Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2003-9-4
pubmed:abstractText
Refractory ceramic fibers (RCFs) are man-made vitreous fibers commonly used in insulation applications above 1000 degrees C. Although they have been subjected to considerable toxicologic evaluation, only the pooled results from two rat inhalation studies provide data that may be suitable for performing a numerical risk assessment. Even in these inhalation studies, good evidence exists that the maximum tolerated dose (MTD) was exceeded and that pulmonary overload occurred, a condition that will cause tumors whatever the dust responsible. Indeed, a significant yield of tumors was only obtained at the highest dose tested. If these results are omitted, there is no statistically significant evidence of carcinogenicity within the RCF results. Although there is little evidence that overload-related tumors are relevant to human risk, we adopted a conservative approach to obtain the estimates of risk regardless of overload, using a biologically based model, the two-stage clonal expansion model, as well as various statistical models, including the benchmark dose model. We argue that the data favor the use of a biologically based model, which gives the best fit when the highest dose RCF exposures are omitted. Continuing with this model, we show that available data from the RCF experiment, less outliers, coupled with results from other experiments with man-made mineral fibers (MMVFs), demonstrate that all MMVFs are potentially carcinogenic, with any risk mediated by the fibers' biopersistence. Application of this "all MMVF data set" model yields a maximum likely estimate for RCF excess unit risk of 4.6 x 10(-5) (95% upper confidence limit = 9.2 x 10(-5) per fiber/ml). This implies that the risk from occupational exposure to RCFs at 1 fiber/ml for a typical working lifetime would not exceed 10(-4).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0895-8378
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1103-18
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
A dose-response model for refractory ceramic fibers.
pubmed:affiliation
Sciences International, Inc., 1800 Diagonal Road, Alexandria, VA 22314, USA. jturim@sciences.com
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't