Dr Apolline Roger
In 1994, French beekeepers started to blow the whistle on the abnormal behaviour and disappearance of their bee colonies foraging on sunflowers and maize. Quickly, beekeepers considered “Gaucho”, a new neonicotinoid authorised the same year for the treatment of sunflower and maize seeds, as the prime suspect.
Were these two events linked by a causal relation or purely coincidental? Neonicotinoids are chemicals which attack the nervous system of all insects, and thus can have a lethal impact on bees. They were nonetheless authorised, under the condition that they are not to be used over a dose previously identified by the industry, and accepted by the regulator, as being non-lethal for bees. However, french beekeepers observations questioned the scientific grounds of this decision. Was the non-lethal dose correctly identified? Furthermore, do neonicotinoid insecticides have chronic sub-lethal effects on bees which were not foreseen when they were authorised?
In 2008, a perfect storm of dry and windy weather, inappropriate technology, and late sowing resulted in the production of a cloud of toxic neonicotinoid dust from insecticide treated maize seeds which severely poisoned 12,000 bee colonies in Germany.
Is this accident teaching us more than the existence of an acute lethal risk in dust clouds released when sowing seeds treated with neonicotinoids?
As always in times of uncertainty, science was called on to bring clarity. In the context of the growing mobilisation of beekeepers and civil society against neonicotinoids, public and business research flourished. The increased knowledge that resulted from this effort has, however, not offered a clear-cut answer to the political question: should public authorities act to protect bees from neonicotinoids?
Answering this question requires an interdisciplinary reflection involving toxicology, ecotoxicoly, insectology, ecosystem science, biology, bee managers’ knowledge, sociology, as well as political and legal sciences. What follows does not pretend to develop this exhaustive approach, but rather seeks to give some reflections and facts to ground the interdisciplinary discussion between GESA master students. The questions we will explore are: (1) What is the societal impact of any restriction on the use of neonicotinoid? (2) What actions would effectively protect bees from neonicotinoids? (3) Are the actions taken so far appropriate?
1) What is the societal impact of restriction on the use of neonicotinoids?
Neonicotinoids have several economic and health benefits, some which are confirmed and some which are claimed, all of which have to be taken into account when considering their restriction.
Economic benefits
Firstly, neonicotinoids are a profitable and massive market for EU industries. They are present in 120 countries and are the most used insecticide worldwide. The biggest producer of neonicotinoid insecticides are European industries: Bayer and BASF (Germany) and Syngenta (Switzerland). Imidracloprid, one of the several neonicotinoid subclasses, is the best selling insecticide worldwide. Bayer is one of its main producers, through products like “Gaucho”. Imidracloprid grossed 824 million dollars in 2010 for Bayer only.
Other economic benefits have to be added to these impressive revenues. At farm level, neonicotinoids require less work from farmers. Indeed, neonicotinoids’ main modus operandi relies on the treatment of the seed itself, even though they can also be sprayed or be used as soil treatment. The seeds are “coated” with the insecticide, which will therefore be diffused internally by the vascular systems of the growing plan. This treatment is holistic; the whole plant is impregnated. It is also systematic; all fields are treated, even when there is no identified threat. The farmer does not need to control the health of his field and to spray it during growth.
More generally, another advantage of this newest generation of insecticides is that they are very efficient in meeting their target. Even though the accounting of the benefits for agriculture is difficult to faithfully establish, the gains resulting from the protection of crops against pest have to be taken into account. However, the efficiency of neonicotinoids might be impaired in the long term by their systemic use. Indeed, their application on all seeds might speed up pest resistance. This issue might be worsened by the wide use of the insecticide, which is broadening with the gradual expiration of patents.
Health and environmental benefits?
Secondly, neonicotinoids are claimed to be safer than the insecticides they replace, such as the highly hazardous organochlorines and organophosphates. It comes first from the fact that they are supposed to target the nervous system of insects, which differs from the nervous system in mammals and other animals. They are therefore claimed to be safer for humans and the environment. In addition, seed-coating is seen as safer than spraying because it limits the environment and farmer’s exposure. The dust cloud accidents might however bring this claim into question.
Any decision to restrict the use of neonicotinoids therefore has to take into account the impact on the agrochemical industry, the economy and agriculture – in particular food production. In addition, it must consider the availability of a safer alternative. Indeed, situations where bee health would be obtained at the cost of human health or serious environmental destruction should be avoided. Restrictions are therefore complex decisions which require to balance essential and potentially contradictory interests. This is why they should be adopted only when there is a reasonable guarantee that they will effectively improves bee’s health.
2) What actions would effectively protect bees from neonicotinoids?
As discussed, neonicotinoids were placed on the market in the mid-90s under the condition that they would be used only at doses identified as not lethal for bees. Should they be authorised but submitted to stricter conditions? Should they, or some of their uses, be entirely prohibited? To be able to answer these questions, a public authority needs to have information on the routes of exposure and on the risks associated with each of these routes. Whereas the former are quite well known, the latter are the target of intense controversy which is partially due, as we will see, to the inadequacy of the risk assessment framework used to identify the impact on bees.
Understanding bee populations decline: the routes of exposure to neonicotinoids
The first route of exposure is the sowing process of neonicotinoid coated seeds. As we saw, the manipulation of seeds when sowing can indeed create a cloud of dust containing high level of insecticides. The cloud can be lethal for honeybees flying through it. What should the reaction be to this known risk? Should seed coating be prohibited? Should the sowing equipment and process be improved to prevent the creation of a cloud? Should sowing of coated seeds be allowed only at times and in locations identified according to bees needs; for example by avoiding blooming period or proximity to plants which attract bees?
The other routes of exposure are all related to food gathering and consumption. Foragers bring contaminated substances back to the hive which will then be used to feed the whole colony (through the form of pollen, jelly, honey, etc.). Firstly, honeybees will be exposed to the low neonicotinoid doses present in nectar and pollen of plants grown from treated seeds or soils, for example sunflowers and maize. However, treated plants are not the only contaminated ones. Neonicotinoids are very persistent. Depending on climate conditions, they can remain in the soil for more than one year. The residues can therefore be absorbed by the succeeding non-treated crop, but also by weeds and wild flowers growing in the area. Secondly, other sources of food can be a source of exposure. Guttation drops, the “sudation” of plants like maize, can contain a high dose. Honeydew, the liquid secreted by some insects feeding on plant sap, might also expose honeybees to the chemical. Finally, high fructose corn syrup, used as winter feed, can also contain low doses of neonicotinoid.
Understanding neonicotinoids impact: the controversial low dose effects
The risk of exposure through food sources differs from the “cloud” accidents. Rather than an acute risk with quick lethal consequences, it involves a chronic exposure to low doses potentially causing cumulative, long-term and synergistic sub-lethal effects.
These effects are the point of contention which deeply divides or challenges scientists. Do neonicotinoids have low dose effects at all? Can low doses of neonicotinoids be linked to bee population decline and colony collapse disorder in particular?
Industry research tends to reject the responsibility of neonicotinoids and to emphasise the multifactorial causes. It also questions the relevance of laboratory studies (which found effects at low doses) and emphasise the positive results of their field studies. On the other hand, some public research found impacts of low doses on bees cognitive abilities (orientation, communication, foraging), in particular when looking at the combination of low doses from different sources, with deadly impacts for the hive. They also established a synergistic effect between neonicotinoids and certain fungicides, the combined exposure to which have adverse impact on bees (bees, like humans, can be jointly exposed to a chemical cocktail of more than 100 chemicals). Other studies showed a synergistic effect between neonicotinoids and bees pathogens or pests. Neonicotinoids are thought to weaken bee’s immune systems; therefore making them more vulnerable. They are also thought to reduce their capacity to produce the enzyme used to sterilise jelly; opening the hives to infection. Furthermore, bees affected by pests and pathogens need more energy, therefore they consume more food, leading to exposure to a higher dose of chemicals. However the results of these studies are denounced by the industry as not being ground in “sound science”. The core of the debate does not focus on the results per se, but on the methods used to obtain them. The knowledge on the bee/neonicotinoid relations is highly dependant on the risk assessment framework used to analyse the impact of the chemicals. The determination of this framework is therefore a highly strategic, politicised and lobbied process. It has resulted in the inadequacy of the methods used to deliver the scientific knowledge grounding the first authorizations of neonicotinoids.
The fuel of scientific controversy: an inadequate risk assessment framework
The scientific debate on bees is poisoned by an unsuitable and out-dated risk assessment framework which focuses on:
– the determination of the lethal dose rather than chronic, long-term and sub-lethal effects;
– on the identification of a causal link between one source/one effect rather than combined and synergistic effects;
Furthermore, the risk assessment framework was created for sprayed chemicals and is therefore not adapted to the specific risks of seed coating. These weaknesses, recognised by EU authorities, are resulting in ignorance on the long term and chronic effects of neonicotinoids, as well as on their cumulative and synergistic effects. The scientific debate is also made even more complex by the fact that field studies on bees & chemicals are extremely hard to organise in light of the foraging radiance. How can the substances to which the bees are exposed be precisely controled? How can it be ensured that the control group is not exposed to any chemicals? However, some new approaches, involving radio-frequency identification equipment attached to each forager, might help to obtain a real life vision of the multifactorial causes of bee populations decline.
For public authorities, however, these questions remain: How can they justify a restriction to economic freedom when faced with contradictory research? How do they justify such a restriction when the neonicotinoids are known as not being the sole cause and are not, for certain, the main cause of bee populations decline?
3) Are the actions taken so far appropriate?
Several principles are supposed to guide EU public authorities in their decision making process in risk regulation.
– Prevention principle: environmental actions should, as much as possible, prevent the risk rather than react to its consequences;
– Proportionality principle: the action should not be more restrictive than necessary to achieve the objective pursued;
-Precautionary principle: this principle provides a justification for public action in situations of scientific complexity, uncertainty and ignorance, where there is a potentially serious or irreversible threats to health and/or the environment. The risk cannot be purely hypothetical, public authorities have to justify their decision using an appropriate strength of scientific evidence.
EU institutions and Member States have to respect these principles. The US recognises the first two, but has a different approach to precaution than the EU. The variety of reactions to the bees/neonicotinoids controversies shows the complexity of the identification of the appropriate public action on the matter.
– The US has not adopted any restriction but is actively promoting research to further understand the multifactorial causes of bee populations decline.
– Germany recommended best practices and better information on sowing equipment and process in order to prevent the formation of toxic dust clouds. It also temporarily prohibited Clothianidin, a subclass of neonicotinoid.
– The EU (and therefore its Member States) has implemented, since 2013, a regulation (Regulation 485/2013) which prohibits the use of 3 neonicotinoids subclasses (Clothianidin, thiamethoxam, imidacloprid. Fipronil was recently added) as a seed or soil treatment for crops attractive to bees and for cereals (except winter cereals). For crops, foliar treatment (sprays) is authorised but only after flowering. For all the other plants, these 4 neonicotinoids can be used but their environmental impact has to be monitored. Only professional uses are authorised. Best practices have to be implemented for equipment and sowing processes.
Other neonicotinoids are not subjected to specific requirements.
Are these actions appropriate? Should they be more restrictive? Less restrictive? What are the alternatives?
Discussion questions:
- Should public authorities prohibit the usage of neonicotinoid insecticides despite their economic and societal benefits?
- Should public authorities prohibit the usage of neonicotinoid insecticides despite the contradictory scientific results related to their role in the bees population decline?
- Should public authorities prohibit the usage of neonicotinoid insecticides even though they are known as not being the sole cause of bees population decline?
- Are the actions taken so far appropriate? Should they be more restrictive? Less restrictive? What are the alternatives?
Indicative Readings:
- Maxim L., van der Sluijs J. “Seed-dressing systemic insecticides and honeybees” in EEA Late lessons from early warnings: science, precaution, innovation 369. http://tinyurl.com/oaflhfg
- Kleinman D.L., Suryanarayanan S. “Dying bees and the social production of ignorance” Science, technology & human values 4 (2012) 492.
- Reynard B.W. “The producer-pollinator dilemma: neonicotinoids and honeybee colony collapse”, 2012 http://repository.upenn.edu/mes_capstones/50/
