Database of 'forever chemicals' will help scientists monitor pollution

Researchers at the US National Institute of Standards and Technology (NIST) have developed a database that can help others identify and categorise per- and polyfluoroalkyl substances (PFAS) through chemical analysis data, including ‘untargeted’ chemical analysis data containing information on both known and unknown PFAS that may be lurking in a sample. Understood to be the first of its kind, the database should be useful for environmental pollution monitoring and other applications.

Governmental agencies and other organisations are increasingly monitoring PFAS in the environment, in light of recent evidence that these manufactured chemicals can potentially cause cancer and other serious health effects. But most PFAS aren’t in the suite of chemicals included in labs for quantitative analysis, and the labs themselves may have incomplete or outdated chemical data on PFAS. Due to the continual discovery of additional PFAS, it is difficult to maintain a central database that collects and organises the scientific community’s knowledge about known and unknown PFAS chemical structures.

“There is no single authority on what is PFAS or what makes up PFAS,” said NIST biologist Jared Ragland. “We know what a few hundred of them look like structurally, but there could be 9000 or more possible different PFAS structures. It’s not a small problem.”

The good news is, mass spectrometers enable scientists to detect known PFAS and to understand newly observed PFAS. This device produces a series of lines on a graph that form a unique pattern, which acts like the ‘molecular fingerprint’ of a chemical compound.

The new database includes this high-resolution mass spectrometry data and currently contains spectra for 132 PFAS. Contextual information, such as the settings of measurement instrumentation and the types of samples that were used, are attached to each entry. It also includes the NIST ‘suspect list’ of close to 5000 curated chemical compounds that are highly likely to be PFAS.

The database can be used to identify PFAS in various sources, such as wastewater, tap water, surface water and groundwater, for monitoring environmental pollution. According to Ragland, “The goal is that the database will be helpful to identify PFAS across the board and characterise novel ones to answer questions about environmental health, toxicology, exposure risk and remediation efficiency.”

Those trained in data analysis will find the database especially useful; however, the NIST researchers hope to increase its accessibility for all users, and have created a user guide that gives step-by-step instructions on how to use the database. The database is also portable, meaning it can be used offline, added to and shared between researchers, and comes with a software tool kit found on GitHub.

Scientists can easily share the database so they can collaborate, for example, on finding novel patterns in the PFAS data. They can also use the database to build new tools or data processing methods to identify specific types of PFAS that don’t already have high-quality mass spectroscopy data. Elements of the database can even be reused for organising and identifying chemicals other than PFAS, such as other emerging contaminants or pesticides in food.

The PFAS database is free and available for download from the NIST Public Data Repository at https://data.nist.gov/od/id/mds2-2905.

Image credit: iStock.com/Suriphon Singha