Exposure effects

Number of people exposed Coaceatratioa, mg/m Duratioa of exposure Effect... 

Exposure effects Inhalation (general) Respiratory irritation Ingestion Skin/eye irritation Skin and respiratory sensitization Mutagenicity Teratogenicity Carcinogenicity ... 

Table 5.56 Typical exposure effects associated with epoxy resin systems ...

A toxic reaction may take place during or soon after exposure, or it may only appear after a latency period. Chronic toxicity requires exposure of several years for a toxic effect to occur in humans. With respect to experimental animals, the animals are usually exposed for most or all of their life time to ascertain the occurrence of chronic toxicity. Acute toxic reactions that occur immediately are easy to associate with the exposure and the exposure-effect relationship can readily be demonstrated. The longer the time interval between exposure and effect, the more difficult it is to delineate the relationship between exposure and effect. 

Biomarkers for internal close of the intoxicant—dose monitoring. Bioniarkers for early biological changes following exposure— effect... 

The commissioning tests are typically performed before a local ventilation system is put into use the purpose is to confirm that the design conditions have been achieved. Hence, commissioning tests apply to methods used in type testing, but in a simple and modified way. In-use tests concentrate on the exposure effects of a local ventilation system. 

Human health effects of operations. This requires assessment of such things as workplace exposures effects of exposure to air toxics, contaminated drinking water and soil and exposures during product use, misuse, and disposal. 

An inventory list of tlie physical properties and liazardous nature (flammability, toxicity, reactivity, corrosiveness, etc.) of all chemicals should be composed. Also, to protect persoiuiel and the community, tlie exposure effects of the chemical should be determined. 

In addition to examining pre-exposure effects, the slow strain-rate testing technique has been used increasingly to examine and compare the stress-corrosion susceptibility of aluminium alloys of various compositions, heat treatments and forms. A recent extensive review draws attention to differences in response to the various groups of commonly employed alloys which are summarised in Fig. 8.57. The most effective test environment was found to be 3 Vo NaCl -F 0.3 Vo HjOj. The most useful strain rate depends upon the alloy classification. 

After 10 days of exposure, reduced social behavior and reduced exploratory behavior were observed in rats exposed to 100 ppm trichloroethylene 6 hours per day 5 days per week for a total of 5 weeks (Silverman and Williams 1975). In rats exposed to 50 or 100 ppm trichloroethylene 8 hours/day, 5 days/week for 6 weeks, effects on sleep patterns were observed (Arito et al. 1994a). At 50 ppm decreased wakefulness was observed during the exposure. Effects remaining at 22 hours after the end of the 6-week exposure included decreased heart rate during sleep at 50 ppm and decreased wakefulness after exposure of 100 ppm (Arito et al. 1994a). Based on the 50-ppm LOAEL identified in the Arito et al. (1994a) study, an intermediate-duration inhalation MRL of 0.1 ppm was calculated as described in the footnote in Table 2-1. 

Subcategories of bioindicators at suboiganismal levels are generally referred to as biomarkers. Biomarkers may reflect either exposure, effect, or susceptibility of these, biomarkers of effect are both more valuable and more difficult to find. An ideal biomarker of mercury effect would be ... 

Early Effects (of radiation exposure)—Effects that appear within 60 days of an acute exposure. 

Delayed. Usual onset of symptoms occurs approximately 2 h after aerosol exposure. Depending on inhaled or ingested dosage, symptoms may appear at times ranging from 30 min to 20 h after exposure. Effects from skin contact may appear 36 h later. Dimethylsulfoxide as a "carrier" increases the percutaneous effect by a factor of at least 25. 

The photodegradation of para-aramid in an 0 atmosphere allows the differentiation between the accelerated experimental photooxidative conditions from its usual daylight exposure effects. This study illustrated an estimation of the rates of photooxidation of a commercial para-aramid product (i.e., DuPont s Kevlar-29 woven fabric) based on the oxygen-18-labelled carbon dioxide ( CC and CC ) decarboxylated from the sample. The oxygen-18-labelled atoms, which are inserted in the macromolecules, were analyzed for the photodegradation processes. This technique also allows the radial l O-distribution measurement from the fiber surface toward the fiber center. 

This new analytical method determines the rate constant and activation energy of Kevlar s photooxidative processes. The 0.2 atm of oxygen-18-labelled environment in a solar chamber simulates the air-exposure under sunlight conditions. The technique also allows the radial 0-distribution measurement from the fiber surface toward the fiber center. The data from the accelerated experimental conditions in the solar chamber in an 02-atmosphere are differentiated from the usual daylight exposure effects. 

Dietrich KN, Krafft KM, Bomschein RL, et al. 1987a. Low-level fetal lead exposure effect on neurobehavioral development in early infancy. Pediatrics 80 721-730. 

Foster WG, Singh A, McMahon A, et al. 1998. Chronic lead exposure effects in the cynomolgus monkey (macaca fascicularis) testis. Ultrastruct Pathol 22(1) 63-71. 

Glickman L, Valciukas JA, Lilis R, et al. 1984. Occupational lead exposure Effects on saccadic eye movements, lnt Arch Occup Environ Health 54 115-125. 

Jason KM, Kellogg CK. 1981. Neonatal lead exposure Effects on development of behavior and striatal dopamine neurons. Pharmacol Biochem Behavior 15 641-649. 

Shukla R, Bomschein RL, Dietrich KN, et al. 1989. Fetal and infant lead exposure Effects on growth in stature. Pediatrics 84 604-612. 

Low level Rn-d exposure-effect studies that may be relevant to the general indoor exposure situation, at least as far as lifetime exposure is concerned, are available for miners in CSSR, US, Canada,... 

Dose-biomonitoring (exposure) - exposure Effects-biomonitoring (response) ... 

Filamentous algae, unidentified 500 pg/L 5-month exposure Effective control 9 ... 

Hatch of viable nauplii reduced by 50% after 12-h exposure no hatch after 36-h exposure. Effect not reversible for at least 30 h after exposure 18... 

Lippman ME, Krueger KA, Eckert S et al. (2001) Indicators of lifetime estrogen exposure effect on breast cancer incidence and interaction with Raloxifene therapy in the multiple outcomes of Raloxifene evaluation study participants. J Clin Oncol 19(12) 3111—3116... 

Merget, R. et al., Exposure-effect relationship of platinum salt allergy in a catalyst production plant conclusions from a 5-year prospective cohort study, J. Allergy Clin Immunol., 105, 364, 2000. 

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