Abstract

A series of acute inhalation exposures was performed with airborne hydrogen fluoride (HF) to establish the concentration response for nonlethal effects in the rat. Exposures were either 2 or 10 min long; concentrations ranged from 135 to 8621 ppm. Three additional exposures (20 to 48 ppm) were performed for 60 min. A mouth-breathing (MB) model with a tracheal cannula was used in most of the exposures to maximize delivery of the HF to the lower respiratory tract. Endpoints on the day after exposure included hematology, serum chemistry, bronchoalveolar lavage, pulmonary function, organ weights, and histopathology. Nasal resistance was measured in nose-breathing (NB) groups. Effects of exposure were generally limited to the respiratory tract and included alveolitis, bronchial lesions, altered parameters of pulmonary function and bronchoalveolar lavage, and mucosal necrosis, inflammation, and fibrinopurulent exudate in airways. Observed changes were concentration related and appeared more pronounced in major airways near the point of entry (trachea in MB animals and nose in NB animals). One group of MB animals exposed for 10 min to 1454 ppm was evaluated at 3 and 14 wk after exposure; the acute effects had resolved by those times. The effects of 2-min exposures were consistently more severe than those from 10-min exposures to the same product of concentration x time. Exposures of MB animals for 60 min to 20 or 48 ppm HF did not result in observable adverse effects, although quasistatic pressure-volume curves were shifted upward slightly after 48 ppm. These data provide an integrated picture of the concentration-related effects of short nonlethal exposures to HF.

• Related Studies :

  • Respiratory impairment among children living in the vicinity of a fertilizer plant

    The study included 162 second-grade children (85 boys and 77 girls) aged 8-9 years, attending two schools in an area with a fertilizer production plant, and 59 second-graders of the same age (32 boys and 27 girls) from a small neighbouring town located 20 km west of the plant, without

  • Epistaxis in a low level hydrogen fluoride exposed industrial staff

    OBJECTIVES: To assess the effect of exposure to hydrogen fluoride (HF) on the airway mucosa in an industrial setting. METHODS: A cross-sectional study encompassing 33 industrial workers in a flame soldering plant and 44 assembly workers unexposed to HF was performed by means of a questionnaire on symptoms and diagnosis regarding

  • Fluoride in Drinking Water: A Scientific Review of EPA’s Standards.

    Excerpts: Summary Under the Safe Drinking Water Act, the U.S. Environmental Protection Agency (EPA) is required to establish exposure standards for contaminants in public drinking-water systems that might cause any adverse effects on human health. These standards include the maximum contaminant level goal (MCLG), the maximum contaminant level (MCL), and the secondary

  • Chronic broncopneumopathy and pneumoconiosis in workers employed in phosphoric acid production.

    Thirty-five subjects employed in a phosphoric acid producing plant were studied by the authors. The investigation included: history, according to the C.E.C.A. questionnaire for chronic bronchitis and emphysema; physical examination, chest X-ray spirometry and lung diffusing capacity for carbon monoxide by the steady state method (DLCOSS). High prevalence of chronic

  • The effects of the inhalation of hydrogen fluoride. I. The response following exposure to high concentrations.

    The effects of inhalation exposure to hydrogen-fluoride (7664-39-3) (HF) were examined in New-Zealand-white-rabbits and guinea-pigs. Animals were exposed to HF in enclosed chambers at concentrations ranging from 8 to 0.024 milligrams per liter (mg/l) for 5 minutes to 41 hours. Mortality rates were recorded, general physical conditions were monitored, and

• Related FAN Content :

  • Fluoride Enhances Toxicity of Beryllium

    Occupational exposure to beryllium is well-documented to put workers' health at risk. The two principal targets of beryllium poisoning are the respiratory system and the skin. Of all beryllium compounds, beryllium fluoride complexes (including beryllium fluoride and beryllium oxyfluoride) appear to be the most toxic. As shown below, studies dating back

  • Respiratory Risks from Occupational Fluoride Exposure

    Starting in the 1930s, scientists have observed that workers exposed to airborne fluorides suffer from an elevated rate of respiratory disorders. For over 50 years, however, US government and industry scientists made repeated assurances that the allowable level of fluoride dusts and gases in industrial workplaces would not cause any