February 27, 2019

More Information On PFAS Health Risks

 |  By: Mike Opperman

A group of chemicals, called Per- and polyfluoroalkyl substances (PFAS), were found in ground water near a Clovis, New Mexico dairy. 

Producers and individuals throughout the dairy industry have raised questions about the impact of PFAS consumption on animal and human health. We posed a few of those questions to representatives at the National Center for Environmental Health (NCEH) and the Agency for Toxic Substances and Disease Registry (ATSDR). Responses to our questions are listed below.

1. At what levels are PFAS found in normal cow’s milk?

PFAS have been measured in milk from cows fed contaminated feed or raised in areas known to have PFAS contamination, as well as in some commercially available milk. However, there isn’t sufficient data to determine a ‘normal’ level.  
2. At what levels are PFAS harmful to humans?

The ATSDR uses Minimal Risk Levels (MRLs) as a screening tool to help identify exposures that could be hazardous to human health. An MRL is an estimate of the amount of a chemical a person can eat, drink, or breathe each day without a detectable risk to health. MRLs are intended to serve as a tool to help public health professionals determine areas and populations potentially at risk for health effects from exposure to a particular chemical. Exposure above the MRLs does not mean that health problems will occur. Instead, it may act as a signal to health assessors to look more closely at a particular site where exposures may be identified.
MRLs do not define regulatory or action levels for ATSDR. When health assessors find human exposures are occurring at higher than the set MRL, it means that they may want to look more closely at the human exposures. It does not mean that people will become sick from those exposures. The way the MRL is calculated can change depending on type and quality of data available. 
MRLs can be set for 3 different time periods (the length of time people are exposed to the substance): acute (about 1 to 14 days), intermediate (from 15-364 days), and chronic (exposure for more than 365 days). ATSDR has developed over 400 human health minimal risk levels (MRLs). MRLs are developed for health effects other than cancer. 
3. Is there a human health concern for drinking milk containing PFAS?

Studies of PFAS exposure in humans have most often looked at populations who drank PFAS in their water. The findings of these studies would likely also be applicable to the consumption of PFAS- contaminated milk. 
4. Can crops acquire PFAS from irrigation or uptake of contaminated ground water?
Studies have shown evidence of uptake of PFAS by plants as a result of the use of PFAS-contaminated irrigation water, the application of biosolids containing PFAS, and PFAS contamination of the soil or groundwater. Uptake and accumulation depend on the plant species and the PFAS chemical structure. However, the extent to which PFAS accumulate in plants is not well studied. 


If you have more questions about PFAS, please send them to us at [email protected] 

For more information on the topic, see the following articles:

What You Need To Know About PFAS

Concerned About PFAS In Your Groundwater? Here's What To Do

Nine Steps for Managing a Crisis

Air Force Pollution Forces New Mexico Dairy To Euthanize 4,000 Cows