Appendix 5 Follow-up lasting ≤3 months
Reference
Country
Princi 1947; U.S.A.
Smith et al. 1955;
United Kingdom
Smith and Kench 1957;
United Kingdom
Murray et al. 1981;
U.S.A.
Falck et al. 1983; U.S.A.
Main issues
Because of the very limited number of studies about the continued exposure found in industry, Princi undertook a 3-month
prospective study in a cadmium smelter (Cd dusts and fumes; CdO, CdS, and CdSO4). 20 male workers exposed for 0.5 to
22 y were examined clinically at monthly intervals. Blood and urine sample were taken at the same time every month. Mean
CdB and Cd-U ranged between 10 and 40 g/100g and 11 to 125 g/l, respectively. No apparent clinical abnormalities were
found with the exception of a yellow ring on the teeth “There were no reports of (…) genito-urinary dysfunction”. Proteinuria is
not mentioned in the publication but Friberg et al (1971; page 81) reported that Princi used the boiling test, which could
explain the negative results for proteinuria.
In the frame of a research work largely devoted to the development of a method of Cd analysis in urine, 12 workers from an
alkaline accumulator factory exposed to cadmium oxide dust were followed up. This prospective part is quite limited (6 weeks
and 12 workers, the exposure of whom was heterogeneous). Proteinuria was measured. A more recent follow-up is available
(see text).
Longitudinal observations of some workers with respect to urinary Cd and protein concentration. Exposure was to Cd oxide
dust (battery factory) or to cadmium (oxide) fume (Cd-Cu alloy). Number of weeks of follow-up is unclear in the exposed
workers (two consecutive weeks?). In other tables the follow-up is short (a working week or a shift). A more recent follow-up
is available (see text)
Actually, the study was not designed to ascertain the long-term renal effects of Cd but to determine the diagnostic value of
urine cytology as a screening test for detecting early Cd-induced renal dysfunction. 21 male workers exposed to dust from the
production of plastics and pigments (Ba/Cd stearate stabilizer and CdSe pigment) entered the study. Mean Cd-U (range) was
5.4 g/l (0.9 to 22). To test reproducibility, urine cytology was carried out twice at 1-month interval. However, proteinuria, Screatinine, and creatinine clearance were determined once only. Renal function was not assessed in the 23 control subjects
participating in the urine cytology study. Of note, cytology proved unreliable and “evaluation of the workers using the standard
tests to detect early renal damage revealed no consistent abnormalities.”
Spot urine samples of 33 men exposed to Cd through brazing were classified as “abnormal” if concentration of glucose, total
proteins, and/or B2MG exceeded the 95th percentile of the control group (41 men). 11 workers had at least one “abnormal”
value. A non-occupational cause was likely in 3 workers. Among the 8 remaining men, 7 had increased 24-hour proteinuria at
a second examination. S-creatinine was not followed up although it was slightly increased in 3 workers. Cd-U in the 7 workers
was between 5 and 61 g/g. Time elapsed between both examinations is unknown. According to the context, the first
examination was a screening and the second conducted shortly thereafter for confirming the screening results. A true followup study of these workers was not found.
References
Falck FYJr, Fine LJ, Smith RG, McClatchey KD, Annesley T, England B, et al. (1983). Occupational cadmium exposure and renal status. Am J Ind Med, 4,
541-9.
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Murray T, Walker BR, Spratt DM, Chappelka R. (1981). Cadmium nephropathy: monitoring for early evidence of renal dysfunction. Arch Environ Health, 36,
165-71.
Princi F. (1947). A study of industrial exposures to cadmium. J Ind Hyg Toxicol, 29, 315-20.
Smith JC, Kench JE. (1957). Observations on urinary cadmium and protein excretion in men exposed to cadmium oxide dust and fume. Br J Ind Med, 14,
240-5.
Smith JC, Kench JE, Lane RE. (1955). Determination of cadmium in urine and observations on urinary cadmium and protein excretion in men exposed to
cadmium oxide dust. Biochem J, 61, 698-701.
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