Reduce exposure to mercury in children — EH‑09 Data Methodology and Measurement

About the National Data

Data

Baseline: 1.06 micrograms per liter (µg/L) was the concentration level of mercury in blood samples at which 95 percent of the population aged 1 to 5 years was at or below in 2015-16

Target: 0.80 µg/L

Numerator
Concentration level of mercury in blood at which 95 percent of the population aged 1 to 5 years is at or below the measured level.
Target-setting method
Projection
Target-setting method details
Linear trend fitted using ordinary least squares and a projection at the 67 percent prediction interval.
1
Target-setting method justification
Trend data were evaluated for this objective. Using historical data points, a trend line was fitted using ordinary least squares, and the trend was projected into the next decade. This method was used because three or more comparable data points were available, the projected value was within the range of possible values, and a projection at the 67 percent prediction interval was selected because, based on the trajectory of the decline and its slope, it was expected that this target best fit the predicted decline by 2030.

Methodology

Methodology notes

In the general population, the total blood mercury concentration is due mostly to the dietary intake of organic forms, particularly methyl mercury. Urinary mercury consists mostly of inorganic mercury (Cianciola et al., 1997; Kingman et al., 1998). These distinctions can help interpret mercury blood levels in people. Total blood mercury levels increase with greater fish consumption (Dewailly et al., 2001; Grandjean et al., 1995; Mahaffey et al, 2004; Sanzo et al., 2001; Schober et al., 2003). Urine mercury levels increase as more occlusal surfaces of teeth are filled with mercury-containing amalgams (Becker et al., 2003).

Reference: CDC Biomonitoring Summary for Mercury

History

Comparable HP2020 objective
Retained, which includes core objectives that are continuing from Healthy People 2020 with no change in measurement.

1. Because Healthy People 2030 objectives have a desired direction (e.g., increase or decrease), the confidence level of a one-sided prediction interval can be used as an indication of how likely a target will be to achieve based on the historical data and fitted trend.