Exposure data base

Finally, for situations in which it is not clear that exposure is and will continue to be below the limit values, a detailed survey with a measurement strategy is required. The methods used are based mostly on instruments for sampling the environment in order to obtain reliable measurements of workplace air concentrations. In general, the measurement strategy must consider the most efficient use of resources for the purpose of obtaining quantitative data on exposures by having a clear idea of what the data will be used for or whether it meets the specified need. For example, if the data pertain to peak exposures, these peaks have to be assessed according to the STEL requirements, if any. 

All data recorded in the data base have been acquired from plant records. Statistical reductions of data for generation of reports or specific end use are available. Data are currently collected from four operating plants (eight units). Time clocks have been installed on components, to record actual exposure time. Event data are available on a broad variety of safety and commercial grade components including pumps, valves, transformers, diesels, filters, tanks (vessels), and heat exchangers. 

Based on the patch method to assess worker or re-entry exposure, researchers have developed a database, which may be used to estimate exposure. Each patch from an individual in a study can be entered into the database separately, the residue data from patches from various body areas can be summed to yield a whole-body exposure number, and the data may be sorted as to worker tasks, equipment used, protective clothing worn, formulation types and other parameters. This is the basis for the currently used Pesticide Handlers Data Base (PHED), which was developed through a joint effort in the 1980s of CropLife America [formerly known as American Crop Protection Association (ACPA) and National Agricultural Chemicals Association (NACA)], the Environmental Protection Agency (ERA) and Health Canada. " The PHED is discussed in detail in another article in this book. 

Mineral Oil Hydraulic Fluids and Polyalphaolefin Hydraulic Fluids. The developmental toxicity data base is generally inadequate. No studies were located regarding developmental toxicity after exposure by any route to mineral oil hydraulic fluids or polyalphaolefin hydraulic fluids. 

Mineral Oil Hydraulic Fluids and Polyalphaolefin Hydraulic Fluids. The data bases regarding the toxicity of mineral oil and polyalphaolefin hydraulic fluids are very limited. Further toxicity testing may elucidate biomarkers of exposure for these classes of hydraulic fluids. 

Kauppinen T, Teschke K, Savela A, et al. 1997. International data base of exposure measurements in the pulp, paper and paper products industries. Int Arch Occup Environ Health 70 119-127. 

Population Characterization. An important part of any exposure assessment is the development of a detailed and up-to-date human demographic data base for the area being studied. These data can provide the basis for estimates of subpopulations associated with different exposure pathways. In national exposure assessments it is common to use an average population density for the total U.S. or to simply distinguish between rural and urban densitites. In a geographic exposure assessment in which site-specific data on pollutant releases, environmental fate and ambient levels are measured or estimated, it is important to have equally detailed population data. Population breakdowns by age, sex, housing and... 

A major application of data base in our laboratories is in the tracking of coatings test exposure data. The two types of exposure records currently implemented are for exterior hardboard siding coatings, and for coil coatings. While these two classes of substrates and the coatings used for them are quite different, the basic structure of the data and reporting requirements are not. 

Table III. Hardboard Exposure Test Data Base...

Hbp C93 S-nitrosation could also be accomplished by exposure to RSNOs (GSNO or CysNO). The rates RSNO-dependent Hb-S-nitrosation was 10-fold larger in oxy-Hb than in deoxy-Hb. Conversely, the rate of spontaneous decay of deoxy-Hb-SNO was -20-fold larger than oxy-Hb-SNO. An explanation for this differential reactivity was presented in a subsequent study (Stamler et al, 1997) where protein modeling data based on the X-ray structures of Hb in T and R states indicated that in OxyHb the SNO of Cys (1 93 is protected from solvent. In contrast, in deoxyHb the SNO is highly exposed to solvent. The implication was that the NO+ on Cys (193-S-NO could be transferred to thiols in RBC and eventually effluxed to induce vasodilation under conditions of low 02 saturation. 

Results of the chemical sampling and analyses from both the land fill and the community were compared against the currently available toxicology data bases the EPA Permissible Remediation Guidelines for chronic exposure, and the Tomes database (Micromedix). Some levels at the landfill... 

The data base for HCFC-141b is extensive and contains studies with human subjects as well as several mammalian species. The study with human subjects was well conducted and addressed clinical symptoms, respiratory effects, cardiotoxicity, hematology and clinical chemistry effects, and pharmacokinetics. The study with humans established a no-effect level (AEGL-1) that may be conservative, because a lowest-observed-effect level was not attained. The AEGL-1 of 1,000 ppm is supported by the animal data, which show an absence of effects at concentrations that are higher by a factor of 10. Animal studies addressed both acute and chronic exposure durations as well as neurotoxicity, genotoxicity, carcinogenicity, and cardiac sensitiza... 

Time scaling Not applied inadequate data. Based on the rapidity with which blood concentrations approached equilibrium in human subjects, the similarity of lethality values in rats exposed for 4 or 6 h, and the fact that cardiac sensitization, the most sensitive end point in studies with halocarbons, is a concentration-dependent threshold effect, the 6-h value was used for all exposure durations. ... 

The original inventory file has grown into a wide ranging data-base with utility for emergency response, Material Safety Data Sheet information and is the cornerstone for Monsanto s Occupational Exposure and Medical Systems. Therefore, the original centralized effort has borne considerable fruit in addition to and independent of the TSCA inventory. 

Suppose there are several animal studies available for a chemical, including some which have involved long-term exposures, and some relating to possible reproductive and developmental effects. Assume data for both mice and rats are available, and that there are well-defined NOAELs for each of the identified toxicity endpoints. The lowest NOAEL from all those available derives from a chronic study, and is 10 mg/(kg day). Given such a data base, and the defaults listed above, a Dy for this chemical applicable to the general population, would be derived as follows... 

We still lack an adequate dose-response relationship for humans exposed to ozone, particularly at concentrations less than about 0.2 ppm. The data base for the development of such a relationship for both short-and long-term exposures is inadequate. Although some data from controlled studies are available for concentrations above 0.3 ppm, methods for extrapolating to lower concentrations are needed. Moreover, it is not clear how to weight the results of pulmonary function tests on humans, animal studies, and epidemiologic studies in a general dose-response relationship. 

The development of criteria for setting air quality standards requires a sufficient data base relating a given dose (concentration of pollutant X duration of exposure) of oxidant (e.g., ozone or PAN) to some mean-... 

An estimated 21,156, 33,257, 11,162, and 1,261,818 workers were potentially exposed to o-, p-, m-, and the mixture of isomers, respectively, in the workplace, according to the National Occupational Hazard Survey (NOHS) conducted between 1972 and 1974 (NIOSH 1984). According to the National Occupational Exposure Survey (NOES) conducted by NIOSH in the workplace between 1980 and 1983, 3,214, 3,269, 5,573, and 121,573 workers were potentially exposed to o-, p-, m-, and the mixture of isomers, respectively (NIOSH 1989). Neither the NOHS nor NOES data bases contain information on the frequency, concentration, or duration of exposure of workers to any of the chemicals listed therein. These surveys provide estimates of the number of workers potentially exposed to the chemicals in the workplace. The most probable routes of occupational exposure are inhalation and dermal contact at places where cresols and/or cresol-containing compounds are produced or used. 

The focus of this book is on methods and processes designed to predict drug-like properties, exposure and safety during hit and lead discovery. We do not intend to cover specific cultural considerations and marketing aspects [3]. What we will highlight is the need of a risk aware environment for drug discovery, where data-based integrated risk assessment is part of daily life of the team and drives the projects towards molecules with features fit for the description of an efficacious and safe medicine. 

Based on human data, environmental exposure or exposure to nickel at hazardous waste sites could result in dermatitis in nickel-sensitized individuals. 

Webb S.F. (2001). A Data-Based Perspective on the Environmental Risk Assessment of Human Pharmaceuticals. Ill—Indirect Human Exposure. In K. Kiimmeier (Ed.). Pharmaceuticals in the Environment. Springer, New York, pp. 221-230. 

Humans may be exposed to 2,3-benzofuran by inhalation, ingestion, or dermal absorption. Based on the limited data available, exposure of the general population to 2,3-benzofuran does not appear to be substantial. However, since this compound has been detected at hazardous waste sites, is reported to be a component of cigarette smoke, and is one monomer in a resin which may be used as a coating on citrus fruits and in packaging materials for foods, human exposure may be possible from these sources. People in Britain who had died in fires had 2,3-benzofuran in some blood samples, but no source of exposure was identified (Anderson and Harland 1980). 2,3-Benzofuran was... 

Exposure to ori/70-toluidine was reported to occur in an Italian plant producing fuchsin (magenta) and safranine T-based dyes (Rubino et al., 1982), in a German plant producing 4-chloro-ori/70-toluidine (Stasik, 1988) and in a plant producing rubber chemicals in the United Kingdom (Sorahan et al, 2000), but no data on exposure levels were provided. 

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