KINTZ RT, STOCKDALE DK. Absenceof toxic effects in silverreclamation workers. Scand J Work Environ Health 1989;15:210-221. Recent reports have alleged that silver presents a toxic hazard to exposed workers. To define the potential risks of long-term exposure to silver better, a cross-sectional investigation was conducted of 27 Caucasian males occupationally exposed to primarily insoluble silvercompounds and 27 matched referents. Physicalexamination and electron microscopy of skin biopsies revealed no cases of generalized argyria. Measurements of facial discoloration judged from color photographs by panels of laymen and physicians, showed no significant difference between the two groups. Although 29 % of the silver workers and none of the referents exhibited ocular silver deposition, optometric and contrast sensitivitytest results revealed no significant deficits in visual performance. The kidney and respiratory findings were essentially normal in both populations. Despite the increased presence of silver in the blood, feces, and hair of the recovery workers versus the referents, there was no evidence that chronic silver exposure adversely affected the health of these employees.Key terms: argyria, argyrosis, biological monitoring, clinical study, contrast sensitivity, epidemiologic study, insoluble silver compound, occupational silver exposure.From an occupational health standpoint, interest in the dermatologic effects of silver (argyria) has lessened considerably during the past few decades as changes in manufacturing processes and improved industrial hygiene practices have significantly reduced workplace exposures . Toxicologic evidence has generally supported the clinical observation that chronic exposure to metallic silver and its soluble salts (and pre sumably insoluble compounds) does not appear to represent a serious health risk to man. However, health data from clinical studies in the United States (1-3), and case histories reported in the European literature during the past 15 years (4-15) have suggested the need to reevaluate the human toxicologic effects of silver for such target organs as the skin, eyes, lungs, and kidneys. In addition, it is important to define more precisely the potential risks of long-term exposure to insoluble forms of silver, which have been incompletely studied and for which there is no workplace standard in the United States (US). This paper describes air sampling results and clinical and epidemiologic findings for a group of silver reclamation employees and their matched referents at a large photographic manufacturing facility . Specific study objectives included investigations of (i)
210ver deposition), (iii) visual contrast sensitivity, (iv) respiratory symptoms and diseases (pulmonary function and chest radiographs) , and (v) renal function (clinical laboratory studies). To augment the determinations of the airborne silver levels, biological monitoring was also performed.
Subjects and methods
Silver recovery operations and air sampling dataThe silver recovery department of...