Reconstruction of historical exposures at a Welsh nickel refinery (1953-2000).
Past epidemiological studies of workers in a nickel refinery in Clydach, Wales, have shown evidence of large excess respiratory cancer mortality risks [lung cancer relative risk (RR) ≈ 3; nasal cancer RR ≈ 140] in those employed prior to 1930, with risks dropping dramatically in workers hired subsequently. The pre-1930 risks have generally been attributed to high exposures to mixtures of nickel compounds. More recent studies of this refinery's workers have focused on those first hired in 1953, when many of the operations that presumably gave rise to the high exposures were no longer in operation. While these studies have shown greatly decreased lung cancer risks overall (RR ≈ 1.4), and no substantive evidence of increased nasal cancer risk, the absence of reliable exposure estimates have made it difficult to ascertain whether the increased lung cancer risks are nickel related or due to other factors. This study uses nickel measurements from the 1970s to the present, documentation of process changes, and dust measurements taken around the 1950s to construct an exposure matrix for the recent cohort. It provides evidence of at least 30-fold decreases in levels of nickel exposure from the 1950s to the present, with estimated inhalable nickel concentrations in the 1950s in excess of 5mg Ni m(-3).
1.DJS Consulting, 3942 Rives Chapel Church Road, Siler City, NC 27344, USA djsivulka@centurylink.net.
Donna J
DJ
Sivulka
2.SKS Consulting Services, 3942 Rives Chapel Church Road, Siler City, NC 27344, USA.
Steven K
SK
Seilkop
3.Vale Europe Ltd (Retired), 755 Clydach Road, Ynystawe, Swansea, SA6 5BA, UK.
Keith
K
Lascelles
4.BRConard Consulting, Inc., 153 Balsam Dr., Oakville, Ontario, L6J 3X4, Canada.
Bruce R
BR
Conard
5.Vale NL Limited, Voisey Bay Mine Site, Happy Valley-Goose Bay, NL A0P 1C0, Canada.
Sian F
SF
Jones
6.Vale Europe Ltd (Retired), 81 Kingrosia Park, Clydach, Swansea, SA6 5PJ, UK.
Eric C
EC
Collinson
D000395:Air Pollutants, Occupational / Q000032:analysis / Q000266:history*; D015331:Cohort Studies; D004391:Dust / Q000032:analysis*; D049673:History, 20th Century; D006801:Humans; D008669:Metallurgy / Q000266:history*; D009532:Nickel / Q000032:analysis / Q000266:history*; D009784:Occupational Diseases / Q000139:chemically induced / Q000266:history; D016273:Occupational Exposure / Q000009:adverse effects / Q000266:history*; D014852:Wales
D000395:Air Pollutants, Occupational; D004391:Dust; D009532:Nickel
Clydach refinery; exposure matrix; monitoring; nickel refinery workers; reconstructed historical exposures