Daily Exposure

Chronic exposure, daily dose in mg Mo/animal 25, as Mo03... 

Chronic exposure, daily dose over 8-h period, in Gy ... 

Overview of Study Design. Four groups of five adult rabbits each receive a single vaginal exposure daily for 10 days. The genitalia are examined daily. Animals are then euthanized and the vagina is examined macroscopically and microscopically. 

Complete symptomatic recovery usually occurs within a week increased susceptibility to the effects of anticholinesterase agents persists for up to several weeks after exposure. Daily exposure to concentrations that are insufficient to produce symptoms after a single exposure may result in the onset of symptoms. Continued daily exposure may be followed by increasingly severe effects. 

The concentration of fluoride in nails and hair appears to be proportional to intake over longer periods of time, taking into account their growth rate [100-103]. Exposure to fluoride may occur in the local environment at the place of residence or via occupational exposure. Daily intake from food, water, dentifrices or fluoride supplements also contributes. The major advantage of nails and hair over fluids and tissues as biomarkers for fluoride exposure is that they can easily be obtained in a non-invasive manner. In contrast to plasma, saliva and urine, whose fluoride concentrations provide a snapshot at a certain point of time and are subject to change due to recent fluoride intake and certain physiological variables, the concentration of fluoride in nails and hair is cumulative and reflects the average level of intake over a time period, but depends on how often the nails are clipped or hair cut. 

Harmonized guidance for appropriate expressions of exposure (daily, time-weighted average or amortized expressions of exposure). 

The acute inhalation toxicity is of low order. Since it is a gas, the route of exposure is primarily inhalation. The target organs are the liver, central nervous system, respiratory system, and blood. Exposure to high concentrations can produce narcosis. A 30-minute exposure to 30% vinyl chloride in air was fatal to experimental animals. Chronic exposure produced minor injury to the liver and kidneys. Such effects were noted at a 7-hour exposure daily to 200 ppm for 6 months. 

The exposure action value (EAV) is a daily amount of vibration exposure, above which employers are required to take action to control exposure. Daily exposure action value is 2.5 m/s. ... 

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