Epidermal hyperplasia in mouse skin following treatment with alternative drinking water disinfectants
Female SENCAR mice were treated with aqueous solutions of hypochlorous acid (HOCl), sodium hypochlorite (NaOCl), chlorine dioxide (ClO/sub 2/), and monochloramine (NH/sub 2/Cl) by whole body exposure (except head) for a 10-min period for 4 days in the first experiment and for 1 day (except NH/sub 2/Cl) in the second experiment. Animals were sacrificed the day following the last treatment (experiment 1) or on day 1, 2, 3, 4, 5, 8, 10, and 12 following treatment (experiment 2), and skin thickness was measured by light microscopy. Concentrations of disinfectants were 1, 10, 100, 300, and 1000 mg/L, for experiment 1 and 1000 mg/L for experiment 2. Thickness of the interfollicular epidermis (IFE) for control animals was 15.4 +/- 1.5 ..mu..m. After 4 days of treatment at 1000 mg/L, HOCl and ClO/sub 2/ increased thickness to 30 +/- 7.0 and 40.2 +/- 11.8, and NaOCl increased thickness to 25.2 +/- 6.1 ..mu.. m. The response to HOCl was found to be dose-related. The time-course study following a single treatment of 1000 mg/L HOCl, showed a progression of IFE thickening of from 18.3 +/- 1.4 at 1 day to 30.8 +/- 8.0 at 8 days, decreasing to 19.1 +/- 6.2 ..mu..m at 12 days. ClO/sub 2/ and NaOCl when tested in this manner did not produce increased thickness of IFE with time, but rather gave a persistent level of increase that remained for the 12 days. NH/sub 2/Cl reduced skin thickness to 13.6 +/- 6.1 ..mu..m. Examination of sections of skin treated with HOCl and ClO/sub 2/ indicated an increase in cell numbers. HOCl and ClO/sub 2/ are therefore capable of inducting hyperplastic responses in the mouse skin. The basis for the decrease in skin thickness resulting from NH/sub 2/Cl treatment remains to be established.
- Research Organization:
- Environmental Protection Agency, Cincinnati, OH
- OSTI ID:
- 5777112
- Journal Information:
- Environ. Health Perspect.; (United States), Vol. 69
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CHLORAMINES
BIOLOGICAL EFFECTS
CHLORINE OXIDES
HYPOCHLOROUS ACID
SKIN
MORPHOLOGICAL CHANGES
AQUEOUS SOLUTIONS
CHLORINE
DISINFECTANTS
DRINKING WATER
EPIDERMIS
MICE
OPTICAL MICROSCOPY
AMINES
ANIMAL TISSUES
ANIMALS
BODY
CHALCOGENIDES
CHLORINE COMPOUNDS
DISPERSIONS
ELEMENTS
EPITHELIUM
GERMICIDES
HALOGEN COMPOUNDS
HALOGENS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
MAMMALS
MICROSCOPY
MIXTURES
NONMETALS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANS
OXIDES
OXYGEN COMPOUNDS
RODENTS
SOLUTIONS
TISSUES
VERTEBRATES
WATER
560300* - Chemicals Metabolism & Toxicology