Whether it’s the water we drink, cook with, or use in everyday tasks, the cleanliness of water directly affects our health and wellbeing. For homeowners, poor water quality can lead to plumbing issues and health concerns.
For businesses, it can impact product integrity, employee safety, and regulatory compliance. Without proper water treatment systems in place, water becomes a haven for numerous contaminants, many of which pose serious health risks.
On a broader scale, untreated or contaminated water poses serious risks to public health and the environment. This is why effective water treatment is not just a luxury—it’s a necessity.
In this blog, we’ll explore the most common contaminants contained in water and the health risks that each poses to those who drink it.
Microbial contaminants found in untreated water
1) Bacteria
Examples include Escherichia coli (E. coli), Salmonella, Campylobacter and Legionella.
Health risks:
Can cause gastrointestinal illnesses such as diarrhea, nausea, and vomiting.
Some strains of E. coli (e.g., O157:H7) can lead to severe kidney damage or even death.
Legionella can cause Legionnaires’ disease—a serious type of pneumonia.
2) Viruses
Examples include Norovirus, Rotavirus, Hepatitis A and Enteroviruses.
Health Risks:
Highly contagious and can spread quickly through communities.
Cause a range of illnesses from stomach flu and liver inflammation (hepatitis) to neurological symptoms.
Particularly dangerous for children, the elderly, and immunocompromised individuals.
3) Protozoa
Examples include: Giardia lamblia, Cryptosporidium and Entamoeba histolytica.
Health risks:
Cause persistent gastrointestinal distress, including diarrhea, cramps, and dehydration.
Cryptosporidium is resistant to standard chlorine disinfection and can cause outbreaks even in treated municipal water.
Can survive in water for long periods, making them hard to eradicate without advanced filtration.
4) Fungi
Examples: Candida, Fusarium species
Health risks:
While less common, waterborne fungi can cause infections in the skin, nails, and lungs, especially in immunocompromised individuals.
Some fungal contaminants produce mycotoxins, which may be harmful if ingested over time.
5) Algae (including Cyanobacteria)
Examples: Microcystis, Anabaena (blue-green algae)
Health risks:
Can produce harmful toxins (e.g., microcystins) that affect the liver, nervous system, and skin.
Can cause taste and odor problems in drinking water.
Harmful algal blooms can make water unsafe for human and animal consumption.
Heavy metals found in untreated water
1) Lead (Pb)
Sources: Corroded lead pipes, plumbing fixtures and industrial waste.
Health Risks:
Extremely toxic, especially to children.
Causes developmental delays, learning disabilities, behavioral issues.
In adults, can lead to kidney damage, high blood pressure, and reproductive problems.
No safe level of lead in drinking water.
2) Mercury (Hg)
Sources: Industrial discharge, mining operations and atmospheric deposition.
Health Risks:
Affects the nervous system, especially in fetuses and young children.
Can impair cognitive thinking, memory, attention, and motor skills.
Long-term exposure may damage kidneys and lungs.
3) Arsenic (As)
Sources: Natural deposits in bedrock, agricultural runoff and industrial waste.
Health Risks:
Known carcinogen; linked to skin, bladder, and lung cancers.
Can cause skin lesions, cardiovascular disease, and neurotoxicity.
Chronic exposure may also lead to diabetes and developmental effects in children.
4) Cadmium (Cd)
Sources: Industrial discharge, batteries, fertilizers and mining.
Health Risks:
Causes kidney damage and weakens bones (Itai-itai disease).
Linked to lung and prostate cancers.
May contribute to high blood pressure and liver damage.
5) Chromium (Cr), especially Hexavalent Chromium (Cr-6)
Sources: Industrial processes, metal plating, dyes and pigments.
Health Risks:
Hexavalent chromium is highly toxic and carcinogenic.
Causes liver and kidney damage, respiratory problems, and skin irritation.
Long-term ingestion is linked to stomach and intestinal cancers.
6) Nickel (Ni)
Sources: Natural deposits, industrial runoff and electroplating.
Health Risks:
Can cause allergic reactions, including dermatitis.
Long-term exposure may affect kidney and liver function.
Classified as a possible carcinogen.
7) Copper (Cu)
Sources: Corrosion of copper pipes and industrial discharge.
Health Risks:
In small amounts, copper is essential—but excess can be harmful.
Causes gastrointestinal distress, including nausea and vomiting.
High levels may lead to liver and kidney damage, particularly in people with Wilson’s disease.
8) Zinc (Zn)
Sources: Galvanized pipes, runoff from mining and industry.
Health Risks:
Generally low toxicity, but excessive levels can cause stomach cramps, nausea, and vomiting.
May interfere with the body’s absorption of other essential minerals.
Chemical contaminants found in untreated water
1) Pesticides and Herbicides
Sources: Agricultural runoff, lawn care and industrial farming.
Health Risks:
Linked to hormonal disruption, reproductive issues, and developmental delays.
Long-term exposure may increase cancer risk.
May impair nervous system and liver function.
2) Nitrates and Nitrites
Sources: Fertilizers, septic systems and animal waste.
Health Risks:
Dangerous for infants, causing methemoglobinemia or “blue baby syndrome” (reduces oxygen in the blood).
Can lead to stomach and bladder issues in adults.
Possible links to certain cancers when converted to nitrosamines in the body.
3) Pharmaceutical Residues
Sources: Improper disposal of medications, human and animal waste.
Health Risks:
May disrupt endocrine function and hormone balance.
Long-term effects are still being studied but may impact immune system and fertility.
Can lead to antibiotic resistance.
4) Volatile Organic Compounds (VOCs)
Examples: Benzene, Toluene, Xylenes and Trichloroethylene.
Sources: Industrial waste, fuel spills, solvents, and dry cleaning.
Health Risks:
Many VOCs are carcinogenic.
Can cause liver, kidney, and nervous system damage.
Some are linked to reproductive issues and immune dysfunction.
5) Per- and Polyfluoroalkyl Substances (PFAS) – "Forever Chemicals"
Sources: Non-stick cookware, firefighting foam and industrial discharge.
Health Risks:
Associated with thyroid disease, immune suppression, liver damage, and cancers.
Persist in the environment and accumulate in the human body over time.
6) Chlorine and Chlorination Byproducts (e.g., Trihalomethanes - THMs)
Sources: Disinfection of water (particularly in poorly controlled systems).
Health Risks:
Long-term exposure to THMs may increase the risk of bladder cancer.
May cause skin irritation and respiratory problems.
Chlorine itself can lead to unpleasant taste and odor in water.
7) Detergents and Surfactants
Sources: Household waste and industrial runoff
Health Risks:
Irritate eyes, skin, and respiratory tract.
May be toxic to aquatic life and disrupt ecological balance.
Some components are endocrine disruptors.
8) Heavy Use Industrial Chemicals (e.g., PCBs, Dioxins).
Sources: Industrial processes and improper waste disposal.
Health Risks:
Known carcinogens and endocrine disruptors.
Can affect immune and reproductive systems.
Persistent in the environment and bioaccumulate in food chains.
9) Fluoride (in excessive amounts)
Sources: Natural deposits, industrial waste and over-fluoridation.
Health Risks:
In moderate levels, it helps prevent tooth decay.
Excessive exposure can cause dental and skeletal fluorosis.
Linked to possible neurodevelopmental effects in children when consumed in high concentrations.
Sediments and particulates found in untreated water
1) Soil and Silt
Sources: Erosion, runoff from land, construction sites and natural sedimentation.
Health Risks:
While not typically harmful on their own, they can:
Harbor bacteria, viruses, and parasites by providing them a protective environment.
2) Sand and Grit
Sources: Groundwater movement, aging pipes, well water and river or stream intake.
Health Risks:
No direct health threat, but contributes to murky water that may hide microbial contamination.
3) Rust and Corrosion Particles (Iron Oxide)
Sources: Corroded iron or steel pipes and fittings.
Health Risks:
Unpleasant metallic taste and discoloration in water.
May contain heavy metals like lead if corrosion affects solder or old pipes.
4) Organic Matter (Decaying Leaves, Plant Debris)
Sources: Runoff from vegetation, stagnant water bodies and forested areas.
Health Risks:
Promotes bacterial and algal growth.
May produce foul odors and tastes, and contribute to the formation of harmful disinfection byproducts like trihalomethanes.
5) Microplastics
Sources: Breakdown of plastic waste, synthetic textiles and personal care products.
Health Risks:
Inflammatory responses.
Hormonal disruption.
Accumulation in organs and tissues over time.
Act as carriers for other pollutants like heavy metals and toxic chemicals.
7) Algae Fragments and Biofilm Particles
Sources: Surface water bodies, aging pipes and stagnant water.
Health Risks:
Can produce harmful toxins (in the case of cyanobacteria).
May cause taste, odor, and color issues.
Conclusion
Untreated water can contain a wide range of harmful contaminants, including microbes, heavy metals, chemicals, and sediments, many of which pose serious risks to human health, plumbing systems, and the environment.
From bacteria and viruses to lead, pesticides, and microplastics, these pollutants can cause everything from short-term illness to long-term chronic conditions. Understanding what’s in untreated water highlights the importance of effective water treatment solutions to ensure safe, clean water for homes, businesses, and communities.
Companies such as Aqualyng, provide specialist water treatment plant hire in Australia, allowing remote communities to gain access to clean, uncontaminated water that is completely safe to drink and bathe in.
