Prenatal Exposure to Toxic Metals and Early Neurodevelopmental

Overview

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Key numbers

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• personal–social scores (approximately −3% to −5%). Elevated cord mercury, arsenic, and
• estimates that 3% of neurobehavioral disorders are directly caused by environmental
• toxicants, with an additional 25% involving gene–environment interplay (5). In Saudi
• licenses/by/4.0/). et al. (6) reported a 1.8% prevalence of learning disabilities, while Al Salloum et al. (7) found
• that 0.69% of children had major neurological disorders, 0.26% had intellectual disability,
• and 0.23% had cerebral palsy. Consanguinity contributes to disability risk (8), but the
• with survival rates exceeding 90% (31,32); however, its long-term neurodevelopmental
• analytical precision are summarized in Table 1. Briefly, whole blood and residual RBC
• standard deviation of ten blank replicates multiplied by Student’s t-value at 99% confidence.
• Limits of Quantification (LOQ) were calculated as 10× the standard deviation (SD) of
• At a corrected age of two months (median: 4.2 months), parents of all 90 infants were
• the “Add to or subtract from a date” calculator (timeanddate.com). All ASQ-3 domain
• Table 1. Summary of blood/RBC sample preparation, instrumentation, calibration, accuracy, and
• • Diluent: 0.5% nitric acid, 0.05% Triton-X, 2% methanol (v/v)
• Sample Preparation • Additives: 250 µg/L gold; 0.1 µg/L internal standards (rubidium-103 for
• • Calibration range for all analytes: 0.25–4.0 µg/L
• follows: cadmium 0.9997 ± 0.0003 (n = 11); lead 0.9994 ± 0.0006 (n = 11);
• arsenic 0.9998 ± 0.0003 (n = 10); mercury 0.9998 ± 0.0002 (n = 10)
• • Recovery (%): cadmium 100–100.4; lead 99.9–101.3; arsenic 101.4–104.3;
• mercury (7.5%) at 0.75 µg/L
• • RSD (%): cadmium 2.0–3.4; lead 2.6–4.6; arsenic 2.4–4.1; mercury 2.3–3.7
• • Cadmium: 1.93, 4.05, 7.22 µg/L
• • Arsenic: 2.83, 9.33, 18.15 µg/L
• • Mercury: 3.57, 7.81, 17.53 µg/L
• • Cadmium: 0.002 µg/L
• • Arsenic: 0.001 µg/L
• • Mercury: 0.002 µg/L
• • Cadmium: 0.006 µg/L
• • Arsenic: 0.004 µg/L
• • Mercury: 0.007 µg/L
• 99% confidence level. *** LOQ was calculated as 10 × SD of the same blank replicates.
• cients were back-transformed and expressed as percentage changes (∆%) in each ASQ-3
• ASQ-3 data (n = 73) and those who underwent IUBT (n = 29), the study was likely under-
• Table 2. (a) Maternal and infant characteristics and neurodevelopmental outcomes by intrauterine
• Demographic/Clinical/ASQ-3-Domains N Mean Median Min Max N Mean Median Min Max
• Educational level (≤12/>12 years schooling) 6 (6.7%)/54 (60%) 9 (10%)/21 (23.3%) 0.032
• Work status (Current/Past and/or Never) 28 (31.1%)/32 (35.6%) 7 (7.8%)/23 (25.6%) 0.042
• Health status (Diseased/None) 35 (38.9%)/25 (27.8%) 18 (20%)/12 (13.3%) 0.532
• Dental amalgam (Yes/No) 43 (47.8%)/17 (18.9%) 20 (22.2%)/10 (11.1%) 0.626
• Newborn gender (Female/Male) 23 (20.1%)/34 (40%) 15 (17.6%)/13 (15.3%) 0.249
• Arsenic levels in blood—third trimester (µg/L) 60 0.40 0.35 0.00 1.70 29 0.42 0.24 0.00 1.86 0.944
• Mercury levels in cord blood (µg/L) 40 1.01 0.85 0.00 4.72 21 0.68 0.52 0.05 2.03 0.129

Methods (brief)

• nearly all maternal and cord blood samples and in every transfusion bag, with several
• Venous blood samples (maternal) were collected during the third trimester, and cord
• blood samples were obtained immediately after delivery. For pregnancies involving IUBT,
• residual RBCs from the transfusion units were also collected to quantify metal concentra-
• In total, 29 maternal venous samples, 21 cord blood samples, and residual RBCs from
• ing pregnancy. Complete residual RBC samples were available for 18 participants; one or
• 2.2. Blood Sample Collection
• Venous blood samples (5 mL) were collected from each participant in ethylenedi-
• mediately after delivery. From each whole-blood sample, a 200-µL aliquot was transferred
• also collected after each procedure to quantify metal concentrations. The volume of blood
• fusion hemoglobin levels. All samples were handled using trace-metal–free materials to
• 2.3. Blood/RBC Sample Preparation and Analysis
• Details of sample preparation, instrumentation, calibration, accuracy checks, and
• samples were diluted 1:50 in a nitric acid–based matrix and analyzed for the four target
• metals using inductively coupled plasma–mass spectrometry (ICP-MS; NexION® 2000,
• metal quality-assurance protocols. Limits of Detection (LOD) were calculated as the
• Limits of Quantification (LOQ) were calculated as 10× the standard deviation (SD) of
• Table 1. Summary of blood/RBC sample preparation, instrumentation, calibration, accuracy, and

Implications

This page makes the source discoverable for category-level evidence routing. Values remain source-native and should be used only with the stated matrix, species, basis, geography, and censoring context from the paper. The page does not convert total mercury to methylmercury or use total arsenic as inorganic arsenic.

Wiki pages this source may touch

• Fish — marine, non-predatory (sardines, anchovies, salmon, cod)
• Shellfish (shrimp, crab, lobster, clams, oysters, mussels)
• Mercury
• Mercury
• Cadmium
• Lead
• Arsenic
• Aluminum

Verification notes

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Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.