Pesticide manufacturers are in close contact with both approval authorities and farmers. They could use their position to make farmers aware of problems that can arise from pesticide misuse. It is not that industry is doing nothing. It just needs to do more.
Professor Ralf Schulz
Researchers from the University of Koblenz-Landau have discovered that the insecticide concentrations actually
found in our water are often higher than the calculated theoretical
values that form the basis of the official European Union approval process. To protect water safety, therefore, the scientists have called for approval authorities to bring their processes up to speed with the collected evidence.
Since the late 1990s, mathematical simulation models known as FOCUS models have been used to predict pesticide concentrations associated with agricultural practices. Pesticides are only approved for use in Europe if their predicted concentrations fall short of ecologically critical effect thresholds. However, the new evidence suggests that the actual and theoretical values of pesticide concentrations in European water are often incongruous.
When farmers treat crops with pesticides, they can be washed by rain into nearby surface water. In high concentrations, pesticides can negatively affect species that live in such waters. The team compared the measured and predicted values of 122 cases, but found no relationship between the values. Moreover, the actual values outweighed the theoretical ones in up to 40 per cent of cases, and with newer insecticides, these percentages were even greater.
I spoke to Professor Ralf Schulz, one of the study’s authors from Landau’s Institute for Environmental Sciences, to find out how we can better protect European water safety…Could you outline some of the negative effects that high pesticide concentrations in water can have on the environment?
We looked at insecticides in particular. Essentially, non-target organisms living in surface water can be negatively affected by insecticides. The population densities of some species might decline, whilst others might even be wiped out altogether in the long-run.
We conducted a study in this area fairly recently and there have been other research projects that have examined the makeup of communities occurring in surface water. When you examine the community composition of different species living in a particular body of surface water and you look at potential pesticide contamination, you can clearly see that even at regulatory acceptable levels in European surface waters, there are negative effects. Of course, there is plenty of evidence to suggest that when concentration levels are above these threshold levels, organisms are negatively impacted.What measures can be taken to ensure that farmers comply with regulations for the application of pesticides?
One of the surest measures would be to ask farmers to stay 10m or 20m from the nearest surface water when applying pesticides. Even better would be to implement buffer strips with hedges or grass but no agricultural crops. In this scenario, farmers would not spray pesticides near surface waters because there would be no crops present. Theoretically, this would be the ideal measure to take; creating buffer strips that are of no agricultural use.
Implementing this strategy across Europe, however, would involve the removal of a lot of agricultural land. This would obviously be a highly contentious measure and I wouldn’t like to recommend it personally. Even so, there are tools that can be used to identify contamination hotspots, and in these areas, non-agricultural buffer strips could be implemented. I would like to emphasise that our study focuses mainly on the shortcomings of the assessment process. Basically, predicted concentrations are often too low.You have suggested that as a precautionary measure, the environmental concentrations of insecticides predicted within the scope of the approval process should be increased by a factor of 10. Would such a measure outlaw the use of a significant number of pesticides currently permitted within the EU?
I guess so but I must say that I haven’t looked at the figures. Approval for some insecticides would probably become particularly difficult. I don’t know the exact figures but I wouldn’t be surprised if this measure caused problems for some insecticides.What can pesticide manufacturers do to improve this situation?
Well they are the people who seek approval for insecticides and for pesticides in general. They are also the people who are earning a lot of money from these compounds. I think that they should therefore have a responsibility to behave proactively and to try to ensure that there are as few negative consequences as possible. Pesticide manufacturers are in close contact with both approval authorities and farmers. They could use their position to make farmers aware of problems that can arise from pesticide misuse. It is not that industry is doing nothing
. It just needs to do more
.How have the approval authorities responded to your findings?
I haven’t yet received feedback from European authorities because our results have only recently been released. I was, however, in contact with Germany’s national authority, Umweltbundesamt (UBA), and they have said that they will consider our findings when deciding upon best practice in the future. They also mentioned that at a national level, the registration processes for certain pesticides may be slightly different from the ones at European level. Normally, each pesticide is registered at the EU level and only afterwards can it be approved for national use. Each nation employs slightly different approval processes so they must each check whether or not their processes are leading to problems. If we are to effectively address ensure water safety, action must be taken by both national and European authorities.