MERCURY IN NEWBORNS AND WOMEN OF CHILDBEARING AGE IN THE LAKE SUPERIOR BASIN

September 25, 2013

Pat McCann

Minnesota Department of Health

WI and MN Statewide GuidelinesMercury is main human health concern

walleye > 20”, northern > 30”

Mercury Levels in Blood from Newborns in the Lake Superior Basin: Goals

• Determine range of mercury concentrations in newborns from Lake Superior Basin

• Assess feasibility of a novel method to analyze mercury in residual dried blood spots from Newborn Screening

• Lake Superior Binational Program, Chemical Committee• Are there exposures of concern in the Superior Basin?• Method to track temporal trends?

• Funded by U.S. EPA GLNPO

3

Design

Total mercury measured in residual dried bloodspots from newborns whose mothers were from in the US portion of the Lake Superior Basin

• Births Nov 2008 through May 2010• 1466 participants (MN =1126, WI =140, MI =200) • MN informed consent

Anonymized design, kept data on: • sex of baby • month of birth• state of mother’s residence

• urban vs. non-urban residence (MN only)

Mercury in Residual Newborn Blood Spots, MN data (µg/l)

N= 1126Wide distributionMedian = 0.83 µg/l

44% below MDL of 0.7 µg/l, most exposures low

10% above 5.8 µg/l (equivalent to RfD)

1% above 58 µg/l (equivalent to BMDL)

Maximum concentration = 211 µg/l

Results

• No association between mercury concentration and sex or urban versus non-urban residence (MN).

• MN results suggest a seasonal exposure pattern• Highest concentrations in summer months

• Mercury levels in infants from MN > WI ~MI• Minnesotans have reported eating more locally-caught fish • Minnesotans may be eating more higher mercury species (walleye and

northern pike)

Star Tribune, Feb 19 2013

Median Hg vs. Month of Birth (ND=0.7µg/l)

Conclusions

• This study provides evidence of mercury exposures in some pregnant women that need to be reduced• 10% of MN babies tested were above EPA RfD for methylmercury

• Results provide fish advisory programs stronger evidence of need to communicate with women of childbearing age about reducing mercury exposure. • Increased public health action is needed to ensure the

public has information that promotes eating fish that are low in mercury.

Reducing Mercury Exposure in Women of Childbearing Age

Goal: Health care providers integrate

fish consumption advice into clinical practice

Partners: Sawtooth Mountain Clinic, Northshore

Cook Co. Hospital, Grand Portage Trust Lands,

Grand Portage Health Service

Design• In-clinic screening questions for high Hg exposure from fish

consumption• Use biomonitoring for Hg and fatty acids (500 women) to validate

• Educational intervention to promote consumption of low Hg fish

Timeline: October 2012 to September 2016

Acknowledgments

• MN Department of Health• Newborn Screening Program• Public Health Laboratory• Environmental Health Tracking and Biomonitoring Program • Environmental Health Division

• MI and WI Newborn Screening Programs • WI Department of Human Services - Henry Anderson• Advice on results interpretation - Philippe Grandjean, Alan

Stern, Michael Gochfeld • Funding provided by U.S. EPA GLNPO• For more information: http://www.health.state.mn.us/fish

• Or contact Patricia McCann: patricia.mccann@state.mn.us