Hair Mercury Levels of Women of Reproductive Age in Ontario, Canada: Implications to Fetal Safety and Fish Consumption

doi:10.1016/j.jpeds.2010.01.020

The Journal of Pediatrics

Volume 157, Issue 1, July 2010, Pages 127-131

https://doi.org/10.1016/j.jpeds.2010.01.020 Get rights and content

Objective

To study hair mercury concentrations among women of reproductive age in relation to fish intake in Ontario, Canada.

Study design

Three groups were studied: 22 women who had called the Motherisk Program for information on the reproductive safety of consuming fish during pregnancy, a group of Japanese residing in Toronto (n = 23) consuming much larger amounts of fish, and a group of Canadian women of reproductive age (n = 20) not seeking advice, were studied. Mercury concentrations in hair samples were measured using inductively coupled plasma mass spectrometry. Seafood consumption habits were recorded for each participant. Based on the types of fish consumed and consumption frequencies, the estimated monthly intake of mercury was calculated. Hair mercury concentrations were correlated to both the number of monthly seafood servings and the estimated ingested mercury dose.

Results

There were significant correlations between fish servings and hair mercury (Spearman r = 0.73, P < .0001) and between amounts of consumed mercury and hair mercury concentrations (Spearman r = 0.81, P < .0001). Nearly two thirds of the Motherisk callers, all of the Japanese women, and 15% of the Canadian women of reproductive age had hair mercury above 0.3 μg/g, which was shown recently to be the lowest observable adverse effect level in a large systematic review of all perinatal studies.

Conclusions

Because of very wide variability, general recommendations for a safe number of fish servings may not be sufficient to protect the fetus. Analysis of hair mercury may be warranted before pregnancy in selected groups of women consuming more than 12 ounces of fish per week, as dietary modification can decrease body burden and ensure fetal safety.

Section snippets

Methods

The study cohort consisted of 3 groups (Table I): (1) a group of Canadian women of reproductive age who had called the Motherisk program in 2006 to 2007 while planning pregnancy for information on the safety of consuming fish during pregnancy (n = 22). All except for one completed post secondary education; (2) a convenience sample of Canadian women of reproductive age who did not consult the Motherisk program and were not concerned about fish consumption were selected in Southwestern Ontario as

Results

Overall, the majority of subjects consumed salmon, as the fish of choice, or canned tuna at least 1 to 2 times a month; when not pregnant other commonly consumed fish were included. When comparing fish consumption habits among the 3 groups, the median number of servings of fish per month of each group differed significantly between the Japanese group and Motherisk callers (P < .001); the highest among the Japanese group (10 servings), followed by the Motherisk callers (4). The Japanese also

Discussion

This study examined fish consumption habits and mercury exposure in three cohorts in Ontario. We corroborated a significant relationship between fish servings and hair mercury, a correlation that was improved when examining the association between calculated mercury intake and hair mercury content. The correlations presented here are comparable with previous studies in which hair mercury was correlated with fish consumption.13, 14, 15, 16, 17, 18, 19

This correlation suggests that only 50% of

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: Supported by a grant from the First Nation and Inuit Branch, Government of Canada and Health Canada. The authors declare no conflicts of interest.

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Original ArticleHair Mercury Levels of Women of Reproductive Age in Ontario, Canada: Implications to Fetal Safety and Fish Consumption

Objective

Study design

Results

Conclusions

Section snippets

Methods

Results

Discussion

Lancet

Environ Res

Obstet Gynecol

Environ Int

Environ Res

Environ Res

EnvironRes

Environ Res

Environ Res

Minamata disease: methylmercury poisoning in Japan caused by environmental pollution

Crit Rev Toxicol

Methylmercury poisoning in Iraq

Science

Methylmercury: significance of intrauterine and postnatal exposures

Clin Chem

Original Article
Hair Mercury Levels of Women of Reproductive Age in Ontario, Canada: Implications to Fetal Safety and Fish Consumption