Biomonitoring of PCDD/Fs in populations living near portuguese solid waste incinerators: Levels in human milk

In the context of two Environmental Health Surveillance Programs, launched in response to public and scientific concern in relation to waste incinerators located near Lisbon and in Madeira Island, two human biomonitoring projects have been started in Portugal, focussed in dioxins and dioxin-like compounds in human milk. Results from the undertaken studies have already provided data on the extent and pattern of dioxin body burden of both studied groups as well as a preliminary temporal trend of dioxin levels for the population residing near Lisbon incinerator. The present paper investigates difference between exposed and non-exposed subjects under study and, from a preventive perspective, possible covariates of the dioxin levels in human milk. Emissions from both incinerators appear to be well controlled as there is no increase of human body burden of dioxins as measured in human milk of individuals living near these facilities. Concerning other determinants of dioxin levels, results suggest confirmation of previously found significant age-dependent trend towards higher levels of dioxins in aged subjects. On the contrary, association between mother's levels of dioxins and parity lost significance. Apart from the issue of incineration, the general conclusion for the general population is that living in Lisbon as compared to Madeira results in higher milk dioxin levels and possible health risks. The profile of the single congeners for PCDD/Fs in human milk from Madeira and Lisbon shows similar contributions for 12378-PCDD, 23478-PCDF, 123678-HCDD and 2378-TCDD, that account altogether for about 84% of the total identified dioxin body burden in the studied groups.