Congener-specific levels of dioxins and dibenzofurans in U.S. food and estimated daily dioxin toxic equivalent intake.

Abstract

Food, especially meat, milk, and fish, is the immediate source of almost all polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and dioxinlike compounds in the general population. To estimate intake of these highly toxic compounds, we performed congener-specific dioxin analyses for the first time on U.S. food for 18 dairy meat, and fish samples from a supermarket in upstate New York. 2,3,7,8 Tetrachlorodibenzo-p-dioxin (TCDD, "dioxin") toxic equivalents (TEqs) on a wet weight basis for the dairy products ranged for 0.04 to 0.7 ppt, meat TEqs ranged from 0.03 to 1.5 ppt, and fish TEqs ranged from 0.02 to 0.13 ppt. Previous human breast milk and infant formula analyses were used with the current preliminary food data to estimate a range of dioxin intake for Americans. Average daily food intake of TEqs for an adult weighing 65 kg was estimated to be between 0.3 and 3.0 pg/kg body weight, for a total of 18-192 pg TEq, using 1986 American consumption rates. Due to the relatively high level of PCDDs and PCDFs commonly found in human breast milk from American women and from women in other industrial countries, a nursing infant may consume an average of 35-53 pg TEq/kg body weight/day in its first year of life. This may be compared with the current U.S. EPA virtually safe dose of 0.006 pg TCDD/kg body weight per day over a 70-year lifetime based on an upper limit cancer risk of 10(-6), or the 10 pg/kg/day used by some European government agencies.

Contribution of PCB exposure from fish consumption to total dioxin-like dietary exposure

“…This is due in part to recent estimates of TCDD cancer slope factor (1E-3 pgTEQ/kg body weight/day) which are 10 times higher than previous estimates (USEPA, 2000). EPA's estimate of general population total dioxin TEQ exposure (including dioxin-like PCBs, PCDFs, and PCDDs) of 1 pg/kg/day is within the range of estimates presented in other assessments (Alcock et al, 1998;Patandin et al, 1999;Schecter et al, 1994) and may carry an upper bound cancer risk of 1 in 1000 (USEPA, 2000). The tolerable daily intake (TDI), a reference value for ensuring that acceptable levels of exposure are not exceeded, determined by the World Health Organization for dioxin TEQ in 1998 is 1-4 pg/kg bodyweight (WHO, 1999).…”

“…Publicly available studies with this level of sensitivity and/or a majority of values above detection the limit for the dioxin-like congeners are limited; examples are presented in Table 2. Information was available for commercial freshwater and ocean fish (Schecter et al, 1994), for Willamette River (Oregon) fish (EVS, 2000), Columbia River Basin (Washington and Oregon) fish (USEPA, 2002), and for fish from Saginaw Bay (Michigan) (Giesy et al, 1997). PCB TEQ concentrations in fish samples had to be recalculated for the commercial and Saginaw Bay (Giesy et al, 1997) studies because consensus TEFs were established (Van den Berg et al, 1998) after their publication.…”

“…The exposure contribution from consumption of fish and seafood has been estimated as less than 20% of dietary total TEQ exposure for the general population (Travis and Hattemer-Frey, 1991;Schecter et al, 1994;Harrison et al, 1998). However, PCB TEQ exposure from fish may be much greater for people with above average fish and seafood consumption or consuming highly contaminated fish.…”

Survey of organochlorine pesticides and polychlorinated biphenyls in commercial pasteurized milk in Iran

“…Although these man-made toxins have been identified and their use reduced in the past decades, their occurrence in our environment still causes concern (Focant et al 2003). Direct exposure from the surrounding media is recognized to be rather low, while more than 95% of human intake seems to be via the consumption of food (Schecter et al 1994), which results in bioaccumulation of PCBs in the aquatic and terrestrial food chains. The main reasons for environmental contamination by these compounds are their extensive mass production, uncontrolled use, insufficient discharge, and persistence in the environment (Ross 2004).…”

Breast-Feeding Exposure of Infants To Environmental Contaminants — a Public Health Risk Assessment Viewpoint: Chlorinated Dibenzodioxins and Chlorinated Dibenzofurans

“…The actual levels measured in food products may vary. For example, when food samples were analyzed for the presence of dioxins in a New York supermarket, calculated TEQs ranged from 0.04 to 0.7 ppt in dairy products, from 0.03 to 1.5 ppt in meat, and from 0.02 to 0.13 ppt in fish (Schecter et al, 1994).…”