“…Since AOM has notably declined over time worldwide (Helm and Helm, 1984;Adadevoh et al, 1989;Papadimitriou et al 1999;Olesen et al, 2000;Anderson et al, 2003;Do Lago et al, 2003;Silva and Padez, 2006)-much more than genetic factors alone can explain-this decrease must presumably have, at least in part, environmental causes. For example, in Denmark, the average AOM declined by 4 months from 13.40 to 13.03 years between 1965/ 1966 and 1982/1983, a 2.4 months drop in AOM per decade was reported in Brazil among a cohort of women born between 1931 and 1977, and in the USA an average drop in AOM by 2.5 months was observed between 1963-1970 and 1988-1994 with a further decline by 2.3 months in (Helm and Helm, 1984Anderson et al, 2003;Do Lago et al, 2003;Anderson and Must, 2005).…”