Reproductive effects in long-evans rats exposed to chlorine dioxide

Subchronic toxicities of ClO2, NaClO2, NaClO3 and NH2Cl were studied in the African Green monkeys (Cercopithecus aethiops). The chemicals were administered in drinking water during 30-60 days subchronic rising dose protocols. The only unexpected and significant toxic effect was elicited by ClO2; this chemical inhibited thyroid metabolism in the animals at a dose of ca. 9.0 mg/kg/day. A statistically significant decrease of serum thyroxine occurred after the fourth week of exposure to 100 mg/l.concentration. The extent of thyroid suppression was dose dependent in each individual monkey, and was reversible after cessation of exposure. NaClO2 and NaClO3 failed to elicit similar effects in doses up to ca. 60 mg/kg/day. Also, NaClO4 or NH2Cl did not cause T-4 suppression in doses of 10 mg/kg/day. The selective thyroid effect of ClO2 was unexplained and it appeared to be paradoxical since ClO2 was rapidly reduced by the oral and gastric secretions to nonoxidizing species (presumably Cl-). No evidence of thyroid effects were detected in the serum of human volunteers who ingested approximately 1 mg/l. of ClO2 in drinking water as a result of routine use in the community water treatment process. Sodium chlorite induced dose-dependent oxidative stress on hematopoesis, causing decreased hemoglobin and red cell count and increased methemoglobin content. At the same time, serum transaminase (SGPT) levels showed significant subclinical elevation. The hematologic effects of NaClO2 rebounded during exposure indicating compensatory hemopoietic activity taking effect during oxidative stress. Sodium chlorate and chloramine did not induce detectable hematologic changes in the animals.

A technically simple, inexpensive method is described for measuring objective parameters of sperm motility. The instruments involved are commercially available, home-oriented videotape equipment. Quantitative measurements of sperm motility are made directly from the video image and are facilitated by use of an analysis transparency that is applied as an overlay to the screen of the television monitor. A protocol is given for describing the motility of a suspension of human spermatozoa in terms of percentage motility, mean swimming speed, and the percentage of progressive sperm. A complete analysis can be done in 20 minutes or less. Examples are presented of videomicrographic assessment of the motility of human and bull spermatozoa.