Zinc levels in urine of female farmers in nonpolluted regions of Japan.

In the winter of 1987-88, 1472 urine samples were collected from female farmers in eight regions of Japan. The wet digests of the samples, previously analyzed for manganese, were used for the determination of zinc (i.e., Zn-U) by inductively coupled plasma emission spectrometry. The logarithms of the values after adjustment to a specific gravity of 1.016 were normally distributed; the geometric mean (geometric standard deviation) was 0.23 mg1-1 (2.00). Effects of aging and smoking on Zn-U were not evident. Inter-regional differences appeared to exist. As no sex differences are apparent from the literature, it appears most likely that the value may possibly represent the "background" level for both men and women, either smokers or nonsmokers, among the general Japanese population. When the Zn-U levels by region and age decade were compared with the concentrations of cadmium, a significant (p less than 0.01) positive correlation was detected, which suggests metabolic parallelism between the two elements.