PFCs: facts & figures

PFC blood levels


PFC levels in the U.S. population

PFC blood levels among people 12 years and older. Data source: National Health and Nutrition Examination Survey.

Perfluorochemicals (PFCs), including PFOS, PFOA and PFHxS, are chemicals that have been used for many years to make products that resist heat, stains, grease and water. Blood levels of PFOS and PFOA have declined in the U.S. population since 1999. The trend over time is less clear for PFHxS.

The median is the level that 50% of people tested fall above and 50% of people tested fall below. The 95th percentile is the level that 95% of people fall below. It shows PFC levels in the most highly exposed people.

These declines are likely a result of reductions in the production of certain PFCs during this time period. 3M, formerly the primary manufacturer of PFOS world-wide, stopped producing PFOS in 2002. Efforts are also underway to reduce PFOA production and use.


PFC blood levels in the U.S. population by sex

Median PFC blood level among people 12 years and older. Data source: National Health and Nutrition Examination Survey, 2011-12.

Men in the U.S. have higher blood levels of PFCs than women. This difference has been seen in many scientific studies, including PFC Biomonitoring in the East Metro of Minneapolis-St. Paul. It may be due to differing product use and the ways PFCs are cleared from the body. Women can clear PFCs through menstruation, childbirth, and breastfeeding.


PFCs in people in Minnesota

In the East Metro of Minneapolis- St. Paul, some drinking water sources were polluted with PFCs. Filtration systems were installed in 2006 on the Oakdale municipal water system and on many private wells to remove these chemicals. Water systems are tested regularly.

MDH has conducted biomonitoring in East Metro residents since 2008. Biomonitoring has shown that the efforts reduce PFCs in drinking water are working.


PFC blood levels in long-term residents of the East Metro

Geometric mean PFC blood level (n = 149). Data source: Minnesota Department of Health and National Health and Nutrition Examination Survey, 2011-12.

PFC blood levels in long-term residents are still higher than levels seen in the U.S. population, but they are getting closer.

PFOS, PFOA, and PFHxS blood levels in long-term East Metro residents tested were higher than levels seen in the U.S. population. These people were exposed to PFCs in drinking water before the filtration systems were installed. Levels of these PFCs decreased between 2008 and 2014 in most people. On average, individual levels of PFOS went down by 45%, PFOA by 59%, and PFHxS by 34% over 6 years.

PFC blood levels in new residents of the East Metro

Geometric mean PFC blood level. Data source: Minnesota Department of Health and National Health and Nutrition Examination Survey, 2011-12.
PFC levels in new Oakdale residents were about the same as levels seen in the U.S. population. Statistical tests did not find significant differences between the two groups. These are people who moved to the East Metro after the 2006 intervention and were not exposed to high PFC levels in their drinking water.

PFCs are common chemicals

Perfluorochemicals (PFCs) are chemicals that have been used for many years to make products that resist heat, stains, grease and water. There are many different PFCs. The three shown here are detected in the blood of most people: perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonate (PFHxS).

People can be exposed to PFCs from using certain products and eating contaminated food. Items that may contain PFCs include furniture, carpets, and clothing that are treated to resist stains and repel water, nonstick cookware, fire-fighting foams, and fast food packaging. In some communities with water sources contaminated with PFCs, such as the East Metro of Minneapolis- St. Paul, exposure can also be through drinking water.

Scientists are studying potential health effects

Scientists still do not fully understand the human health effects of PFC exposure. Studies of workers in PFC production jobs have not found consistent evidence that PFCs are increasing the risk of health problems. A large study of people exposed to PFOA in drinking water in West Virginia and Ohio found that there is a “probable link” between PFOA and some health conditions, but found no link with many other conditions. Research continues on PFCs and health effects such as birth outcomes, hormone balance, cholesterol levels, and immune response.

Biomonitoring shows PFC levels in the body

Biomonitoring measures the amount of PFCs in a person’s blood. It shows the levels of PFCs a person has in their body from all different sources of exposure. Charts on this page show levels in micrograms (mcg) of PFC per liter (L) of blood. Some PFCs are cleared from the body more quickly than others. PFOS, PFOA, and PFHxS stay in the body for years. There are no reference levels for "safe" or "unsafe" amounts of PFCs in the body.

Data shown for the U.S. population are from the National Health and Nutrition Examination Survey (NHANES). NHANES provides valuable comparison data that are not available for the statewide population in Minnesota.

What is being done about PFCs in Minnesota?