Mains water, groundwater, food-grade water, non-potable water, bathing waters… We are in constant contact with this vital resource, yet it is not always without risk to our health.
Agricultural, industrial and human pollution, bacterial contamination and the presence of toxic chemical substances all contribute to the many, often invisible, threats affecting water quality. In the UK, drinking water quality is closely monitored by regulatory bodies such as the Drinking Water Inspectorate (DWI) and the Environment Agency. While tap water is considered safe and compliant with legal standards, monitoring data show that trace levels of certain substances — including nitrates and disinfection by-products such as chlorine — may still be present within authorised limits.
Nitrates, pesticides, heavy metals, microplastics, viruses and parasites… At high concentrations or after long-term exposure, their presence in drinking water distribution systems can lead to serious health issues: infectious diseases, digestive disorders, dermatitis, hormonal disruption and even certain cancers. Vulnerable groups — such as infants, children, pregnant women and immunocompromised individuals — are particularly at risk.
Tap water quality, bathing precautions and wastewater management are therefore key topics to understand in order to protect long-term health in the face of drinking water contamination. This applies in the UK, as elsewhere.
What are the main sources of water pollution?
Among the most common sources of contamination are industrial discharges containing toxic chemical substances such as heavy metals, hydrocarbons and solvents. The widespread use of pesticides and fertilisers in agriculture also contributes to declining water quality through surface run-off and infiltration into groundwater.
Urban wastewater, when not adequately treated, introduces organic pollutants, pharmaceutical residues and microplastics into aquatic environments. Biological contaminants such as enteric viruses, pathogenic bacteria and parasites mainly originate from human and animal waste.
Chemical pollution: a serious threat
Lead, mercury, arsenic, nitrates and pesticides are among the most concerning pollutants. Long-term exposure has been associated with increased risks of cancer, neurological disorders, kidney disease and reproductive problems.
Even at low levels, endocrine-disrupting substances present in water — such as pharmaceutical residues or phthalates — are suspected of interfering with hormonal systems.
| Chemical substance | Potential health effects |
| Lead | Neurological disorders, developmental delays in children |
| Mercury | Damage to the nervous system, kidneys and foetus |
| Arsenic | Cancers of the skin, bladder and lungs |
| Nitrates | Infant methaemoglobinaemia, digestive cancers |
| Pesticides | Endocrine disruption, cancers, neurological disorders |
Biological pollution: a public health issue
Noroviruses and rotaviruses are linked to many cases of gastroenteritis. Certain bacteria such as Escherichia coli and Salmonella can cause potentially life-threatening infections, particularly in vulnerable individuals.
Parasites such as Cryptosporidium and Giardia are known to cause severe intestinal disorders.
What are the health effects of water pollution?
The impact of water pollution on public health is a growing concern, as contamination levels continue to rise. Children, pregnant women and older adults are disproportionately affected.
Short-term risks linked to pollutants
Ingesting contaminated water can lead to acute digestive symptoms, including nausea, vomiting, diarrhoea and abdominal pain. These effects are often caused by microbial infections linked to pathogenic bacteria and viruses.
Acute chemical poisoning, resulting from high exposure to nitrates or pesticides, may also cause digestive, neurological or respiratory symptoms. Severe complications are also possible, particularly in older adults or people with weakened immune systems.
| Contaminant | Short-term effects |
| Enterotoxigenic E. coli | Watery diarrhoea, dehydration |
| Salmonella | Typhoid fever, gastroenteritis |
| Norovirus | Acute gastroenteritis, vomiting |
| Nitrates | Infant methaemoglobinaemia |
| Pesticides | Digestive, neurological and respiratory disorders |
Long-term risks from low or high exposure
Chronic exposure to chemical contaminants in polluted water, even at low doses, increases the risk of long-term health conditions. Heavy metals (lead, mercury, arsenic), pesticides and endocrine disruptors have been associated with cardiovascular disease, neurological disorders, hormonal dysfunction and cancer.
Foetal development and early childhood growth are particularly sensitive to these toxins, with potential impacts on brain development and fertility.
An underestimated risk to the human microbiome
The human microbiome is a complex bacterial ecosystem that plays a crucial role in overall health. Water contaminants — including antibiotic residues, biocides and heavy metals — can disrupt this delicate balance.
Even temporary alterations to the microbiome are suspected of contributing to chronic digestive disorders, allergies, autoimmune diseases and metabolic conditions such as obesity and diabetes.
The long-term effects of contaminated water on the microbiome remain poorly understood, but they represent a major public health challenge for the years ahead.
The impact of water contaminants on mental health
While the physical effects of water pollution are well documented, mental health consequences are often overlooked. Lead, mercury, chlorine and endocrine disruptors are neurotoxic and can impair cognitive and emotional functions.
Chronic exposure to these pollutants has been associated with an increased risk of neurodevelopmental disorders in children, as well as depression, anxiety and neurodegenerative diseases in adults.
Polluted water: risks for vulnerable populations
Children, pregnant women and older adults are particularly sensitive to water pollutants due to their physiology and life stages. Children, whose organs are still developing, may absorb contaminants more readily, leading to developmental disorders.
Pregnant women should exercise increased caution, as even small quantities of pollutants can cross the placental barrier and affect the foetus. In older adults, weakened immune defences and reduced detoxification capacity increase vulnerability.
| Group | Main risks | Recommendations |
| Infants and young children | Developmental disorders, cognitive delays | Use water suitable for infants; prioritise breastfeeding |
| Pregnant women | Foetal malformations, neurodevelopmental disorders | Avoid water high in nitrates, pesticides and heavy metals; use filtration |
| Older adults | Infectious diseases, dehydration, cognitive disorders | Stay hydrated, use filters and monitor water quality |
How can tap water be made healthier in the UK?
In the UK, tap water is generally considered safe. However, despite disinfection measures, it may still contain trace contaminants. To further improve water quality, many households choose gravity-fed filtration systems combined with activated carbon filters.
These systems reduce a wide range of contaminants by passing water through specialised cartridges, bringing water quality closer to recommended health-based guideline values while improving taste.
- Activated carbon captures unwanted molecules thanks to its porous structure, while ceramic elements retain suspended particles.
- They are easy to use and require no electricity.
- They provide purified water with a neutral taste, suitable for everyday consumption.
How can we reduce water pollution?
Reducing water pollution starts with simple everyday actions. Avoid disposing of toxic products such as medicines, paint or solvents in toilets or sinks, as these disrupt wastewater treatment processes and contaminate aquatic environments.
- Choose biodegradable household products and natural cosmetics to reduce pollutant loads.
- Use pesticides and fertilisers sparingly in gardens to limit run-off into groundwater while preserving beneficial organisms.
- Dispose of hazardous waste — such as batteries or engine oil — at designated recycling centres.
By adopting these responsible habits and choosing effective home filtration, you can help protect this vital resource: drinking water. You can also consult your local water supplier for publicly available water quality reports, or use home testing kits for additional reassurance.
Other filtration methods exist, such as reverse osmosis systems or filter jugs. However, gravity-fed filters remain one of the most relevant options for both drinking water and household appliances, as they effectively remove many pollution-related molecules. Weeplow also offers specific filters designed for use with coffee machines.
