In the western world, when we turn on our taps, we take it for granted that the drinking water that comes out is safe. But a lot of work goes on behind the scenes to ensure this is the case. Analysts must test for a multitude of hazards along the supply system.
However, in addition to traditional contaminants, such as particulates and microbes, there is an ever-increasing list of emerging chemicals of concern coming from a multitude of sources and, in many cases, with unknown consequences. This problem also stretches beyond the end consumer, potentially impacting the ecosystems that rely on the bodies of water that feed into the drinking water system for habitat and survival.
We spoke to Fiona Regan, Professor of Chemistry at Dublin City University and Director of the DCU Water Institute, about the challenges facing our water resources.
Karen Steward (KS): In your opinion, what currently are the greatest threats to water safety, and what do you think are likely to become the most concerning dangers for the future?
Fiona Regan (FR): Bacterial contamination poses a significant contamination risk globally where treatment systems are either inefficient or non-existent. However, a huge threat currently is the increasing cocktail of chemicals that are entering our waters from a range of sources (wastewater, run-off etc.) These chemicals are in low concentrations, but chronic exposure and the impacts of these chemicals on our ecosystem is not well understood. There is a growing need for more studies on chemicals and transformation products in our water.
KS: Where do you think the responsibility lies to prevent surface water contamination?
FR: This is a great question and one that challenges water managers everywhere. The cost of treatment is increasing as policy drives more stringent legislation.
Surface waters are used as drinking water sources and also as receiving waters for treated wastewater. Wastewater is a large source of chemicals, that if not adequately treated, contributes greatly to surface water contamination. I believe that source reduction is needed via chemical producers who need to address their wastewater management. There are many players from powerful industries, so there is no simple solution. Agriculture contributes pesticides through imperfect practices and runoff due to rainfall. A similar challenge arises with the pharmaceutical group of chemicals. Over prescription and widespread use of some watchlist or priority pharmaceuticals is a concern.
A further concern is the inadequate performance of treatment processes for some chemicals that increases the cost of treatment for specific chemicals where advanced processes are necessary. The public are paying for this while the source of the problem may be the producer.
KS: What role do you think education has to play in helping to reduce chemical contamination?
FR: Education plays a really key role in helping reduce chemical contamination. A good example of where there is impact, is with microplastics. A powerful message of marine pollution is helping to change practices. Similarly, education can play a key role in the agriculture community to manage pesticide and fertilizer use better.
Rising concerns about antibiotic resistance has helped drive a reduction in the inclusion of triclosan in some personal care products, but also education can play an important role in helping to reduce the use of every day personal care products and pharmaceuticals. People can change habits when they understand the impact of their practices.
KS: Can you tell us about some of the greatest challenges in detecting contaminants in surface water and how they are being addressed?
FR: The greatest challenges in detecting contaminants are: being able to measure the concentrations that exist in the environment in relation to contaminants of concern; to determine the toxicity of these levels; being able to sample the water to provide a representative sample for such levels; and the ability to measure in real-time rather than just spot samples.
I work in an area where technologies play a key role in the research that I do and in helping solve problems. In the area of emerging contaminants research technology is an essential tool in what we do. We need the best analytical techniques to help identify compounds in mixtures, determine transformation products and to extract samples from difficult matrices. We use GC and LC-MS technologies in this case with SPE.
Outside of the essential tools for my work, we also have a research patch that develops new technologies for monitoring - so we work on microfluidic sensing technologies for nutrients, bacteria and more recently eDNA. These technologies involve optical sources and detection, microfluidic channels, electronics and telemetry with designs based on the types of assays that need to be performed. Some systems are being commercialized and some are at early stages of development.
KS: In which area do you feel there is the greatest potential or scope to make a difference?
FR: There is a great opportunity for analytical chemistry now to develop methods that can provide solutions to growing challenges, such as detection of low concentrations for example. The ability to screen waters for large numbers of chemicals in order to rule out certain groups and focus efforts on groups that are persistent.
There is a real need to be able to measure more frequently waters that are at risk of contamination in order to monitor improvements over time or observe trends with the wet and dry season for example. Biosensors and chemical sensors provide opportunities in this regard, though significant investments are needed to realize this vision. We need sensors to allow real-time monitoring of chemicals or groups of chemicals.
Analytical chemistry involving improved methods of sampling and extraction, separation and detection and scale of application can drive policy to reduce use of certain chemicals due to their persistence and occurrence. There is a need though to link analytical capability to risk and toxicity and effect-based biomonitoring. This is an area of important development over the coming years.
Professor Fiona Regan was speaking to Dr Karen Steward, Science Writer for Technology Networks.