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...

Mortality in a 1942-1990 cohort of 858 men and 21 women employed in the manufacture and use of hydroquinone was evaluated through 1991. Average exposure concentrations, 1949-1990, ranged from 0.1 to 6.0 mg/m3 for hydroquinone dust and from less than 0.1 to 0.3 for quinone vapor (estimated 8-h time-weighted averages). Compared with general population and occupational referents, there were statistically significant deficits in total mortality and deaths due to cancer. No significant excesses were observed for such hypothesized causes as kidney cancer [2 observed vs 1.3 expected (both control groups), P approximately 0.39], liver cancer (0 vs 0.8, 1.3), and leukemia (0 vs 2.3, 2.7). Dose-response analyses of selected causes of death, including renal carcinoma, demonstrated no statistically significant heterogeneities or linear trends according to estimated career hydroquinone exposure (mg/m3-years) or time from first exposure.

The mortality experience of two overlapping cohorts of employees engaged in the manufacture of photographic film support was evaluated to assess the potential chronic health effects of methylene chloride exposure. In the first analysis, we examined causes of death among 1311 men initially employed between 1946 (when the solvent was first used) and 1970; in the second, we updated mortality in a 1964 to 1970 employed cohort of 1013 men. Follow-up was through 1994. The mean exposure among members of the 1946 to 1970 cohort was 39 ppm (8-hour time-weighted average) for 17 years, and the median length of follow-up from first exposure was 34 years. Members of the 1964 to 1970 cohort received an average exposure of 26 ppm for 24 years; median time from first exposure was 35 years. Compared with general population vital statistics, mortality in both cohorts was below expectation for all causes of death, ischemic heart disease, and cancer, including such sites as the lung and liver, which were target organs identified in animal toxicology studies. No statistically significant increases were observed for any cause of death. The combined results of this study and three others in the photographic film and textile fibers industries (approximately 7300 subjects) show that long-term exposure to methylene chloride does not increase the risk of death from any cause including specific diagnoses that have been associated with this widely used solvent.

What are the optimum survey procedures for supplementing regular mortality statistics? This report presents some results of methodological studies which have been undertaken to develop procedures for querying sources of information identified on death certificates. The survey procedures are evaluated primarily in terms of response rates.