Human exposure vapour

Human exposure to ethylbenzene occms mainly via inhalation of vapour and/or mist and, to a smaller extent, by dermal contact or ingestion. Ethylbenzene is produced by the incomplete combustion of natural materials, making it a component of smoke from forest fires and cigarettes. It is also a constituent of asphalt and naphtha (Agency for Toxic Substances and Disease Registry, 1997a WHO, 1996a). 

Bramwell, E.C.B., Ladell, W.S.S., Shephard, R.J. (1963). Human exposure to VX vapour. PTP 830. Chemical and Biological Defence Estahlishment, Porton Down, Salisbury, Wiltshire, UK. 

Bramwell ECB, Ladell WSS, Shepard RJ. Human exposure to VX vapour. Porton Technical Paper 830, January 1963. 

MOD29. Human exposure to VX vapour. Unpubhshed MOD report. 

Site-Specific Target Level For a given exposure pathway and contaminant, the SSTL represents a concentration in the affected source medium (soil, groundwater, surface water, or sediment) that is protective of a human or ecological receptor located at a relevant point of exposure (POE). For example, for the human health soil-to-air exposure pathway, the SSTL is the mean concentration in the affected surface soil zone that will prevent unsafe human exposures via vapour or particulate release to air. For each... 

Toxicity rating Commonly used term LDso Single oral dose for rats (g/kg) 4hr Vapour exposure causing 2 to 4 deaths in 6-rat group (ppm) LDso Skin for rabbits (g/kg) Probable lethal dose for humans... 

Parsons et al.66 reported on the determination of total mercury as a toxic element in urine at the trace level using ICP-MS. The main sources of exposure in the human body are inhalation of Hg vapour released from dental amalgams and the consumption of fish species that accumulate, for example, methyl mercury (MeHg). 

I ARC (1992) I. ARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 54, Occupational Exposures to Mists and Vapours from Strong Inorganic Acids and Other Industrial Chemicals, Lyon, pp. 41-130... 

The absorption of 1,1,1-trichloroethane by the skin in humans has been shown to be dependent on the duration of exposure and the area of skin exposed (Fukabori et al., 1977 Riihimaki Pfaffli, 1978 Stewart Dodd, 1964). 1,1,1-Trichloroethane vapours are absorbed through exposed skin to some extent, although absorption through the respiratory tract is expected to predominate during whole-body exposure to vapours. A quantitative examination of the relative magnitudes of percutaneous and respiratory absorption indicated that a whole-body exposure to 600 ppm [3280 mg/m ] 1,1,1-trichloroethane for over 3.5 hours was equivalent to an inhalation exposure of only 0.6 ppm [3.3 mg/m ] over the same time period (Riihimaki Pfaffli, 1978). 

Blood concentrations of 1,1,1-trichloroethane in humans following dermal exposure are dependent on the duration of exposure. A two-hour exposure once a day resulted in higher blood levels than one-hour exposures twice a day (Fukabori et al., 1977). At the end of a whole-body dermal exposure to 600 ppm [3280 mg/m ] 1,1,1-trichloroethane vapour for 3.5 hours, the blood concentration of 1,1,1-trichloroethane reached a maximum of approximately 0.09 mg/L (Riihimaki Pfaffli, 1978). This level quickly dropped after exposure ceased. In comparison, the steady-state blood concentration of 1,1,1-trichloro-ethane during inhalation exposure to 325 ppm [1770 mg/m ] for four hours was approximately 4 mg/L (Astrand et al., 1973) and during exposure to 350 ppm [1910 mg/m ] for six hours was approximately 2 mg/L (Nolan et al., 1984). 

Bluhm RE, Bobbit RG, Welch LW, Wood AJ. Elemental mercury vapour toxicity, treatment and prognosis after acute, intensive exposure in chloralkali plant workers. Part I History, neuropsychological findings and chelator effects. Human ExpToxicol 1992 11 201-10. 

In humans, the toxicity of mustard as regards effects of the vapour upon the eyes increases as the exposure is increased. In terms of Ct (mg min m-3) the following may be used for guidance ... 

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