Table 1—

Descriptive statistics of umbilical cord trace element and mineral concentrations

Element	n		Geometric mean ppb		Phase 2:Phase 1	95% CI	Percentile method‐GMs		IPR
Element	Phase 1	Phase 2	Phase 1	Phase 2	Phase 2:Phase 1	95% CI	20th	80th	(80:20)
Selenium	1881	642	0.0591	0.0657	1.11	1.07–1.15	0.76	1.26	1.64
Zinc	2005	911	5.7840	7.4483	1.29	1.24–1.33	0.75	1.29	1.71
Copper	2005	911	0.3968	0.7069	1.78	1.71–1.85	0.73	1.31	1.79
Manganese	2005	822	0.0671	0.0407	0.61	0.57–0.64	0.62	1.60	2.58
Magnesium	2004	911	42.2705	45.6626	1.08	1.05–1.11	0.80	1.21	1.52
Iron	2005	886	45.6013	46.9678	1.03	0.96–1.10	0.52	1.99	3.85
Lead	0	885	na	0.0270	na		0.55	1.87	3.40
Mercury	1755	817	0.0127	0.0018	0.15	0.14–0.16	0.54	1.83	3.38

Method‐GMs: method geometric means
IPR: interpercentile ratio
NA: not applicable