Role of dietary patterns for dioxin and PCB exposure

Abstract

Dietary patterns were related to intake and blood concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs), dioxin-like polychlorinated biphenyls (dl-PCBs) and selected non-dioxin-like-PCBs (ndl-PCBs). Intake calculations were based on an extensive food frequency questionnaire and a congener-specific database on concentrations in Norwegian foods. The study (2003) applied a two-step inclusion strategy recruiting representative (n=73) and high consumers (n=111) of seafood and game. Estimated median intakes of sum PCDD/PCDFs and dl-PCBs of the representative and high consumers were 0.78 and 1.25 pg toxic equivalents (TEQ)/kg bw/day, respectively. Estimated median intakes of ndl-PCBs (sum chlorinated biphenyl (CB)-28, 52, 101, 138, 153, 180) were 4.26 and 6.40 ng/kg bw/day. The median blood concentrations of PCDD/PCDFs/dl-PCBs were 28.7 and 35.1 pg TEQ/g lipid, and ndl-PCBs (sum of CB-101, 138, 153 and 180) 252 and 299 ng/g lipid. The Spearman correlations between dietary intake and serum concentration were r=0.34 (p=0.017) for dl-compounds and r=0.37 (p<0.001) for ndl-PCBs. Oily fish was the major source of dl-compounds and ndl-PCBs in high and representative consumers. Four dietary patterns were identified by principal component analysis. Two were related to high intakes, one dominated by oily fish ((Omega-3)), the other by fish liver and seagull eggs ("northern coastal"). Only the latter was closely associated with high blood concentrations of dioxins and PCBs.

Sex, BMI and age in addition to dietary intakes influence blood concentrations and congener profiles of dioxins and PCBs

“…An extensive database comprising concentrations of dioxins and PCBs in Norwegian foods has recently been established [13]. A separate database, with concentrations in different fish species from Lake Mjøsa, was created (see the online Supporting Information Table S1).…”

“…A separate database, with concentrations in different fish species from Lake Mjøsa, was created (see the online Supporting Information Table S1). Dietary exposure was assessed using a validated 12-page semi-quantitative food frequency questionnaire covering consumption over the last 12 months [13,14]. In addition, questions about consumption of fish from Lake Mjøsa were asked [8].…”

“…Briefly, to serum samples 13 C-labeled internal standards were added and extracted by means of solid-phase extraction, and the lipids removed using sulphuric acid-silica columns. Both procedures were performed on an automated solid phase extractor.…”

“…were determined as described in detail previously [11]. Briefly, 13 C-labeled internal standards were added and the samples liquid/liquid extracted by means of n-hexane and n-hexane/2-propanol. The lipid content was determined gravimetrically by weighing the dried fat residue.…”

Nordic dietary surveys

“…These were then grouped into consumption of ten different types of seafood. The consumption frequencies were converted into food amounts (g/day) by the use of standard, gender specific portion sizes (Kvalem et al 2009). PFC concentrations in serum were significantly associated with the consumption or lean fish, fish liver, schrimps and meat.…”