Carcinogens INDEX

Bartone. J.C. Human Carcinogens Index of New Information with Authors. Subjects and References. Abbe Publishing Association of Washington DC. Washington, DC, 21XK). 

TCDD given 2 days prior to or concurrently with methylcholanthrene did not affect methyl-cholanthrene-induced carcinogenicity in C57BL/6 mice (Kouri et al. 1978) in contrast, 2,3,7,8-TCDD pretreatment (intraperitoneal or subcutaneous) of DBA/2 mice slightly increased the carcinogenic index. 

The carcinogenicity of tar and other PAH containing materials was first demonstrated in animal experiments in the early 1900. Dibenzo[a,h]anthracene (DBA), synthesised in 1929, and benzo[a]pyrene (BaP), isolated from pitch in 1930, were the first pure PAH s shown to be carcinogenic to animals. The first review article on PAH carcinogenicity in mice was published in 1932 [40]. The Iball carcinogenicity index calculated from tumour incidence and latent period has been introduced in 1939 [4,41]. It is defined as ... 

It is important to calculate die hazard index separately for clironic, subclironic, and short-temi exposure periods as described below. It is also important to remember to include RfDs for die noncancer effects of carcinogenic substances. 

To assess die overall potential for non carcinogenic effects posed by several exposure pathways, the total haziird index for each exposure duration (i.e., chronic, subchronic, and shorter-term) should be calculated separately. This equation is described below ... 

In health risk assessments, non carcinogenic risks are estimated via Hazard Indices . A general equation for a liazard index (HI) is as follows ... 

If tlie pollutant causes iui acute non carcinogenic risk, tlie inaximuin one hour concentration is used for C, and tlie acute reference exposure limit is used for tlie REL. Likewise, if tlie pollutant causes a clironic non carcinogenic risk, tlie one year average concentration is used, as is tlie clironic reference exposure limit. In tliis procedure, a Iiazard index is calculated for each pollutant separately, and tlien tlie indices are summed for each toxicological endpoint (i.e., tlie respiratory system, tlie central nervous system, etc.). Finally, tlie total hazard index is tlien compared to a value wliich is considered significant. 

Carcinogenic classification Biological Exposure Index Group A5 ACGIH 1996 ACGIH 1996... 

With tso as an index of carcinogenicity, an interspecies relative potency (IRP) can be defined, e.g.,... 

Chronic daily intake (CDI), Hazard Index (HI), and Cancer Risk (CR) for carcinogenic effects were calculated and exposures associated with HI<1 and CRdE-6 were considered negligible. 

Early work on the structure of carcinogenic PAHs was done by John Iball at the University of Dundee, Scotland (29) he had suggested the use of the "Iball index" (30) as a measure of the... 

IARC (1991) Monographs on the evaluation of carcinogenic risks to humans. Available from http //monographs.iarc.fr/ENG/Monographs/PDFs/index.php... 

The press centre on the Website of British Petroleum pic (BP) is a good source of information, at http //www.bpamoco.com/centres/press/index.asp. For example, the page http //www.bpevo.com/bpevo main/asp/evo glo 0003.asp lists the terms used by most petrol companies, and http //www.bp.com/location rep/uk/bus operating/ manu ops.asp cites the amounts of the known carcinogen, benzene, found naturally in petrol. 

The EPA makes decisions about clean-up of abandoned hazardous waste sites under the so-called Superfund law. Risk assessment outcomes are one guide to the decision process. The agency has declared that, for carcinogenic contaminants, clean-up must reach lifetime risks somewhere in the range of one in 10 000 to one-in-one million most decisions seem to aim at risks of one in 100 000 or lower. Hazard index values for non-carcinogens are not expected to exceed one. Costs and technical feasibility figure heavily in these decisions. 

US-NTP. 2007. Study results and research projects website, definition of carcinogenicity results. http //ntp. niehs.nih.gov/index.cfm objectid = 07027D0E-E5CB-050E-027371D9CC0AAACF... 

In order to express the carcinogenic response or potency, a dose descriptor is used, for example the Tumorigenic Dose (TD). The TD is often set at a defined incidence, for example 5%, the TD5, defined as the dose (or concentration) associated with a 5% incidence of mmors. The dose descriptor can serve as the basis for development of an Exposure/Potency Index (EPl), which is the estimated daily human exposure divided by the TD. A calculated EPl of 10 for the TD5 represents a one million-fold difference between the human exposure and that at the lower end of the dose-response curve, on which the estimate of potency is based. 

The T25 was originally proposed as a simplihed carcinogenic potency index as a practical method for potency considerations in carcinogen classihcation systems (Dybing et al. 1997) and is used within the EU context of classihcation and labeling of chemical substances (see Section 2.4.1.8) for inclusion of potency considerations in setting specihc concentration limits for carcinogens in Annex I of Directive 67/548/EEC (EC 1999). 

Dybing, E., T. Sanner, H. Roelfzema, K. Kroese, and R.W. Tennant. 1997. T25 A simplified carcinogenic potency index Description of the system and study of correlations between carcinogenic potency and species/site specificity and mutagenicity. Pharmacol. Toxicol. 80 272-279. 

Aristolochic acid was tested for therapy of tuberculosis, chronic bronchitis, bronchial asthma, pneumocardial diseases, etc. Clinical results showed curative effects, and the index of immune function of cases increased significantly compared to the control group (111). In Germany, an aristolochic acid preparation called Tardolyt that had been used as an antiinflammatory was canceled due to its potential carcinogenicity (72). 

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