Toxic chemicals indices

Rosen JF, Chesney RW, Hamstra AJ, et al. 1981. Reduction in 1,25-dihydroxyvitamin D in children with increased lead absorption. In Brown SS, Davis DS, eds. Organ-directed toxicity Chemical indices and mechanisms. New York, NY Pergamon Press, 91-95. 

SuNDEEMAN FW Jr and Horak E (1981) Biochemical indices of nephrotoxicity exemplified by studies of nickel nephropathy. In Brown SS and Davies DS, eds. Organ-Directed Toxicity Chemical Indices and Mechanisms, pp. 52—64. Pergamon, London. 

Tyler, B. J., A. R. Thomas, P. Doran, andT. R. Greig (1996). A Toxicity Hazard Index. Chemical Health and Safety 3 (January/February), 19-25. 

For offsite equipment the scores 0-3 have been used instead of scores 0-4 for ISBL equipment (HeikkilS and Hurme, 1998b), since the offsites represent only one third of all losses (Instone, 1989) and are therefore not as essential as ISBL. Also much of the risks of OSBL are due to the large inventory of flammable or toxic chemicals, which are discussed by the inventory, flammability and toxicity indices, not by the Equipment Safety Index. Also the equipment of same size is probably safer in OSBL than in ISBL because of the larger spacings in layout. 

An ethanolic extract would contain some essential oil, but there is no evidence that the essential oil is responsible for these effects. Since the oil constitutes only some 1.5% of the raw material, and since all the major components of the essential oil are apparently non-toxic (see Chemical Index), it seems inconceivable that juniper oil could be responsible for the reproductive toxicity noted above. 

WHO (2005) Toxic hazards, http //www.who.int/heli/risks/toxics/chemicals/en/index.html. Cited 18 January 2009. 

Managing pediatric victims of chemical terrorism is an especially difficult challenge. In addition to the obvious physiologic and anatomic differences compared to adults (Table 61.1), there are important psychological and behavioral differences that put children at risk (Rotenberg and Newmark, 2003). Anecdotal reports have claimed that children are likely to be the first to manifest symptoms, to develop more severe manifestations, and to be hospitalized for other related illnesses. In fact, it is anticipated that children will be overrepresented among the initial index cases in a mass civilian exposure to toxic chemicals. Children have many characteristics that make them vulnerable to toxic exposures. The smaller mass of a child automatically reduces the dose of toxic agents needed to cause... 

The Mond index was developed from the Dow F El by personnel at the ICI Mond division. The third edition of the Dow index, Dow (1973), was extended to cover a wider range of process and storage installations, the processing of chemicals with explosive properties, and the evaluation of a toxicity hazards index. Also included was... 

The animal assay for evaluating toxic constituents (natural or added) of food uses lethality as an index and determines the dose of that toxic chemical to kill/affect 50% of the test animal, referred to as LD50 dose. The response criteria can be toxicity, carcinogenicity, mutagenicity, reproduction, and metabolism. 

Substance hazard index The SHI is an index to identify the toxic chemical substances that... 

When applied, the limits should not be used as an index of relative hazard and toxicity, nor should they be used as the dividing line between safe and dangerous concentrations. The list is not comprehensive and the absence of a substance does not indicate that it is safe. The WEL values are set on the recommendations of the HSC s Advisory Committee on Toxic Substances. This follows a scientific assessment by another committee, the Working Group on the Assessment of Toxic Chemicals (WATCH). These committees decide whether to assign a limit to a particular substance and the concentration to be adopted. 

The reference dose for a toxic chemical—an equivalent term is the acceptable daily intake (ADI)—is taken to represent the threshold level of exposure above which a noncancer health effect can result in humans. The hazard index (HI) indicates... 

Airborne toxic chemicals may pose a risk of toxic effects directly on the lungs as well as toxic effects on other organs and tissues after entering the bloodstream through the lungs. The reference dose for an air pollutant is termed the reference concentration, or RfC. The reference concentration differs from the reference dose in that it is the actual concentration of a chemical in the air, not the average daily dose of chemical that enters the bloodstream. The air qnality index (AQI) is an estimate of the risk of effects from air pollutants, particularly in people with preexisting conditions such as asthma. The air quality index is calculated as the ratio of the concentration of an air pollutant to its reference concentration multiplied by 100 ... 

Two other approaches are used to estimate noncancer risks from toxic chemicals margin of exposure and therapeutic index. Both are less formal and more approximate than the hazard index. The margin of exposure (MOE) is the ratio of the NOAEL in an animal toxicity study to the CDI projected for a human population. Uncertainty factors are omitted from the calculation. Eor example, if the NOAEL for reproductive toxicity were, say, 1.5 mg/kg/day, and the CDI were 0.003 mg/kg/day, then the MOE would be 500. The MOE is interpreted by comparing it to a margin of safety (MOS) established by a government agency. In general, an MOE of less than 100 is considered to be cause for concern. 

Risks from other pathways of exposure and/or other chemicals of concern are considered to be additive unless there is evidence that the toxicities of two or more chemicals are synergistic (i.e., enhance each other so that risk is greater than the sum of the risk from either chemical alone) or inhibitory (i.e., interfere with each other so that risk is less than the sum of the risk from either chemical alone). Very little is known about the interactions between toxic chemicals, and risks from multiple chemicals and multiple exposure pathways are usually added together to obtain an estimate of total risk. In the case of noncancer health risk, the hazard index (HI) is calculated separately for each chemical and each exposure pathway, and total risk is equal to the sum of the HI values from aU chanicals and aU pathways. In the case of cancer risk, the cancer incidence is calculated for each ch ical and each exposure pathway, and total risk is equal to the sum of the caucer incideuces from all chemicals and all pathways. Cancer risk is the probability of getting cancer (morbidity), not the probability of dying from cancer (mortality). Many people get cancer and survive. 

As Fig. 34 demonstrates the value of each term is characterized by dots in front of the word the more dots the more specific the term. 30b shows that heart, neoplasm is a subterm under heart, disease. The brackets around the term crimes indicate that this expression is not an index heading. It cannot be used for searching the General Subject Index and is only mentioned in this hi-erachy to clarify the systematic division of the Hierachy Areas. This context demonstrates clearly that the term toxic chemical and physical damage does not lead in the desired direction. 

Workers in the metals treatment industry are exposed to fumes, dusts, and mists containing metals and metal compounds, as well as to various chemicals from sources such as grinding wheels and lubricants. Exposure can be by inhalation, ingestion, or skin contact. Historically, metal toxicology was concerned with overt effects such as abdominal coHc from lead toxicity. Because of the occupational health and safety standards of the 1990s such effects are rare. Subtie, chronic, or long-term effects of metals treatment exposure are under study. An index to safety precautions for various metal treatment processes is available (6). As additional information is gained, standards are adjusted. 

As computing capabiUty has improved, the need for automated methods of determining connectivity indexes, as well as group compositions and other stmctural parameters, for existing databases of chemical species has increased in importance. New naming techniques, such as SMILES, have been proposed which can be easily translated to these indexes and parameters by computer algorithms. Discussions of the more recent work in this area are available (281,282). SMILES has been used to input Contaminant stmctures into an expert system for aquatic toxicity prediction by generating LSER parameter values (243,258). 

Lewis, D. J. (1979). The Mond Fire, Explosion and Toxicity Index Applied to Plant Layout and Spacing. i3th Annual Loss Prevention Symposium, April 2-5, 1979, Houston, TX, 20-26. Loss Prevention, No. 13. New York American Institute of Chemical Engineers. 

When die hazard index exceeds miity, diere may be concern for potential health effects. While any single chemical with an exposure level greater than the toxicity value will cause die hazard index to e.xceed unity, die reader should note diat for multiple chemical exposures, die hazard index can also exceed unity even if no single chemical exposure exceeds its RfD. 

If there are specific data germane to the assumption of dose-additivity (e g., if two compounds arc present at the same site and it is known that the combination is five times more toxic than the sum of the toxicitics for the two compounds), then tire development of the hazard index should be modified accordingly. The reader can refer to the EPA (1986b) mi.xiure guidelines for discussion of a hazjird index equation that incorporates quantitative interaction data. If data on chemical interactions are available, but arc not adequate to support a quantitative assessment, note the information in the assumptions being documented for the risk assessment. 

---