Table 5.

Comparison of lead concentrations from the present study and previous studies.

Reference	Place	Sampling years	Numbers	Population	Arithmetic mean	Geometric mean
Present study	China	2012 - 2014	800	Pregnant women	6.35 μg/L 13.67 μg/Pb g creatinine	3.35 μg/L 7.99 μg/Pb g creatinine
Ding et al. 2014 [27]	China	2009 -2010	1647	General population	—	2.85 μg/L
Jain 2013[26]	USA	2003 - 2010	1565	Pregnant women	—	0.63 μg/L
Woodruff et al.2011 [21]	USA	2003 - 2004	268	Pregnant women	—	0.81 μg/L
Shirai et al. 2010 [22]	Japan	2007 - 2008	78	Pregnant women	1.19 μg/Pb g creatinine	0.48 μg/Pb g creatinine
Hinwood et al. 2013 [23]	Australia	2008 - 2010	157	Pregnant women	0.66 μg/L 0.87 μg/Pb g creatinine	—
Fort et al. 2014 [24]	Spain	2004 - 2006	657	Pregnant women	5.2 μg/Pb g creatinine	—
Adekunle et al. 2010 [25]	Nigeria	2006 - 2008	214	Pregnant women	28.5 μg/Pb g creatinine	—

—No data.