Assessment of Fertility and Infertility in Boron-Exposed Turkish Subpopulations 6: Relevant Data From All Centers

SUMMARY In this last article, part of a large-scale work to reveal health effects of boron exposure, findings of fertility-infertility states of subjects exposed to borates environmentally and/or occupationally in a country with the world's largest deposits are described. The study covered all centers of borate production, namely, Bigadic county of Balikesir; Kestelek village of Mustafa Kemal Pasa county, Bursa; Emet and Hisarcik counties of Kutahya, and Kirka town, Seyidgazi of Eskisehir, an area nearly 350 km long and 150 km wide. Drinking water piped out from springs and wells has boron concentrations 0.2 to 29 ppm (mgB/kg or mgB/l). Dust amount at work-sites was below permissible level of 10 mg/m 3 . The work, questionnaire-based, was realized in field as an observational one. Residents were visited at home and coffee houses in villages and public buildings in towns, and workers at facilities and ore pits without any selection. The inquiry was mainly concerned with marital state and childbearing properties of probands, and of other members in the kindred. Infertility of the primary type among 2529 probands (participants), as a convenient sample, was 3.1%, changing from 0.0 to 6.5% regarding subpopulations from 12 centers, differences being statistically insignificant. No differences with respect to birth place and professional state as well were revealed either. Pedigree data showed the rate was 3.2% covering 14,320 marriages over 3 generations. No appreciable concentration of infertiles either in subgroups or in so-called 'borate families' in borate towns was observed. Approached as an independent test, marriages of male and female sibs of proband and his (her) spouse ranged from 2.4 to 4.2%. None of these was so far higher than found in different sets of controls and of general population over 50,000 families. Childlessness was found 1.7% among workers versus 4.3% among employees from all facilities, the difference attributable to socio-cultural grounds. It was then once more concluded that continuous boron exposure at the present level does not affect human reproductive performance adversely primarily and secondarily over 3 generations for at least 60-70 years.