Environmental and lifestyle factors affecting nickel concentrations in human colostrum: A cross-sectional study in...

Nickel (Ni) is a ubiquitous environmental pollutant capable of traversing the placental barrier. While adult exposure primarily occurs via drinking water, data regarding Ni concentrations in colostrum remains sparse. This study aimed to investigate how maternal lifestyle and environmental factors influence Ni levels during the earliest stage of lactation.

We conducted an observational, cross-sectional analysis of colostrum from 99 Caucasian mothers in Poland. Colostrum samples were collected between days 1 and 3 postpartum. Ni was quantified using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Statistical associations were examined between Ni levels and maternal age, residence, pre-pregnancy BMI, and smoking status (non-smokers, former smokers, and current smokers). A semi-quantitative food frequency questionnaire evaluated the impact of dietary, specifically meat, fish, and vegetable intake.

Ni was undetectable in approximately 90% of participants, with a study median of 0.00 μg/L (range: 0.00-15.1 μg/L). Active smoking was the most prominent determinant of increased Ni levels (p < 0.001), with current smokers reaching a median of 12.00 μg/L. Notably, former smokers maintained Ni levels comparable to lifelong non-smokers. Maternal age also showed a significant link (p = 0.033), with younger mothers exhibiting more frequent detectable levels. Conversely, residence, pre-pregnancy BMI, and dietary patterns yielded no significant correlations (p > 0.05).

Tobacco use is the primary modifiable factor for Ni transfer to colostrum, whereas general dietary and environmental exposures in the region appear minimal. The parity between former and non-smokers highlights the clinical importance of smoking cessation prior to conception.