To date, no case of human poisoning has been attributed to cyanotoxins in France. However, according to the list of cyanobacteria determined on various bathing water bodies and to some cases of animal poisoning through drinking water in the natural environment, the Directorate General for Health requested the French Agency for Food Safety (Afssa) to assess the risks associated with the presence of cyanobacteria in water for human consumption and the French Agency for Environmental and Occupational Health (Afsset)3
Regarding bathing water, data collected from the health monitoring system showed that:
to assess the risks associated with bathing. Experts from both agencies collected and analyzed data that were previously scattered from various entities, so as to update knowledge on cyanobacteria in France. The joint report has been published in 2006 (Afssa/Afsset, 2006).
- the representativeness is difficult to evaluate because the data mainly come from the West and the Center part of the country (absence of data from Eastern part and overseas territo- ries),
- data are lacking on the spatial and temporal distributions of blooms potentially toxinogenic and on the production of microcystins,
- data are lacking in the presence of cyanobacteria in brackish and marine waters, - data are mainly available from July to September,
- the amount of data collected at bathing or water sports’ sites between 2002 and 2004 in- cludes 2,680 samples;
- the sub-sample of samples (500 samples) for which there is a result for microcystin level is biased compared to the total number of samples with regard to the abundance of cyanobac- terial cells since toxins are only looked for when the cell number is higher than or equal to 100,000 cells/mL;
- data are inadequate to estimate the exposure of the French population to microcystins through bathing water, and their contribution to the total intake compared to drinking water; - a new threshold was recommended at 13 µg/L ± 5 % eq MCs for banning bathing and rec-
reational activities, to protect the most sensitive population (children between 2 and 7 years old).
In 2009, Afsset issued a report on artificial bathing waters open to the public. Such "natural bathing waters" may be artificial or natural ponds and public swimming pools that are not sub- ject to technical treatment and disinfection; rather their water is treated by biofiltration. Thus they are a hybrid between a bathing site in a natural lake or river and an outdoor pool. The use of such systems has increased these last 10 years in France. They are however not covered by any health regulations and are therefore not subject to any water monitoring obligations. Afsset highlighted the need to set regulations for such bathing sites in order to guide their development and avoid major health risks due to the development of toxic microalgae (including cyanobacte- ria) or pathogens (Afsset, 2009).
Regarding drinking water, in terms of risk assessment, Afssa's expert group could only issue an opinion on one toxin, microcystin LR, considering that the risk of its presence in water for hu-
3 On 1st July 2010, Afssa and Afsset merged to become Anses (French Agency for Food, Environmental and Occupational
man consumption is negligible. Moreover, Afssa recommended amending regulations to update the parameters to be looked for using the standardised analytical method of microcystins in public water supplies (Afssa/Afsset, 2006).
The 2006 report concluded that more data are needed on:
- the toxicity of cyanotoxins (short and long term, carcinogenicity) to set health based guidance values for toxins alone and in mixtures
- the monitoring of cyanobacteria and cyanotoxins in water for drinking water production and for recreational activities (freshwater, brackish and marine waters)
- analytical methods and availability of standards (especially for other toxins than MC-LR) - the understanding of production of toxins
- the distribution of toxins in the environment (water, sediments, aerosol) and in living organ- isms (animals and plants) and their bioavailability.
The agencies also recommended creating a national database to collect monitoring data.
Regarding food, Afssa issued an opinion in 2008 specifically regarding the contamination of food (fish, shellfish, and crustaceans) related to cyanobacterial proliferation. The opinion mainly concluded that data are lacking on the presence and the toxicokinetics of cyanotoxins in fish tissues as well as on their bioavailability for humans (especially regarding the bound microcys- tin). Most of the data available on tissue contamination were investigated in Asia, and are there- fore difficult to extrapolate for European countries. Nevertheless these data show:
- a contamination of the freshwater mollusks which, even if they are not directly eaten by hu- mans, can be transferred via the food web to upper predators like fish,
- a contamination of marine bivalves mollusks, especially mussels of the common species My-
tilus edulis,
- a significant contamination of the muscles of freshwater fish
- some studies show that elimination of the toxins in fish and gastropods could take a long time (several days after the end of exposure via contaminated feed). Such data suggest a background level of fish contamination even in absence of cyanobacterial proliferation (or be- tween 2 bloom events).
Based on the Tolerable Daily Intake for chronic exposure of 0.04 µg/kg bw/day set by the WHO, a default body weight of 60 kg, a daily consumption of fish of 86 g (high percentile in the French database) and an intake of water (2 L at 1 µg/L), the limit for adults would be 5.6 µg MCs/kg of fish (or edible part of fish). For children, this value would be 1.4 µg/kg of fish (default body weight of 10 kg and daily consumption of 57 g). If data are available to show the absence of MCs in drinking water, the limits become 28 and 7 µg/kg of fish, respectively.
Afssa reiterated the need for studying the contamination of microcystins in fish and its bioavai- lability for humans. A study on this topic is currently on-going at the French agency (Anses), jointly with the French National Museum of Natural History from Paris (UMR 7245 MCAM MNHN – CNRS).
In 2008, the French Museum of Natural History (UMR MCAM) reported for the first time in France the presence of saxitoxins (STXs) in a water body used for recreational activities (e.g. bathing) (Ledreux et al., 2010). Based on Australian, Brazilian and New Zealand recommenda- tion values, Afssa recommended to do not eat fish from this water body and to set a monitoring of the level of STXs (Afssa, 2009). The co-occurrence of toxins (for example STXs and micro- cystins) was not considered in these recommendations.
Date Site [Chl. A] (µg/L)
Potentially toxic cyanobacteria (in per cent of total phytoplankton biomass)
[STXs] (µg eq. STX.L-1) 08 September 2008 1 153 ± 0,9 Microcystis aeruginosa (1 %)
Microcystis wesenbergii (2 %) Aphanizomenon flos-aquae (36 %) Aphanizomenon gracile (6,5 %)
Aphanizomenon aphanizomenoïdes (< 1 %)
4.8 ± 0,5
08 September 2008 2 208 ± 4 Microcystis wesenbergii (1,5%) Aphanizomenon flos-aquae (71,5 %) Aphanizomenon gracile (7,5 %)
Aphanizomenon aphanizomenoïdes (< 1 %)
6.7 ± 3,5
In April 2010, around sixty people reported cutaneous and respiratory irritations in Mayotte Isl- and (a French territory in Indian Ocean), probably subsequent to bathing and/or inhalation of spray on the beach. The appearance of these irritating symptoms was concomitant with a mas- sive bloom of Lyngbya majuscula, a potentially toxic filamentous and benthic cyanobacteria, in association with marine plants Phanerogamae. A large quantity of these plants contaminated by the cyanobacteria was found on the beach. A collective expertise has been performed by the French Agency for Environmental and Occupational Health (Afsset) on this topic and several recommendations have been proposed for the management of this crisis, (e.g. collection of the algal mats using appropriate personal protective equipment (Afsset, 2010).