10 Probabilistic Exposure Assessment to Phycotoxins by Recreational. . .
119
Chronic Exposure
The chronic exposure assessment corresponds to the level of exposure after a
daily consumption of shellfish, thus the useful consumption data are the daily
consumption rates. Table 10.4 illustrates the chronic-exposure levels issued from
the probabilistic exposure approach for harvested-, purchased-bivalves and “all
bivalves”.
Domoic Acid and Analogs
For DAs, it shows that, for “all bivalves”, the median value and the mean are unchanged between T2a and T2b scenarios and equal to 0.11 and 0.09 g/kg bw/day,
respectively; the 95th percentile value is slightly different in T2a and T2b scenarios
(0.26 and 0.28 g/kg bw/day, respectively).
Okadaic Acid and Analogs
Concerning OAs, the “all bivalves”-related exposure distribution presents maximal
means of 54.1 and 56.2 ng/kg bw/day for T2a and T2b scenarios, respectively, as
well as median values of 39.0 and 41.1 ng/kg bw/day and 95th percentiles of 149
and 155 ng/kg bw/day. One should note that the censored value scenario (T2a or
T2b) has a very limited effect upon the chronic dietary exposure to phycotoxins.
Comparing the contribution by harvested bivalves to purchased bivalves, Table 10.4
shows clearly that, for OAs, the level derived from harvest are about five-fold greater
than those derived from purchase, this is mainly because the OA levels of harvested
bivalves takes into account levels above the regulatory limit.
Spirolides
Concerning SPX, the chronic distribution of exposure (for “all bivalves”) leads to
a mean value of 5.4 ng/kg bw/day, a median of 4.6 ng/kg bw/day, and a 95th
percentile of 11.9 ng/kg bw/day. For SPX, the amount derived from harvest are
about two-fold those derived from purchase.
Species Contribution
Figure 10.1 illustrates the contribution of each bivalve shellfish to the daily
ingestion of each of the phycotoxins under study. It evidences that the three greatest
contributor species are the cockles and the carpet shell clams from harvest as well
119
Chronic Exposure
The chronic exposure assessment corresponds to the level of exposure after a
daily consumption of shellfish, thus the useful consumption data are the daily
consumption rates. Table 10.4 illustrates the chronic-exposure levels issued from
the probabilistic exposure approach for harvested-, purchased-bivalves and “all
bivalves”.
Domoic Acid and Analogs
For DAs, it shows that, for “all bivalves”, the median value and the mean are unchanged between T2a and T2b scenarios and equal to 0.11 and 0.09 g/kg bw/day,
respectively; the 95th percentile value is slightly different in T2a and T2b scenarios
(0.26 and 0.28 g/kg bw/day, respectively).
Okadaic Acid and Analogs
Concerning OAs, the “all bivalves”-related exposure distribution presents maximal
means of 54.1 and 56.2 ng/kg bw/day for T2a and T2b scenarios, respectively, as
well as median values of 39.0 and 41.1 ng/kg bw/day and 95th percentiles of 149
and 155 ng/kg bw/day. One should note that the censored value scenario (T2a or
T2b) has a very limited effect upon the chronic dietary exposure to phycotoxins.
Comparing the contribution by harvested bivalves to purchased bivalves, Table 10.4
shows clearly that, for OAs, the level derived from harvest are about five-fold greater
than those derived from purchase, this is mainly because the OA levels of harvested
bivalves takes into account levels above the regulatory limit.
Spirolides
Concerning SPX, the chronic distribution of exposure (for “all bivalves”) leads to
a mean value of 5.4 ng/kg bw/day, a median of 4.6 ng/kg bw/day, and a 95th
percentile of 11.9 ng/kg bw/day. For SPX, the amount derived from harvest are
about two-fold those derived from purchase.
Species Contribution
Figure 10.1 illustrates the contribution of each bivalve shellfish to the daily
ingestion of each of the phycotoxins under study. It evidences that the three greatest
contributor species are the cockles and the carpet shell clams from harvest as well