Water Pollution: Understanding The Causes And Effects

Water pollution occurs when toxic substances enter and contaminate water bodies such as lakes, rivers, and oceans. This can happen through oil spills, industrial waste, agricultural runoff, and sewage discharge. Oil drilling operations, shipping, and land-based sources like factories, farms, and cities are major contributors to oil pollution. Harmful chemicals, bacteria, and viruses from human and animal waste, as well as pesticides and fertilizers, can contaminate water supplies, leading to health issues and ecosystem disruption. Global warming also plays a role, with rising temperatures decreasing oxygen levels and causing dead zones where aquatic life cannot survive. Radioactive waste from nuclear energy facilities and coal and gas industries further exacerbate water pollution, highlighting the need for proper waste disposal and alternative energy sources.

Oil spills and leaks

Oil spills became a significant environmental issue in the 1960s due to intensified petroleum exploration and production on continental shelves and the use of supertankers capable of transporting large amounts of oil. While stringent shipping and environmental regulations have made large oil spills from supertankers rare, thousands of minor spills still occur annually. Oil spills can harm sea creatures, ruin beaches, and make seafood unsafe to eat. They can also cause respiratory and reproductive problems in humans, as well as liver and immune system damage.

Oil spills on water release liquid petroleum hydrocarbons, particularly in the marine ecosystem, due to human activity. Oil spills on land are different in that the oil does not spread as quickly, and the effects remain localised. Oil spills on water can be challenging to clean up, and the cleanup process can take weeks, months, or even years. The type of oil spilled, the temperature of the water, and the types of shorelines and beaches involved are all factors that influence the cleanup process. It is important to note that cleanup activities can never remove 100% of the spilled oil, and scientists must ensure that their actions do not cause further harm.

Oil pollution in marine environments can come from various land-based sources, including factories, farms, and cities. Oil can enter waterways through runoff from roads and rivers, as well as from oil and fuel leaks from cars, trucks, and recreational boats. Oil pollution can also result from natural seepage from the ocean floor, adding to the overall amount of oil in the world's waterways. To address oil spills, the Oil Pollution Act of 1990 established that those responsible for spills can be held accountable for paying for cleanup and restoration efforts.

Industrial waste

The types of industrial waste generated include cafeteria garbage, dirt and gravel, masonry and concrete, scrap metals, trash, oil, solvents, chemicals, weed grass and trees, wood and scrap lumber, and similar wastes. Industrial solid waste can be solid, liquid, or gases held in containers.

The increased population has led to a rise in the demand for goods, which has caused rapid industrialization. This has led to an increase in industrial waste, which has become one of the biggest sources of water pollution. Industrial waste gets into water systems through the improper disposal of waste and wastewater.

To prevent water pollution from industrial waste, proper wastewater treatment is crucial. Several treatment plants use chemical, electrochemical, biological, and physical processes to release potable water. Modern wastewater recirculation systems enable the reuse of production wastewater, preventing water pollution.

Technologies have been developed to address solid waste and other environmental and recycling problems. For instance, membrane systems and vacuum distillation systems can treat wastewater and enable its reuse. Effective wastewater management is essential for environmental protection and public health.

Sewage

In terms of human health, low-income communities are particularly at risk as their homes are often closest to the most polluting industries. Waterborne pathogens from sewage can cause diseases such as cholera, giardia, and typhoid, and thousands of people in the United States are sickened each year by Legionnaires' disease, which can be contracted from contaminated water sources. According to the World Health Organization (WHO), bathing in polluted seas causes approximately 250 million cases of gastroenteritis and upper respiratory disease annually.

To address sewage pollution, it is crucial to stop sewage overflows and leaks and ensure that sewage is properly treated before being released into waterways. This requires significant investment in wastewater infrastructure, including updating old pipes and expanding natural areas to prevent stormwater from rushing into sewers. In addition, individuals can play a role in improving water quality by properly disposing of items that should not be flushed down the toilet, such as wipes, nappies, and cooking fats, as these can cause blockages and flooding.

While there have been efforts to improve sewage treatment, such as the Clean Water Act in the United States, the infrastructure in many places is aging and overwhelmed. This has led to accidental or illegal releases of sewage, contributing to water pollution. In the UK, for example, there were over 400,000 instances of sewage being released into waterways in 2020, and water companies have been fined for illegal discharges.

Agricultural runoff

Agricultural operations apply about half a million tons of pesticides, 12 million tons of nitrogen, and 4 million tons of phosphorus fertilizer to crops annually in the continental United States. When it rains, these chemicals are washed off the land and into nearby water sources, causing pollution. This is known as nonpoint source pollution, and it is challenging to control because the contaminated water is not collected and conveyed to a single point for treatment.

Fertilizers and livestock manure contain high levels of nitrogen and phosphorus, which can stimulate algal blooms in lakes and rivers. These blooms can lead to hypoxic conditions, which are low-oxygen environments that are harmful to aquatic life. Algal blooms can also affect the recreational use of local streams and downstream reservoirs and estuaries. Additionally, the toxins released by some algae can be harmful to humans, causing chronic diseases such as endocrine and neurological disorders and even cancer.

Soil erosion, nutrient loss, and the runoff of pesticides and other contaminants from agricultural land are leading causes of water quality impairment. Excessive sedimentation from erosion can overwhelm aquatic ecosystems, smother breeding areas, and degrade coastal and marine ecosystems, including coral reefs.

To address these issues, farmers can adopt regenerative agriculture strategies, such as improving soil health through planting cover crops and streamside buffer crops, which can significantly reduce nutrient runoff and improve water quality.

Radioactive waste

However, radioactive water pollution is often caused by human activity, particularly nuclear energy production. Uranium, the element used in the creation of nuclear energy, is a highly toxic chemical. Radioactive wastewater is produced after using nuclear technology, and if not treated and disposed of properly, can be extremely hazardous to the environment. Radioactive wastewater treatment technologies include dilution and mixing, evaporative concentration, solidification, and long-term isolation.

Incidents of radioactive waste being dumped or discharged into the oceans have occurred worldwide. For example, a French nuclear reprocessing plant discharged radioactive waste into the English Channel, and the Soviets dumped nuclear waste into the Arctic Ocean, Kara Sea, and Barents Sea. The Fukushima Daiichi nuclear power plant in Japan also released contaminated water into the Pacific Ocean after the 2011 earthquake and tsunami.

The impact of radioactive contamination on marine life and humans is still unclear. While no definitive link has been established between radioactive waste and harm to marine life, there have been instances of die-offs of seals and other marine animals in areas where nuclear waste was dumped. Scientists are concerned about how radioactivity might affect marine life and how it moves up the food chain. Radioactive iodine, for example, is taken up by seaweed or plankton and can be transferred to fish, which are in turn eaten by larger fish.

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