No further clues from global investigation

born infants.In comparison, the crude prevalence in the total population born in 1981-91, according to the medical birth registry, was 0-43/10000 newborn infants (26 cases, population 602 301).In all four cases the infants had been singletons born alive at full term with birth weights over 3500g.One had additional birth defects.The four families lived at farms in different parts of Norway, with no temporal clustering of the pregnancies (conceptions between 1971 and 1988).None of the families had a greenhouse or an orchard.Of the 21843 infants potentially exposed to benomyl, one was diagnosed as having microphthalmia (0 46/ 10 000).This child came from a farm that grew field vegetables.Our data do not indicate that parental agricultural activity is a specific risk for anophthalmia in children.Even with this large cohort, comprising roughly a seventh of all births in Norway during the period studied, no firm conclusions concerning this rare birth defect can be drawn.The use ofproxies as exposure variables adds to the uncertainty.Nevertheless, our data do not support the suggestion that benomyl is a risk factor.