A paper just published in Studies in Conservation by Kim Bell and Robin Canham of Queen's University Library, Canada, has analysed the card mounts of stereocards, based on a limited sample of North American cards recently donated to the library. Their analysis by X-ray fluorescence (XRF) spectroscopy has indicated the significant presence of different heavy metals in the mounts, reflecting the chemistry used to colour them. This should not be a particular surprise as Victorian wallpapers, book cloths, papers and textiles have long been recognised as problematic. Bell and Canham's research is the first time XRF has been applied to stereograph card mounts.
It is worth quoting part of their conclusion: While this is an initial study, this research identified the significant presence of potentially harmful heavy metals, specifically arsenic-, lead-, and chromium- based pigments on nineteenth century stereograph cards and highlights the pervasive use of toxic substances in Victorian-era consumer goods. These findings extend our understanding of the historical usage of toxic pigments beyond popular previously recognized mediums such as wallpapers, textiles, and books, and demonstrates the prevalence of health hazards in historical collections. and, they add, it is imperative that GLAM [galleries, libraries, archives, and museums] workers know the inherent risks present in their collection materials to protect themselves and their communities.
Although Bell and Canham do not make any assessment of the direct risk to individuals handling cards, by being in proximity with stereograph card mounts, or the risk through inhalation or ingestion, this new knowledge should act as a prompt for collections to update their risk registers, and ensure that staff and visitors are properly attired, made aware of the risk with handling or storage, and that any risk is mitigated.
Toxicity in 3D: XRF Analysis for the Presence of Heavy Metals in a Historical Stereograph Collection at Queen’s University Library, Canada
Kim Bell and robin Canham
Studies in Conservation, published 14 January 2025, online, open access
Taylor and Francis
See: https://www.tandfonline.com/doi/full/10.1080/00393630.2025.2450976
Image: The desktop setup of the Bruker III-SD pXRF with sample stage accessory on top. The stereograph card was placed on top of the sample stage with the edge of the card just covering the examination window. A sheet of Mylar® polyester film was placed on top of the stereograph to prevent abrasion. The accessory shield was placed on top of the film. Photo credit: Robin Canham.
With thanks to Rebecca Sharpe for drawing attention to the paper.
Comments
This paper is certainly of significance, but at present is sadly short on detail. While many later stereos produced in the USA were pasted onto brightly coloured eye-catching mounts, and bright green (arsenic) is undoubtedly common, the paper notes that among the limited selected sample taken of yellow cards lead or chromium were "common", but this implies that not all were so tinted. In Britain early views before 1860 were usually on grey/brown card which, one hopes, is harmless enough. From around 1860 photographers like Francis Bedford used yellow mounts, published by Catherall & Prichard of Chester, and the very thin translucent layer of colour was clearly brushed onto the sheets of card using a laquer (shellac?) solution on one side of the card only, later on both. Other producers followed suit, such as G.W. Wilson, John Latham, Alfred Pumphrey and others, and yellow became almost ubiquitous, although different shades of yellow imply varying sources of pigment. In my innocence I've always assumed that the Victorians probably used a tincture of turmeric, but now quite clearly this is not always the case.
In as far as the serious British collector is concerned, most stereos of this period are kept in mylar or archive standard polypropylene sleeves, and so these see only limited handling, but I'm sorry for whoever has accumulated a valuable collection of early views, presenting them to a museum or archive, only to ring alarm bells among curators and archivists, but I can already hear those bells ringing. I hope this will be no reason to refuse such collections out of hand, as students can readily work from good quality scans, and the originals would see minimal handling. I can see we'll all just have to invest in a handheld spectrometer to test everything that comes our way.
Interesting. I've passed the info on to our Collection Care team.