Pesticides: the dark secrets of the Guadiana river

Credit: Creative Commons
The Guadiana river flows through the city of Badajoz, Extremadura.

The plains of the Guadiana and its tributaries have been used to produce cereals, olives, honey and fruit for almost two thousand years. Ildefonso Cabanaillas and farmers like him have relied on the river’s irrigation ever since Roman Emperor Augustus found present-day Merida in Spain’s Extremadura region.

A tomato and maize producer, Cabanaillas and the association of small farmers (UPA) in Extremadura are facing very different conflicts to their Roman predecessors, however. “We are fighting with unequal weapons every year,” he tells IE from the group’s headquarters in Badajoz, a city on the banks of the Guadiana.

“Before, with two or three products we had everything under control, and now we need to make various combinations of pesticides [to have the same effect], which makes everything more expensive. It’s almost as if the pests already have a shield.”

Fellow tomato farmer Jose Delgado is equally disgruntled. “We are paying the price for everything,” he says. “And the situation started when traceability began to be imposed.”

Delgado says he already keeps a “harvest book” to ensure all his produce meets EU sanitary and environmental rules. And while supportive of sustainability initiatives, he fears the costs of new binding EU regulation aimed at reducing pesticide use. “I think it’s great,” he adds. “But who’s going to pay for it? Are our products going to be worth more?”


Credit: Paulo Pena
Farmer Jose Delgado in Extremadura.

Spain spent more than €1 billion on pesticides in 2017, making it Europe’s third largest market. At the same time, costs have skyrocketed. EU data shows an 80 per cent rise in overhead costs for farmers like Delgado and Cabanaillas in the past decade. Across the border, Portugal’s farmers are also angered by rising costs and dwindling profits. Many have recently taken to the streets to protest, using the slogan: “We want to produce!”

While farmers all along the Guadiana contend with rising prices and a wave of EU measures, ecologists are trying to uncover the true extent of the river’s pesticide problem.

‘Extensive’ contamination

Today, a cocktail of toxic substances flow through the Guadiana, which stretches more than 800 kilometres from Portugal’s Alentejo region up through inland Spain. A study released earlier this year assessed that contamination in the river was “extensive” and that urgent measures were needed to rectify it.

The analysis of government data by NGO Ecologistas en Acción found “approximately 22 per cent of the substances analysed in the water matrix used quantification limits higher than those indicated by the Water Framework Directive and Spanish regulations.”

Underground waters containing traces of the toxic pesticides malathion, atrazine, chlorpyrifos and mercury were all identified. Meanwhile, glyphosate, the world’s most widely used weedkiller, linked to multiple health problems, was found in the largest quantities.


Credit: Creative Commons
It is hoped a planned EU law on pesticide reduction will drastically cut chemical use across Europe.

Statistical secrecy

Despite the analysis, which was conducted for all of Spain’s rivers, the NGO says the original research was flawed. They claim it failed to analyse the impacts of 80 per cent of pesticides used in fields, meaning contamination likely goes much deeper.  

“I have been fighting in Spain for years for access to this data,” report co-author Koldo Hernández says. “What we have encountered is the so-called ‘statistical secrecy’ because member states can determine what can be public. In Spain, as in most European countries, the data is not real, it is only data obtained through surveys answered by the industry.”

Hernandez wrote an official complaint to the EU Commission Ombudsman Emily O’Reilly, requesting the government data be released. In March, O’Reilly delivered a damning response: “The Ombudsman finds it questionable that the Commission concludes that the principle of statistical secrecy takes precedence over transparency of information on emissions into the environment.”

The Commission invoked an exception under EU rules on public access to documents, saying that disclosure would “harm the commercial interests of the companies from which the data was collected.” In response to IE, O’Reilly’s office said: “We have observed that there is often a tendency [by the European Commission] to be too quick to discount the overriding public interest in disclosing the information in question.”

Lobby against reduction plans

EU data on pesticides is fragmented, often missing, and only collected every five years. It means thorough statistics on the Guadiana and Europe as a whole are scarce. A new regulation mandating member states to collect data for the first time is now planned, albeit only from 2028.

Petros Kokkalis, the Greek MEP rapporteur for the new so-called SAIO reform, says opponents wanted to maintain current regulations so the planned EU law on pesticide reduction – recently unveiled in Brussels – becomes harder to monitor. While those efforts failed, the lobby machine will likely ramp up again to fight the new reduction target plans.

The EU is already the “world champion of caution”, according to Igancio Huertas, head of the UPA farmers association back in Badajoz. When asked what he thinks has caused the toxicity in the Guadiana, he says: “We are not doctors or scientists.”

For Huertas, the major concern is dealing with excessive price rises. He uses the example of glyphosate. The highly toxic herbicide produced by Bayer’s Monsanto is no longer patented and can now be sold by dozens of other chemical companies. “It has practically the same chemical base, but costs about three times as much,” he says. “This is something that obviously generates a great deal of rejection and uncertainty for us.”


Credit: Creative Commons
UPA members attended the huge 20M Rural – Together for the Countryside protests in Madrid, March 2022.

Cabanaillas says farming is now impossible without chemical pesticides. Even with them, business gets worse each year. “The word profit in agriculture no longer exists,” he says.

The permanent dependence of Europe’ farmers on pesticides means few areas go untouched. A recent study said 85 per cent of pears and nearly 60 per cent of apples grown in Portugal are contaminated.

Be it the rice paddies on the banks of the Mondego, Tagus and Sorraia rivers “sprayed with pesticides by plane”, the fruit grown in western regions, or the olive and almond groves found by the Alqueva lake, which uses the Guadiana waters, the problem is country-wide, says Alexandra Azevedo from environmental group Quercus. But without data, the full picture of the impact on Portugal’s water, soil and land remains unknown. “We don’t know more because they don’t do analyses,” Azevedo says.

With such analysis missing, government secrecy persisting and ever-dependent farmers, pesticides will continue to seep into the ancient Guadiana plains and beyond. “Reducing the use of pesticides in Spain is going to be like separating a mother from her new-born baby,” Hernández says.