Water Pollution: A Global Crisis And Its Impact

Water pollution is a pressing issue that poses a significant threat to the world's water resources and has far-reaching implications for the environment, human health, and economic development. It refers to the contamination of water sources such as rivers, lakes, oceans, and groundwater by various substances, including industrial waste, agricultural runoff, sewage, and plastic pollution. According to the United Nations, water pollution affects one in every three people on the planet, and it is estimated that over 500,000 people worldwide die each year from waterborne diseases caused by polluted water. The effects of water pollution are wide-ranging, from environmental damage and destruction of biodiversity to health risks and economic impacts. With rising global temperatures, industrial activities, and improper waste disposal, addressing water pollution has become crucial for the well-being of current and future generations.

Industrial agriculture

Sources of Water Pollution from Industrial Agriculture

Industrial Animal Agriculture

Concentrated animal feeding operations (CAFOs), or factory farms, are a major source of water pollution. These facilities house thousands of animals and generate vast amounts of waste, which is often stored in pits or open ponds (lagoons). These waste containment areas are prone to leaking and can rupture during storms, leading to surface and groundwater contamination. To dispose of the waste, CAFOs spray manure onto farm fields, which can result in environmental damage and the contamination of water supplies. Animal waste can contain pharmaceutical residues, heavy metals, and harmful bacteria. For example, chicken manure is high in phosphorus and nitrogen, and when excess waste is spread on cropland, it can run off into streams and rivers, leading to eutrophication and hypoxia, which are harmful to aquatic life.

Industrial Crop Production

The excessive use of synthetic fertilizers in industrial crop production is another significant source of water pollution. Nutrients such as nitrogen and phosphorus from fertilizers leech into surface and groundwater, causing algal blooms and nitrate contamination. This impacts drinking water supplies, recreational activities, fishing, and aquatic ecosystems.

Negative Effects of Water Pollution from Industrial Agriculture

Algal Blooms, Dead Zones, and Acidification

High levels of nutrients in water from industrial crop fertilizers and animal waste cause excessive aquatic plant growth, known as eutrophication. This leads to hypoxia, or low-oxygen water, which can result in harmful algal blooms (HABs) that produce biotoxins, killing fish and other aquatic life, and creating "dead zones" where aquatic creatures cannot survive. Ammonia from agricultural runoff can also acidify waterways, affecting the ecology of streams and rivers.

Heavy Metal Contamination

In CAFOs, pigs and chickens are fed excessive amounts of heavy metals like copper and zinc to promote growth and prevent disease. Other metals present in animal waste include cadmium, lead, mercury, and arsenic. These metals accumulate in the soil when animal waste is sprayed on farm fields and can contaminate water supplies, posing risks to both human health and the environment.

Nitrates and Other Contaminants in Drinking Water

Elevated nitrate levels in drinking water can be dangerous to humans, causing low oxygen levels in infants ("blue-baby syndrome") and low birth weight. High nitrate levels may also indicate the presence of other agricultural contaminants in the water, such as pesticides.

Pathogen Contamination and Disease Outbreaks

Animal waste contains high levels of pathogens that can cause human diseases. When CAFO lagoons leak, contaminated water can enter waterways and groundwater. These pathogens can survive spraying onto farm fields and can be transported to surface water through runoff, posing risks to human health during recreational activities and through contaminated drinking water.

Addressing Water Pollution from Industrial Agriculture

There is a growing movement to address water pollution from industrial agriculture, including lawsuits and grassroots organizing by local communities. The EPA has also come under pressure to revisit its regulatory policies towards CAFOs, and there is a push for more proactive federal policy on CAFO water pollution. Additionally, organizations like Food and Water Watch and Public Justice are working to fight against policies that support CAFOs and facilitate water pollution.

Marine plastic pollution

The problem is exacerbated by the durability of plastic, with every bit of plastic ever made still existing today, according to the EPA. As a result, billions of pounds of plastic are now found in the oceans, making up about 40% of the world's ocean surfaces. At current rates, plastic is projected to outweigh all the fish in the sea by 2050.

The impact of plastic pollution on marine life is devastating. Studies show that a quarter of fish in California markets had plastic in their guts, and half of all sea turtles worldwide have ingested plastic. Marine mammals, such as the critically endangered Hawaiian monk seals, have also been affected, with large amounts of plastic debris found in their habitats, including areas serving as pup nurseries.

In addition to the direct impact on marine life, plastic pollution also affects human health. Microplastics, which are smaller than 5mm in size, have been found in human blood and placentas, as well as in food and drinks like tap water, beer, and salt. The chemicals used in plastic production are known to be carcinogenic and can cause various health issues, including developmental, reproductive, neurological, and immune disorders.

The plastic pollution crisis calls for urgent action and a global plastics treaty to reduce plastic production, phase out harmful subsidies, and improve waste management and consumer behaviour. It is essential to address this issue at its root by regulating plastics as pollutants and preventing plastic pollution from reaching the oceans.

Sewage and wastewater

Wastewater is a major threat to nature and human health. According to the United Nations, more than 80% of the world's wastewater is released into the environment without being treated or reused. This untreated wastewater introduces a cocktail of contaminants, including pathogens, pharmaceuticals, microplastics, heavy metals, and endocrine disruptors, which threaten our food and water security, as well as marine life.

The consequences of wastewater pollution are dire. In one instance, a sewage leak in the River Trent in Staffordshire killed over 15,000 fish. Contamination of water sources can also cause the spread of diseases such as E. coli, diarrhea, and hepatitis A. Even properly treated sewage can have its problems, with microscopic plastic fibres from washed clothes making their way through wastewater treatment plants and into marine ecosystems, where they harm animals and damage the food chain.

However, sewage and wastewater are not solely negative. They also contain valuable information that can be used for monitoring and research purposes. For example, wastewater analysis can be used to monitor the use of illegal drugs or determine the presence of pesticide metabolites, which can be beneficial for the food and agricultural sector. Additionally, analysing wastewater can detect markers of oxidative stress in collective samples, indicating that bodies are unable to neutralise certain diseases. This can help researchers understand the effects of environmental pollution on specific communities.

Atmospheric deposition

The environmental impact of atmospheric deposition is twofold. On the one hand, it provides a cleansing effect by removing pollutants from the air and transporting nutrients to plants. On the other hand, the deposition of certain substances, such as sulfur and nutrients, can lead to the acidification and eutrophication of aquatic ecosystems. This process has far-reaching consequences for both the chemistry and biology of lakes, with sulfur deposition, for example, leading to acidified waters and the leaching of aluminum. Atmospheric deposition of pollutants can also introduce toxins and chemicals into the environment, negatively impacting human health and contributing to the creation of acid rain.

The health of people, animals, and ecosystems can be adversely affected by the atmospheric deposition of pollutants. Pollutants deposited on water surfaces can be assimilated into the water and sediments for extended periods, leading to direct ingestion by biota or acceleration in the leaching of soil base cations, metals, and plant nutrients. Furthermore, pollutants can be transported from their original deposition sites through groundwater fluxes, surface runoff, and soil erosion, further spreading their impact.

Oil spills

The magnitude of harm caused by an oil spill depends on various factors, including the amount and type of oil, location, season, weather conditions, and the effectiveness of clean-up efforts. Oil spills can injure and kill marine animals, birds, and mammals through internal exposure (ingestion or inhalation) and external exposure. They can also lead to the loss of habitats, such as wetlands and oyster reefs, disrupting the life cycles of animals and causing shoreline erosion.

The most common causes of large and sudden oil spills are accidents during offshore drilling and ruptures in large transport vessels, such as tanker ships. Additionally, intentional discharges, such as tanker ship captains cleaning their tankers and washing residue oil into the ocean, can also contribute significantly to oil spills.

The largest accidental oil spill in history occurred in the Gulf of Mexico in 2010, when a surge of natural gas blasted through a well cap, leading to the release of 206 million gallons of oil. This accident also claimed the lives of 11 workers and injured 17 more.

While nature can help disperse and break down the oil over time, the process is slow and unreliable. Experts employ various methods, such as scooping, soaking, and burning, to mitigate the damage caused by oil spills. However, these are considered damage control measures rather than permanent solutions.

Frequently asked questions