Cyndie Picot

A Preliminary Risk Assessment of Human Exposure to Phycotoxins in Shellfish: A Review

ABSTRACT Over the past few decades, phycotoxins, secondary metabolites produced by toxic phytoplankton, have seen an increase in their frequency, concentrations, and geographic distribution. As shellfish accumulate phycotoxins making them unfit for human consumption, they are considered as an important food safety issue. Thus, a consumer exposure assessment on phycotoxins is necessary. Exposure assessment requires two types of information: contamination and consumption data. Shellfish contamination data on major toxins encountered by at-risk populations (Domoic Acid group, Okadaic Acid group, and Saxitoxin group) have been reviewed. Consumption data have been reviewed for both general and potential high-consumer populations. Then, we undertook acute and chronic exposure assessments, combining available French contamination data and our own consumption data. Studies including exposure assessment were then reviewed. Lastly, risk characterization was undertaken. It can be concluded that both acute and chronic exposure to phycotoxins via shellfish consumption is a matter of concern, mainly for high consumers identified in this review (specific populations and shellfish harvesters). However, the results for risk characterization must be improved. There is a need for (i) toxicological data to establish a Tolerable Daily Intake; (ii) an assessment of consumption and contamination data, undertaken at the same time, so as to assess exposure.

Probabilistic dietary exposure to phycotoxins in a recreational shellfish harvester subpopulation (France)

Phycotoxins, secondary phytoplankton metabolites, are considered as an important food safety issue because their accumulation by shellfish may render them unfit for human consumption. However, the likely intakes of phycotoxins via shellfish consumption are almost unknown because both contamination and consumption data are very scarce. Thus, two 1-year surveys were conducted (through the same population: recreational shellfish harvesters and from the same geographical area) to assess: shellfish consumption and contamination by major toxins (domoic acid (DA) group, okadaic acid (OA) group and spirolides (SPXs)). Recreational shellfish harvesters had been targeted as an at-risk subpopulation because they consume more shellfish than general population and because they eat not only commercial shellfish species controlled by official authorities but also their own harvests of shellfish species may be in non-controlled areas and more over shellfish species non-considered in the official control species. Then, these two kinds of data were combined with deterministic and probabilistic approaches for both acute and chronic exposures, on considering the impact of shellfish species and cooking on phycotoxin levels. For acute risk, monitoring programs seem to be adequate for DAs, whereas OAs could be a matter of concern for high consumers (their acute intakes were up to ninefold the acute reference dose (ARfD)). About chronic risk, OAs are a matter of concern. The daily OAs intakes were close to the ARfD, which is, by definition, greater than the tolerable daily intake. Moreover, SPX contamination is low but regular, no (sub)chronic SPX toxicity data exist; but in case of (sub)chronic toxicity, SPX exposure should be considered.

Relevant shellfish consumption data for dietary exposure assessment among high shellfish consumers, Western Brittany, France

Shellfish consumption can be a major pathway of exposure to pollutants for humans. It is fundamental to know if people eat enough shellfish to cause health problems, firstly in high consumers as recreational shellfish harvesters. The objectives of this study were to investigate the types of shellfish eaten, number of meals, portion size, sources of shellfish and shellfish consumption rates among French recreational shellfish harvesters; to determine factors affecting consumption patterns and to examine the reliability of the two methods used: a Food Frequency Questionnaire and a one-month food diary. The mean consumption rates were 11.63 and 26.21 g/person/day for shellfish derived from a self-harvested source only and from all sources, respectively. Harvester consumption rates were between 6- and 15-fold higher than the general French population. The comparison between the FFQ and the food diary showed that results were reliable. Thereby, our results are relevant to assess risk due to shellfish consumption.

Reproductive disorders in hairdressers and cosmetologists: a meta-analytical approach.

Reproductive disorders in hairdressers and cosmetologists: a meta‐analytical approach: Jean‐Bernard Henrotin, et al. National Research and Safety Institute, France

A Practical Example of Risk Assessment – Risk Assessment to Phycotoxins in a Recreational Shellfish Harvester’s Subpopulation

The past few decades have seen an increase in the frequency, concentrations, and geographic distribution of marine algal toxins (phycotoxins), secondary metabolites produced by marine microalgae (phytoplankton). Among the 3400–4000 known phytoplankton species, only about 2 % are potentially harmful (Fremy & Lassus, 2001). Bivalve molluscs filter-feed on these micro-algae, accumulate toxins, and may be consumed by humans (Shumway et al,. 1995; Van Dolah, 2000). In order to determine whether phycotoxins are a matter of concern for human health, a risk assessment must be undertaken. It comprises four steps: hazard identification, hazard characterization, exposure assessment and risk characterization (WHO, 1985).

Probabilistic Exposure Assessment to Phycotoxins by Recreational Shellfish Harvesters: Results and Influence of Shellfish Species and the Cooking Process

Phycotoxins, secondary phytoplankton metabolites, are considered as an important food safety issue because of their accumulation by shellfish until they becoming unfit for human consumption. However, the likely intakes of phycotoxins via shellfish consumption are almost unknown. The aim of this study is to assess both acute and chronic exposure levels to phycotoxins for high shellfish consumers (i.e. recreational shellfish harvesters), to develop a realistic probabilistic exposure assessment model, and to evaluate the influence of shellfish species and cooking process on exposure levels. Exposure assessment requires data on shellfish consumption and contamination. Two one-year surveys were conducted (by the same population, from the same geographical area) to assess shellfish consumption and shellfish contamination by major toxins (Domoic Acid group (DAs), Okadaic Acid group (OAs) and Spirolides (SPXs)) (Picot, Evaluation du risque lie a l’exposition aux phycotoxines via la consommation de coquillages chez les pecheurs a pied du Finistere, Ph.D. thesis, Universite de Bretagne Occidentale, Brest, France, 2010). These two kinds of data were combined with a probabilistic MCMC (Markov-Chain, Monte-Carlo) method. Assessments were made for both acute and chronic-exposures considering the impact of shellfish species and cooking on phycotoxin levels. For acute exposures, according to the shellfish species considered, the mean exposure levels ranged from 20 to 740; from 3.8 to 702; and from 0.7 to 78.4 ng/kg pc, for DAs, OAs and SPXs, respectively. Results reveal inter-species variabilities have a considerable impact on exposure levels and consequently should be considered to choose the monitored species in monitoring programs. Concerning chronic exposures, mean exposures were equal to 110; 54 and 5.4 ng/kg pc/day for DAs, OAs and SPXs, respectively. The impact of cooking differs according to the phycotoxin. For lipophilic toxins, the cooking increased the exposure by a factor about 1.5–2. For DAs, considering the cooking process, the exposures decreased for cockles and razor clams but increased for mussels, donax and hard shell clams. Thus, the actual banning levels based on raw bivalves might over or under protect the consumers when they cooked shellfish.