Overview
Abaas and colleagues measured nickel in breast milk from lactating mothers living in Hilla City, Iraq. The study is routeable for human-milk nickel exposure because it reports breast-milk nickel concentrations in ppb and evaluates associations with maternal and environmental variables. It is human-milk exposure evidence, not infant formula evidence.
Key numbers
- Sample size: 68 apparently healthy lactating mothers, sampled mid-February through end of April 2012.
- Mean nickel concentration in breast milk: 23.83 +/- 15.57 ppb (µg/L).
- Subgroup means (mean ± SD, µg/L): rural (n=36) 30.81 ± 16.59 vs urban (n=32) 24.95 ± 19.55 (p<0.05); near street (n=32) 31.59 ± 17.41 vs far from street (n=36) 25.3 ± 18.89; near industrial area (n=22) 30.99 ± 12.98 vs normal area (n=46) 24.31 ± 13.40; tap water (n=43) 26.15 ± 2.31 vs bottled (n=18) 17.4 ± 2.43 vs river (n=7) 22.12 ± 5.42; smoker (n=8) 47.5 ± 20.05 vs non-smoker (n=60) 20.68 ± 11.89.
- The authors describe the overall mean as high compared with concentrations reported in Turkey (3 µg/L) and the USA (15 µg/L) per the paper’s Table 8.
- Prevalence of mothers with abnormal nickel concentration: 45 of 68 (66%) per Table 9. The abstract’s “99% and 93% respectively” appears to be templating leftover from a multi-metal study; the paper itself only reports nickel and Table 9 is the only prevalence table.
Methods (brief)
Ten millilitres of breast milk were self-expressed by manual breast pump after washing the breast with deionized water and discarding the first drops; midstream milk was collected into sterile polypropylene tubes, transported at -18 to -21 °C, and stored at -30 °C at the chemical laboratory of the College of Science, Babylon University. Nickel was determined by graphite furnace atomic absorption spectrometry with a calibration curve at 232 nm (Figure 1). Statistical analysis used SPSS v17 with Student’s t-test and one-way ANOVA at p<0.05 significance. The paper reports total nickel concentration.
Implications
Certification: Human-milk exposure context only; not a commercial product benchmark source.
Courses: Useful for geographic-variance teaching in infant exposure.
App: Can inform human-milk exposure context if the app tracks breastfeeding separately.
Related evidence
Update history
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