Fertility history of currently employed male semiconductor workers.

Fertility among men working in semiconductor manufacturing during 1984-89 was assessed in a 1990-91 cross-sectional study of eight companies. Men working in wafer fabrication rooms (fabs) (n = 241, 165 births) were compared to men in nonfabrication (nonfab) jobs (n = 447, 300 births). Results showed that 17% of fab men and 14% of nonfab men reported ever trying for > or = 1 year to conceive [relative risk (RR) = 1.21, 95% confidence interval (CI) = 0.83-1.74]. Crude birth rates (births/1,000 person months) were similar [15 fab, 17 nonfab; crude fertility ratio (FR) = 1.09, 95% CI = 0.86-1.36], as were birth rates adjusted by Cox models for confounders (adjusted FR = 0.98, 95% CI = 0.80-1.19, p = 0.79). Fab men who worked in furnace, thin-film, or ion implantation areas were more likely than nonfab men to report previous difficulty conceiving (25%, RR = 1.79, 95% CI = 1.09-2.94), and their past fertility was lower (nine births/1,000 person months; crude FR = 0.66, 95% CI = 0.40-1.02; adjusted FR = 0.73, 95% CI = 0.50-1.09, p = 0.12). Problems included lack of contraception data and misclassification of fab subgroups.

Iron deficiency and educational achievement in Thailand.

This double-blind clinical trial was conducted in Thailand to assess the impact of iron treatment on the IQ and educational attainment of 1358 9-11-y-old children. The children were classified into one of three groups: iron replete, iron depleted, and iron-deficient anemic. The Raven Progressive Matrices was used to measure IQ. A Thai language and a math test were administered to assess school attainment. A 50-mg/d tablet of ferrous sulphate was given for 2 wk and a 100 mg/d tablet, for 14 wk. An anthelminthic drug was given on the day of the blood test before treatment and 3 mo after the intervention started. There is evidence of a positive association between iron status and IQ and a language school achievement test but there is no support for the internal validity of the hypothesis that this association is causal.