Covering Environmental Health When Science Is Lacking

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A man standing on a hillside observing a crop-duster flying over adjacent fields.
In 1978, as part of the U.S.-backed war on drugs, the Colombian government started air spraying coca and marijuana crops, without enough evidence of the potential risks the measure could pose on rural communities’ health. Archivo Fotográfico El Espectador


In September 1998, glyphosate rained down on a pregnant woman named Yaneth Valderrama. Valderrama was washing clothes in a creek in the rural area of Solita village, in Caquetá, a region in southern Colombia where thousands of coca plantations grew. For years, as part of a U.S.-backed “war on drugs,” the Colombian government had been spraying herbicides from airplanes in an effort to kill coca and marijuana crops.

When Valderrama, then 27 years old, heard the roar of the three planes’ engines, she ran towards her house. She didn’t make it, and the poison rain drenched her. Two days later, she had a miscarriage. She then fell severely ill, and six months later, she was dead. Her husband, Iván Medina Claros, remembers that the doctors who tried to help her told him to “get a good lawyer and sue the state, because they killed her with glyphosate.”

Twenty years later, in March 2019, Juan Miguel Hernández, then a reporter for Colombia’s El Espectador newspaper, was in Caquetá reporting a completely different story when someone tipped him off about Valderrama’s tragic death and her husband’s ongoing efforts for justice. A few weeks before his trip, Colombian authorities had proposed restarting glyphosate spraying, which had been paused since 2016. Hernández found Valderrama’s husband, and after talking and spending time with him and his family, the journalist was moved and convinced by the story. Hernández knew that the unknown story of a woman killed by glyphosate rain could completely change the public conversation. He called his editor in Bogotá and asked for more time to report.

When he came back to the newsroom, he told the story to his colleagues at the science desk. One of them, María Mónica Monsalve, remembers that Hernández and the videographer who accompanied him on the trip, Oscar Guesguan, “were convinced that glyphosate had killed Yaneth.” Monsalve, who had been researching the scientific literature about the health effects of glyphosate as part of her coverage of the ongoing public debate, challenged her colleagues’ position. The available evidence about the chemical didn’t support such a firm conclusion, she told them.

Suddenly, what seemed like a straightforward story—of harm, of injustice, and of clear cause and effect—became much messier. How would Hernández write about the uncertainty and unanswered questions that surrounded Valderrama’s death?

Many journalists covering environmental health issues in neglected and highly vulnerable communities face similar obstacles. They may find themselves in the same confounding situation: A person or community has experienced illness or injury that they trace to some kind of environmental pollution, often at the hands of rich and powerful actors. And yet no scientific data exist that can directly support their claims.

“These stories are really tricky because you need to recognize that absence of evidence is not evidence of absence.” —Dan Fagin

Reporters find themselves balancing different concerns: They want to expose injustices (and sometimes outright crimes) and to highlight the struggles of sick and often marginalized people, but they also don’t want to draw incorrect conclusions about complicated situations. “These stories are really tricky because you need to recognize that absence of evidence is not evidence of absence,” says Dan Fagin, whose Pulitzer Prize–winning book, Toms River: A Story of Science and Salvation, covered the investigation of a cancer cluster caused by industrial pollution. “Just because we don’t have evidence doesn’t mean there isn’t some kind of causal thing going on. But it’s also true that just because there is evidence doesn’t necessarily mean that there’s causation.”

For more than 20 years, Fagin has taught environmental journalism at New York University. He says that the top mistake students make when considering stories about environmental damages to human health is to not cover them at all—to be intimidated by the burden of proof and back off, leaving an important story untold. “The answer with environmental health stories is never, ‘I’m not going to cover this because the evidence is weak,’” he says. Instead, it’s to rely on deep empathy, rigorous reporting, and healthy skepticism at every step of the way.


Where the (Polluted) Wind Blows

Many investigations about environmental health impacts begin with rumors and anecdotes, local reports from people who have noticed a change in their health and suspect they know why: A nearby mine is filling the air with asphyxiating particles, a monoculture farm is discharging its wastewater into a river, a local factory is producing toxic tailings. Finding these stories requires acute attention to what can seem like prosaic and disjointed details about the life of a community.

Many times, reporters find environmental health stories while looking for other things, says Nitin Sethi, an Indian investigative reporter and editor of the independent project The Reporters’ Collective. “I know dozens of [journalists] in India who first come to know of a problem because of the social consequences of the environmental damage,” he says. “A friend or a source or somebody we know in a village area will call us and say, ‘Look, in our place all our young males have disappeared to the cities to work because agriculture is not taking place.’ … I think a preponderance of times when you land up in these villages, you find there’s a concrete reason why agriculture didn’t take off.” That reason could be a coal plant in people’s backyards, or other polluting projects near their villages, Sethi says.

Other journalists, like South African environmental writer and editor Sipho Kings, dig clues from companies themselves. “When a large, polluting company released great financial results, I would read into them and just go to the community next to them and talk to people,” he wrote in an email. “Profits so often come about because shortcuts are taken, and those shortcuts manifest in externalities and a polluted environment.”

Talking to those communities should always be the first step, Fagin says. He listens to personal stories while also gently asking for any medical records or legal actions that can support the claims. When he wrote Toms River, talking to people whose children had been diagnosed with cancer after drinking the river’s polluted water helped him figure out what he would ask when he began questioning companies and governmental agencies.

During this early reporting stage, Sethi also makes a point of visiting nearby communities, so he can compare them to the one where he suspects that contamination is affecting people’s lives. If those nearby communities, with essentially the same geography and ecology, are thriving in comparison with the potentially polluted area, then he starts having more confidence about the case. He then moves on to look for outside sources and scientific evidence.


Giving Up the “Smoking Gun”

It is while looking for scientific evidence to back up the claims of affected communities that things tend to get messy for environmental health reporters.

Studies on health impacts of certain chemicals or pollutants are often limited to lab tests with animals, which don’t necessarily help in understanding how a chemical could affect human bodies. Other times, there is no research at all. In cases about exposure to a new chemical—such as when vaping devices were newly available—the problem could be the contradicting findings, says Inside Climate News investigative reporter Liza Gross. Other times, it can be difficult to sort out straightforward cause and effect when there are a variety of pollutants, or when contamination is longstanding.

“You can find all sorts of things in the scientific literature,” says Gross, who always follows her visits to potentially affected communities with a deep dive into any available literature about an issue. But, she cautions, “you need to know how to evaluate what is really [a] reliable conclusion based on data versus what is just pure speculation. So I’ve long relied on scientists I trust who can sort of help me make sense of the literature.”

While reporting in India, says Sethi, a frequent challenge is the extent and complexity of the pollution that communities face. “There are times when we’ve been in areas where there has been coal mining, there’s been an aluminum plant, and maybe five other things. And you really can’t narrow it down to say, ‘this is the source of the problem.’” However, Sethi still feels it’s important to report on the communities’ suffering, even if he can’t prove the direct reasons for it. “I would say in 20 years of my career, it wouldn’t be more than a fourth or a fifth of the times when I’ve written on something where there has been hard evidence” directly linking a harm to a specific cause.

A community’s experience is a form of evidence, but not the only one, Fagin says. You can report out the claims and the scientific possibilities, but the end goal is to explain to the reader what is known and provable and what isn’t.  That’s why, for Fagin, speaking early with all parties involved is critical.

After a first round of interviews with the community, he questions the companies and government officials about specific complaints people pose. (Is the increase in cancer cases being systematically monitored? Why didn’t the company start better cleanups earlier?) He then uses those answers to go back to the community and independent experts and ask new questions. He repeats this process of “cross-fact-checking” sources enough times to put together the pieces of the evidence puzzle and see where the holes are. “The goal is to narrow the areas of actual disagreement, which ultimately allows me to be very clear in the story about what’s still in dispute instead of having to fall back on vague sound bites,” Fagin explains. Once those holes are clear, it is easier for him to write about them.

Reporting until you feel comfortable explaining the “gray area” is the first step to success, says Liza Gross.

For Gross, reporting until you feel comfortable explaining the “gray area” is the first step to success. She wrote about vaping before it was a national crisis, and about flame retardants when they hadn’t yet been regulated in California. In most of her stories, she says, she doesn’t necessarily expect that there’s one piece of evidence that will “prove” who’s right. Instead, she focuses on exploring and communicating the unknown, the possible harms, and the search for answers.

This is the approach Hernández and Monsalve took in the award-winning short documentary they produced about Yaneth Valderrama’s case, which was taken up by the Inter-American Commission on Human Rights (IACHR). Most of the existing research about glyphosate toxicity analyzes the chemical when it’s used as instructed. The large aerial spraying that happened to her was not a recommended use, and there were no studies about what could happen if a human were to be doused with the herbicide.

Even if there were, Monsalve says, there are lots of variables that could affect the outcome: “Toxicity and carcinogens are not absolute. So we tried very hard to explain that.” They worked with the graphic designers at the newspaper to create graphic explanations of why it was so hard to prove that Yaneth’s death was caused by glyphosate.


Sit in the Mud, Follow the Money

A lack of evidence can be frustrating for journalists. It can also, says Sethi, be a story in itself. He argues that all journalists should treat scarce or nonexistent data as a question to be answered: Why isn’t it there?

A friend of Sethi’s, a contractor for India’s forest service, once told him that his job was not just to protect the forest from threats that lie within. Instead, he said, “My job is to stand on the edge of the forest, looking outside and outwards.” Sethi thinks of this often in his work as a journalist, he says: “I think a journalist is like that—you’re supposed to stand on the outskirts, looking at those who influence that space rather than just what’s happening to that space.” If data are missing or studies aren’t done, he questions who is responsible for producing the science and why it’s missing.

Whenever he’s reporting a story on environmental health issues, Sethi estimates that he spends two-thirds of his time in government offices, befriending officials if he can, and looking for documents proving that the government, at some level, knew about the problem and was therefore obligated to act—but chose to do nothing.

If people in power have failed to protect the vulnerable, or even abetted their harm, Sethi says, he’s found a story.

He starts looking in local offices and goes all the way up, trying to figure out who is the highest-ranked person that knows about the situation and if they violated or changed the law to avoid doing something. “You have to sit amongst them, in the middle of the muck that you want to throw some light on.” If people in power have failed to protect the vulnerable, or even abetted their harm, he’s found a story.

For her part, Gross often employs the well-known mantra of “following the money.” She has been covering legislation around environmental hazards in California and other epidemiology issues for nearly 20 years, and many times, understanding how the money is flowing helps her reporting. In 2011, for example, she did a five-month investigation for Environmental Health News exposing that California legislators who opposed regulations for flame-retardant chemicals had received money from that industry. She did so by reviewing public databases about campaign financing. “You can’t say, ‘Oh, there’s the smoking gun’” that definitively proves why legislators let the industry off the hook, she says. “But you can say, ‘There’s a pattern.’”

As Hernández and Monsalve dug into archival documents about Valderrama’s death, they noticed that back in the ’80s, when the glyphosate fumigations were just starting as part of Colombia’s war-on-drugs strategy, the government promised to conduct studies about safety. The reporters couldn’t find the results anywhere, so they found the scientist in charge of those studies and asked him what happened. He told them that the government never finished the studies, though it told the public that it had. After that conversation and a couple of others with lawyers, Hernández and Monsalve realized that “it didn’t matter if [they could directly prove that] glyphosate had killed Yaneth or not,” as Hernández put it. “What matters is that the state didn’t meet its obligation to take care of one citizen, but on the contrary, put her at risk.”


Braiding Logic and Evidence

Unlike science stories that revolve around an unambiguous discovery, the majority of environmental health stories can’t give readers the satisfaction of a neatly solved mystery. Instead, journalists have to stitch the clues together while avoiding getting into opinion territory.

Fagin cautions that relying on their own “common sense” about what happened, rather than hard evidence of causality, could steer journalists into advocacy territory, defending a certain version of the story. That doesn’t mean that he advocates for a he-said-she-said approach, pitting the stories of impacted people against the denial of polluters, or simply letting people make sense of the information on their own. Instead, he relies on what he calls “the weight of the evidence.” After talking to all the sources and reading all the background information that he can, what conclusions can he draw? “You know you’re doing analysis and not advocacy when you are constantly thinking about the evidence and when you’re being totally transparent with readers about what you know and what you don’t know,” Fagin says.

For Sethi and Kings, writing is about presenting the facts in a clear way, and leaving it to the reader to see the links between them. “If you can bring people to that point—of saying, ‘If you just logically thought that A would mean B would mean C’—I’m quite happy doing that,” Sethi says. “I do like to rely on the intelligence of our readers and citizens to know the truth.”

For Hernández and Monsalve, relying on the evidence—or, in their story about Valderrama, on its lack—is vital. When they released their documentary, the discussion about re-starting the aerial spraying of coca crops was heavily politicized and polarized. Instead of being seen as weighing in on one side, Monsalve explains, they wanted to bring new information into the conversation.

Hernández says that he felt he’d achieved his goal when the doorman of his parents’ apartment in Bogotá asked him about the video. The man told him that he was worried sick about his brother, a police officer in charge of spraying the chemical. That was when Hernández knew, he says, “that science had allowed the documentary to transcend ideology.”



María Paula Rubiano
María Paula Rubiano A. Mateo Guerrero

María Paula Rubiano A. is a TON early-career fellow sponsored by the Burroughs Wellcome Fund and a freelance science journalist writing about biodiversity, environmental justice, food, and sustainability for ScienceYale Environment 360AudubonAtlas ObscuraEl Espectador, and more. Follow her on Twitter at @Pau_Erre.

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