Poison in the water
By law, drinking water suppliers in Brazil are responsible for testing 27 pesticides every six months in the systems they manage and reporting the results to the federal government. All the test results are then compiled in a database called Sisagua. Through a freedom of information request, Public Eye accessed a government database of drinking water monitoring from 2014–2017.
The usual suspects
It is clear that only a fraction of the pesticides currently in use in the country are monitored. But according to the Ministry of Health, the 27 monitored pesticides were selected on the basis of their level of use, the likelihood of their ending up in drinking water and their toxicity. This approach of targeting a reduced number of substances is in line with what is recommended by WHO and what is being done in the EU or the US.
Twenty-one of the 27 pesticides are on the PAN list of highly hazardous pesticides; eleven of them are listed because of their proven chronic hazards to human health. Seven pesticides covered by the monitoring program are no longer authorized for use – some were even banned in the 1990s – but continue to be tested because they are extremely persistent. At least one of these – DDT, a likely human carcinogen and an endocrine disruptor – is a legacy from Syngenta.
Of the 20 pesticides that are still authorized for use and are monitored in drinking water, seven are currently sold by Syngenta in Brazil. Five are listed by PAN as “highly hazardous”. Among them are four substances listed for their high chronic hazards to human health; atrazine, a reproductive toxicant and endocrine disruptor according to USEPA and the EU; diuron, a likely human carcinogen according to USEPA; glyphosate, probably carcinogenic to humans according to IARC; and mancozeb, a likely a human carcinogen according to USEPA and an endocrine disruptor according to the EU. Confronted with these facts, Syngenta wrote: “We do not consider the active ingredients mentioned in the question to be highly hazardous”.
Contaminated drinking water
Pesticide residues were found in 86% of drinking water samples tested. A total of 454 Brazilian municipalities, with a population of 33 million, detected pesticide residues in their drinking water above the legal limits at least once during the four-year period. Overall, the level of contamination of the drinking water in Brazil is far higher than what is found in the EU or Switzerland. While in the EU only 0.1% of drinking water samples exceed the limit of 0.1 micrograms per litre, in Brazil 12.5% of test results found residues of pesticides above this concentration.
Atrazine is one of the most frequently detected substances. This herbicide is classified as an endocrine disruptor and a reproductive toxicant. It was banned in Switzerland and the European Union over ten years ago because of water contamination. But Syngenta continues selling it in Brazil where it is found in 85% of drinking water samples tested.
The limits in the Brazilian legislation are mostly taken from WHO guidelines for drinking water quality. Of great concern is that the entire process takes place behind closed doors and is heavily influenced by the pesticide industry. Further, the studies the regulators rely on are confidential and typically conducted by, or on behalf of, the pesticide companies. The studies look at the effects of one pesticide at a time, and do not take into account the “cocktail effect”, i.e. the fact that people are exposed not to a single substance but to a mixture of pesticides that can interact and have additive or synergistic effects. Also, in many cases “we simply don’t know enough about the substances to establish those limits”, explains Dr. Wanderlei Pignati, a professor at the Federal University of Mato Grosso.
This is a main reason why the EU chose to adopt a uniform low limit in drinking water applicable to all pesticides. There is now a growing body of evidence that chemicals – in particular endocrine disrupting ones – can act at very low doses, and that the current methods of assessing these chemicals are out-of-date and grossly inadequate in determining “safe” levels of exposure. It should also be emphasized that the limits for pesticides in drinking water set in Brazil or by the WHO are based on an average adult person, and so do not provide adequate protection for pregnant women and unborn or young children, particularly vulnerable
populations facing exceptional risks.
A cocktail of pesticides
A major concern is that a cocktail of 27 toxic substances is regularly found in the drinking water of Brazilian municipalities. Seven of these substances are currently sold by Syngenta in Brazil. 1,396 municipalities, with a combined population of over 85 million, detected traces of all 27 pesticides in their drinking water during the four-year period. All these substances interact and can have additive – or even synergistic – effects. The unsettling conclusion is that millions of Brazilians are exposed to a cocktail of pesticides in their drinking water that has never been tested, and the effects of which remain largely unknown.
These results are even more worrying considering the relatively low level of testing. Our analysis shows that despite legal requirements, an average of only 31% of Brazilian municipalities submit drinking water test results each year to the federal government. Only 3% tested the 27 pesticides twice a year during the four-year period. It therefore appears likely that the monitoring programme misses peak concentrations that generally occur after the pesticide application. While there is generally more testing in the states with the highest pesticide use, this is not the case in Mato Grosso, the number one user of pesticides, where only 24% of municipalities submitted at least one test result during the four years.
The costs of monitoring
Millions of Brazilians are thus exposed to water contaminated with residues of highly hazardous pesticides. We estimate the cost of the completed monitoring process at about USD 2 million per year, paid for by water providers, municipal and federal authorities, and ultimately the general public.