Water Pollution's Land Impact: A Complex Environmental Issue

Water pollution is a pressing issue that jeopardizes human health and safety. When harmful substances contaminate bodies of water, they degrade water quality and render it toxic to both the environment and humans. This is a widespread issue, with less than 1% of the Earth's freshwater being accessible to us.

Water pollution can cause land pollution in several ways. Firstly, through agricultural runoff, where pesticides and other chemicals used in farming seep into the groundwater and harm animals, plants, and humans. Secondly, through sewage and wastewater, which often contain harmful chemicals and bacteria that, even after treatment, can breed disease and cause health issues. Thirdly, through industrial waste, which is often dumped into freshwater systems and can make water unsafe for human consumption, alter temperatures, and create dead zones devoid of marine life.

Water pollution, therefore, has a significant impact on land pollution, and both issues must be addressed to protect human health and the environment.

Agricultural runoff: pesticides and fertilisers seep into groundwater, harming animals, plants, and humans

Agricultural runoff is a major contributor to water pollution, and subsequently, land pollution. Every year, approximately half a million tons of pesticides, 12 million tons of nitrogen, and 4 million tons of phosphorus fertiliser are applied to crops in the United States alone. A significant portion of these chemicals does not remain in the fields but is washed away by rainfall or irrigation water into nearby water bodies. This water then flows over farms and fields, picking up pollutants such as pesticides and fertilisers, and eventually making its way into rivers, lakes, and oceans.

Pesticides and fertilisers can have detrimental effects on both the environment and human health when they are not properly managed. They can cause direct mortality in fish, amphibians, and invertebrates, as well as reproductive failure and developmental abnormalities. Furthermore, these chemicals can bioaccumulate in the tissues of aquatic organisms, leading to higher concentrations as they move up the food chain, a process known as biomagnification. This poses risks not only to aquatic species but also to predators such as birds and humans who consume contaminated fish.

For example, the Great Barrier Reef has suffered extensive damage from agricultural runoff. Pesticides, herbicides, and excess nutrients from nearby sugarcane farms have flowed into the marine environment, disrupting the delicate ecological balance of the reef and contributing to coral bleaching and reduced biodiversity.

In addition to the impact on aquatic life, pesticides and fertilisers can also affect terrestrial plants. Eutrophication, or the human-accelerated process by which a water body becomes abundant in aquatic plants and low in oxygen content, can occur when increased levels of nitrogen and phosphorus from fertiliser and manure stimulate algal blooms in lakes and rivers. As these aquatic plants die, microorganisms use them as a food source, further reducing the dissolved oxygen content of the water and suffocating fish and other aquatic species.

Agricultural runoff can also have direct impacts on human health. Contamination of drinking water sources with pesticides and fertilisers can lead to various health issues, including cancer, reproductive disorders, endocrine disruption, and neurological impairments. High concentrations of nitrates in drinking water, particularly from nitrogen-based fertilisers, can interfere with the blood's ability to carry oxygen, potentially leading to methemoglobinemia, commonly known as "blue baby syndrome", which can be fatal if not promptly treated.

To mitigate the effects of agricultural runoff, sustainable farming practices, improved irrigation techniques, buffer zones, and nutrient management plans can be implemented. Adopting conservation practices, such as crop rotation, cover cropping, and reduced tillage methods, can help reduce the environmental impact of agricultural activities while ensuring economic viability for farmers.

Marine dumping: plastic and other materials washed from land pollute the ocean

Marine dumping is a significant contributor to ocean pollution, with plastic being one of the most common pollutants. Plastic waste in the ocean has devastating effects on marine life, ecosystems, and human health.

Plastic pollution in the ocean is primarily caused by littering and improper waste disposal. When plastic is not disposed of properly, it can be blown away, ending up in waterways and eventually reaching the ocean. This is particularly common in areas with ineffective waste management systems, such as middle-income countries, which are the world's plastic emissions hotspots. Coastal cities in these countries are at the highest risk of plastic pollution, as plastic waste is more likely to be washed into the ocean during storms and heavy rain events.

Another major source of plastic pollution in the ocean is industrial fishing. About 20% of the ocean's plastic pollution comes from fishing activities, with discarded or lost fishing gear having a high chance of accumulating offshore due to its durability and distance from coastlines.

Once plastic enters the ocean, it can have severe and long-lasting impacts. Plastic can persist in the ocean for hundreds of years, breaking down into microplastics that enter the marine food chain. These microplastics have been found in marine animals, including fish, turtles, seals, and crustaceans, leading to health issues and even death. Microplastics have also been detected in drinking water, salt, beer, and soil, posing risks to human health.

In addition to the direct impacts on marine life and human health, plastic pollution in the ocean also has economic costs. The presence of plastic in the ocean affects tourism, fisheries, and aquaculture, with annual costs estimated to be up to $19 billion USD globally.

To address the issue of marine dumping and plastic pollution, it is essential to improve waste management systems and promote recycling. Reducing the use of single-use plastics and disposing of waste properly can help prevent plastic from reaching the ocean in the first place. Additionally, supporting legislation and organizations dedicated to reducing plastic pollution and improving waste management is crucial.

Sewage and wastewater: untreated sewage and wastewater from households, agriculture, and industry flow back into the environment

Sewage and wastewater from households, agriculture, and industry flowing back into the environment untreated is a significant contributor to water pollution. This occurs when wastewater is discharged directly into water bodies without prior treatment to remove harmful substances. Globally, more than 80% of wastewater is released back into the environment without treatment or reuse, and this figure exceeds 95% in some underdeveloped countries.

Households

In developing countries, sewage disposal is a significant challenge due to limited access to sanitary conditions and clean water. Untreated sewage can contaminate the environment and cause health issues such as diarrhoea. On the other hand, in developed countries, sewage is typically conveyed through sewage pipes and treated in water treatment plants before disposal, often into the sea. However, even in these countries, sewage can cause problems when people flush chemicals and pharmaceuticals down the toilet. During illnesses, sewage can also carry harmful viruses and bacteria, causing health issues in the general population.

Agriculture

Agricultural practices, including the use of chemical fertilizers and pesticides, are significant contributors to water pollution. When it rains, these chemicals, along with animal waste, are washed into waterways, leading to nutrient pollution. This type of pollution is the number-one threat to water quality worldwide and often results in algal blooms, which can be harmful to both people and wildlife.

Industry

Industrial activities generate wastewater containing metals, solvents, and toxic sludge. In many areas, industries still discharge their waste directly into water bodies. Additionally, oil and gasoline drips from vehicles contribute significantly to marine oil pollution.

Impact on Land Pollution

Water pollution, particularly from untreated sewage and wastewater, can have a cascading effect on land pollution. When contaminated water is discharged into water bodies, it can lead to the contamination of soil and a loss of fertile land for agriculture. This, in turn, affects food availability and poses risks to human health.

Industrial waste: toxic chemicals and pollutants are dumped into freshwater systems, making water unsafe for human consumption

Industrial waste is defined as waste generated by manufacturing or industrial processes. This waste can be solid, liquid, or gases held in containers, and it is divided into hazardous and non-hazardous categories. 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 discarded by commercial establishments or individuals.

The production of all kinds of industrial goods generates wastewater that can be contaminated with toxic substances. These include toxic chemicals, organic and inorganic substances, toxic solvents, and volatile organic chemicals. If these wastes are released into aquatic ecosystems without adequate treatment, they will cause water pollution.

In the United States, about 44% of assessed streams, 64% of lakes, and 30% of bays and estuaries are still classified as polluted. Globally, an estimated 80% of industrial and municipal wastewater is discharged into the environment without any prior treatment, with adverse effects on human health and ecosystems.

The discharge of residual pollution into public waters has serious consequences. Many of the hazardous substances from industry are difficult to biodegrade and, therefore, accumulate in water sediments. This can cause fish, crustaceans, and other creatures to become ill and, in some cases, die. Through cracks in the ground, the polluted water from rivers and the contaminants from the water sediments can enter the groundwater and, thus, the drinking water.

Health risks associated with industrial waste in water include gastrointestinal diseases such as cholera, giardia, and typhoid. Water pollution can also lead to gastrointestinal illness, inhibiting nutrient absorption and malnutrition, with particularly pronounced effects on children.

In addition, water pollution can cause skin diseases and even skin cancer. Exposure to polluted marine recreational waters can have adverse consequences, including frequent skin discomfort such as rashes or itching.

Furthermore, water pollution can pose health risks through the three links of the water system: the source of water, the treatment of water, and the delivery of water. Arsenic, nitrate, chromium, and trihalomethane are major carcinogens in water sources. Carcinogens may also be introduced during chlorine treatment. The effects of drinking water pollution on cancer are complex, and many water pollutants are considered carcinogenic, including herbicides, pesticides, and fertilizers that contain and release nitrates.

Radioactive waste: radioactive materials from nuclear plants and military weapons are released into the environment

Radioactive waste from nuclear plants and military weapons has been released into the oceans for decades. Radioactive isotopes can enter the food chain through plankton and kelp, contaminating fish and other marine life, and ultimately reaching humans.

Radioactive Waste from Nuclear Plants

Radioactive waste is produced by nuclear power stations, reprocessing plants, and the military. As the nuclear energy industry grows, the amount of radioactive waste being disposed of increases. Nuclear power plants use water to cool their radioactive cores, and during this process, the water becomes contaminated with radionuclides. This contaminated water is then stored in large steel tanks or released into nearby bodies of water, such as the ocean.

In 2011, an earthquake and tsunami in Japan caused the Fukushima Daiichi nuclear power plant to release thousands of tons of radioactive water into the Pacific Ocean. This was a significant nuclear accident, second only to Chernobyl. Since then, authorities have used over a million tons of water to cool the plant's disabled reactors, and this highly contaminated water has had to be released into the ocean.

Radioactive Waste from Military Weapons

The Soviet Union dumped large quantities of radioactive material into the Arctic Ocean, Kara Sea, and Barents Sea. This included reactors from nuclear-powered submarines and icebreakers, as well as liquid and solid nuclear waste from military bases and weapons plants.

Impact on the Environment and Human Health

Radioactive waste released into the ocean can spread and be found far from its source. For example, elevated levels of radioactive cesium and iodine were found in small fish dozens of miles from Fukushima. Radioactive material can be absorbed by phytoplankton, zooplankton, kelp, and other marine life, and then transmitted up the food chain to fish, marine mammals, and ultimately, humans.

Radioactive isotopes such as cesium-137, with a half-life of 30 years, and plutonium have been found in seals and porpoises in the Irish Sea. Studies have shown that radioactive material released into the ocean can travel with ocean currents, be deposited in marine sediments, and climb the marine food web.

The impact of radioactive contamination on marine life and humans is still not fully understood, but it is known that exposure to toxic substances in the environment can trigger diseases, including cancer. Radioactive iodine is taken up by the thyroid in humans and marine mammals and can cause thyroid issues. Cesium acts like potassium and is taken up by muscle tissue, potentially leading to cardiovascular issues.

Preventing and Managing Radioactive Waste

To prevent radioactive waste from entering the ocean, it is recognized that radioactive material should be isolated and encased in glass and concrete to prevent leakage on the ocean floor. Radioactive waste is now kept on land for some time to allow radioactivity levels to decrease.

However, the long-term storage of radioactive waste is a challenge. Rapidly developing technology, such as nuclear fusion, may help reduce nuclear waste generation in the future. In the meantime, it is crucial to set internationally accepted regulations for radiation exposure levels to protect human health and the environment.

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