution Act have been implemented to enforce removal procedures, assign liability, and prevent future spills. Additionally, the United Nations treaty, the Convention for the Prevention of Pollution from Ships (MARPOL), mandates the use of oil-pollution prevention equipment and imposes restrictions on discharges near land. While progress has been made, there is still a long way to go in mitigating the impacts of oil pollution on water sources and sanitation.

Radioactive substances

Radioactive contamination poses significant hazards due to the production of ionizing radiation during the radioactive decay of contaminants. This radiation includes alpha, beta, gamma rays, and free neutrons, which can have detrimental effects on human health. The degree of hazard depends on various factors, including the concentration of contaminants, the energy of the emitted radiation, the type of radiation, and proximity to the human body.

• Nuclear weapons production and nuclear energy generation: The production of nuclear weapons and energy through fissionable material can release radioactive elements into water supplies.
• Uranium mining: Mining for uranium can introduce radioactive elements into water sources.
• Medical treatments: The use of radioactive iodine in medical treatments can contaminate water supplies.
• Oil and gas drilling: Drilling activities can unearth radioactive elements that naturally exist in bedrock, leading to potential water contamination.
• Natural occurrence: Radioactive elements, such as radium, uranium, and radon, can be found naturally in rock and soil and can dissolve in water, leading to contamination.

To protect public health, drinking water systems test and filter out contaminants, including radioactive substances. The U.S. Environmental Protection Agency (EPA) sets Maximum Contaminant Levels (MCLs) for radionuclides in public drinking water under the Safe Drinking Water Act. These standards aim to ensure that drinking water provided to customers meets all federal, state, and local drinking water standards.

There are several treatment methods available to address radioactive contamination in water:

• Chemical precipitation: This method involves co-precipitating the precipitant and radionuclides in the waste liquid, reducing the specific activity of the wastewater.
• Ion exchange: Ion exchange resins or inorganic materials are used to separate and extract specific ions from the wastewater.
• Evaporative concentration: This method evaporates water from the waste liquid, leaving behind non-volatile radionuclides for further treatment and disposal.
• Membrane separation: Membrane technology utilizes selective separation to purify, concentrate, or separate the wastewater. Different types of membranes, such as reverse osmosis, ultrafiltration, nanofiltration, and microfiltration, are used depending on the size of particles or molecules to be removed.
• Adsorption: Porous adsorbent materials, such as zeolite, activated carbon, or biomass adsorbents, are used to remove radionuclides from the waste liquid.
• Biotechnology: This approach utilizes plants or microbial cells to remove radionuclides through biotransformation, biosorption, bioaccumulation, sedimentation, or solubilization mechanisms.

While these treatment methods offer promising solutions, ongoing research and development are necessary to improve their effectiveness and address limitations. The goal is to minimize the presence of radioactive substances in water, protect public health, and ensure the safe and sustainable use of nuclear technology.

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