• This section details the state's efforts to monitor PFAS in white-tailed deer. DNR and MDHHS have been investigating this in response to questions from hunters concerned about harvesting white-tailed deer in contaminated areas of Michigan. These are the first studies of their kind; very little scientific information exists on white-tailed deer and PFAS exposure.  

    It should be noted that the organs (including liver and kidneys) of deer may contain higher levels of chemicals than muscle. For this reason, MDHHS recommends that people not eat the organs from any deer, fish, or other wild game statewide, as many chemicals, including PFAS, can accumulate in these organs.


    Oscoda Area Deer Sampling

    MDHHS has reduced the coverage area of its 'Do Not Eat' advisory for white-tailed deer taken from the Clark's Marsh area in Oscoda Township. The new advisory covers white-tailed deer taken from within three miles of the marsh instead of the previous five miles.

    In October of 2018, MDHHS and DNR issued a 'Do Not Eat' advisory for white-tailed deer taken within five miles of Clark's Marsh in Oscoda Township. One white-tailed deer out of twenty tested in the Oscoda area was found to have high levels of PFOS. The level of PFOS in the muscle of the white-tailed deer was 547 parts per billion (ppb), exceeding the level for a do not eat advisory. PFAS was either not found or was found at low levels in muscle samples from the other 19 white-tailed deer.

    Although only one white-tailed deer of this group tested at such high levels, the advisory was issued to protect the health of anyone eating venison taken within approximately five miles of Clark's Marsh. An additional 22 muscle samples from hunter-submitted white-tailed deer, collected near Clark's Marsh during the regular 2019 hunting season, were also tested for PFAS. No PFAS were detected in those muscle samples.

    In 2020, an additional 44 white-tailed deer harvested near Clark's Marsh were tested for PFAS in liver and muscle samples. Deer from the 2020 collection did have detectable levels of various PFAS, including PFOS. Based on the white-tailed deer samples collected from 2018 and 2020, MDHHS has been able to establish a relationship between detections of PFOS in deer liver samples and the deers' proximity to Clark's Marsh. The data show that deer living closer to the marsh were more likely to have PFOS in their liver.

    As a result, in July 2021, MDHHS reduced the coverage area of its 'Do Not Eat' advisory for white-tailed deer, from the previous five-mile radius down to a three-mile radius of Clark's Marsh. The updated three-mile radius is shown in this map (map link here). The DNR has estimated a three-mile area as the expected travel range of white-tailed deer living in or near the marsh. 


  • Other Statewide Deer Sampling

    DNR also collected an additional 60 white-tailed deer from other areas of the state for PFAS testing in 2018 as part of the Michigan PFAS Action Response Team's work on the emerging contaminant.  In addition to the testing in Oscoda, 20 white-tailed deer were taken near each of the PFAS investigation sites in Alpena, Rockford, and Grayling, which have known contamination in lakes and rivers. The white-tailed deer muscle tested from these areas was found to have no PFAS or very low levels of the chemicals. An additional 48 samples of white-tailed deer muscle collected from across the state during the 2017 hunting season were also tested and show no PFAS contamination or very low levels of PFAS.


    Huron River Deer Sampling

    White-tailed deer in Oakland County's Proud Lake Recreation Area were tested in 2019 because elevated PFOS levels had been found in fish collected from Kent Lake, which is connected to the Huron River.

    In April 2019, samples from 20 white-tailed deer from this area were taken to test for PFAS. Samples of muscle, liver, kidney, and heart were tested for various PFAS, and no PFAS were found in any muscle or heart samples. Based on the data, MDHHS concluded consumption guidelines are not needed for eating the white-tailed deer.

    MDHHS recommends you avoid eating organs from any deer taken in Michigan.

    If you have health-related questions, contact MDHHS at 800-648-6942. 

    Hunters can contact the DNR at 517-284-6057 or DNR-CustomerService@michigan.gov for information about white-tailed deer tags that were used in this region.