In order to rule out the possibility of omitting some individuals in the study at field visits described in previous articles, either because of the reluctance of the subject or because of his appointment elsewhere, fertility and
infertility states of
borate workers of the
Borax and
Acid Plants in Bandirma, Balikesir are given. Balikesir is one of the four provinces with large
borate deposits of Turkey, and Bandirma is 1 of its 19 districts. This county is relatively far away from
borate deposits, and
drinking water piped out through the springs has a
boron amount between 0.10 and 0.82 ppm B. That the participants are occupationally exposed to the
mineral in essence is therefore conceivable. At the first phase of the investigation, 191 workers were interviewed, as detailed previously. Among these, there were six infertiles of the primary type with a rate 3.1%.
Boron-unrelated infertile couples among sibs were found to be 2.6-3.6%, and 3.2% for three generation marriages-none being higher than those revealed in different sets of controls. In the second stage of work, computerized files of all workers of the facility and all employees of the general management sharing the same location were checked without an interview. Twenty-four subjects (3.4%) out of 712 workers were childless versus 2.7% among 108 employees, and 2.2% among 91 workers of a distantly located
sulfuric acid plant of the same complex. The differences were not significant, and these recent findings support the conclusion already reached almost unambiguously that
boron exposure at the present levels does not interfere with human reproduction.