Adults
Intake of environmental pollutants in adults via the diet has been monitored in a number of investigations from the National Food Administration. In the case of organic environmental pollutants, such as PCBs and dioxins, intake estimates of these compounds were made in conjunction with the latest revision of dietary advice on oily Baltic fish (Darnerud et al., 1995; Wicklund Glynn et al., 1996). Data on concentrations used for these estimates were from the beginning of the 1990s and consumption data consisted of the Swedish Board of Agriculture’s per capita statistics for food. In 2002, new intake estimates based on the dietary survey Riksmaten 1997-98 were published (Becker & Pearson, 2002), where samples for concentration data were mainly collected in the period 1998-99 (Lind et al., 2002). The estimated intake of PCBs and dioxins in the latter study was considerably lower, only 20-30% of the values produced in the 1995 study. One explanation may be the decline in concentrations of these compounds that has taken place in the environment during the past decade. For example, a decline in the concentration of PCBs, but also of other organic environmental pollutants, could be observed between 1991 and 1997 in Swedish beef and pork (Wicklund Glynn et al., 2000). However, better analytical methods and changes in consumption patterns may also have played a part.
An updated calculation of dioxin intake was made during 2005. It included new concentration data obtained in targeted investigations and within the framework of
the National Food Administration’s monitoring programme (Ankarberg & Petersson Grawé, 2005). In addition to new concentration data being available, the concentrations in Baltic herring have been weighted on the basis of actual catch data from the Swedish Board of Fisheries, so that dioxin concentrations in various parts of the Baltic Sea are matched against the catch volumes of Baltic herring for the corresponding area of the sea. In the case of salmon, new estimates for consumption of farmed versus wild salmon have been made, which are based on the volumes imported from Norway and the volumes landed at Swedish ports respectively. The national median intake for all consumers is calculated at 1.1 pg total-TEQ/kg body weight/day, and the 95 percentile occurs at 2.9 pg/kg body weight/day. Dioxin intake for women of childbearing age (17-40 years) is somewhat less, 93 pg total-TEQ/kg body weight/day, and in this case the 95 percentile occurs at 2.0 pg total-TEQ/kg body weight/day. Around half the dioxin intake is calculated to come from fish and fish products, with other animal products making up the remainder. This new calculation also includes theoretical regional intake, which assumes that the Baltic herring consumed comes from neighbouring fishing grounds in the Baltic Sea. Overall, this new estimate of the national intake involves no major changes compared with the 2002 estimate, but certain regional differences have been observed.
In certain groups of consumers with particular dietary habits, intake of organic environmental pollutants can be considerably greater, e.g. as a result of higher fish consumption. Intake of organic environmental pollutants has thus been shown to be higher in east coast fishermen than in west coast fishermen or in the general population, since east coast fishermen eat more oily east coast fish, which have higher concentrations of organic environmental chemicals than other fish. It was also found that east coast fishermen had higher concentrations of these compounds in their blood (Asplund et al., 1994). In a study of male high consumers of fish from Sweden and Latvia, the concentration of organic environmental pollutants in blood, including a number of PCB-congeners, was correlated with intake of oily Baltic fish (Sjödin et al., 2000).
Children
Data from the 1989 dietary survey HULK (Household food purchasing and dietary habits; Becker, 1994) have been used for calculations of dioxin intake among children and young people aged 1-17 years (Appelgren et al., 2002). Overall, these calculations show that exposure to dioxins (PCDD/DF + DL-PCB) on a body weight basis decreased with increasing age from the ages 1-3 to 19-24 years. The younger age groups (1-10 years) had a mean daily exposure that exceeded 2 pg TEQ/kg body weight/day. Boys had a higher exposure than girls, regardless of whether the basis for calculations was per kg body weight or per person. Dairy products represented the largest proportion of total exposure, ~30%, followed by meat products (20-25%), fish (15-20%), fats (7-12%), other fatty foods (7-12%) and eggs (3-7%). In this calculation, PCDD/DF made up around 70% and DL- PCB around 30% of the total-TEQ exposure. It should be noted that the above- mentioned results reflect the dietary patterns of children and young people during
the 1980s, which may differ from those prevailing at the present time, and that the concentration data were mainly collected during 1998-99.
Intake of dioxins and dioxin-like PCB has also been calculated on the basis of consumption data from Riksmaten – barn 2003 and data on actual concentrations in animal foods (Becker & Enghardt Barbieri, 2004; Enghardt Barbieri et al., 2006; Concha et al., 2006). Preliminary results showed that median intake of dioxins/dioxin-like PCBs (total-TEQ) in 4-year-olds was 2.3-2.4 pg/kg kg body weight/day, in 7-8-year olds 1.8-1.9 pg/kg body weight/day, and in 11-12-year olds 1.2-1.3 pg/kg body weight/day. Based on median intake, fish, meat and dairy products were approximately equally significant for the total intake of dioxins in children in these ages. Compared with the dietary study HULK (see above), intake of dioxins and dioxin-like PCBs appears to have decreased for the corresponding age groups (Concha et al., 2006).