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HERO ID
2539749
Reference Type
Journal Article
Title
The Concentration of No Toxicologic Concern (CoNTC) and Airborne Mycotoxins
Author(s)
Hardin, BD; Robbins, CA; Fallah, P; Kelman, BJ
Year
2009
Is Peer Reviewed?
1
Journal
Journal of Toxicology and Environmental Health, Part A: Current Issues
ISSN:
1528-7394
EISSN:
1087-2620
Volume
72
Issue
9
Page Numbers
585-598
Language
English
PMID
19296408
DOI
10.1080/15287390802706389
Web of Science Id
WOS:000264338000004
Abstract
The threshold of toxicologic concern (TTC) concept was developed as a method to identify a chemical intake level that is predicted to be without adverse human health effects assuming daily intake over the course of a 70-yr life span. The TTC values are based on known structure-activity relationships and do not require chemical-specific toxicity data. This allows safety assessment (or prioritization for testing) of chemicals with known molecular structure but little or no toxicity data. Recently, the TTC concept was extended to inhaled substances by converting a TTC expressed in micrograms per person per day to an airborne concentration (ng/m3), making allowance for intake by routes in addition to inhalation and implicitly assuming 100% bioavailability of inhaled toxicants. The resulting concentration of no toxicologic concern (CoNTC), 30 ng/m3, represents a generic airborne concentration that is expected to pose no hazard to humans exposed continuously throughout a 70-yr lifetime. Published data on the levels of mycotoxins in agricultural dusts or in fungal spores, along with measured levels of airborne mycotoxins, spores, or dust in various environments, were used to identify conditions under which mycotoxin exposures might reach the CoNTC. Data demonstrate that airborne concentrations of dusts and mold spores sometimes encountered in agricultural environments have the potential to produce mycotoxin concentrations greater than the CoNTC. On the other hand, these data suggest that common exposures to mycotoxins from airborne molds in daily life, including in the built indoor environment, are below the concentration of no toxicologic concern.
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