Clean drinking water is one of the most essential needs for human survival. Yet across the globe, millions still consume water that is far from safe. This isn’t just a problem of taste or appearance; contaminated water can lead to a wide range of diseases, some of them deadly.
According to the World Health Organization (WHO), contaminated drinking water contributes to over 485,000 diarrhoeal deaths every year. And that’s just scratching the surface. Unsafe water is also linked to illnesses like cholera, typhoid, hepatitis, fluorosis, arsenic poisoning, and even cancer in extreme cases.
Let’s dive into what makes drinking water unsafe, what diseases it can cause, and how to identify if the water you’re drinking could be putting your health at risk.
What the WHO Says About Unsafe Water
The WHO defines safe drinking water as water that is free from pathogens, harmful chemicals, and unpleasant taste or odor, and meets established guidelines for quality.
Here are a few alarming facts from WHO reports:
- At least 2 billion people use a drinking water source contaminated with feces.
- Unsafe water, inadequate sanitation, and poor hygiene account for at least 10% of the global disease burden.
- Contaminated water is a major cause of childhood mortality, especially in regions with poor infrastructure.
Waterborne diseases are preventable, but only if we understand how contamination happens and how to measure water quality effectively.
Understanding Water Quality: pH and TDS
Two of the most critical indicators of water safety are:
1. pH Level
The pH scale measures how acidic or alkaline the water is, on a scale of 0 to 14:
- Ideal pH for drinking water: 6.5 to 8.5
- A low pH (acidic) can make water corrosive, leading to the leaching of heavy metals like lead and copper from pipes.
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A high pH (alkaline) might make the water taste bitter or affect sensitive stomachs but is generally less harmful than acidic water.
Water with pH outside the safe range doesn’t necessarily cause disease directly, but it often indicates the presence of chemical contaminants or imbalances that can lead to health issues over time.
2. TDS (Total Dissolved Solids)
TDS is the total concentration of dissolved substances in water. It includes:
- Essential minerals like calcium, magnesium, and potassium.
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Unwanted contaminants like nitrates, arsenic, lead, or industrial waste.
- 50 to 300 ppm (parts per million) – considered excellent.
- 300 to 500 ppm – acceptable for daily consumption.
- Above 500 ppm – may cause taste issues or health risks.
- Above 1000 ppm – unsafe and potentially dangerous.
High TDS isn’t always bad if the dissolved solids are healthy minerals. But if those solids include contaminants, the risks skyrocket.
Top Diseases Caused by Unsafe Drinking Water
Let’s look at the most common and most serious diseases caused by contaminated water:
1. Diarrhoeal Diseases
- Caused by: Bacteria (E. coli, Shigella), viruses (rotavirus, norovirus), and parasites (Giardia, Cryptosporidium).
- Symptoms: Watery stool, vomiting, stomach cramps, dehydration.
- Impact: Over 485,000 deaths annually, primarily in children under five.
Diarrhoea is more than just a short-term discomfort. In developing countries, repeated diarrhoeal episodes lead to malnutrition, growth stunting, and even cognitive issues in children.
2. Cholera
- Caused by: Vibrio cholerae bacteria.
- Symptoms: Profuse watery diarrhoea, rapid dehydration, low blood pressure, and potential death if untreated.
- Transmission: Contaminated water and food.
Cholera outbreaks often occur in areas with poor water treatment and sanitation. It’s highly infectious and can spread rapidly through communities.
3. Typhoid Fever
- Caused by: Salmonella typhi bacteria.
- Symptoms: High fever, weakness, abdominal pain, rash, and intestinal issues.
- Spread through: Drinking or eating food washed with contaminated water.
Typhoid is more prevalent in places where sewage treatment is poor or non-existent. If untreated, it can lead to severe complications including intestinal perforation.
4. Hepatitis A
- Caused by: Hepatitis A virus.
- Symptoms: Jaundice, fever, fatigue, abdominal pain, dark urine.
- Transmission: Consuming water or food contaminated with infected faecal matter.
Though less deadly than other forms of hepatitis, Hepatitis A can still cause long-term liver issues if not diagnosed early.
5. Dysentery
- Caused by: Shigella bacteria or amoeba (Entamoeba histolytica).
- Symptoms: Bloody or mucus-filled stool, severe abdominal pain, fever.
- Spread by: Poor hygiene, contaminated drinking water, and inadequate sanitation.
6. Arsenic Poisoning
- Source: Natural deposits or industrial waste leaking into groundwater.
- Regions at risk: Parts of India (West Bengal, Bihar), Bangladesh, South America.
- Health effects: Skin lesions, peripheral neuropathy, increased risk of cancer (lungs, bladder, kidneys), and cardiovascular problems.
Even small amounts of arsenic over time can be fatal.
7. Fluorosis
- Caused by: High fluoride levels in drinking water.
- WHO guideline: Fluoride >1.5 mg/L can lead to health problems.
- Types:
- Dental fluorosis: Discoloration or pitting of teeth in children.
- Skeletal fluorosis: Joint stiffness, pain, and bone deformities over time.
Excess fluoride is often a natural contaminant in groundwater in regions with volcanic rock or deep aquifers.
8. Nitrate Poisoning (Methemoglobinemia or “Blue Baby Syndrome”)
- Cause: Nitrate contamination from fertilizers and sewage leaks.
- Symptoms in infants: Shortness of breath, blue-tinted skin, and in severe cases, death.
Infants are particularly vulnerable to nitrates, which interfere with oxygen transport in the blood.
Why Testing Your Water Matters
Even if your water looks clean and smells fine, that doesn't mean it's safe. Testing is the only reliable way to understand its quality. A basic water test should include:
- pH
- TDS
- Bacterial presence
- Heavy metals (lead, arsenic, mercury)
- Nitrate levels
- Fluoride concentration
Tip: If you rely on groundwater or a borewell, test at least once every six months. Municipal water can also become contaminated through damaged pipes or outdated systems.
Prevention: How to Protect Yourself and Your Family
Here’s what you can do right now to reduce your risk of waterborne illness:
Use a Certified Water Purifier
Choose a purifier based on your water source. If you’re on groundwater or high-TDS water, an RO (Reverse Osmosis) system is ideal. If TDS is already low, UV + UF systems work well to eliminate microbes without removing beneficial minerals.
Store Water Safely
Clean your water storage tanks and containers regularly. Keep them covered to prevent dust and insect contamination.
Boil Water in Emergency Situations
If you're unsure about water quality during a flood or disruption in water supply, boil it for at least 5–10 minutes.
Stay Updated on Water Quality Reports
Check with your local municipality or water supplier about testing results or known contamination events.
What About Alkaline Water?
If your tap water has a consistently low pH (acidic), it might be worth switching to alkaline water for a while. With a pH between 8 and 9, alkaline water can help neutralize excess acidity in the body and may offer better hydration. But remember, the key is cleanliness: water must be free of pathogens and contaminants first, whether alkaline or not.
Conclusion
Diseases caused by contaminated drinking water are preventable. Yet they remain a massive global health threat because of poor infrastructure, limited awareness, and inaction. Understanding what’s in your water, its pH, TDS, microbial load, and chemical profile can go a long way in keeping you healthy.
Whether you’re sourcing your water from a borewell, tanker, or municipal pipeline, don't assume safety. Test it. Treat it. Store it properly.