What Makes Water Polluted And Unsafe?

Water pollution is a widespread problem that jeopardizes human health. Water bodies can be polluted by a wide variety of substances, including toxic chemicals, waste, plastic, oil, and other harmful substances. These pollutants can contaminate rivers, reservoirs, lakes, and seas, making the water unsafe for human consumption and damaging aquatic ecosystems. Water pollution has severe consequences for both human health and the environment, and it is important to address this issue to ensure access to clean and safe water.

Oil spills and tanker leaks

Oil tanker spills are considered a significant ecological threat due to the vast amount of oil released in each accident. The shipping industry, through both legal and illegal discharges, contributes about one-third of the oil in the waters worldwide, while tanker spills account for about 10%. The largest oil spill in history occurred during the Gulf War in 1991 when oil wells and tankers in Kuwait were destroyed, releasing over 888 million litres of oil into the Persian Gulf. Other notable oil tanker spills include the Exxon Valdez in 1989, which released more than 260,000 barrels (over 40 million litres) of oil in Alaska's Prince William Sound, and the Prestige in 2002, which spilled 77,000 tonnes of crude oil off the coast of Galicia, Spain.

The impact of oil spills on marine life is devastating. Oil penetrates the plumage of birds and the fur of mammals, reducing their insulating ability and making them more susceptible to temperature changes and hypothermia. It also impairs the water repellency of birds' feathers, exposing them to harsh elements detrimental to their health. Additionally, oil spills can cause stunted growth, fin erosion, reproduction impairment, enlarged livers, and changes in respiration and heart rates in fish and shellfish. The death or injury of many sea creatures, including birds, sea mammals, fish, algae, and coral, often results from these incidents.

The economic repercussions of oil spills can be significant, particularly when they disrupt commercial fishing activities. In the case of the Prestige oil tanker spill, large zones were cordoned off for fishing, with bans lasting for more than eight months, affecting fishermen, ship owners, and companies in the industry. Cleanup and recovery efforts following oil spills are challenging and depend on various factors, including the type of oil spilled, water temperature, and the presence of shorelines.

To address the issue of oil spills and tanker leaks, regulations and innovations have been implemented. For example, the International Convention for the Prevention of Pollution from Ships, known as MARPOL, mandated in 1992 that large tankers have double hulls, significantly reducing the number and impact of oil tanker spills. Additionally, organisations like the International Tanker Owners Pollution Federation (ITOPF) track and document significant oil spill incidents, raising awareness and facilitating a coordinated response to mitigate the environmental and economic damage caused by these events.

Radioactive waste

The release of radioactive waste into water bodies has occurred in several incidents worldwide. For example, a British nuclear fuels plant has repeatedly released radioactive waste into the Irish Sea, and a French nuclear reprocessing plant has discharged waste into the English Channel. The Fukushima Daiichi nuclear power plant in Japan also released large amounts of radioactively contaminated water into the ocean after the 2011 earthquake and tsunami. These incidents have raised concerns about the potential impact on marine life and humans.

The presence of radioactive waste in water highlights the importance of proper waste management and treatment. Public drinking water systems employ various methods, such as testing, filtering, and setting maximum contaminant levels, to ensure that the water supplied to customers is safe for consumption and meets all relevant standards. These measures help prevent water sources from becoming contaminated by radioactive materials and protect public health.

Microplastics

A 2022 study found that microplastics accumulate within freshwater systems, especially at the source of a river or stream, where the flow of water is relatively low, allowing for the piling up of microplastics. This accumulation has far-reaching implications for the ecosystem. Furthermore, the melting of ice in the Arctic and Antarctic regions due to climate change is expected to release a significant amount of plastic into the oceans, which will have a detrimental impact on the marine food chain.

To reduce microplastic pollution, individuals can favour products made with biodegradable materials and sustainable packaging, as well as recycle and reuse plastic products. It is also important to reduce plastic consumption and properly dispose of waste to prevent it from ending up in waterways.

Groundwater pollution by metals

Water pollution is a widespread problem that jeopardizes human health. Unsafe water kills more people annually than war and other forms of violence combined. Water pollution can occur in various sources, including rivers, reservoirs, lakes, and seas.

Groundwater, a vital source of freshwater, is also susceptible to pollution by metals and industrial production waste. Metals can contaminate groundwater through several sources, including wastewater recharge, agricultural practices, mining activities, rock-water interaction, and weathering. High salinity, alkalinity, and anoxic conditions can also contribute to metal contamination in groundwater.

Research has identified hazardous levels of heavy metals in groundwater, posing significant health risks to humans. For example, a study in Sialkot, Pakistan, found high levels of potentially harmful metals (PHMs) in drinking groundwater sources, including nickel, zinc, copper, chromium, lead, manganese, and iron. Similar studies in other regions of Pakistan have reported lead concentrations in drinking water exceeding the World Health Organization's (WHO) permitted limit.

The presence of heavy metals in groundwater can have both beneficial and detrimental effects on human health. While some metals, like chromium (III), are necessary for insulin secretion and normal glucose metabolism, exposure to high levels of heavy metals can lead to acute and chronic toxicity, liver, kidney, and intestinal damage, anemia, and cancer.

It is important for well owners to be aware of the potential for metal contamination in their groundwater and to take steps to protect their drinking water sources. Proper waste disposal, reducing industrial discharges, and implementing agricultural practices that minimize metal runoff can help mitigate the problem of groundwater pollution by metals.

Pesticides and herbicides

Pesticides are chemicals designed to kill or control pests, including insects (insecticides), weeds (herbicides), and fungi (fungicides). Herbicides are a type of pesticide. They are used to protect crops from weeds. Pesticides are used in agriculture, in homes and businesses, on lawns and gardens, along roads, in recreational areas, and on pets and livestock.

The United States has become the largest producer of food products in the world, partly due to its use of modern chemicals (pesticides) to control insects, weeds, and other organisms that attack food crops. However, there are concerns about the potential adverse effects of pesticides on the environment and human health. Pesticides can contaminate surface water and groundwater, which are critical sources of drinking water. They can reach water-bearing aquifers from applications on crop fields, seepage of contaminated surface water, accidental spills and leaks, improper disposal, and even through injection waste material into wells.

To prevent water contamination from pesticides and herbicides, individuals can consider landscaping that reduces runoff and avoid applying these chemicals to their yards.

Frequently asked questions