Water Pollution: A Slow, Deadly Poisoning Crisis

Water pollution is a global issue that poses a significant threat to human health and the environment. It is caused by a range of human activities, including industrial production, improper waste disposal, and agricultural practices, as well as natural factors such as the natural presence of chemicals in groundwater. This contamination of water sources has severe implications for human health, with unsafe drinking water being a leading cause of various diseases and contributing to premature deaths worldwide. The impact of water pollution on health includes the spread of diarrheal diseases, skin diseases, malnutrition, and even cancer, with children and women being particularly vulnerable. The economic toll of water pollution-related illnesses and deaths is also significant, resulting in substantial losses for countries and societies.

Waterborne diseases

Diarrhea

Diarrhea is the second leading cause of death for children under the age of five, causing more childhood deaths than malaria, AIDS, and measles combined. It is estimated that about 1 million people die each year from diarrhea as a result of unsafe drinking water, sanitation, and poor hand hygiene.

Cholera

Cholera is a waterborne disease commonly found in humanitarian emergencies or marginalized villages with poor sanitation and rampant poverty. It is spread through contaminated water and causes severe dehydration and diarrhea. Cholera can be fatal within days or even hours of exposure to the bacteria, but only about 10% of infected people will develop life-threatening symptoms.

Typhoid

Typhoid is a bacterial infection that can be treated with antibiotics. It is typically spread through contaminated food and water sources.

E. coli

E. coli infections can cause symptoms similar to dysentery and other waterborne diseases. While most cases of E. coli pass within a week, older individuals and young children are at a higher risk of developing severe symptoms.

Giardia

Giardia is a waterborne infection caused by a parasite. It is often spread through contaminated water sources such as ponds and streams but can also be found in town water supplies and swimming pools. While there is no vaccine for giardia, the infection usually clears up on its own, and simple preventive measures like handwashing and drinking bottled water can be effective.

To prevent waterborne diseases, it is crucial to practice safe sanitation and hygiene and have access to clean water. This includes washing hands frequently, ensuring proper waste disposal, and refraining from drinking or swimming in potentially contaminated water sources.

Cancer

Water pollution is a severe issue that jeopardizes human health. It occurs when harmful substances, often chemicals or microorganisms, contaminate water bodies, degrading water quality and making it toxic to humans and the environment. This problem is widespread, with over 2 billion people living in water-stressed countries and 1.7 billion people using a drinking water source contaminated with faeces. Microbial contamination of drinking water can transmit diseases such as diarrhoea, cholera, dysentery, typhoid, and polio, causing approximately 505,000 diarrhoeal deaths annually.

One of the critical concerns regarding water pollution is its link to cancer. Several studies have found a connection between contaminated drinking water and an increased risk of cancer. According to a report by the Environmental Working Group (EWG), 22 carcinogens commonly found in tap water, including arsenic, byproducts of water disinfectants, and radionuclides such as uranium and radium, could lead to over 100,000 cancer cases over a lifetime. Arsenic exposure, for instance, is linked to skin, bladder, and lung cancer. Additionally, byproducts of disinfectants are known or possible human carcinogens that can cause liver and bladder cancer.

The presence of nitrate-nitrite in drinking water and diet has also been associated with an increased risk of colorectal cancer. Furthermore, water sources contaminated with uranium, radium, disinfection by-products (DBPs), and other contaminants may elevate the risk of leukemia, bladder, pancreatic, and colorectal cancer. These carcinogenic substances can have severe health consequences, especially for vulnerable populations such as infants, children, and pregnant women.

The sources of water contamination vary. Nutrient pollution, caused by excess nitrogen and phosphorus, is the primary threat to water quality globally, leading to toxic algal blooms. Additionally, wastewater from industrial, commercial, and agricultural activities introduces metals, solvents, toxic sludge, and other contaminants into water bodies. Stormwater runoff carries pollutants like road salts, oil, grease, and chemicals into waterways. Inadequate management of wastewater results in dangerously contaminated drinking water for millions of people.

The issue of water pollution and its health impacts, including cancer, is not limited to developing nations. Even in developed countries like the United States, multiple crises have highlighted the failures in public water system management. For example, the situation in Flint, Michigan, where cost-cutting measures and aging infrastructure led to a lead contamination crisis, demonstrates the dangers of chemical and industrial pollutants in water.

Addressing water pollution requires collective efforts. Technologies exist to remove carcinogenic substances from water, but the challenge lies in their cost and public acceptance of higher water bills. Nonetheless, it is essential to prioritize safe drinking water and take preventive measures to protect water sources from contamination. By working together, we can reduce the health risks associated with water pollution, including the risk of cancer, and ensure access to clean and safe water for all.

Unsafe drinking water

Water can become unsafe to drink due to various contaminants, including human and animal waste, industrial and agricultural waste, and natural sources. Human wastes from sewage and septic systems can introduce harmful microbes such as Giardia, Cryptosporidium, and E. coli into water sources. Industrial activities can contaminate water with organic solvents, petroleum products, and heavy metals, while agricultural practices can contribute pesticides and fertilizers to water bodies. Additionally, natural underground conditions can result in high levels of contaminants like arsenic, fluoride, and other heavy metals in groundwater.

The health effects of consuming contaminated drinking water can range from gastrointestinal illnesses to chronic diseases. Short-term exposure to high doses of chemicals can cause skin discolouration and nervous system or organ damage. Long-term exposure to lower doses of contaminants can lead to chronic conditions such as cancer. It is important to note that the specific health impacts depend on factors such as the type of contaminant, its concentration in the water, individual susceptibility, and the duration of exposure.

Access to safe and readily available water is crucial for public health and is recognized as a basic human right by the United Nations. Safe water is essential for drinking, domestic use, food production, and recreational purposes. In 2022, 6 billion people used safely managed drinking water services, while 2.2 billion people lacked access to these services. The lack of safe drinking water disproportionately affects people in low-income, informal, or illegal settlements, who often have limited access to improved sources of drinking water.

To address the issue of unsafe drinking water, it is essential to prioritize water treatment and sanitation practices. While treatment can effectively remove many contaminants, it may also leave behind harmful byproducts such as trihalomethanes. Therefore, continuous improvement in water treatment technologies and processes is necessary. Additionally, proper management of human and animal waste, as well as industrial and agricultural waste, is crucial to prevent the contamination of water sources.

Poor sanitation

Unsafe water and poor sanitation are significant issues, particularly in low- and middle-income countries (LMICs). In these settings, the lack of access to clean water and proper sanitation facilities can lead to the spread of infectious diseases, causing a high mortality rate. Diarrhoeal diseases, for example, are a significant cause of death in these regions, with inadequate water, sanitation, and hygiene being contributing factors.

The absence, inadequacy, or improper management of water and sanitation services pose severe health risks. This is especially critical in healthcare facilities, where patients and staff are at an increased risk of infection and disease when water, sanitation, and hygiene services are lacking. The WHO and UNICEF have jointly developed the WASH FIT (Water and Sanitation for Health Facility Improvement Tool) to address this issue. WASH FIT provides a continuous cycle of improvement for small, primary healthcare facilities in LMICs through assessments, risk prioritization, and targeted actions.

Unsafe water and poor sanitation are also associated with acute respiratory infections, soil-transmitted helminthiases, and undernutrition. The impact of these issues is far-reaching, affecting not only physical health but also well-being and economic growth. The United Nations recognizes the human right to water and sanitation, aiming to achieve universal and equitable access to safe and affordable drinking water for all by 2030.

The agricultural sector is a significant contributor to water pollution, with farming and livestock production accounting for about 70% of global freshwater consumption. Agricultural pollution, including farm waste and fertilizer runoff, is the leading cause of contamination in rivers and streams, the second-biggest source in wetlands, and the third in lakes. Industrial waste and municipal discharges also contribute significantly to water pollution, rendering it toxic and dangerous for human consumption.

Industrial and agricultural activities

Agricultural activities contaminate water with nitrates, phosphorus, pesticides, soil sediments, salts, and pathogens. Farm waste and fertilizer runoff, as well as the use of pesticides and nitrogen fertilizers, are significant contributors to water pollution. The high degree of public participation and education in the agricultural sector has helped improve water quality in some regions, but overall, agricultural pollution has overtaken contamination from settlements and other industries as the main factor in the degradation of inland and coastal waters.

The use of heavy metals like copper and zinc in industrial agriculture to promote growth and prevent disease in livestock can contaminate water supplies and cause health issues in humans, such as gastrointestinal and liver disorders. Elevated nitrate levels in drinking water can cause "blue baby syndrome," a potentially fatal condition in infants. The accumulation of nutrients in lakes and coastal waters due to agricultural activities leads to eutrophication, which impacts biodiversity and fisheries.

Inadequate wastewater treatment is a significant issue, with more than 80% of the world's wastewater flowing back into the environment without proper treatment. This untreated wastewater is used for irrigation in water-scarce regions, posing risks to both the environment and human health. The consumption of contaminated drinking water can lead to waterborne diseases, with an estimated five million people dying annually from these illnesses.

To address these issues, regulations, economic incentives, and educational initiatives are necessary. Implementing policies that encourage sustainable practices in industries and agriculture can help reduce water pollution. Additionally, improving wastewater treatment facilities and promoting proper waste management techniques are crucial steps in mitigating the harmful effects of industrial and agricultural activities on water sources and, consequently, on human health.

Frequently asked questions