Trace organic compounds (TOrCs) – potential risks to public health
TOrCs in drinking water can be present at low levels - with potential harmful risk to public health.
To evaluate drinking water quality, one needs to consider physical, chemical and microbiological parameters. Physical and chemical parameters can be heavy metals, turbidity and trace organic compounds for instance, whilst viruses, parasites and bacteria are microbiological parameters.
Trace organic compounds originate from pesticides, pharmaceuticals, industrial compounds, chlorinated flame retardants and consumer product chemicals such as household chemicals, amongst others. TOrCs in water can be present at low levels but with potential harmful risk to public health. Due to the potential harmful risk, TOrCs are highlighted in the World Health organization (WHO) guidelines for drinking water quality.
Diving into the unknown
Wastewater discharge is the main contributor to TOrCs in drinking water, one reason being that these compounds are poorly attenuated in conventional water treatment processes. There are several hundred identified TOrCs, with numerous new organic chemicals being released daily. To monitor all these compounds is unfeasible, which is the reason we need to establish prioritized indicator compounds.
Rapid direct injection methods
By doing a detailed literature review and using a scoring system, Tarun Anumol and colleagues from University of Arizona present new research where they established 20 prioritized indicator TOrC which can be detected with a rapid direct injection method.
- Minimal sample preparation reduces the risk for contamination – conventional analysis of these compounds is challenging with various sample extraction and several human intervention steps, which increase contamination risks and reduce accuracy and reproducibility.
- Rapid direct injection methods increase efficiency and functions with low sample volume – the method only needs one injection and < 100 μL sample volume while providing reporting limits of 3-39 ng L-1(302 ng L-1 for sucralose), minimal sample preparation increases efficiency.
By analyzing effluent from four different wastewater treatment plants, the 20 prioritized TOrC were detected in three out of four effluents. Certain of the prioritized TOrCs are also effective indicators for seasonal variability, consumption patterns and treatment process efficiency.
Trace organic compounds are poorly attenuated in conventional water treatment processes and wastewater discharge is the main contributor to TOrCs in drinking water.
The research by Tarun Anumol and colleagues provides knowledge and guidance towards effective wastewater monitoring schemes to detect trace organic compounds, an important piece of the puzzle towards increased drinking water quality.
You can read the full paper for free* using the link below:
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About the webwriter
Jesper Agrelius is a MSc student in Environmental Science at Linköping University, Sweden. His main interests regards environmental science, especially climate change and biogeochemistry. You can follow him on Twitter @JesperAgrelius.
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