Common Contaminants Tested in Drinking Water

Water is essential for all aspects of life. Freshwater is important for human consumption, daily household activities, agriculture, and industrial activities. Billions of people across the globe do not have access to safe drinking water. Contaminated water gives rise to various waterborne diseases and jeopardizes public health. Chemical industries and agricultural practices are the major sources of water contamination. Water may contain inorganic, organic, biological, and radiological contaminants. Water testing laboratories play a crucial role in the qualitative and quantitative analysis of drinking water. They must be capable of detecting a myriad of contaminants in drinking water.

Common Water Contaminants in Drinking Water

The chemical properties of water govern its quality. The presence of contaminants in water can make it highly hazardous for consumption. Some of the common contaminants present in drinking water are as follows:

1. Arsenic: The presence of arsenic in drinking water is known to cause cancer in human beings. Apart from various types of cancers, including lung and skin cancers, arsenic is also known to cause health effects such as hyperkeratosis, peripheral vascular diseases, and digestive problems.
2. Fluoride: High fluoride concentration in drinking water causes dental issues, such as dental fluorosis and mottling of teeth. A high concentration of fluorides can also lead to skeletal fluorosis, increasing the risk of fractures. As per the U.S. Environmental Protection Agency (EPA), the maximum concentration of fluoride in drinking water should not exceed 4.0 mg/L.
3. Selenium and Uranium: The consumption of excessive selenium can lead to physical health issues such as loss of hair and weak nails. It also causes changes in peripheral nerves. Uranium is found in groundwater and tends to cause kidney diseases.
4. Nitrates: Nitrates in water are the result of agricultural waste that is released into the water. The presence of nitrates in drinking water is more harmful to children and infants. It can lead to methemoglobinemia in children. Methemoglobinemia is a fatal disorder that results in low blood oxygen levels.
5. Perfluorooctanoic Acid (PFOA) and perfluorooctanesulfonic (PFOS) Acid: These are man-made chemicals commonly used in the manufacturing of products, such as paper, paints, and electronics. Manufacturing industries release their industrial waste into the water, disturbing the environmental balance. The presence of these acids in water can cause diseases such as cancer, liver and immune effects.

Other metals that are known to be harmful, if present above the permissible limit in drinking water, are aluminum, iron, copper, and cadmium.

Organic contaminants, such as pesticides, volatile organic compounds (VOCs), and dyes, are harmful to the environment as well as human health. Exposure to unsafe levels of these contaminants may lead to cancer, nervous system disorders, and kidney diseases in humans.

Biological contaminants such as bacteria and microorganisms are naturally present in water. Some common harmful bacteria present in untreated drinking water are E. coli and Legionella pneumophila. Microorganisms, such as Cryptosporidium and protozoa, are also commonly known to cause severe health issues such as diarrhea, stomach cramps, nausea, fatigue, dehydration, and headaches in infants and adults.

The presence of radioactive materials in water usually originates from industrial waste and can cause harmful diseases, such as cancer.

Role of Water Testing Laboratories

Water testing laboratories assure the quality of drinking water through accurate and reliable testing of water samples. However, they face numerous challenges on a day-to-day basis. This includes managing a large number of samples and tests, automating workflows, reducing the turnaround time, and meeting regulatory requirements. Water testing laboratories need a robust data and quality management system to overcome the operational challenges and follow regulatory requirements, such as NELAP, ISO/IEC 17025:2017.

A Laboratory Information Management System (LIMS) helps assure the reliability and quality of test results. A LIMS helps manage samples and test results, streamline QA/QC processes and digitize operational workflows. A LIMS maintains a sample chain of custody and a read-only audit trail which is required during audits. A water LIMS flags out-of-specification test results if a sample exceeds regulatory limits of various contaminants. It helps generate certificates of analysis (CoAs) as per customers’ and regulatory requirements.

Conclusion

The drinking water should be free from contaminants and microorganisms for public safety. Both developed and developing countries have increased agricultural and industrial activities for economic development. However, this is affecting the quality of water and posing risks to public health. Contaminants in drinking water are harmful to the health and well-being of people. Not only it affects health, but also it disturbs the environmental balance. The onus of public safety lies with water testing laboratories. Water testing laboratories should generate accurate and valid test results to flag contaminated water samples. Laboratories must deploy a robust water LIMS to automate their processes and meet quality standards. A LIMS enables water testing laboratories to overcome operational roadblocks, meet regulatory requirements, and amplify productivity.