Lydie Soler

Fuzzy Web Data Tables Integration Guided by an Ontological and Terminological Resource

In this paper, we present the design of ONDINE system which allows the loading and the querying of a data warehouse opened on the Web, guided by an Ontological and Terminological Resource (OTR). The data warehouse, composed of data tables extracted from Web documents, has been built to supplement existing local data sources. First, we present the main steps of our semiautomatic method to annotate data tables driven by an OTR. The output of this method is an XML/RDF data warehouse composed of XML documents representing data tables with their fuzzy RDF annotations. We then present our flexible querying system which allows the local data sources and the data warehouse to be simultaneously and uniformly queried, using the OTR. This system relies on SPARQL and allows approximate answers to be retrieved by comparing preferences expressed as fuzzy sets with fuzzy RDF annotations.

Assessment of seasonality in exposure to dioxins, furans and dioxin-like PCBs by using long-term food-consumption data

According to the European Food Safety Authority (EFSA) guidance related to uncertainties in dietary exposure assessment, exposure assessment based on short-term food-consumption surveys, such as 24-h recalls or 2-day records, tend to overestimate long-term exposure because of the assumption that the dietary pattern will be similar day after day over a lifetime. The aim of this study was to make an assessment of dietary exposure to polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), also called ‘dioxins’ and ‘dioxin-like PCBs’, using long-term household purchase and consumption survey data collected by TNS-Secodip. Weekly purchases of the major dioxins and dl-PCB vector products of these contaminants were collected for 328 single-person households, who participated at TNS-Secodip consumption surveys from 2003 to 2005 and who were single-person households in order to estimate better their consumption. These data were combined with average contamination levels of food products. Weekly gross average exposure was estimated at 10.2 pg toxic equivalent (WHO TEQ) kg−1 bw week−1 (95% confidence interval [9.6, 10.9]). According to the typical shape of the distribution of individual weekly exposures, it is sensible to fit an exponential law to these data. The mean was therefore 12.1 pg WHO TEQ kg−1 bw week−1. This value is higher than the arithmetic mean because it better takes into account inter-individual variability. It was estimated that about 20% of persons in this sample were exceeding the current health-based guidance value mainly due to high consumption of seafood and/or dairy products. Thanks to long survey duration (3 years) and the weekly recording of food consumption, it was possible to demonstrate the actual seasonality of dietary exposure to dioxins and dl-PCBs with a maximum between March and September; similar seasonality is observable for fish consumption. Autoregressive integrated moving average (ARIMA) models were adjusted to the time series and it was demonstrated that the number of times the upper limit of confidence intervals exceeds the provisional tolerable weekly intake (PTWI) is about 15 weeks per year on average. Finally, compared with the results obtained from data collected in the short-term surveys (1 week), this study does not suggest that short-term consumption surveys tend to overestimate the long-term exposure.