Contaminants of emerging concern
Sources of these pollutants include agriculture, urban runoff and ordinary household products (such as soaps and disinfectants) and pharmaceuticals that are disposed to sewage treatment plants and subsequently discharged to surface waters.
The concept of CECs gained significant attention in the early 21st century as advances in analytical techniques allowed for the detection of these substances at trace levels in various environmental matrices.
[3] The recognition of the potential risks posed by CECs has led to a growing body of research aimed at understanding their sources, fate, and effects in the environment, as well as the development of strategies for their management and removal.
[12] Contaminants of emerging concern (CECs) can be broadly classed into several categories of chemicals such as pharmaceuticals and personal care products, cyanotoxins, nanoparticles, and flame retardants, among others.
[15] Personal care products often contain a complex mixture of chemicals such as preservatives (e.g., parabens), UV filters (e.g., oxybenzone), plasticizers (e.g., phthalates), antimicrobials (e.g., triclosan), fragrances, and colorants.
[23] The runoff can contain a CEC’s which are not regulated or whose environmental impacts are not well understood,[12] contributing to the pollution of aquatic ecosystems, and potentially affecting human water sources.
A nationwide survey revealed that soil erosion, nutrient loss, and pesticide runoff from America's vast agricultural lands are leading causes of water quality pollution.
[25] This waste can include a wide variety of CECs like heavy metals, solvents, and various organic compounds that are not regularly detected for or removed by standard treatment processes.
[28] These pollutants can include CECs like microplastics from synthetic materials, polycyclic aromatic hydrocarbons (PAHs) from vehicle exhausts, and pharmaceuticals from improperly disposed medications.
Permeable pavements and rain gardens are being implemented and tested in some urban areas to mitigate the effects of runoff, helping to filter pollutants before they reach the water system.
[31] However, some WWTPs, particularly older or under-resourced ones are not equipped to effectively remove all CECs, such as advanced pharmaceuticals, personal care product ingredients, and certain types of industrial chemicals.
For example, endocrine-disrupting chemicals (EDCs) have the potential to imitate natural hormones, which can lead to reproductive failures and eventually population declines or increases in fish and amphibians.
EDCs are found in a variety of common contaminants, including pesticides and industrial chemicals, and they can also lead to altered growth and reproduction in aquatic life (US EPA) (USGS.gov).
Ongoing monitoring and regulatory efforts are crucial for assessing the full scope of CECs' impacts and for the development of effective strategies to mitigate their presence in aquatic ecosystems (NOAA.gov).
[41] Studies have shown that even at low concentrations, the presence of CECs in drinking water can correlate with neurological disorders and can decrease cognitive function over time.
[44] Certain perfluoroalkyl substances (PFAS), which are a type of CEC, have been linked to different adverse health outcomes like increased cholesterol levels, changes in liver enzymes, and reduced vaccine efficacy, which raises concerns about widespread exposure to these chemicals.
[45] The CDC also identifies exposure to high levels of CECs with negative effects on the immune system, by compromising the body’s ability to fight infections and increasing the risk of rheumatological diseases.
[44] Exposure to a combination of various CECs, which can occur through contaminated drinking water or food chains, may lead to cumulative on human health that are not yet fully understood.
[41][42] The health of wildlife populations is an important indicator of environmental quality, and the presence of CECs can signal broader ecological issues that require attention.
High-performance liquid chromatography (HPLC) paired with mass spectrometry (MS) can help identify organic CECs, due to their high sensitivity and selectivity EPA.
Metals and metalloids are typically analyzed using techniques like inductively coupled plasma mass spectrometry (ICP-MS), which allows for the simultaneous analysis of multiple elements USGS.
The use of remote sensing and geographic information systems (GIS) for spatial analysis is expanding, these tools facilitate the tracking of pollution spread NASA Earth Science.
In the case of THMs, this meant lowering the pH, increasing the feed rate of coagulants, and encouraging domestic systems to operate with activated carbon filters and apparatuses that can perform reverse osmosis.
There is also an element of environmental injustice, in that lower income communities with less purchasing and political power cannot buy their own system for filtration and are regularly exposed to harmful compounds in drinking water and food.
In January 2024, the White House Office of Science and Technology Policy announced a coordinated federal research initiative to address CECs in surface waters.
The OECD Workshop on Managing Contaminants of Emerging Concern in Surface Waters brought together experts from various countries to discuss challenges and solutions related to CECs, emphasizing the importance of international collaboration in tackling this global issue.
Additionally, they push for a comprehensive detection framework, and advocate for precautionary policies to prevent the release of harmful chemicals into the environment (Environmental Working Group).
