The Michigan Department of Health and Human Services (MDHHS) and Kent County Health Department (KCHD) today released a review of cancer incidence data for per- and polyfluoroalkyl substances (PFAS) found in some drinking water samples in northern Kent County.

The report found one type of cancer was elevated in the selected areas of northern Kent County, but it does not provide enough information to be conclusive as to why it is elevated.

Prostate cancer results were elevated.

MDHHS and KCHD say those results are difficult to interpret because the associations with PFAS exposure are weak and there are other factors known to influence prostate cancer incidence that are beyond the scope of the review. They say the data review cannot determine the linkage of any cancer occurrence with environmental conditions including PFAS exposure nor the cause of increases or decreases of any cancer types over time.

A number of cancers have been found to be associated with PFAS according to currently available literature. They have been reported in scientific literature with incidence of kidney and testicular cancers, with possible but weak evidence for prostate and ovarian cancers.

MDHHS examined the incidence of invasive cancers from 2000 to 2014 in twelve United States census tracts and two ZIP codes (49341 and 49306) in selected areas of northern Kent County. These ZIP codes include the communities of Rockford, Plainfield Township, Cannonsburg, and Belmont, Mich.

The ZIP code and U.S. census tract boundaries serve as the geographic scope of this analysis, but do not exactly match the MDEQ Northern Kent County PFAS Environmental Investigation areas.

Findings include:

  • Prostate cancers were significantly higher than expected for the two combined ZIP codes for all three 5-year time periods examined but declined across time.
  • The incidence of urogenital cancers from the twelve Kent County census tracts did not differ from expected when compared to white State of Michigan residents cancer rate.
    • However, four census tracts had significantly higher rates than those for white Kent County residents in the first time period only.
    • Kidney and renal pelvis cancers were higher than expected for the combined ZIP codes for the 2000 – 2004 time period, but this difference declined over time.
  • The yearly incidence of urogenital cancers for the two Kent County ZIP codes indicate no trends, however some individual years and all years combined have significantly higher than expected rates based on Michigan rates.
    • This is primarily driven by the prostate cancer incidence findings.
  • Testicular cancers were not significantly higher than expected for the combined ZIP codes during the overall 2000-2014 time period.
  • Ovarian cancers were not significantly higher than expected for the combined ZIP codes during the overall 2000-2014 time period.

The cancer incidence report establishes a baseline of information that can be used going forward. Future work will include collecting people’s blood for PFAS testing and information on their exposure to PFAS. Kent County was chosen for this assessment because no other area in Michigan has as many wells exceeding the advisory level nor are any test results as high.