Investigation of iodine concentration in salt, water and soil along the coast of Zhejiang, China.
OBJECTIVE
We aim to describe the environment iodine concentration in salt, water and soil along Zhejiang Province coast in the China foreland. It will be helpful for us to judge whether this area is insufficient in iodine and universal iodized salt is necessary or not.


METHODS
We collected iodized salt samples, drinking water samples (tap water in the towns, and well water or spring water in the villages), water samples from different sources (ditches, lakes, rivers) and soil samples through random sampling in June, 2005. Salt, water and soil iodine was detected by arsenic-cerium redox method. Statistical analysis was expressed as mean+/-SEM by Windows SPSS 13.0.


RESULTS
(1) The iodine concentration in salt was 27.9+/-4.33 mg/kg (n=108). (2) Seventy-five water samples were collected. The water iodine value was 0.6-84.8 microg/L (mean of 11.66 mug/L). The watershed along the Qiantang River has significantly higher iodine content than the water in Lin'an in mountain area (P<0.01). The iodine content and mean iodine content of tap water, well or spring water and natural water sources were 4.30+/-2.43 microg/L (n=34), 23.59+/-27.74 microg/L (n=19) and 12.72+/-10.72 microg/L (n=22) respectively. This indicated that among environmental water sources, the ditch iodine content was the highest with river water iodine being the lowest (P<0.01). (3) Soil iodine value was 0.11-2.93 mg/kg (mean of 1.32 mg/kg). Though there was no statistical difference of soil iodine in different districts (P=0.131), soil iodine content correlated positively with water iodine content.


CONCLUSIONS
Iodine concentration in salt accords with national policy of adding iodine in salt. Foreland has more iodine in water than mountain area. The data reflected that water and soil iodine in foreland area was not high, which suggests universal iodized salt should be necessary. Environment iodine has relatively close association with pollution.
Lu
Ying-li
YL
Department of Endocrinology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China. luyingli2008@126.com
Wang
Ning-jian
NJ
Zhu
Lan
L
Wang
Guo-xing
GX
Wu
Hui
H
Kuang
Lin
L
Zhu
Wen-ming
WM
D002681:China; D007455:Iodine / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D012965:Sodium Chloride / Q000032:analysis*; D017673:Sodium Chloride, Dietary / Q000032:analysis; D012987:Soil / Q000032:analysis*; D014867:Water / Q000032:analysis*; D014881:Water Supply / Q000032:analysis*
D017673:Sodium Chloride, Dietary; D012987:Soil; C034024:iodized salt; D014867:Water; D012965:Sodium Chloride; D007455:Iodine