PFAS in the Environment

Don't you like clean water.

Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that are resistant to heat, water, and oil. They are also known as "forever chemicals" because they do not break down in the environment and can accumulate in the body over time. PFAS are found in many products and industrial processes, including: 

Clothing, Carpets, Furniture fabrics, Adhesives, Food packaging, Non-stick cookware, Fire-fighting foams, Metal plating, Microelectronics, and Batteries. 

PFAS can contaminate the environment during production, use, and disposal. They can be found in soil, water, air, and food, and some can accumulate in the food chain. People can be exposed to PFAS by using products that contain them, eating contaminated food, or drinking contaminated water.

The U.S. Environmental Protection Agency (EPA) has classified PFAS as an emerging contaminant and has set enforceable limits for certain PFAS in public water systems. The EPA is also working to protect people and the environment from other sources of PFAS.

I love drinking water, in fact, everyone drinks water so this is pretty important.

According to the recent EPA regulations, the maximum concentration of PFAS (specifically PFOA and PFOS) in drinking water is set at 4 parts per trillion (ppt).

Who wants to be a part per trillionaire.

Perfluorooctanoic acid (PFOA) is a synthetic chemical that's part of a group of man-made chemicals called perfluorinated alkylated substances, the same PFAS.

Perfluorooctane sulfonic acid (PFOS) is a man-made chemical that's part of a group of chemicals called again perfluorinated alkylated substances (PFASs).

The low concentrations of PFAS and their derivatives make it difficult for mass spectrometry, Raman spectroscopy, and probes to measure. 

The concentration limit of a mass spectrometer, often referred to as the "limit of detection" (LOD), can reach the attomolar range (10^-18 M), meaning it can detect extremely low concentrations of analytes, depending on the specific molecule, instrument type, and sample matrix; however, this can vary significantly depending on the specific analysis conditions and the compound being measured.

If you want a mass spectrometer, then let me know, I got a guy.

Highly sensitive:

Modern mass spectrometers can achieve very low detection limits, allowing for the analysis of trace amounts of substances.

Factors affecting LOD:

The limit of detection is influenced by factors like the sample matrix complexity, ionization efficiency of the molecule, instrument noise, and data analysis methods.

Signal-to-noise ratio:

The LOD is typically defined as the concentration at which the signal generated by the analyte is significantly higher than the background noise, usually with a signal-to-noise ratio of 3.

Practical considerations:

While the theoretical LOD may be very low, real-world applications often require higher concentrations to achieve reliable quantification due to sample preparation challenges and matrix effects.

PFAS cause reproductive effects such as decreased fertility or increased high blood pressure in pregnant women. Developmental effects or delays in children, including low birth weight, accelerated puberty, bone variations, or behavioral changes are also found. Increased risk of some cancers, including prostate, kidney, and testicular cancers are also effects.

As of November 1, 2024, there are 10,934 cases filed against PFAS manufacturers and their AFFF foams. The number of cases is growing regularly. 

Since 1999, the National Health and Nutrition Examination Survey (NHANES) has measured blood PFAS in the U.S. population. Nearly all people in the U.S. have PFAS in their blood. Certain PFAS blood levels are declining with reduced production and use.