General occupational safety and health rules subdivision z toxic and hazardous substances

The data in the Table 6 indicate the geometric mean of CDU levels observed among the general population is 0.52 µg Cd/l urine (unadjusted), with a geometric standard deviation of 3.0. Normalized for creatinine, the geometric mean for the population is 0.66 µg/g CRTU, with a geometric standard deviation of 2.7. Table 7 provides the distributions of CDU concentrations for the general population studied by Kowal and Zirkes. The data in this table indicate that 95% of the CDU levels observed among those not occupationally exposed to cadmium are below 3 µg/g CRTU.

Table 8 is a summary of results from available studies of CDU concentrations observed among cadmium-exposed workers. In this table, arithmetic and/or geometric means and standard deviations are provided if reported in these studies. The absolute range for the data in each study, or the 95% confidence interval around the mean of each study, also are provided when reported. The lower and upper 95^th percentile of the distribution are presented for each study

in which a mean and corresponding standard deviation were reported. Table 8 also provides estimates of the years of exposure, and the levels of exposure, to cadmium in the work place if reported in these studies. Concentrations reported in this table are in µg/g CRTU, unless otherwise stated.

Table 8. - Urine Cadmium Concentrations in Workers Exposed to Cadmium in the Workplace
Study number	Work environment (worker population monitored)	Number in Study (n)	Employment in years (mean)	Mean concentration of cadmium in air (µg/m3)	Concentrations of Cadmium in Urine a
					Arithmetic mean (+S.D.) b	Absolute range or (95% C.l.) c	Geometric mean (GSD) d	Lower 95th percentile of range e ( ) f	Upper 95th percentile of range e ( ) f	Reference
1	Ni-Cd battery plant and Cd production plant: (Workers without kidney lesions) .... (Workers with kidney lesions) ……..……..	96 25	3-40 …….. ……..	<90 ……………. …………….	16.3+16.7 48.2+42.6	…………	……….	…… (0) (0)	…….. (44) (120)	Lauwerys et al. 1976.
2	Ni-Cd battery plant: (Smokers) …….………... (Nonsmokers) ….……….	…… 7 8	…….. (5) (9)	……………. 10.1 7.0	………….. 5.5 3.6	………… 1.0-14.7 0.5-9.3	………. ………. ……….	…… …… ……	…….. …….. ……..	Adamsson et al. (1979).
3	Cadmium salts production facility …….	148	(15.4)	…………….	15.8	2-150	……….	……	……..	Buchet et al. 1980.
4	Retrospective study of workers with renal problems: (Before removal) ….… (After removal) ……....	19 …… ……	15-41 (27.2) (4.2)g	……………. ……………. …………….	………….. 39.4+28.1 16.4+9.0	………… 10.8-117 80-42.3	………. ………. ……….	…… (0) (1.0)	…….. (88) (32)	Roels et al. 1982.
5	Cadmium production plant: (Workers without renal dysfunction) …….... (Workers with renal dysfunction) ……....	…… 33 18	…….. 1-34 10-34	……………. …………….	………….. 9.4+6.9 22.8+12.7	………… 2-27 8-55	………. ………. ……….	…… (0) (1)	…….. (21) (45)	Ellis et al. 1983.
6	Cd-Cu alloy plant …….…	75	Up to 39	Note h	6.9+9.4	…………	……….	(0)	(23)	Mason et al. 1988.
7	Cadmium recovery operation	45	(19)	87	9.3+6.9	…………	……….	(0)	(21)	Thun et al. 1989.
8	Pigment manufacturing plant	29	(12.8)	0.18-3.0	…………..	0.2-9.5	1.1	……	……..	Mueller et al. 1989.
9	Pigment manufacturing plant	26	(12.1)	<3.0	…………..		1.25+2.45	0.3	6	Kawada et al. 1990.
a Concentrations reported in µg/g Cr. b S.D. – Standard Deviation. c C.I. – Confidence Interval. d GSD – Geometric Standard Deviation. e Based on an assumed lognormal distribution. f Based on an assumed normal distribution. g Years following removal. h Equivalent to 50 for 20-22 yrs.