Potential nephrotoxic effects of exposure to silver.

Abstract

A cross sectional study was conducted on workers engaged in manufacturing precious metal powder. Of the 27 workers, 96% had raised urine silver concentrations (range 0 5-52 0 ig/l, mean 113 yg/l) and 92% had raised blood silver concentrations (range 0-05-6-2.pg/100ml, mean I 0 pg/l00 ml). Nineteen per cent also had raised urine cadmium concentrations (range 1 9-760 4ug/l, mean 11 8 jg/l). Most workers had symptoms of respiratory irritation and nose bleeds were reported in eight (30%) of the 27 workers. Deposition of silver in the cornea of the eye was detected in five of eight (63%) of the long term workers. Although not statistically significant, corneal deposition was associated with complaints of decreased night vision. The urinary enzyme N-acetyl-B-D glucosaminidase (NAG) was significantly raised in four individuals and was correlated with blood silver concentrations and age. In addition, the group's average NAG concentration was significantly higher than that found in a control population. No association between age and urinary NAG was found in the control group. Estimated creatinine clearance was also significantly lower in the group exposed to silver than in the control group. Kidney function appears to have been adversely affected by exposures at work but because of the exposure to cadmium the role of silver in causing the decrement in kidney function could not be definitely determined.There are no known acute effects of exposure to silver metal but some silver compounds such as silver oxide and silver nitrate are irritating and exposure to them has been associated with nose bleeds and abdominal pain.' With chronic exposure, silver binds to sulphydryl proteins in cells and, depending on the duration and amount of exposure, individuals may develop darkening of the conjunctiva and darkening of the skin especially in sun exposed areas. The darkening may be described as a slate grey colour. The chronic effects of silver are considered to be limited to these changes in the pigmentation of the skin and eyes without any corresponding functional defects.Silver is also deposited in the cornea of the eye. In a previous study of silver exposure extensive eye examinations to follow up complaints of decreased night vision in workers with corneal opacities from silver showed no cause for this complaint.2 Whether silver affects the kidney like other heavy metals such as mercury or cadmium has not been specifically investigated. One previous study in workers exposed to silver found limited evidence of an effect of silver on creatinine clearance.' The present study examines the chronic effects of exposure to silver, concentrating on the effects on renal function.Accepted 21 July 1986 Industrial hygiene and backgroundThe company in which the study was undertaken manufactures silver and other precious metal powder.It uses pure metals (silver bars, cadmium, gold, platinum, and paladium) as well as silver containing wastes (spent chemical catalysts) as its raw materials. Numerous chemicals including nitric acid, ...

A randomized controlled evaluation of absorption of silver with the use of silver alginate (Algidex) patches in very low birth weight (VLBW) infants with central lines

“…Chest radiograms and results of clinical examination of respiratory function were predominantly normal, with no demonstrated relationships between abnormalities and duration of employment. Similar complaints were recorded for workers involved in the manufacture of silver metal powders, although the workers were concurrently exposed to acids, hydroquinone, formaldehyde, caustics, solvents, and cadmium (Rosenman et al 1987). …”

“…Levels of silver in feces, blood, and urine have been associated with recent exposure via inhalation, oral, and dermal routes. Levels in these biological media may serve as more reliable, primary biomarkers of exposure to silver than levels in hair (DiVincenzo et al 1985;Rosenman et al 1979Rosenman et al , 1987. These biomarkers appear to be independent of the route of exposure, but have not been quantitatively correlated with level and duration of exposure.…”

“…Occupational exposure to silver metal dust has been associated with increased excretion of a particular renal enzyme (N-acetyl-β-D glucosaminidasej, and with decreased creatinine clearance (Rosenman et al 1987). Both of these effects are diagnostic of marginally impaired renal function.…”

“…Occupational exposure to silver dusts can also lead to respiratory irritation (Rosenman et al 1979(Rosenman et al , 1987. One occupational study describes a group of 30 employees of a manufacturing facility involved in the production of silver nitrate and silver oxide (Rosenman et al 1979).…”

“…Furthermore, the amount of deposition in the eyes was found to correlate significantly with reports of changes in skin color and decreased night vision. The complaint of decreased night vision was also recorded in a study of workers involved in the manufacture of metal silver powders (Rosenman et al 1987). …”