Chemicals in Drinking Water-Understanding: The Complete Guide

Clean drinking water, safe to drink and free of chemical, biological, or physical agents, is important for good health. Water, however, does contain naturally many types of substances: chemicals, minerals, and microorganisms.

While most of these substances do not pose a serious health threat, some chemicals can pose potential health problems at high concentration.

This booklet provides detailed information about commonly encountered chemicals in drinking water supplies, their sources, health implications, and measures taken for safety.

Why do chemicals exist in drinking water?

Chemicals in drinking water can be from natural sources, human activities, or the water treatment processing itself. The major sources include:

1. Natural Sources:

• Minerals dissolving from rocks and soil into groundwater.

• Natural geological formations releasing elements such as arsenic or fluoride.

2. Human activities:

• Agricultural runoff of fertilizers, pesticides, and herbicides.

• Industrial discharges releasing heavy metals and organic compounds.

• Urban runoff containing pollutants from oils, grease, and other chemicals.

3. Water Treatment Processes:

• Disinfectants are chemicals used to kill harmful microorganisms.

• By-products of treatment, such as trihalomethanes and haloacetic acids.

Common Chemicals in Drinking Water

1. Major Minerals

• Calcium and Magnesium: Naturally occurring elements in water that add to its hardness. These are not harmful, may create scaling problems in piping.

• Potassium and Sodium: These are normally present in the water naturally or are added to it during softening. Small amounts of them are harmless, but in certain human biological disorders, such as hypertension, their intake becomes dangerous.

2. Disinfecting Chemicals

• Chlorine: This is one of the most commonly used water disinfection chemicals. While effective, it reacts with organic materials to form by-products.

• Chloramine: A mixture of chlorine and ammonia, often used as a substitute for chlorine. This has longer-lasting effects compared to chlorine.

• Ozone and UV Treatment Residues: Advanced methods leave less residues but it is often combined with traditional disinfectants.

3. Disinfection Byproducts (DBPs)

Trihalomethanes are formed in water when chlorine is applied to organic materials. High doses of THMs have long-term health consequences, such as cancer.

• Haloacetic Acids: Another class of chlorination byproducts that may be carcinogenic.

4. Heavy Metals

Lead: It is most often found in water through older plumbing. Even low levels cause significant neurological and developmental problems, especially in children.

•Arsenic: Found naturally in some groundwater sources. Chronic exposure can lead to skin conditions and cancer.

• Mercury and Cadmium Rare but toxic metals coming from industrial wastes or polluted earth.

5. Fluoride

• Added to water supplies in some areas to prevent dental decay; excessive intake results in either dental fluorosis or skeletal problems.

6. Nitrates and Nitrites

• Usually from fertilizers applied to fields, it can pollute groundwater. High levels can be toxic, causing a condition called methemoglobinemia (blue baby syndrome) in infants.

7. Volatile Organic Compounds (VOCs)

• Chemicals such as benzene, toluene, and xylene from industrial pollution or fuel spills. Some organic compounds can result in long-term exposure to health conditions like cancer.

8. Pesticides and Herbicides

Chemicals like atrazine and glyphosate, which are linked to farming, can leach into the water supply. Long-term exposure causes endocrine disruption, potentially causing cancer.

Health Implications of Drinking Water Chemicals

Although many chemicals are safe or even beneficial in small quantities, health problems can result from a number of substances if one is exposed to them for a very long time:

Short-term effects may be generated due to contaminants like chlorine or microbial residues, which may cause stomach upset, skin irritation, or nausea.

Long-term effects include chronic illnesses, developmental disorders, and cancers because of heavy metals, DBPs, and persistent organic pollutants.

Regulating and Ensuring Water Safety

The quality of drinking water is regulated by various organizations and governments operating to safeguard public health. Some of the key standards that relate to this are:

1. WHO – World Health Organization: establishes international norms for safe drinking water.

2. United States Environmental Protection Agency (EPA): Establishes the Safe Drinking Water Act (SDWA) with maximum contaminant levels (MCLs).

3. European Union: It also regulates drinking water quality through the Drinking Water Directive.

Common Measures to Ensure Safety:

• Filtration and Treatment: Removing the impurities by methods like reverse osmosis, activated carbon, and advanced oxidation. • Monitoring and Testing:

Such activities would ensure that water quality is regularly checked on their compliance with standards.

• Public Awareness: Educating communities on maintaining clean water systems and recognizing contamination signs.

What Can You Do as a Consumer?

1. Testing Your Water: Use home testing kits or professional services to identify contaminants.

2. Invest in Water Filters: Consider filters for peculiar problems – lead, fluoride, or VOCs.

3. Know Your Water: Read local water quality reports from utilities or environmental agencies. 4. Reduce pollutants Minimalize the usage of chemicals inside your home and in the yard to avoid runoff.

While the presence of chemicals in water is inevitable, knowing their sources, impacts, and management is pragmatic if water is intended to be safe. In improving the quality of water, the agencies involved, utilities, and consumers have important roles to play.

An informed, proactive approach can provide a wholesome water for drinking and, therefore, can keep a healthy and sustainable lifestyle.

References

1. World Health Organization WHO – Drinking Water Guidelines.

2. United States Environmental Protection Agency-Drinking Water Standards.

3. European Commission – Drinking Water Directive.

4. NGWA = National Ground Water Association.