The rats were winning.
There were so many earlier this summer outside the CalEPA building in downtown Sacramento officials had to close its outdoor playground out of fear state employees’ kids would catch rodent-borne diseases.
To fight back, building officials set out a controversial type of rat poison whose use may soon be banned statewide by the California Legislature. The poison didn’t stay out very long once word got out the state’s top environmental regulators were using a poison widely condemned by California’s powerful environmental groups.
“Effective immediately, I’m putting a moratorium on the use of rodenticides around the 1001 I Street Building, “ CalEPA agency undersecretary Serena McIlwain said on June 19 in an email to staffers. “We will continue to monitor the situation daily and will work aggressively to find effective, less toxic alternatives.”
The rats-versus-pesticide fight at the building that houses the Department of Pesticide Regulation couldn’t haven been more carefully designed to highlight the complexities of two budding crises in California.
The state is seeing a troubling resurgence of rodents, which can carry a wide array of diseases that have been around since the Middle Ages. The megalopolis of Los Angeles County, for one, has seen skyrocketing cases of one such disease, typhus. At the same time, researchers are finding widely used rodent poisons at sometimes lethal levels in the bodies of beloved California predators such as birds of prey and mountain lions.
Remarkably, anticoagulant rodenticide have been found in almost all of the mountain lions tested in California. Each year, the state Department of Fish and Wildlife performs dozens of autopsies known as necropsies on mountain lion carcasses. Nine out of every 10 cougars tested have traces of anticoagulant poisons in their livers.
As a result of the widespread wildlife poisoning, nearly every prominent environmental group in the state is advocating for a ban on anticoagulant rodenticides.
The needs of native wildlife appear be winning in this overwhelmingly liberal, environmentally conscious state. The California Legislature is poised to ban the toxins over the objections of well-financed chemical industry lobbyists and pest control operators, apartment owners and restaurateurs wary of rodent infestations.
But the rat infestation combined with a pesticide ban is no laughing matter to some experts, who say a disease outbreak similar to the one in Los Angeles could happen in downtown Sacramento if rats such as those infesting the CalEPA headquarters aren’t kept in check.
“When you’re at the stage where you have to close down your playground because you’re worried about exposing children to rats and the disease they harbor, you need to use your full arsenal,” said Niamh Quinn, a scientist who studies rodent infestations at the University of California Cooperative Extension.
Environmentalists say there are other options to manage the state’s pests, such as making cities more sanitary (rodents are often drawn to the trash from the state’s growing numbers of homeless encampments, some experts say) and by using pesticides that are less likely to contaminate wildlife.
Environmentalists say the scientific evidence is clear: anticoagulant rat poison seeping into the environment is harming wildlife in all corners of the state.
In the rugged northern forests, rat poisons used to protect marijuana grows have been found in Pacific fishers (a weasel-like predator) and in northern spotted owls. In 2017, a San Francisco coyote died from internal bleeding caused by the toxins. And in Southern California, rodenticides are playing hell on a fragile population of mountain lions in the bushy foothills above Malibu’s celebrity mansions.
“We’ve seen exposure everywhere we’ve looked,” said biologist Laurel Serieys, whose research at UCLA found that Southern California bobcats were suffering from severe mange outbreaks tied to rodenticide contamination.
Mangy, sickly cougars
In 2017, federal researchers in the Santa Monica Mountains above Malibu were thrilled to discover two spotted kittens — a male and female with striking blue eyes. They were the heirs of a famous father.
A couple of years earlier, the cubs’ father, a male 150-pound cougar labeled by researchers as P-45, had crossed the 101 freeway. Scientists hoped P-45 would inject critically needed genetic diversity into an isolated, increasingly inbred population of a dozen or so lions hemmed in by deadly freeways.
Like his father, the male kitten was fitted with a tracking collar to study his movements as part of a years long research project that tracks the Los Angeles County cats.
When they recaptured the young male they’d named P-47 in January 2018, biologists were pleased to see he weighed as much as his father, a healthy 150 pounds — making them the two largest cougars recorded in the 17-year National Park Service study.
The biologists hoped P-47 would soon begin breeding. Those hopes died in March of this year, when P-47’s collar sent out a “mortality signal.” When the biologists found the dead cat, they discovered he’d survived the punishing wildfires that ripped through the area last fall only to die an agonizing, slow death from internal bleeding caused by rat poisons.
It’s not clear how he ingested the toxins, but the National Park Service said a test of his liver found that P-47 was contaminated with six different rat poison compounds, including the four “second generation anti-coagulant rodenticides” that would be banned across California under the bill making its way through the state legislature. (One of the second generation poisons in P-47 was Bromadiolone, the same poison initially deployed at the CalEPA building in Sacramento.)
Such poisons are known as “second generation” because they were developed after rats and mice began evolving immunity to the first kinds of anti-coagulant toxins that had been formulated prior to the 1970s. The newer versions are more powerful, and can cause fatal internal bleeding in rats and mice up to five to seven days after a single feeding.
First-generation poisons kill rodents in around the same number of days as the second generation varieties, but because they use a less potent toxin, they usually require rats and mice to come back to the bait multiple times to get a lethal dose, according to the US Environmental Protection Agency. The first-generation toxins can also be harmful to non-targeted animals. (The other two compounds in P-47’s system were first-generation varieties.)
The poisons spread up the food chain from predators eating rodents during the five- to seven-day window it takes them to die.
This secondary contamination works this way: A rat eats the poison and is sickened and disoriented. It stumbles out in the open where it is easy pickings for a coyote. That coyote later is eaten by a mountain lion. The dose may not be fatal to the cougar, but the toxin stays in its body, building up over time. The contamination can last for years, and research suggests it can even leapfrog in utero from an animal to its offspring.
Most animals contaminated with the rodenticides usually appear otherwise healthy, but in some cases the effects of built-up poison becomes noticeable. For instance, scientists have been finding disturbing numbers of cougars and bobcats in Southern California that have developed cases of mange as their immune systems become compromised by the poisons.
The most famous cat to come down with mange linked to rat poison was P-22, a male mountain lion that lives in LA’s Griffith Park. His image was captured in an iconic National Geographic photograph as he strolled past the Hollywood Sign. In 2014, biologists captured him, found poison in his blood and treated him for mange. Before releasing him, they snapped a pitiful photo of his mangy face that was widely shared by anti rat poison activists.
P-22 has since recovered.
Banning these poisons has been a difficult task, even in environmentally conscious California. Tired of mountain lions getting poisoned in his district, Assemblyman Richard Bloom, D-Santa Monica, has for half a decade tried to pass legislation that would ban the second-generation poisons and limit the use of the first-generation varieties.
But of the five rat poison bills Bloom’s introduced since 2014, only one — a 2014 bill that prohibited their use in state wildlife areas — passed.
The bills met fierce opposition from pest control companies, the California Chamber of Commerce, apartment owners, food processors, restaurant associations and other industry groups wary of rodent infestations.
Reckitt Benckiser, a company based in the United Kingdom that makes rodent poison under its d-Con brand, spent about $1.2 million lobbying state leaders and officials during the last decade, according to forms submitted to the California Secretary of State. Pest Control Operators of California spent about $550,000 on lobbying state leaders and officials during the last decade.
Yet this session, thanks in part to the outcry over P-47’s death, Bloom’s Assembly Bill 1788 passed the Assembly on a 49-16 vote. It could be voted on in the Senate in the coming weeks.
In its current form, Bloom’s bill would only allow government officials to use the second generation rodenticides “for public health activities” and it could be applied in certain “agricultural settings” including food production sites, factories, breweries, or wineries.
The only other exemption in the bill allows for the poisons to be used to manage rat and mouse infestations to protect sea birds and other wildlife on offshore islands, such as the Farallons.
Almost 30 miles offshore from San Francisco, the Farallons have some of the highest densities of nonnative mice anywhere in the world. There are so many, the ground at times can appear to ripple from the mass movement of their tiny, brown bodies. Because hungry mice are a serious strain on the islands’ fragile ecosystems, the U.S. Fish and Wildlife Service has proposed dumping 1.5 tons of rodenticide, over the objections of some environmental groups.
Otherwise, the bill completely bans all second generation poisons, and it prohibits the use of first-generation rodenticides on state properties.
“This bill will make significant progress in preventing our wildlife from incidental poisoning while ensuring the public health of residents of California is protected,” Bloom’s office said in an emailed statement.
But Bloom’s office acknowledges AB 1788 is “not a panacea.” The bill wouldn’t address rodenticide use at illegal marijuana grows, and the products would still be widely used at agricultural sites where wildlife can easily be exposed.
The ban also would mostly affect people specially trained to use the poisons. In 2014, state pesticide regulators prohibited California stores from selling second-generation poison baits to anyone without a special license, though the baits remained widely available online.
Rodent control professionals say it’s already difficult for them to keep 39 million Californians safe from rodents and the diseases they carry, particularly in low-income communities and around homeless populations.
“If you live in an area where there’s substandard sanitation and substandard housing, through no fault of your own, that’s a challenge,” said Chris Reardon, a former official with the Department of Pesticide Regulation who now advocates for the for Pest Control Operators of California.
Typhus cases appear to be the only rodent borne disease to be on the rise, according to the most recent data available from the California Department of Public Health.
But Reardon said urban rodent populations have exploded since the drought, likely due to winter flooding pushing the rodents toward cities.
If they aren’t knocked back using rodenticides, pest control professionals ask: how long before the state sees a spike in the plague or hantavirus — deadly diseases that sometimes pop up in California?
Of the 73 people who have caught hantavirus in California since 1993, nearly one out of three have died, health officials say.
“We believe this is a public health issue,” Reardon said. “And so you look at rodent control and the tools we currently have in California they’re relatively limited anyway.“
The pesticides that would be banned have antidotes to treat children and pets if they accidentally consume the poisons. Critics of Bloom’s bill say the alternative types of highly lethal poison baits generally don’t have such antidotes.
‘I could actually die from this’
For Quinn, the University of California rodent expert, there should be just as much concern about the alarming increase in typhus cases popping up in Los Angeles County as there are about the mangy mountain lions prowling the Hollywood Hills.
“If you’re a mountain lion biologist and one of your precious mountain lions dies in the Santa Monica Mountains, that’s a huge deal, but if you’re me, and you’re in a classroom, and a maggoty rat, or multiple maggoty rats, are falling down out of the ceiling, that’s also a huge deal,” she said. “There has to a be a middle ground somewhere, and a middle ground is not a complete ban on the use of anticoagulant rodenticides, but it more than likely will be.”
Low levels of typhus, a bacterial infection spread by fleas carried by rats, cats and opossums, has always been found in Los Angeles County. But from 2013 to 2017, the average number of reported cases doubled to nearly 60 cases per year, excluding Long Beach and Pasadena, according to the Los Angeles County Department of Public Health.
Then, last year, the infection reached near crisis levels.
In 2018, the county tracked a total of 109 cases of flea-borne typhus, including 19 cases in downtown Los Angeles. Eight of the downtown cases were homeless people, according to county health officials. Those figures don’t include Pasadena and Long Beach, which saw an additional 39 cases.
Typhus is rarely fatal with treatment, but it’s certainly miserable. The Centers for Disease Control and Prevention says infected people can suffer fever, body aches, muscle pain, vomiting, coughs and rashes. In severe cases, the infection can damage a person’s liver, kidneys, heart, lungs, and brain.
Elizabeth Greenwood, a Los Angeles city attorney, says she caught typhus last year. She’s since filed a $5 million claim with her employer alleging she contracted the infection from the fleas on the rats that were attracted to the trash-strewn homeless camps around her City Hall building in downtown LA. (Pest inspectors would later find no evidence of the fleas, according to a February report to the city council).
Before doctors figured out what sickened her, she said she spent weeks at home so weak she could barely leave her bed. Her headaches were punishing.
She remembers thinking: “’This was the worst illness I’ve ever had. ... I could actually die from this. This is how bad I feel.’”
Following Greenwood’s claims, the city of Los Angeles in February and March set out at least 12 pounds of second-generation and first-generation rodenticides outside its city hall buildings, according to figures city officials provided to The Bee. This, despite the City of Los Angeles being one of the supporters of Bloom’s bill.
Greenwood has mixed feelings about the use of rodenticides. On one hand, she said she understands why environmentalists oppose using the the toxins because of the risk they pose to non-targeted wildlife.
On the other, typhus is no joke.
“If their child came home with this illness, I would imagine that most ... very staunch environmentalists would actually pause before they were quite so vehement (about banning the poisons),” she said. “Because it’s really bad. It does kill people.”
Bloom’s office said that because his bill would allow the use of rodenticides in public health emergencies, the city of Los Angeles could still deploy the poison in a future typhus outbreak.
“But, even in this unusual situation, the main solution is to provide better sanitation,” Bloom’s office said in its statement.
Better sanitation didn’t end up solving the rat infestation this summer at the CalEPA building in Sacramento.
McIlwain, the agency’s undersecretary who placed a moratorium on rat poison, rescinded her order less than two weeks later.
In a June 28 email to staff, she said efforts to trap rodents and clean trash weren’t getting the job done, so her office was planning to set out an “alternate” first generation poison, instead of the Bromadiolone originally deployed.
Under Bloom’s bill, those poisons both would be banned from use on state property.
Because no one actually reported falling ill to a rodent-borne disease, Bloom’s office said it was unclear whether the bill’s language would allow Cal EPA to cite “public health” and use the poisons for future infestations.
The bill makes no exceptions for when rodents overrun playgrounds.