Temporal variation of total mercury levels in the hair of pregnant women from the Maternal-Infant Research on Environmental Chemicals (MIREC) study. (February 2021)

• Record Type: Journal Article
• Authors: Lukina, Anna O.; Fisher, Mandy; Khoury, Cheryl; Than, John; Guay, Mireille; Paradis, Jean-François; Arbuckle, Tye E.; Legrand, Melissa
• Is Part Of: Chemosphere. Volume 264(2021)Part 1
• Publication Date: 2021-02
• Subjects: Biomonitoring -- Pregnancy -- Total mercury -- Temporal trends -- Hair -- Hair-to-blood ratios; (MIREC) Study Maternal-Infant Research on Environmental Chemicals -- T-Hg total mercury -- MeHg methylmercury -- BMI pre-pregnancy body mass index -- GM geometric mean -- CI confidence intervals -- ppm parts per million -- ppb parts per billion -- ppt parts per trillion; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.128402
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Prenatal exposure to total mercury (T-Hg) comes from both natural and anthropogenic sources. T-Hg can cross the blood-brain and placental barriers, and may be associated with future neurological and physiological dysfunctions. Scalp hair is an optimal and non-invasive indicator of chronic T-Hg exposure. As part of the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, hair samples from 350 women were collected within weeks after giving birth, to determine temporal variations in T-Hg levels from preconception to delivery, and to compare these levels to corresponding levels measured in other matrices (maternal and umbilical cord blood, and infant's meconium). A maximum of 12 one-cm hair segments were cut starting at the scalp; segments closer to the scalp reflected recent exposure (within the last month). For proper comparison, the hair segments were matched with the collection dates for other matrices. GM hair T-Hg levels greatly decreased during pregnancy, from 0.26 μg g −1 (preconception or full-length hair) to 0.18 μg g −1 (at delivery or segments closer to the scalp). A similar decreasing trend was found for T-Hg in maternal blood: 1st trimester (0.60 μg L −1 ) to 3rd trimester (0.47 μg L −1 ). The median hair-to-blood ratios of T-Hg levels varied from 364 (1st trimester), to 408 (3rd trimester), to 229 (cord blood). Very low T-Hg levels were detected in meconium. Mercury levels in blood and hair correlated with consumption of large predatory fish. Highlights: Mercury exposure was evaluated in the pan-Canadian MIREC pregnancy cohort. T-Hg levels in scalp hair significantly decreased during pregnancy, from conception to delivery. T-Hg levels in hair were significantly correlated with T-Hg levels in blood. Median hair-to-blood ratios of T-Hg levels increased from 364 to 408 during pregnancy. Consumption of predatory fish weakly correlated with T-Hg levels in hair and blood.