Abstract
Objectives
To examine biomarkers of heavy metal exposure in women of reproductive age as part of an ongoing periconceptional surveillance program in Southern India.
Methods
Participants were women of reproductive age (15–40 y) who were not pregnant or lactating and resided in households within the 50 km2 catchment area of our community-based research site. Venous blood samples were collected in metal-free blue top K2EDTA vacutainers, and urine samples were collected in acid-washed containers. Plasma and red blood cells were separated by centrifugation, processed, and stored <−80 °C until analysis. Heavy metal concentrations of lead, mercury, arsenic, cadmium, and chromium were measured via inductively coupled plasma-mass spectrometry in a pilot sub-sample (n = 70). Descriptive statistics for plasma heavy metal concentrations were reported (median, interquartile range [IQR]).
Results
Half of participants had at least one heavy metal detected in plasma (48.6%). For lead, 30.0% of women had detectable concentrations in plasma (median (IQR): 0.2 (0.2, 0.2) µg/dL), with 1.4% having plasma lead concentrations ≥0.5 µg/dL. For mercury, 17.1% of participants had detectable concentrations in plasma (median (IQR): 4.5 (2.0, 8.0) µg/L) and 7.1% of samples were >5.8 µg/L. A total of 31.1% of participants had detectable chromium plasma concentrations (median (IQR): 2.5 (1.0, 15.0) µg/L), with 15.7% of samples >2.1 µg/L. Concentrations of two or more heavy metals detected in plasma were found in 41.4% of participants: 7.1% lead and mercury, 18.6% lead and chromium, 10.0% mercury and chromium, and 5.7% with all three detected in plasma. No participants in this pilot sub-sample had plasma concentrations of arsenic or cadmium above the detection limit for this method (≥1.0 µg/L).
Conclusions
Findings from this pilot study provide preliminary evidence of heavy metal exposure – including lead, mercury, and chromium – in women of reproductive age in this setting. Because of potential interactions between exposure to heavy metals and folate status that may impact the risk of birth defects, biomarker surveillance of heavy metals remains a critical component of this program.
Funding Sources
Centers for Disease Control and Prevention.
AF was supported by the National Institutes of Health #5 T32 HD087137
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