Brazilian biologist Guilherme Malafaia Pinto now ranks highly on a list that no scientist wants to be on: the researchers who have had the most scientific articles retracted (when a published paper is withdrawn due to errors or misconduct). Pinto, a researcher at the Goiano Federal Institute (IF-Goiano), Urutaí campus, and head of its Laboratory for Toxicology Applied to the Environment, has so far had 45 articles retracted—all published in the same journal, Elsevier’s Science of the Total Environment (STOTEN). According to the Retraction Watch website, only 10 authors in the world have had more papers retracted than the Brazilian.
Retraction notes usually indicate the problem with the article, but in this case they simply stated that the peer review process—an analysis by experts that results in a recommendation to publish or not—was compromised. Malafaia, the corresponding author, gave STOTEN a list of suggested researchers who would be qualified to review the papers—whether or not to use these names was the prerogative of the editors. The problem was that for three of the named scientists, he provided fake email addresses.
The editors of STOTEN sent dozens of articles submitted by the biologist to these fake email addresses, receiving back well-written opinions that endorsed their quality. Although the manuscripts were also reviewed by other researchers chosen by the editors, Elsevier decided to retract them anyway, stating that they had “lost confidence in the validity/integrity” of the articles. All the retraction notes cite Malafaia as the person responsible for providing the email addresses, while the number of fictitious reviewers named for each paper varied from one to three.
Before the case came to light, the Brazilian made a name for himself as a young researcher with a high academic output: over the course of his 15-year career, he supervised 40 master’s students, 15 PhD students, and published almost 350 articles. He published 40 in the last year alone—one every nine days. On his résumé, he highlights his strong position in rankings of scientific output and citations. He also served on the editorial board of several publications, including as a volunteer at STOTEN, where he coordinated a special edition and reviewed more than 400 manuscripts for the journal.
When asked for a comment, Elsevier responded via its press office that the articles were brought to the attention of its integrity team by one of the journal’s editors, and that after confirming the use of fictitious emails, “the decision was made to retract the articles.” The publisher is working together with IF-Goiano, which opened a preliminary investigation at the end of 2024 and has six months to determine the biologist’s responsibility. The name of at least one reviewer whose identity was stolen was confirmed in an article in the journal Science. Toxicologist Michael Bertram of the Swedish University of Agricultural Sciences was contacted by Elsevier last year and said he did not recognize the Gmail account provided by Malafaia, nor did he have any knowledge of the 30 manuscripts he had supposedly reviewed. Bertram said he had not been given enough information to know who impersonated him, but he found the high number of articles published by the same group of authors to be suspicious. “They are extremely prolific,” he told Science. He also criticized STOTEN’s editorial processes. “I’m an associate editor at Proceedings of the Royal Society B and whenever I choose a reviewer, I always make sure to check their email address.”
Malafaia categorically denies having participated in reviews of his own articles or knowing who wrote the opinions. Despite acknowledging that he was the one who gave the email addresses, he claims he did so without realizing that they were fake. He says he took the names and contact details of the reviewers from a Chinese electronic scientific publishing platform called CNKI more than 10 years ago. When Elsevier asked him to show them the source of the information, he responded that he was no longer able to find it. “The journal required me to name six potential reviewers for each manuscript I submitted. Since I had already gathered the names, I copy and pasted the information into the articles without knowing if they would be used,” claimed the biologist.
In a 28-page open letter published in November 2024, the researcher defended his work and argued that the peer review problem did not benefit him, based on a statistically supported linguistic analysis that compared reviews of his retracted articles with reviews of his other papers that were not retracted. He thus suggested that less severe punishments than retractions should have been applied.
Léo Ramos Chaves / Revista Pesquisa FAPESP
Most of his argument emphasized the shared responsibility STOTEN had in the misconduct of which he is accused. “It was the editors’ obligation to check the email addresses. The journal didn’t want to take responsibility and made me a scapegoat,” he says. He highlights that the journal he worked for as an editor was recently accused of adopting unorthodox practices and that its editors are under pressure. In October 2024, Clarivate Analytics, which calculates the impact factor of scientific journals and compiles them in a list called the Journal Citation Reports, temporarily suspended STOTEN from its ranking due to concerns about the quality of the articles. The title publishes about 7,000 papers per year and its most recent impact factor was 8.2, higher than any scientific journal in Brazil.
Some of the journal’s editors, such as Damià Barceló of the University of Almeria in Spain and Daniel C. W. Tsang of Hong Kong Polytechnic University, have been criticized for being involved in networks of researchers who publish frequently in the journal, a practice known as “edit-for-pal.” In correspondence with Malafaia, Elsevier told him that the problems with STOTEN are “largely irrelevant” to his case. Following the retraction, the Brazilian biologist filed a complaint against Elsevier with the Committee on Publication Ethics (COPE), claiming that he was not given access to important information that would help in his defense. In response to COPE, Elsevier defended the need to retract the articles and said it was not accusing Malafaia directly of peer review manipulation, but only of having provided the fake email addresses. “I asked that the investigation be conducted based on concrete evidence that proves I was involved in reviewing my own articles and that technological tools be used to trace the origin of the opinions,” says Malafaia. “This was never done. Since there is no formal accusation against me of manipulating the peer review process, why would they do this check?”
In the open letter, he says the retractions “have had a devastating impact not only on my scientific career, but also on my personal life and on those around me.” Reputational damage is a concern for the more than 50 other authors listed on the articles. Many were Malafaia’s students, but his network of colleagues also included leaders of research groups from major universities. “I was approached by coauthors asking to remove their names from the articles and even requesting a statement that Guilherme did not know them personally,” says pharmacologist Ives Charlie da Silva, who is currently doing a postdoctoral fellowship at the Chemistry Institute of Araraquara of São Paulo State University (UNESP) and coauthored some of the retracted articles. “I responded to all of them that I trust the quality of the papers and that until it is proven that the manipulated reviews came from Guilherme’s computer, I will continue to side with him.”
Silva says he played a direct role in developing the collaborative networks that resulted in the articles. “Guilherme has a very active laboratory and knows how to ask good research questions. I have known him for over 10 years and have built bridges with researchers from various other states, inviting them to participate in studies, provide samples, and carry out parts of experiments or analyses according to their specialties,” he explains. In October 2021, the Pesquisa FAPESP website published a report that mentioned one of the studies that would later be retracted: an experiment led by Malafaia in which Silva was lead author, analyzing the influence of the SARS-CoV-2 virus on animals in aquatic environments. The coauthors included researchers from the University of São Paulo (USP), the Federal University of Goiás, the Federal University of Ceará, and the Federal University of Alfenas.
Dr. Luciani Silveira de Carvalho, head of the multiuser zebrafish unit (a fish often used in scientific tests) at the Animal Testing Center of USP’s School of Medicine (FM-USP), says that she began working with Malafaia’s network of collaborators during the pandemic. One of her PhD students, Bianca Ventura Fernandes, was invited by Silva to participate in a study on the toxicological effects of SARS-CoV-2 in zebrafish. When the article was ready, the student, responsible for some of the experiments, was a lead author. “They invited me to be a corresponding author because I was Bianca’s advisor, but I thought it was unnecessary. Ives then suggested that Guilherme sign as corresponding author, since the original idea was his, and since it would increase the chance of publishing the study in STOTEN, a journal with a significant impact factor in which he had already published several papers. We accepted immediately,” she recalls. The physician has defended the integrity of the article, and in a WhatsApp group of coauthors of the retracted papers, she has defended the researcher from IF-Goiano. According to her, the group is divided. “Some people were very critical, while others, myself among them, considered the retractions unfair. Others are on the fence.”
Malafaia continues to work at IF-Goiano. When asked for a comment by Pesquisa FAPESP, the institution said in a statement that the case is being evaluated by its ethics committee and an investigative committee. The institutions with which the coauthors are affiliated do not intend to get involved in the investigation. “In order to open any kind of investigation, we would have to receive a complaint, which we have not received to date,” says Edson Cocchieri Botelho, dean of research at UNESP, who plans to bring up the case for discussion at the ethics events that the university holds every year. Physicist Paulo Nussenzveig, USP’s dean of research and innovation, notes that the coauthors share responsibility for an article and all of them should read it and give their approval for its publication. “But appointing reviewers is specifically the responsibility of the corresponding author. They don’t need to consult other authors to do this,” he says. Nussenzveig highlights that knowing and trusting collaborators is essential to good research practices, although it is not always easy. “In very large networks, it is very difficult for everyone to know each other.” He deems it inappropriate, however, to use the fact that someone has a good relationship with a journal as a reason for choosing a collaborator. “I want to work with productive researchers who have innovative ideas and are capable of putting them into practice.”
Ecologist Daniel Brito of the Federal University of Goiás serves on the university’s academic integrity committee and teaches ethics courses to postgraduate ecology and evolution students. He says the repercussions of the retractions are bad for Brazilian science and fears that such episodes can undermine the public’s trust in scientists. “On the other hand, it also shows that science’s self-correcting mechanisms are working,” he says.
The rules for formulating the list of authors of a scientific article may vary depending on the field, but the most established convention is the Vancouver system, which states that the lead author—whose name appears first in the list and must be given when the paper is cited in other articles—must be the researcher who did the majority of the work. “This is the author who carried the study on their back, generally a postgraduate student or an early-career researcher who spent hours and hours in the lab working on the experiments,” explains Sigmar de Mello Rode, former president of the Brazilian Association of Scientific Editors (ABEC).
The last name on the list is the most prestigious position and belongs to the person who conceived of or supervised the research, generally the head of the laboratory or the advisor of the lead author. The other coauthors compete for intermediate positions, most commonly appearing in decreasing order of contribution. “The order of the author names is often the subject of intense discussion among participants,” says the former ABEC president.
Another important position is the corresponding author, who is responsible for submitting the manuscript for publication and responding to the editors’ questions and demands during the peer review process. There is no rule regarding who should be chosen for this role, but according to Rode, it ideally should not be the lead author, but rather someone who has a formal link with the institution where the experiments were conducted, such as the research group’s leader. “It shouldn’t be a postgraduate student, because they might leave a short time later,” explains Rode. Not all fields follow these rules. “The research leader may appear first in some humanities disciplines.” In large research consortia, whose articles may have hundreds of coauthors, one alternative is to list them in alphabetical order, but this is becoming rare, due to the desire to be transparent about the contribution made by each author.
The story above was published with the title “A cascade of retractions” in issue in issue 349 of march/2025.
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