With respect to dietary habits, we selected fathers with a high intake of fish (≥3 times per week), as a major source of persistent endocrine disrupting chemicals. Due to small numbers, we could not select a group of fathers with Vemurafenib mouse regular intake of soy replacements for meat or dairy, which are rich sources of phytoestrogens. A number of fathers who did not report occupational exposures, had a low or average dietary intake of fish, were not obese, and did not frequently use personal care products was selected as well. The aim of this selection

strategy was to obtain a sufficient exposure gradient in the study population to assess differences between low and high exposure groups, expecting that the exposures at time of pregnancy (4 to 11 years

ago) would partly correspond with current exposures of the fathers. The selected fathers received selleck inhibitor an invitation letter and study information by regular mail and were contacted by telephone to ask for their consent, which was later confirmed in writing. We chose to restrict the study population to men, because the menstrual cycle in women would bring about many methodological difficulties. From February until April 2007, all study participants were visited at home or at work for a single blood draw and interview. Participants were asked to abstain from alcohol and drinks or foodstuffs that contained soy in the 24 h before the blood draw, because these could lead to temporarily elevated levels of plasma phytoestrogens. Blood (10 ml) was collected in glass heparin coated vacutainers and was cooled

in a closed box during transportation. After spinning, plasma was stored in glass collection tubes and frozen at − 80 °C until further work up. Current exposures to and determinants for potential endocrine disruptors were assessed with structured interviews, in which we included questions on age, weight, ethnic origin, living environment (urban vs. country side), smoking, personal care products (used within the past two days), leisure time activities (home improvements, hobbies), and specific occupational exposures (see Table 3). Questions Interleukin-2 receptor were phrased as: ‘Do you work with pesticides, e.g. to control weeds, insects, or fungi?’ Subjects were asked about exposure intensities (e.g. number of hours per week) and when they were last exposed to specific agents. General questions about tasks and activities at work were included as well. Referring to the past 4 weeks, subjects scored their intake frequency of food items such as seafood, chicken, beef, pork, or eggs, as sources of persistent endocrine disrupting chemicals. In order to assess the long-term effects of phytoestrogens, we collected data on the regular intake of soy replacements for meat or dairy.