boron and Infertility--Male

This review focuses of industrial chemicals that research has indicated may adversely affect human male reproductive capacity. The study of male reproductive toxicity is impeded by a dearth of clinical endpoints. Males lack an obvious and easily measurable reproductive cycle, and the primary clinical indicator, semen analysis, offers unsure clues to reproductive performance. However, progress is being made in developing and evaluating tests to identify chemical hazards and estimate human health risks. Agents with confirmed adverse effects of male reproduction include carbon disulfide, dibromocklopropane, lead, and oral contraceptives. Agents with inconclusive effects include anesthetic gases, arsenic, benzene, boron, cadmium, carbaryl, chlordecone, chloroprene, DNT and TDA, ethylene dibromide, manganese, mercury, pesticides, PCP, radiation ionizing and nonionizing, solvents, dioxin, and vinyl chloride. Finally, agents with no observed adverse effects include epichlorohydrin, glycerine, benzoic acid, and polybrominated biphenyls. The literature suggests a need for further research in the following areas: 1) chemicals that are reactive and capable of covalent interactions in biological systems, 2) chemicals defined as mutagens and/or carcinogens in short-term laboratory tests, 3) chemicals demonstrated to cause aneuploidy or other chromosomal aberrations, 4) chemicals that affect sperm motility in vitro, 5) chemicals that share hormonal activity or affect hormone action, and 6) chemicals that act directly or indirectly to affect the hypothalamo-pituitary-gonadal axis.

Topics: Anesthetics; Arsenic; Benzene; Boron; Cadmium; Carbaryl; Carbon Disulfide; Chlordecone; Contraceptives, Oral, Hormonal; Dinitrobenzenes; Ethylene Dibromide; Humans; Infertility, Male; Lead; Male; Manganese; Methylmercury Compounds; Occupational Diseases; Pentachlorophenol; Pesticides; Polychlorinated Dibenzodioxins; Propane; Reproduction; Solvents; Vinyl Chloride

Boric acid and sodium borates have been considered as being "toxic to reproduction and development", following results of animal studies with high doses. Experimentally, a NOAEL (no observed adverse effect level) of 17.5 mg B/kg-bw/day has been identified for the (male) reproductive effects of boron in a multigeneration study of rats, and a NOAEL for the developmental effects in rats was identified at 9.6 mg B/kg-bw/day. These values are being taken as the basis of current EU safety assessments. The present study was conducted to investigate the reproductive effects of boron exposure in workers employed in boric acid production plant in Bandirma, Turkey. In order to characterize the external and internal boron exposures, boron was determined in biological samples (blood, urine, semen), in workplace air, in food, and in water sources. Unfavorable effects of boron exposure on the reproductive toxicity indicators (concentration, motility, morphology of the sperm cells and blood levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and total testosterone) were not observed. The mean calculated daily boron exposure (DBE) of the highly exposed group was 14.45 ± 6.57 (3.32-35.62) mg/day. These human exposures represent worst-case exposure conditions to boric acid/borates in Turkey. These exposure levels are considerably lower than exposures, which have previously led to reproductive effects in experimental animals. In conclusion, this means that dose levels of boron associated with developmental and reproductive toxic effects in animals are by far not reachable for humans under conditions of normal handling and use.

Topics: Adult; Air Pollutants, Occupational; Borates; Boric Acids; Boron; Chemical Industry; Dust; Environmental Pollutants; Food Contamination; Gonadotropins, Pituitary; Humans; Infertility, Male; Male; Middle Aged; Occupational Exposure; Prostate-Specific Antigen; Semen; Semen Analysis; Spermatozoa; Testosterone; Turkey; Water Pollution, Chemical; Young Adult

Topics: Animals; Animals, Newborn; Boron; Female; Humans; Infertility; Infertility, Male; Male; Maternal-Fetal Exchange; Pathology; Pharmacology; Pregnancy; Pregnancy, Animal; Rats; Reproduction; Research; Testis; Toxicology