Exposure of populations to dioxins and related compounds.

The present situation with respect to the exposure of the general human population to PCDDs, PCDFs and (dioxin-like) PCBs and specific issues that should be taken into consideration for a risk assessment of these exposures have been summarized. The information is based on studies performed in The Netherlands and Germany in the last 10 years. Additional data have been collected through a literature search and through many contacts with researchers and national authorities. The most important route for human exposure to PCDDs, PCDFs and (dioxin-like) PCBs is food consumption contributing over 90% of total exposure, with products of animal origin and fish making the greatest contribution to this exposure. The dietary intake of PCDDs and PCDFs by the general population of industrialized countries is on average 1-3 picograms of (i)-TEQ per kilogram body weight per day. If the contribution of dioxin-like PCBs are also considered, the daily TEQ intake can be a factor of two to three higher. Special consumption habits and consumption of highly contaminated foodstuffs may lead to lower and higher TEQ intakes. In general, TEQ intake increases during childhood and stabilizes in adults of about 20 years of age. However, when normalized by body weight exposure is found to decrease with childhood age due to increasing body weight. Exposure has been shown to have fallen over time in all countries where data are available. Countries that started to implement measures to reduce dioxin emissions in the late 1980s, such as The Netherlands, United Kingdom and Germany, clearly show decreasing PCDD/PCDF and PCB levels in food and consequently a significantly lower dietary intake of these compounds by almost a factor of 2 within the past 7 years.