Polluted Water: Understanding The Diseases It Causes

Water pollution is the release of substances into bodies of water, making it unsafe for human use and disrupting aquatic ecosystems. Polluted water is linked to a variety of diseases, with children being particularly vulnerable. Diarrhea is the most well-known disease linked to contaminated water, causing the deaths of nearly 300,000 children under five annually. Other waterborne diseases include cholera, typhoid fever, hepatitis, and dengue fever. In addition, water pollution can cause skin diseases, malnutrition, and even cancer. Furthermore, insects that breed in water, such as mosquitoes, can transmit diseases like encephalitis and polio. Poor water quality can also lead to parasitic infections, such as schistosomiasis and cryptosporidiosis. The impact of water pollution on human health is significant, and access to clean drinking water is crucial to prevent water-related diseases.

Diarrhoea and other gastrointestinal issues

Diarrhoea is the most widely recognised disease associated with contaminated water. According to the World Health Organization (WHO), unsafe drinking water and poor sanitation are the leading causes of approximately 505,000 diarrhoeal deaths each year, with children being the most affected. The 2021 UNESCO World Water Development Report estimates that about 829,000 people die annually from diarrhoea caused by unsafe drinking water, sanitation, and hand hygiene, including nearly 300,000 children under the age of five. This represents 5.3% of all deaths in this age group.

Data from Palestine suggests that people who drink municipal water directly are more likely to suffer from diarrhoea than those who use desalinated and household-filtered drinking water. Other gastrointestinal issues linked to contaminated water include cholera, dysentery, hepatitis A, typhoid, and polio. These diseases are transmitted through microbiologically contaminated drinking water and poor sanitation, exposing individuals to preventable health risks.

Safe and readily available water is essential for public health, and it is crucial for drinking, domestic use, food production, and recreational purposes. Improved water supply, sanitation, and better management of water resources can positively impact countries' economic growth and contribute to poverty reduction. Since 2014, the WHO has been testing household water treatment products to ensure they meet health-based performance criteria and protect users from pathogens that cause diarrhoeal diseases.

To address the issue of diarrhoeal diseases and improve gastrointestinal health, interventions such as providing safe and sufficient water, promoting good hygiene practices, and ensuring proper sanitation are crucial. Oral Rehydration Therapy (ORT) has been strongly recommended to reduce infant mortality due to gastrointestinal problems, which are prevalent among children, especially in developing countries.

Skin diseases

Water pollution can cause a variety of skin diseases, particularly when the polluted water comes into contact with the skin. Here are some examples:

Skin Lesions and Skin Cancer

Arsenic-contaminated drinking water has been linked to skin lesions and skin cancer. Studies have found a consistent dose-response relationship between water arsenic exposure and skin lesions, with increased risk even at low-to-moderate doses. Arsenic-induced skin cancers have also been observed, particularly basal cell carcinomas and squamous cell carcinomas.

Melanosis and Keratosis

Excessive arsenic in drinking water due to pollution has been associated with skin diseases, primarily melanosis and keratosis. A study found a correlation between arsenic concentrations in biological samples (hair and blood) from patients with skin diseases and the intake of arsenic-contaminated drinking water.

Scabies

Water pollution, especially in rivers, has been linked to an increased incidence of scabies, as observed in a study conducted in Bangladesh.

Skin Rashes and Irritation

Swimming in polluted water can lead to skin rashes and irritation. This can be caused by various factors, including chlorine in pool water, freshwater parasites, saltwater stings, and sea lice. Chlorine can strip the skin of its protective oils, leading to dry, itchy, and red skin. Freshwater parasites, such as schistosomes released by infected snails, can burrow into the skin and trigger allergic reactions, resulting in itchy red dots. Jellyfish and Portuguese man-of-war stings in saltwater can cause immediate pain, burning, and the development of red welts. Sea lice in the ocean can also lead to itchy rashes under swimsuits.

Oxidative Stress and Air Pollution

While not directly related to water pollution, it is worth noting that air pollution can also impact skin health. Oxidative stress, caused by particulate matter, ozones, and aryl hydrocarbon receptors (AhR), can lead to the overproduction of destructive reactive oxygen species (ROS) that damage the skin. Urban dust, cigarette smoke, and diesel dust are significant contributors to air pollution and can have detrimental effects on skin cells.

Parasitic diseases

One example of a parasitic disease caused by polluted water is cryptosporidiosis, which is caused by the cryptosporidium parasite. This parasite is found in contaminated water and can cause stomach cramps, diarrhoea, and vomiting. Another parasitic disease is schistosomiasis, caused by a small parasitic worm that lives in water. Schistosomiasis can remain dormant for years, but it damages internal organs over time.

In addition to these, the galloping amoeba parasite affects the stomach lining and can cause both cyst and non-cyst forms, leading to chills, fever, and diarrhoea. The presence of parasites in drinking water can also be indicated by the detection of coliform bacteria, specifically E. coli, which suggests the water may contain harmful pathogens. These pathogens can cause a range of symptoms, including diarrhoea, vomiting, cramps, nausea, headaches, fever, fatigue, and even death in certain cases.

Encephalitis

The culex mosquito is just one example of insects that live or breed in water and can transmit diseases. These insects, known as vectors, breed in clean water, and household drinking water containers can serve as breeding grounds. This means that water does not have to be visibly polluted or contaminated to be dangerous.

Inadequate management of urban, industrial, and agricultural wastewater means that the drinking water of millions of people is contaminated or chemically polluted. This is especially true in developing countries, where basic water supply and treatment facilities are lacking due to underinvestment. As a result, the incidence of infectious and parasitic diseases, as well as exposure to industrial chemicals, heavy metals, and algal toxins, is increased.

The quality of drinking water is essential for human health. Poor drinking water quality has been linked to various diseases, including skin diseases, malnutrition, and even cancer. According to the World Health Organization (WHO), 80% of the world's diseases and 50% of child deaths are related to poor drinking water quality.

To improve water quality and reduce the risk of diseases like encephalitis, it is crucial to address the issues of water pollution and inadequate wastewater management. This includes investing in basic water supply and treatment facilities, improving sanitation, and implementing regulations and policies that protect water sources from contamination.

Cancer

Consuming polluted water can have severe implications for human health. According to the United Nations, in 2016, more than two million people worldwide died from diarrhoeal diseases, with poor sanitation and unsafe drinking water being the leading cause of nearly 90% of deaths, affecting children the most. The World Health Organization (WHO) also reports that 80% of the world's diseases and 50% of child deaths are linked to poor drinking water quality.

Water pollution can be caused by both human and natural factors. Human activities that directly affect water quality include urbanization, population growth, industrial production, and climate change. Natural factors include the natural environment, such as loess and mudstone, which are the main sources of hexavalent chromium pollution.

One of the most concerning health risks associated with polluted water is cancer. Certain contaminants in water sources, such as arsenic, disinfection byproducts (DBPs), nitrate, and uranium, have been linked to an increased risk of various types of cancer. Ingesting high levels of arsenic, for example, is a known cause of bladder cancer, and studies have shown a dose-response relationship between cumulative arsenic exposure and bladder cancer risk.

Additionally, long-term exposure to contaminated drinking water has been associated with rectal and bladder cancers. This is particularly concerning in areas where water sources are predominantly groundwater, such as aquifers, as these have higher concentrations of arsenic and radioactive materials. In contrast, water systems that rely on surface water sources, like reservoirs, tend to have lower levels of contaminants but serve larger populations.

Other types of cancer that have been linked to polluted water include leukemia, pancreatic, and colorectal cancer. Studies have also suggested a potential link between dermal and inhalation exposures to trihalomethanes (THM), a component of DBPs in treated water, and an increased risk of bladder cancer.

Improving water quality and investing in source water protection measures are crucial for reducing the potential incidence of cancer and other diseases caused by environmental pollution.

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