After a plant suffers an injury, metabolites called terpenoids are released to enhance its defenses. A new study led by scientists from Tokyo University of Science (TUS) has found that rose essential oil (REO) has the ability to stimulate defense genes in the leaves of tomato plants.
REO also attracts herbivore predators that protect plants from moths and mites. Because of these effects, the researchers concluded that REO can be effective as a sustainable organic pesticide.
“[O]ur study showed that rose essential oil (REO), rich in β-citronellol, played a crucial role in activating defense genes in tomato leaves. As a result, leaf damage caused by herbivores, such as Spodoptera litura and Tetranychus urticae, was significantly reduced,” the researchers wrote in the study. “Our findings suggest a practical approach to promote organic tomato production that encourages environmentally friendly and sustainable practices.”
The bioactivities of EOs have been shown to be exceptionally safe and to benefit human health. In addition, they have been found to induce neurotoxic effects in insects, causing a repellent response.
Plant EOs have an abundance of terpenoids that are able to control defense responses in plants by regulating the expression of their defense genes. When komatsuna and soybean plants are grown near mint, they show a marked improvement in their defense properties that make them resistant to herbivores. This happens through “eavesdropping” — a process during which the mint plant releases volatile compounds that trigger defense genes.
“Today, applying chemical pesticides is the method of choice for crop protection, but the damage they cause to the environment and ecosystems, along with the need to increase food productivity, stresses the need for safer alternatives,” the press release said. “Thus, there is an urgent need for investigation of plant defense potentiators. In this regard, the availability of EOs makes them attractive candidates as environmentally friendly plant defense activators.”
The lack of enough proven EOs to meet demand presents a challenge, however. To address this issue, the research team looked at tomato defense responses activated by 11 EOs.
“EOs used as fragrances for various purposes contain odor components, which may have the ability to work like volatile compounds in conferring pest resistance. We aimed to investigate the effects of these EOs on plants’ insect pest resistance,” said professor Gen-ichiro Arimura of the TUS Department of Biological Science and Technology in the press release.
The research team profiled how EOs enriched with terpenoid affected tomato plants. They applied solutions diluted with ethanol from 11 distinct EOs to potted tomato plant soil. After studying the leaf tissue’s gene expression through molecular analyses, they found that REO boosted the levels of plant defense genes PIR1 and PIN2.
The tomatoes treated with REO also showed less leaf damage from Spodoptera litura moth larvae and Tetranychus urticae mites.
The team also measured REO activity in a field experiment. They found 45.5 percent less damage from tomato pests than the control. The researchers feel REO could act as an effective pesticide alternative during winter and spring when there is less severe pest infestation. In addition, they think it could potentially lower pesticide use by nearly 50 percent during the summer.
“REO is rich in β-citronellol, a recognized insect repellent, which enhances REO’s efficacy. Owing to this, damage caused by the moth larvae and mites was significantly minimized, confirming REO as an effective biostimulant. The findings also showed that a low concentration of REO did not repel T. urticae but attracted Phytoseiulus persimilis, a predator of these spider mites, thus exhibiting a dual function of REO,” Arimura explained in the press release.
The study, “Novel Potential of Rose Essential Oil as a Powerful Plant Defense Potentiator,” was published in the Journal of Agricultural and Food Chemistry.
The study demonstrated the capacity of EO enriched with β-citronellol in turning on the defense genes of tomato leaves. It also showed that REO effectively enhances plant defense in a safe manner that does not leave toxic residue or result in phytotoxicity.
“Our study suggests a practical approach to promoting organic tomato production that encourages environmentally friendly and sustainable practices. This research may open doors for new organic farming systems. The dawn of potent environmentally friendly and natural pesticides is upon us,” Arimura said.
Wisconsin has passed two bills allowing for the development of a statewide charging network. The bipartisan bills, Wisconsin Acts 121 and 122 (2023), were signed into law by Governor Tony Evers on March 20.
As reported by Wisconsin State Journal, the laws allow the state to utilize about $78 million of federal funding from the Bipartisan Infrastructure Law’s National Electric Vehicle Infrastructure (NEVI) program. The funding will go toward increasing the number of charging stations along major state highways and interstates.
“We don’t have to choose between protecting our environment and natural resources or creating good-paying jobs and infrastructure to meet the needs of a 21st-Century economy — in Wisconsin, we’re doing both,” Evers said in a press release. “Expanding EV charging infrastructure is a critical part of our work to ensure Wisconsin is ready to compete and build the future we want for our kids — one that is cleaner, more sustainable, and more efficient. Thanks to President Biden’s Bipartisan Infrastructure Law, we’re ready to get to work.”
The federal funding goes toward Level 3 chargers, or fast-chargers, that can recharge EVs in an hour or less, the Associated Press reported. While the federal government recommends that charging stations along Alternate Fuel Corridors (AFCs) be placed no more than 50 miles apart, the secretary of the Wisconsin Department of Transportation, Craig Thompson, noted that the expanded state EV charging network will be spaced apart by 25 miles or less to better support the increased demand for electric vehicles.
“WisDOT is ready to activate the federal funding and help industry quickly build fast chargers across the state,” Thompson said. “Electric vehicle drivers in Wisconsin will soon be able to travel about 85 percent of our state highway system and never be more than 25 miles away from a charger.”
Act 121 allows businesses, like gas stations or other businesses along the charging network, to sell electricity for charging by kilowatt hours rather than the amount of time charged, creating more incentive for businesses to join the network. The former law required businesses that had EV charging stations to be regulated like a public utility company, the Wisconsin State Journal reported.
The state will charge an excise tax of $0.03 per kilowatt hour of electricity sold at all new charging stations and any existing level 3 charging stations. Existing level 1 and level 2 charging stations will not be charged the excise tax, and the excise tax does not apply to residential level 3 chargers, according to the bill.
As the Associated Press reported, the state currently has around 580 chargers available to the public, and the newly signed bills will support the addition of 65 fast-charging stations.
At 11 a.m. on the last Wednesday of February, Denver opened the first application window of the year for its e-bike rebate program, which offers residents upfront rebates of $300 to $1,400 for a battery-powered bicycle. Within three minutes, all of the vouchers for low and moderate income applicants had been claimed. By 11:08 a.m., the rebates for everyone else were gone too, and the portal closed.
Even in its third year, Denver’s ambitious campaign to get residents to swap some of their driving for riding remains as popular as ever. “It’s exciting that people are really interested in this technology,” Mike Salisbury, the city’s transportation energy lead, told Grist. “Every trip we can convert to an e-bike will be a big climate win.”
Transportation is among the biggest sources, if not the biggest source, of a city’s carbon emissions. To cut that footprint, officials often turn to costly, intensive transit projects and building out electric vehicle infrastructure. Denver is doing those things, but also propping up smaller forms of mobility. It spent more than $7.5 million in just two years on e-bike vouchers, supporting the purchase of nearly 8,000 of the battery-powered bicycles, which can zip along at up to 28 mph, power up hills, and carry passengers or cargo.
“We’re just very bullish on e-bikes,” said Salisbury. “They have this huge potential to replace vehicle trips.”
The vouchers are saving some 170,000 miles in car trips per week and around 3,300 metric tons of greenhouse gas emissions annually, according to the city. Its Office of Climate Action, Sustainability, and Resiliency calls it “one of the most effective climate strategies that the city and county of Denver has deployed to date.”
There are about 160 of these incentive programs across the U.S. and Canada, and while Denver wasn’t the first to implement one, the size and success of its undertaking has attracted the attention of other governments and utilities. Congress is taking note as well: California Representative Jimmy Panetta reintroduced the federal Electric Bicycle Incentive Kickstart for the Environment Act, or E-BIKE Act, which would offer a 30 percent federal tax credit for e-bike purchases, last year.
Funded through a voter-approved $40 million Climate Protection Fund, which directs a portion of the city’s sales tax toward decarbonization initiatives, the program offers income-based rebates that can be redeemed at designated bike shops. Providing the discount at the register helps those who might otherwise be unable to afford the upfront cost, which typically begins around $1,200 and can reach several thousand dollars.
Residents making less than 60 percent of the area median income of around $52,000 can get $1,200 for a standard e-bike and $1,400 for a cargo model (useful for carrying gear, making deliveries, or hauling kids). Moderate-income recipients receive between $700 or $900, and everyone else can get $300 or $500. Online applications open several times each year and vouchers are offered on a first-come, first-served basis.
Denver residents redeem the rebates of $300 to $1,400 directly at designated bike shops, alleviating the need to make a hefty upfront payment. Hyoung Chang / The Denver Post via Getty Images
The goal is to reduce emissions from the transportation sector, Denver’s second-largest contributor of greenhouse gases, by targeting short vehicle trips. According to Salisbury, 44 percent of residents’ trips are under 5 miles and most are under 10, feasible distances to travel on an e-bike.
“E-bikes aren’t going to replace every single trip for every single person,” he said. “But there’s this huge potential to replace, especially in an urban environment, shorter distance trips that someone is making by themselves. Or they can use an e-cargo bike to take their kids to school.”
That’s one of the many ways Jeff Gonzales, a marketing professional and father living near the University of Denver, uses the power-assisted bike that he bought two years ago with the help of a voucher.
At the time, Gonzales drove a customized Toyota Tacoma pickup. “It was awesome, but it was a gas guzzler,” he told Grist. Gas was so expensive that he and his wife were trying to minimize their driving as much as possible. But their two toddlers were getting too heavy to tow with the family’s bike trailer, affectionately called “the chariot.” When an employee at his local bike shop mentioned the rebates for power-assisted bicycles, he decided to take one for a test ride.
“I was like, ‘This is pretty cool,’ and then I asked them, ‘Can I hook the chariot behind it?’ They said ‘Absolutely.’” Gonzales sold his truck, applied for a voucher, and bought the bike. He began riding it to the grocery store, taking the kids to school, and even making the 24-mile round-trip commute to his office twice a week.
“That first summer we had it, I think there were times that we didn’t get in the car for about two weeks at a time,” he said.
After selling his pickup truck, Jeff Gonzales began using an e-bike to take his kids to school and commute to work.
Courtesy of the City of Denver / Jeff Gonzales
In a 2023 survey of voucher recipients, 43 percent of respondents cited commuting as their primary reason for getting an e-bike, and 84 percent said the machines replaced at least one vehicle trip per week. The city estimates that recipients are eliminating a weekly average of 21 miles in their cars.
Commuting on two wheels often allows riders to avoid traffic or take more direct routes than those offered by public transit. “People are sharing feedback with us on how it’s enabled them to get to their job much faster, easier, at a much lower cost, without having to make two or three transit transfers to get to a place,” said Salisbury.
Gonzales said he often finds biking to work quicker, but even when the ride doesn’t save time, it’s more enjoyable. “It sucks to sit in traffic,” he said. “I’d rather be moving on a bike, and if I get tired, I can increase the power level, but I’m still moving.”
The clean energy nonprofit Rocky Mountain Institute, or RMI, found that if the country’s 10 most populous cities shifted a quarter of all short vehicle trips to e-bike rides, they could save 4.2 million barrels of oil and 1.8 million metric tons of CO2 in one year. That’s the equivalent of taking four natural gas plants offline. As an added bonus, those riders also would save a combined total of $91 million per month in avoided fuel and vehicle maintenance costs, according to RMI.
But a recent study from Valdosta State University and Portland State University questions the cost effectiveness of achieving greenhouse gas emissions this way. “Even when e-bike incentive programs are designed cost-effectively,” the authors concluded, “the costs per ton of CO2 reduced still far exceed those of alternatives or reasonable social costs of GHG emissions.” A rebate program can still be beneficial, the study concludes, but may need to be justified through its additional benefits, like promoting exercise and relieving traffic congestion.
Salisbury said the report’s critique overlooks how cities must tackle emissions in multiple ways. “There are lots of other things the city is working on, like building bus rapid transit and other infrastructure, but those take a long time,” he said. “If we want to see reductions as soon as possible, we need to look at programs that can contribute to that right away.”
He also pointed out that increasing access to e-bikes takes specific aim at one of the city’s most difficult sectors to decarbonize. “Yes, it’s cheaper to invest in a solar array, but that’s not going to do anything for transportation emissions.”
That’s not to say that getting residents to swap four wheels for two is as simple as doling out a voucher. E-bikes require infrastructure, including bike lanes that can accommodate both motorized and analog riders, as well as places to charge and safely store bikes.
In the past five years, the city has added 137 miles of “high-comfort” bike lanes. Last month, it launched the Denver Mobility Incentive Program, offering grants to nonprofits and other organizations to install bike storage lockers, places to plug in, and even set up e-bike libraries where residents can borrow rides for free.
“It’s all part of an ecosystem,” said Salisbury. “Dropping 8,000 e-bikes on the road would be much less effective if we didn’t have that co-developed infrastructure.”
Gonzales uses that infrastructure when he has to cut through busy downtown Denver to reach his office. “About 90 percent of the time I’m on protected bike lanes,” he said. “It makes me feel a lot more comfortable about biking 12 miles across town.”
As part of its strategy to encourage bike commuting, Denver has added about 137 miles of “high-comfort” bike lanes in the last half decade.
Hyoung Chang / The Denver Post via Getty Images
The city has also had to grapple with how to ensure that all residents can access the program. While more than 44 percent of the vouchers have gone to low-income applicants, the first-come, first-served application process has been criticized for favoring people with the time and computer access to log on as soon as the portal opens. And so far, the racial demographics of the recipients has not proven reflective of the city’s population. In 2023, only 8 percent of survey respondents were Latino and 3 percent were Black, while Denver’s population is 29 percent Latino and almost 9 percent Black. Despite offering up to $1,400 for adaptive bikes, the program has only distributed about 20 so far.
In response, Denver has worked with community-based organizations to funnel rebates directly to people who might not know about or be able to apply for them. It plans to distribute 600 vouchers through such groups this year.
The people least able to access the program may also be the ones who would put it to the most use. Survey results have indicated that applicants who received vouchers through community organizations are replacing 80 percent more vehicle miles than standard-voucher recipients.
This also marks the first year that Denver will offer a specific rebate amount for moderate-income applicants, an attempt to address the “missing middle” of people who earn closer to the city’s median income but need a bit more help to afford a ride.
What the city will continue to struggle with this year is a demand for all levels of vouchers that far exceeds supply. The next round of applications will open on April 30.
One of those applications might come from the Gonzales family. With a third baby now in tow, they’re thinking of getting a second power-assisted bike to transport the whole family. “When the little man gets bigger, we’d probably get another,” said Gonzales, especially if the city is still offering vouchers. “They’re not the cheapest things in the world, so the rebate program certainly helps.”
Thousands of warehouse workers across the U.S. are likely regularly exposed to the cancer-linked chemical ethylene oxide. More than half of the country’s medical equipment is sterilized with the compound, which the EPA considers a carcinogen. Ethylene oxide evaporates off the surface of these medical products after they’ve been sterilized, creating potentially dangerous concentrations of air pollution in the buildings where they’re stored.
By and large, the EPA does not regulate these buildings — in fact, regulators don’t even know where most of them are. The Office of Safety and Health Administration, the federal agency in charge of worker protection that is known by its acronym, OSHA, has also done relatively little to evaluate worker exposure in these warehouses. But last week, OSHA opened a new investigation into a Georgia warehouse that stores medical devices sterilized with ethylene oxide, raising questions about whether the federal government is beginning to respond more quickly to these risks.
On March 13, the U.S. Marshals Service and the Douglas County sheriff’s office assisted OSHA in executing a search warrant at a warehouse leased by the medical device company ConMed in Lithia Springs, 17 miles west of Atlanta. The surprise inspection was initiated almost two weeks after a Grist and Atlanta News First investigation revealed that workers employed by ConMed had been unknowingly exposed to the chemical. Ambulances were routinely called to the facility as workers convulsed from seizures, lost consciousness, and had trouble breathing.
The workers sued the company in 2020, but the lawsuit was ultimately dropped earlier this year after a judge dismissed some of their claims, citing state labor laws. (Under Georgia law, once employees seek workers’ compensation from the state, they are barred from suing employers separately.) ConMed denies the lawsuit’s allegations that it knowingly exposed workers to ethylene oxide and maintains that no individual medical emergency can be tied to exposure to the chemical. A company representative told Grist that it is “committed to fully complying” with all applicable regulations and conducts monthly ethylene oxide testing for its employees to review.
“Given our many years of full cooperation with OSHA, as well as the fact that OSHA has inspected our Lithia Springs facility five times since 2019, ConMed was surprised by the manner in which OSHA elected to inspect the facility on March 13,” a company representative told Grist in an email.
Ethylene oxide is a powerful fumigant, but it poses significant health risks and is linked to lung and breast cancers as well as diseases of the nervous system. Once medical devices are treated with ethylene oxide, the chemical continues to evaporate off the surface of the product as it moves through the supply chain. While the devices are trucked to warehouses, stored, and then shipped to hospitals, the products continue to quietly off-gas ethylene oxide, putting workers who come into contact with it at risk.
In a new rule it published last week, the EPA said that it will begin regulating toxic emissions from warehouses located on the same site as the sterilizer plants that actually apply the chemical. However, the agency argued that constraints stemming from the regulatory definition of the sterilization industry mean that offsite warehouses will be excluded from oversight. Even if the agency could clear that bureaucratic hurdle, it does not have “sufficient information to understand where these warehouses are located, who owns them, how they are operated, or what level of emissions potential they may have,” in the agency’s words.
What little the EPA knows about the threat from offsite warehouses was gleaned from a study conducted by state regulators in Georgia. That effort initially identified seven off-site warehouses and found that at least one of the state’s warehouses was emitting more ethylene oxide than the sterilization plant that first treats the medical products before sending them out for storage. Federal officials will begin gathering data on warehouses, according to the new EPA rule, and use it to determine whether a completely new regulation governing storage facilities should be developed. Such a process could take years, according to experts who spoke to Grist. All the while, warehouse workers across the country will continue to inhale ethylene oxide, in many cases without their knowledge.
“Up until eight years ago, a lot of people had no idea that the sterilizer facility, which looks like your regular office park facility, was poisoning them,” said Marvin Brown, an attorney with the environmental nonprofit Earthjustice. “Now we have this additional issue of these warehouses that are continuing to poison people, and most people have no idea that they live next to one or work at one.”
Brown and other experts Grist spoke to said the agency could take one of two approaches to regulating warehouses. It could expand the definition of regulated facilities under the sterilizer rule it finalized earlier this month, or it could create a new category of facilities that covers warehouses and develop a separate rule. Both come with challenges.
Reopening a new rule that has already been finalized is tricky, according to Scott Throwe, a former EPA enforcement official who worked on a number of rules that the EPA rolled out in the decade after amendments to the Clean Air Act were passed in 1990. “It’s a huge can of worms,” he said. “Once you open a rule, then you have to fix this and you have to fix this. It snowballs.”
Alternatively, the EPA could draft a new rule entirely, he added, but the agency is unlikely to do that either, because of the sheer amount of effort such a process would take. Throwe said that the EPA’s decision not to include offsite warehouse regulations in its new rule means that the agency doesn’t have either the time, the resources, or the will to tackle those emissions at this time.
“They’re going to declare victory on this one and move on,” he said. “They ain’t reopening that rule unless someone sues them.”
A spokesperson for the EPA said that the agency has an “incomplete list” of warehouses and that it has not conducted any risk assessments of them. As a next step, the agency expects to follow up with sterilization companies that did not provide detailed information about the location of their warehouses in response to a 2021 request. Once those responses are received, the agency plans to conduct emissions testing at some of the warehouses. If the agency decides to pursue a separate rule for warehouses, that process could take four to five years, the spokesperson said.
More than 50 percent of all U.S. medical supplies are sterilized by ethylene oxide.
Getty Images
The rule governing medical sterilization facilities was one of the first industry-specific air quality regulations that the EPA ever crafted. In its amendments to the Clean Air Act in 1990, Congress published a list of 189 toxic air pollutants and asked the agency to develop regulations for each industry emitting at least one of them. Officials published the first standards for medical sterilizers in 1994 with little fanfare, according to Throwe. At the time, regulators and toxicologists were unaware of the true risks of ethylene oxide, which was used to fumigate a range of materials, from books to spices to cosmetics. With the new law giving the agency just a decade to craft dozens of new regulations, officials rushed the process, sacrificing the efficacy of some standards along the way.
“It was like drinking from a firehose,” Throwe said. “Unrealistic statutory deadlines became court-ordered deadlines.”
Drafting new regulations for a polluting industry, regulators quickly learned, was a lot of work. In addition to collecting and analyzing copious amounts of data on a particular type of plant’s emissions and configuration, officials had to consult engineering experts to understand what kinds of technologies they could ask companies to use to control their emissions. Decades later, the process for revising these regulations to better protect exposed communities is no different. It took the EPA almost a decade to publish its new sterilizer regulations, and it did so under a court-ordered due date after missing a previous deadline to update the rule. If the agency were to issue a new rule for warehouses, the time and resource commitment would be steep, Throwe said.
While the EPA is not responsible for worker safety, it has found a roundabout way to increase protections for those coming in close contact with ethylene oxide. Since ethylene oxide is a fumigant, the agency is also pursuing separate oversight under a federal pesticide law. The Federal Insecticide, Fungicide, and Rodenticide Act requires the agency to evaluate pesticides every 15 years and determine where, how, and how much of a given pesticide may be used. In April, the EPA proposed a new set of requirements including reducing the amount of ethylene oxide used for sterilization and mandating that workers wear protective equipment while engaging in tasks where there is a high risk of exposure to the chemical. Since the law applies to all facilities where ethylene oxide is used — not just sterilization plants — warehouse workers could benefit from the requirements once it is finalized.
Some state and local agencies are proactively regulating warehouses themselves. After the Georgia Environmental Protection Division found that one warehouse was estimated to emit about nine times as much ethylene oxide as the facility that sterilized it, the agency began trying to find similarly dangerous warehouses. After scouring the internet and reaching out to companies, the agency identified four warehouses that were emitting more ethylene oxide than permitted under state law. The agency is now in the process of issuing permits and requiring controls for those facilities.
In Southern California, which has a large concentration of sterilization facilities, the local air quality regulator has included requirements for offsite warehouses in a rule that primarily targets sterilization plants. The rule categorizes warehouses into two tiers — those with an indoor space of 250,000 square feet or more and those with between 100,000 and 250,000 square feet. Depending on the size of the facility, the warehouses are subject to different reporting and monitoring requirements. In the course of developing the rule, the agency identified 28 warehouses that fall into one of these two tiers. The agency finalized the rule in December, and larger warehouses will be studied for a year to determine whether they emit significant amounts of ethylene oxide.
Editor’s note: Earthjustice is an advertiser with Grist. Advertisers have no role in Grist’s editorial decisions.
If you were to create a recipe for plastics, you’d need a very big cookbook. In addition to fossil fuel-based building blocks like ethylene and propylene, this ubiquitous material is made from a dizzying amalgam of more than 16,000 chemicals — colorants, flame retardants, stabilizers, lubricants, plasticizers, and other substances, many of whose exact functions, structures, and toxicity are poorly understood.
What is known presents many reasons for concern. Scientists know, for example, that at least 3,200 plastic chemicals pose risks to human health or the environment. They know that most of these compounds can leach into food and beverages, and that they cost the U.S. more than $900 billion in health expenses annually. Yet only 6 percent of plastic chemicals — which can account for up to 70 percent of a product’s weight — are subject to international regulations.
The unchecked production, distribution, and disposal of plastics and other petrochemical-based products has led to “a perpetual cycle of human exposure to EDCs from contaminated air, food, drinking water, and soil,” Tracey Woodruff, a professor of reproductive sciences at the University of California, San Francisco, wrote in the New England Journal of Medicine earlier this month. Philip Landrigan, a public health physician and professor of epidemiology at Boston College, told Grist that the crisis has “quietly and insidiously gotten worse while all attention has been focused on the climate.”
Although some policymakers have taken steps to protect people from EDCs — the European Commission, for example, in 2022 proposed stricter labeling regulations that would require companies to alert consumers of their hazards — many in the field believe the overarching response has been incommensurate with the scale of the crisis. Because so many plastics and petrochemical products are traded internationally, some endocrinologists and public health authorities believe a global approach is needed.
“This is an international problem that is affecting our world and its future,” said Andrea Gore, a professor of pharmacology and toxicology at the University of Texas, Austin.
Plastic covering a beach in Lima, Peru.
Ernesto Benavides / AFP via Getty Images
Gore and others are appealing to the negotiators of the U.N. global plastics treaty, who meet for their next round of talks next month in Ottawa, Canada. There is increasing interest among delegates for a treaty that not only protects the environment, but public health — a step that the international nature of the EDC problem makes clear must be taken.
The endocrine system is complex, involving a series of glands throughout the body that secrete chemical messengers called hormones. These molecules lock onto a cell’s receptors to induce some kind of response: perhaps the production of another hormone, or the correction of a nutrient imbalance. Endocrine hormones control a long list of necessary human functions like growth, metabolism, reproduction, lactation, and managing blood sugar — any malfunction, let alone absence, of these processes can lead to health problems like infertility, diabetes, hypertension, and death.
EDCs tamper with the endocrine system, often by mimicking hormones to trigger the corresponding response, or by blocking them to prevent it from happening at all. Research has identified at least 1,000 of these substances in pesticides, inks, building materials, cosmetics, and plastic products, but the nonprofit Endocrine Society, whose members include physicians and scientists, calls this “only the tip of the iceberg” due to the enormous number of chemicals yet to be tested.
Some of the most common or familiar EDCs found in plastics include phthalates, used to make the material more flexible; bisphenol A, or BPA, used to make strong, clear products; and PFAS, a class of more than 14,000 chemicals used to make food containers, outdoor clothing, and other products oil- or water-repellent. Other EDCs of concern include organophosphate ethers, benzotriazoles, and PBDEs, all of which are used to make plastic products fire- and light-resistant.
What makes this particularly worrisome is that humans can be exposed to endocrine-disrupting chemicals simply by touching plastic, inhaling microplastics within dust, and eating food or drinking water that has been in contact with plastic. According to one 2022 study, more than 1,000 chemicals — including many EDCs — commonly used in packaging like takeout containers can migrate into food. A separate study from 2021 found that more than 2,000 chemicals can leach from a single plastic product into water.
As noted in a report published last month by the Endocrine Society and the nonprofit International Pollutants Elimination Network, or IPEN, exposure to endocrine-disrupting substances can occur throughout the plastic life cycle. Fracking for oil and gas — the material’s main ingredients — uses more than 750 chemicals, many of which are known or suspected endocrine disruptors, and people living near these operations may have an elevated risk of developmental or reproductive problems. More EDCs are released during plastics manufacturing, sometimes in air and water emissions, other times on the backs of nurdles, tiny plastic pellets that can be shaped into larger products. These pebble-sized pieces often spill directly from factories or during transportation, and can release their chemicals once in the environment.
Volunteers pick up plastic nurdles at a beach in Tarragona, Spain.
Josep Lago / AFP via Getty Images
At the end of the plastic life cycle, incinerators and landfills can release PFAS, dioxins, PCBs, and other endocrine disruptors as air or soil pollution — some of which may contaminate nearby food supplies. Littered plastics tend to make their way into the ocean, where they break down into microplastics and leach some of those same EDCs, along with others like dibutyltin and mercury.
Those facing the greatest risk tend to be residents of low-income communities and people of color. “They’re more likely to be living in areas where there’s more pollution,” Gore said — like from nearby plastics manufacturing facilities or waste disposal sites. Plus, she added, low-income families often live without easy access to fresh produce and are more dependent on foods packaged in plastic. “We know people of lower socioeconomic status have disproportionate exposures.”
Reducing exposure to endocrine disruptors presents a challenge for several reasons. The biggest is the U.S. and other countries’ lax approach to chemical regulation, which doesn’t usually require that new compounds be tested for endocrine-disrupting properties or other safety concerns before they can enter production and get incorporated into products. “Right now we operate on the basis that all chemicals are innocent until proven guilty,” Landrigan told Grist.
Even when scientists agree that something is harmful, bureaucratic delays and industry lobbying often impede regulation. The Toxics Substances Control Act, or TSCA — the United States’ main chemical law — has for example only banned a handful substances in the nearly 50 years since it was passed, a period in which at least 100,000 new chemicals have entered the market, according to Landrigan. This is partly due to the unrealistic expectation that scientists draw a direct, causal link between a substance and specific health effects, which would require unethically exposing people to toxicants and observing the outcomes.
Another unfortunate side effect of that expectation is a phenomenon called “regrettable substitution,” where companies swap chemicals known to be harmful for lookalikes that haven’t been studied as extensively. Later research often reveals the substitute is just as toxic as the original, if not more so. This has occurred on a wide scale with EDCs such as PFAS, as well as bisphenols — although now that several countries have restricted BPA from plastic products like baby bottles, products labeled (often inaccurately) as free from that substance are now being manufactured with bisphenol S, despite research suggesting it also disrupts the endocrine system.
Some scientists accuse the chemical industry of “weaponizing uncertainty” to delay or kill regulation, a strategy they liken to Big Oil’s campaign to raise doubt about the reality of climate change. But for many EDCs in particular, they agree there is strong enough associative evidence of their harms — from cell and animal studies, as well as observations in people who have been exposed to the chemicals at work or as a result of an accident — to warrant bans and restrictions.
Scientists and public health advocates have been trying to reform chemical regulations for years now, but the U.N.’s global plastics treaty presents an opportunity to do so on an international level. “A global treaty can’t reform TSCA,” Landrigan said, “but it can set benchmarks telling countries that if they want to ship their products internationally, they have to conform to certain standards.”
One leading proposal for the treaty is that negotiators create a comprehensive inventory of the many chemicals used in plastic production, along with a list of “chemicals of concern” identifying which should be prioritized for phasing out. According to Sara Brosché, a science adviser for IPEN, this list should include classes of chemicals rather than individual ones. “EDCs would be one very clear category” to be phased out, she told Grist, along with carcinogens and so-called “persistent organic pollutants” that don’t break down naturally in the environment.
Scientists also support listing and phasing out “polymers of concern,” the types most likely to contain EDCs and other hazardous substances. Polyvinyl chloride, for example — frequently used in plastic water pipes — can expose people to endocrine disruptors including benzene, phthalates, and bisphenols.
So far, these ideas have only been suggested for inclusion in the treaty; negotiators don’t even have a first draft yet, and are still debating whether the primary goal should be to “end plastic pollution” or to “protect human health and the environment … by ending plastic pollution.” The existing text, a laundry list of nearly every suggestion made thus far, leaves plenty of room for countries to simply “minimize,” “manage,” or vaguely “regulate” hazardous plastic chemicals, rather than eliminate them altogether. The final draft is due by year’s end, though many expect an extension, with further negotiations continuing into 2025.
To Landrigan and many others, the most important thing is that the treaty include a global cap on plastic production, which could triple by 2060 to more than 1.2 billion metric tons annually if current trends continue. That’s the weight of more than 118,000 Eiffel Towers. “We see the current exponential increase in plastic production as simply not sustainable,” he said. “It will overwhelm the planet.” Less plastic will mean fewer opportunities for EDC exposure, he added. And that will surely save lives.
When it comes to air quality, neighboring countries are in it together. In 2023, wildfire smoke from across the Canadian border became a primary source of air pollution in major U.S. cities, according to a report released this week.
The annual World Air Quality Report by IQAir, a Swiss air quality technology company, showed that U.S. residents enjoyed cleaner air in 2023 than 75 percent of the 134 countries and territories measured. However, the report also found that most of the U.S. had almost double the levels of air pollution deemed acceptable by the World Health Organization, or WHO. The overall amount of unhealthy air nationwide crept up slightly from the previous year, but some cities, such as Milwaukee, saw up to a 50 percent increase. The report found that although air quality still suffered from the usual climate-change worsening culprits, such as fossil fuel industries, smoke from Canadian wildfires was behind many of these spikes.
“We really want to encourage people to treat air quality just like they would treat the weather, look to see what the air quality is before you spend extensive time outdoors,” Christi Chester Schroeder, an air quality science manager at IQAir, told Grist.
For its report, IQAir collected data from over 30,000 monitoring stations around the world. Annual pollution averages for each country and territory were based on measured amounts of PM2.5, or fine particulate matter 2.5 micrometers or smaller. When inhaled, these tiny, invisible particles can enter the lungs and bloodstream. According to guidelines set by WHO, yearly air pollution averages should not exceed 5 micrograms of PM2.5 per cubic meter of air. U.S. residents are exposed to almost double that.
A scientist points to an air pollution map at a monitoring station in Boulder, Colorado, in 2023. Hyoung Chang/The Denver Post via Getty Images
For most of 2023, PM2.5 levels across the country averaged about 9.1 micrograms per cubic meter of air, with the worst air concentrated in large cities including Washington, D.C., and New York City. The report showed pollution levels spiked in the summer, when hot, stagnant air and sunshine can interact with pollutants to create pockets of unhealthy air. In Washington, D.C., and Chicago, PM2.5 levels more than doubled in June, up to over five times WHO guidelines. Columbus, Ohio, was the most polluted U.S. city for the second year in a row.
But the IQAir report also contained good news for the U.S.: Aggressive wildfire mitigation efforts seem to be working, which led to a less severe fire season and cleaner air on the West Coast as compared to previous years. In Portland, Oregon, PM2.5 levels dropped by almost 40 percent, while Los Angeles saw a 10 percent decrease. Of the 25 most populated cities in the U.S., Las Vegas had the cleanest air.
According to Schroeder, “A big theme of this year’s report was transboundary haze,” a term that describes when smoke travels across borders. This past summer, Canada endured its worst wildfire season on record. As the blazes tore through 5 percent of the country’s forests, they created huge plumes of soot that drifted into the eastern U.S., blanketing New York City in an orange haze and impacting air quality as far south as Florida.
“The wind is the most efficient transportation system on earth,” said Joel Thornton, a professor of atmospheric chemistry at the University of Washington. Even though large wildfires have become an unsurprising reality, Thornton found that last year’s in Canada were unprecedentedly bad. As forests continue to be unseasonably drier and warmer due to climate change, the stage is set for these fires to get even worse, he said. “It’s a harbinger of what’s to come.”
Last month, the Environmental Protection Agency finalized new standards for air pollution, bringing the annual average limit down from 12 micrograms of PM2.5 per cubic meter of air to 9 micrograms. The new target still exceeds the WHO’s guidelines of 5 micrograms, but could still bring huge improvements. According to the Biden administration, the new rules would prevent an estimated 4,500 premature deaths every year and save billions in health costs. To reflect their tightened standards, the EPA also updated the Air Quality Index, a handy color-coded scale that runs from green (“good”) to maroon (“hazardous”).
Experts like Thornton say that wildfires may hamper efforts to meet the EPA’s new standard, even as government regulations, such as the Clean Air Act, have made U.S. air safer than most of the world’s. “Wildfires are basically wiping out a lot of that progress,” Thornton said. A 2023 study published in Nature found that wildfire smoke undid almost 25 percent of air quality improvements since 2000.
Currently, the EPA does not take pollution levels from wildfires into account in its regulatory actions, as part of an “Exceptional Event Rule” that kicks in when natural disasters skew environmental data. As the weather warms and fire season inches closer, fire management strategies may become key to sparing communities from blazes and unsafe air alike.
Used by manufacturers for decades in products like nonstick cookware, water-repellent clothing, stain-resistant fabrics, cosmetics, firefighting foam and food packaging, more than 12,000 of the human-synthesized chemical compounds are known to exist, according to the study.
“There are thousands of these chemicals,” said Birgit Geueke, co-author of the study and a senior scientific officer with Food Packaging Forum, as New Scientist reported. “We wanted to get a picture of what is known about the presence of PFAS in food packaging.”
Scientists have discovered that PFAS have adverse health impacts, leading to many being banned, reported Phys.org. Recent research has demonstrated that the toxic substances can migrate into food.
“Due to their unique chemistry, PFASs have enabled convenience in many parts of modern life. However, their molecular properties have also granted them hazardous properties, including persistence, raising alarms due to their ubiquitous presence as contaminants in food, drinking water, and the environment,” the researchers wrote in the study. “Today, various PFASs have been identified in sera from humans and wildlife globally. Exposure to some PFASs has been linked to a wide range of adverse health outcomes such as cancer, thyroid disease, decreased response to vaccination, and high cholesterol.”
The study, “Per- and Polyfluoroalkyl Substances in Food Packaging: Migration, Toxicity, and Management Strategies,” was published in the journal Environmental Science & Technology.
After compiling records on known PFAS in food packaging from the FCCmigex database, the research team found a total of 68 PFAS compounds — 61 had been previously banned from use in food packaging.
While examining the compounds found in food packaging, the team noted the lack of evidence as to why and how they ended up there.
“We utilized ToxPi to illustrate that hazard data are available for only 57% of the PFASs that have been detected in food packaging. For those PFASs for which toxicity testing has been performed, many adverse outcomes have been reported,” the researchers wrote. “The data and knowledge gaps presented here support international proposals to restrict PFASs as a group, including their use in food contact materials, to protect human and environmental health.”
The researchers recommended that a thorough review of food packaging be conducted, as well as the establishment of new rules and a method of enforcement for these pervasive and harmful chemicals.
“Ideally, a restriction would ban PFASs on a global scale to prevent the continued production and use in countries that lack legislation or the capacity for compliance monitoring,” the researchers wrote in the study. “A class-based phase-out of PFASs in food contact materials, including food packaging, would effectively protect public health while enabling the creation of a safe, circular economy.”
In a historic move, the Biden administration has announced new tailpipe emissions regulations, which call for a 56% reduction in the average carbon dioxide emissions of passenger cars, medium-duty vehicles and light-duty trucks by 2032.
The new rules will apply to vehicles with model years from 2027 to 2032 and beyond, a press release from the United States Environmental Protection Agency (EPA) said.
“With transportation as the largest source of U.S. climate emissions, these strongest-ever pollution standards for cars solidify America’s leadership in building a clean transportation future,” said EPA Administrator Michael S. Regan. “The standards will slash over 7 billion tons of climate pollution, improve air quality in overburdened communities, and give drivers more clean vehicle choices while saving them money.”
The updated standards will provide almost $100 billion in net benefits to society annually, with $13 billion in public health benefits from improved air quality, and reduced fuel, repair and maintenance costs of $62 billion.
When the new rules have been completely phased in, they will provide an estimated $6,000 in fuel and maintenance reductions per vehicle for the average driver.
“The President’s agenda is working. On factory floors across the nation, our autoworkers are making cars and trucks that give American drivers a choice – a way to get from point A to point B without having to fuel up at a gas station. From plug-in hybrids to fuel cells to fully electric, drivers have more choices today. Since 2021, sales of these vehicles have quadrupled and prices continue to come down. This growth means jobs, and it means we are moving faster and faster to take on the climate crisis,” said Ali Zaidi, national climate advisor to the Biden-Harris administration.
The rules expand on existing passenger car and light truck emissions standards by the EPA and are projected to produce 7.2 billion tons less carbon emissions through 2055 — four times the total transportation sector emissions for 2021. Ozone and fine particulate matter will also be reduced, lowering the occurrence of respiratory and cardiovascular illnesses, heart attacks, aggravated asthma and preventing as many as 2,500 premature deaths.
“Compared to the existing MY 2026 standards, the final MY 2032 standards represent a nearly 50% reduction in projected fleet average GHG emissions levels for light-duty vehicles and 44% reductions for medium-duty vehicles. In addition, the standards are expected to reduce emissions of health-harming fine particulate matter from gasoline-powered vehicles by over 95%. This will improve air quality nationwide and especially for people who live near major roadways and have environmental justice concerns,” the press release said.
Emissions from volatile organic compounds and nitrogen oxides will also be reduced by 75%, reported The Guardian.
However, stricter emissions are not happening fast enough, critics say, allowing automakers to keep producing gas-powered vehicles.
“This rule could’ve been the biggest single step of any nation on climate, but the EPA caved to pressure from big auto, big oil and car dealers, and riddled the plan with loopholes big enough to drive a Ford F150 through,” said Dan Becker, Center for Biological Diversity’s safe climate transport campaign director, as The Guardian reported.
The standards are predicted to help speed up the adoption of green vehicle technologies.
“The step EPA is taking today will slash climate pollution and air pollution,” said Amanda Leland, Environmental Defense Fund’s executive director, in the press release. “The U.S. has leapt forward in the global race to invest in clean vehicles, with $188 billion and nearly 200,000 jobs on the way… These clean car standards will help supercharge economic expansion and make America stronger.”
Before the Easter Bunny stocks up to fill baskets on March 31, he may want to note the uptick in prices for chocolate egg candies. While grocery costs have been increasing for many items, the increase in cost of chocolate is linked to climate change, experts say.
Extreme heat in West Africa has impacted cocoa crops, creating a decline in yields. Researchers with World Weather Attribution said the extreme heat, which led to temperatures being 4 degrees Celsius higher in February, was made 10 times more likely because of human-caused climate change.
The heat led to drought, which local farmers said weakened the cacao trees. The crops were already vulnerable because of heavy rainfall from late 2023, The Guardian reported.
As a result, some popular Easter egg-shaped chocolates have increased in price by 50%, BBC reported. Further, cocoa prices have risen to $8,500 per metric ton this week, with just over one week until the holiday. In mid-March 2024, cocoa prices had already risen by more than double compared to last year, Reuters reported.
“Farmers in West Africa who grow the main ingredient of the Easter eggs many of us are looking forward to are struggling in the face of both extreme heat and rainfall,” said Amber Sawyer, energy and climate analyst at the Energy and Climate Intelligence Unit (ECIU) in the UK, as reported by The Guardian. “Wealthy nations like the UK can provide support to developing countries [but] ultimately we have to reach net zero emissions. There are limits to the conditions in which crops can grow.”
The study by World Weather Attribution also revealed similar heat waves could happen in West Africa about every two years without greater action to curb fossil fuel-related emissions. Without climate change, the researchers noted this type of extreme heat would be a once-in-100-years event in West Africa.
The drought and extreme heat doesn’t just threaten crops, however. The study highlighted that a heat wave can be a “silent killer” that harms local populations, particularly because of a lack of investment to help countries become more resilient to extreme heat.
“Major investment is needed in Africa to build resilience to dangerous heat. The UN has estimated that the cost of adaptation for developing countries is between US$215-$387 billion per year this decade,” World Weather Attribution said in the study. “However, rich countries haven’t yet met the promises they have made to help developing countries become more resilient to the growing risks of climate change. In addition, these commitments fall drastically short of the finance required — in 2021, the global community spent just US$21 billion to help developing countries adapt to climate change.”
