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Harvard Study Reveals: Planetary Health Diet Can Extend Your Life and Save Earth Too

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Friday, June 14, 2024

A study by Harvard T.H. Chan School of Public Health highlights the dual benefits of the Planetary Health Diet (PHD), which not only reduces the risk of premature death by up to 30% but also significantly decreases environmental impacts. The PHD, which advocates for a varied diet of minimally processed plant foods with limited meat and dairy, is shown to lower greenhouse gas emissions, fertilizer needs, and cropland use, demonstrating the deep connection between dietary choices and both human and planetary health.Adhering to the Planetary Health Diet significantly reduces the risk of premature death and environmental impact, including lowered rates of major diseases and reduced greenhouse gas emissions and land use.According to a new study from Harvard T.H. Chan School of Public Health, adopting a healthy, sustainable diet, as outlined in the 2019 EAT-Lancet report, can significantly reduce both the risk of premature death and environmental impact. This landmark study is the first to directly assess the effects of following the dietary guidelines proposed in the report, which recommends a diverse intake of minimally processed plant foods while permitting limited amounts of meat and dairy. The researchers refer to this recommended diet as the Planetary Health Diet (PHD).The study was recently published in The American Journal of Clinical Nutrition.“Climate change has our planet on track for ecological disaster, and our food system plays a major role,” said corresponding author Walter Willett, professor of epidemiology and nutrition. “Shifting how we eat can help slow the process of climate change. And what’s healthiest for the planet is also healthiest for humans.” While other studies have found that diets emphasizing plant-based foods over animal-sourced foods could have benefits for human and planetary health, most have used one-time dietary assessments, which produce weaker results than looking at diets over a long period of time.The researchers used health data from more than 200,000 women and men enrolled in the Nurses’ Health Study I and II and the Health Professionals Follow-Up Study. Participants were free of major chronic diseases at the start of the study and completed dietary questionnaires every four years for up to 34 years. Participants’ diets were scored based on intake of 15 food groups—including whole grains, vegetables, poultry, and nuts—to quantify adherence to the PHD.Health and Environmental Benefits of the PHDThe study found that the risk of premature death was 30% lower in the top 10% of participants most closely adhering to PHD compared to those in the lowest 10%. Every major cause of death, including cancer, heart disease, and lung disease, was lower with greater adherence to this dietary pattern.In addition, the researchers found that those with the highest adherence to the PHD had a substantially lower environmental impact than those with the lowest adherence, including 29% lower greenhouse gas emissions, 21% lower fertilizer needs, and 51% lower cropland use.The researchers noted that land use reduction is particularly important as a facilitator of re-forestation, which is seen as an effective way to further reduce levels of greenhouse gases that are driving climate change.“Our study is noteworthy given that the U.S. Department of Agriculture has refused to consider the environmental impacts of dietary choices, and any reference to the environmental effects of diet will not be allowed in the upcoming revision of the U.S. Dietary Guidelines,” said Willett. “The findings show just how linked human and planetary health are. Eating healthfully boosts environmental sustainability—which in turn is essential for the health and wellbeing of every person on earth.”Reference: “Planetary Health Diet Index and risk of total and cause-specific mortality in three prospective cohorts” by Linh P Bui, Tung T Pham, Fenglei Wang, Boyang Chai, Qi Sun, Frank B Hu, Kyu Ha Lee, Marta Guasch-Ferre and Walter C Willett, 10 June 2024, The American Journal of Clinical Nutrition.DOI: 10.1016/j.ajcnut.2024.03.019Other Harvard Chan School authors included Linh Bui, Fenglei Wang, Qi Sun, Frank Hu, Kyu Ha Lee, and Marta Guasch-Ferre.The study was funded by National Institutes of Health (NIH) research grants UM1 CA186107, P01 CA87969, R01 HL034594, U01 CA176726, U01 CA167552, R01 HL035464, R01 DK120870, and R01 DK126698.

Adhering to the Planetary Health Diet significantly reduces the risk of premature death and environmental impact, including lowered rates of major diseases and reduced greenhouse...

Energy Vitality Human Health Lifespan

A study by Harvard T.H. Chan School of Public Health highlights the dual benefits of the Planetary Health Diet (PHD), which not only reduces the risk of premature death by up to 30% but also significantly decreases environmental impacts. The PHD, which advocates for a varied diet of minimally processed plant foods with limited meat and dairy, is shown to lower greenhouse gas emissions, fertilizer needs, and cropland use, demonstrating the deep connection between dietary choices and both human and planetary health.

Adhering to the Planetary Health Diet significantly reduces the risk of premature death and environmental impact, including lowered rates of major diseases and reduced greenhouse gas emissions and land use.

According to a new study from Harvard T.H. Chan School of Public Health, adopting a healthy, sustainable diet, as outlined in the 2019 EAT-Lancet report, can significantly reduce both the risk of premature death and environmental impact. This landmark study is the first to directly assess the effects of following the dietary guidelines proposed in the report, which recommends a diverse intake of minimally processed plant foods while permitting limited amounts of meat and dairy. The researchers refer to this recommended diet as the Planetary Health Diet (PHD).

The study was recently published in The American Journal of Clinical Nutrition.

“Climate change has our planet on track for ecological disaster, and our food system plays a major role,” said corresponding author Walter Willett, professor of epidemiology and nutrition. “Shifting how we eat can help slow the process of climate change. And what’s healthiest for the planet is also healthiest for humans.”

While other studies have found that diets emphasizing plant-based foods over animal-sourced foods could have benefits for human and planetary health, most have used one-time dietary assessments, which produce weaker results than looking at diets over a long period of time.

The researchers used health data from more than 200,000 women and men enrolled in the Nurses’ Health Study I and II and the Health Professionals Follow-Up Study. Participants were free of major chronic diseases at the start of the study and completed dietary questionnaires every four years for up to 34 years. Participants’ diets were scored based on intake of 15 food groups—including whole grains, vegetables, poultry, and nuts—to quantify adherence to the PHD.

Health and Environmental Benefits of the PHD

The study found that the risk of premature death was 30% lower in the top 10% of participants most closely adhering to PHD compared to those in the lowest 10%. Every major cause of death, including cancer, heart disease, and lung disease, was lower with greater adherence to this dietary pattern.

In addition, the researchers found that those with the highest adherence to the PHD had a substantially lower environmental impact than those with the lowest adherence, including 29% lower greenhouse gas emissions, 21% lower fertilizer needs, and 51% lower cropland use.

The researchers noted that land use reduction is particularly important as a facilitator of re-forestation, which is seen as an effective way to further reduce levels of greenhouse gases that are driving climate change.

“Our study is noteworthy given that the U.S. Department of Agriculture has refused to consider the environmental impacts of dietary choices, and any reference to the environmental effects of diet will not be allowed in the upcoming revision of the U.S. Dietary Guidelines,” said Willett. “The findings show just how linked human and planetary health are. Eating healthfully boosts environmental sustainability—which in turn is essential for the health and wellbeing of every person on earth.”

Reference: “Planetary Health Diet Index and risk of total and cause-specific mortality in three prospective cohorts” by Linh P Bui, Tung T Pham, Fenglei Wang, Boyang Chai, Qi Sun, Frank B Hu, Kyu Ha Lee, Marta Guasch-Ferre and Walter C Willett, 10 June 2024, The American Journal of Clinical Nutrition.
DOI: 10.1016/j.ajcnut.2024.03.019

Other Harvard Chan School authors included Linh Bui, Fenglei Wang, Qi Sun, Frank Hu, Kyu Ha Lee, and Marta Guasch-Ferre.

The study was funded by National Institutes of Health (NIH) research grants UM1 CA186107, P01 CA87969, R01 HL034594, U01 CA176726, U01 CA167552, R01 HL035464, R01 DK120870, and R01 DK126698.

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Iowa Farmers Are Restoring Tiny Prairies for Sustainability Boons

Farmers in the heartland are restoring swaths of the prairie with government help. The aim is to reduce nutrient runoff from cropland, and help birds and bees.

The little tracts of wilderness grow on Maple Edge Farm in southwest Iowa, where the Bakehouse family cultivates 700 acres of corn, soybeans and alfalfa. Set against uniform rows of cropland, the scraps of land look like tiny Edens, colorful and frowzy. Purple bergamot and yellow coneflowers sway alongside big bluestem and other grasses, alive with birdsong and bees.The Bakehouses planted the strips of wild land after floodwaters reduced many fields to moonscapes three years ago, prompting the family to embark on a once-unthinkable path.They took nearly 11 acres of their fields out of crop production, fragments of farmland that ran alongside fields and in gullies. Instead of crops, they sowed native flowering plants and grasses, all species that once filled the prairie.The restored swaths of land are called prairie strips, and they are part of a growing movement to reduce the environmental harms of farming and help draw down greenhouse gas emissions, while giving fauna a much-needed boost and helping to restore the land.As the little wildernesses grew, more and more meadowlarks, dickcissels, pheasants and quail showed up, along with beneficial insects. Underground, root networks formed to quietly perform heroic feats, filtering dangerous nutrient runoff from crops, keeping soil in place and bringing new health to the land.“We’re thinking about our farm as a small piece of the overall good puzzle,” said Jon Bakehouse, on a visit to the family’s fields one sunny morning earlier this summer. “On a larger scale, we’re all in this together.”Subscribe to The Times to read as many articles as you like.

Air quality alert issued for Deschutes County

On Wednesday at 3:15 p.m. an air quality alert was issued for Deschutes County.

On Wednesday at 3:15 p.m. an air quality alert was issued for Deschutes County."Oregon Department of Environmental Quality has issued an Air Quality Advisory. until 11 a.m. Friday. A Smoke Air Quality Advisory has been issued. Wildfires burning in the region combined with forecasted conditions will cause air quality to reach unhealthy levels. Pollutants in smoke can cause burning eyes, runny nose, aggravate heart and lung diseases, and aggravate other serious health problems. Limit outdoor activities and keep children indoors if it is smoky. Please follow medical advice if you have a heart or lung condition," states the National Weather Service.Air quality alerts: Recommendations from NWSWhen an air quality alert pops up on the radar, deciphering its implications is crucial. These alerts, issued by the weather service, come with straightforward yet essential guidance to ensure your safety:Retreat indoors whenever feasible:If possible, remain indoors, especially if you have respiratory issues, other health concerns, or fall within the senior or child demographics.Trim outdoor activities:When venturing outside becomes unavoidable, limit your outdoor exposure strictly to essential tasks. Reducing your time outdoors is the name of the game.Tackle pollution sources:Exercise prudence when it comes to activities that exacerbate pollution, such as driving cars, wielding gas-powered lawnmowers, or utilizing other motorized vehicles. Minimize their use during air quality alerts.A no to open burning:Refrain from igniting fires with debris or any other materials during air quality alerts. Such practices only contribute to the problem of poor air quality.Stay informed:Keep yourself informed by tuning in to NOAA Weather Radio or your preferred weather news station. Staying in the know ensures that you can make informed decisions about outdoor activities during air quality alerts.Respiratory health caution:If you have respiratory issues or health problems, exercise extra caution. These conditions can make you more vulnerable to the adverse effects of poor air quality.Following the recommendations from the weather service helps bolster your safety during air quality alerts, minimizing your exposure to potentially harmful pollutants. Stay vigilant, stay protected, and make your health the top priority.Advance Local Weather Alerts is a service provided by United Robots, which uses machine learning to compile the latest data from the National Weather Service.

Nearsightedness Has Become a Global Health Issue

Myopia is projected to affect half of the world’s population by 2050. A new report says it needs to be countered by classifying it as a disease and upping children’s outdoor time

In 350 B.C.E. Aristotle noted that some people went about their days with what he called “short sight.” People with this condition, he found, would habitually narrow their eyelids to focus their vision—an observation widely credited as the first attempt at defining nearsightedness, or myopia. More than two millennia later, health officials are paying new attention to this old condition for a startling reason: myopia has reached epidemic levels worldwide.Myopia’s prevalence has dramatically increased in recent decades, now affecting as much as 88 percent of the population in some Asian countries. Although it seems most acute in Asian cities, myopia’s growing prevalence is by no means an exclusively regional trend. By 2050, according to one estimate, five billion people—half the world’s population—will be nearsighted. The U.S., which has been less diligent than some other countries in tracking myopia cases, saw a jump in prevalence from 25 percent of people aged 12 to 54 in the early 1970s to 42 percent in the early 2000s, according to the last major national survey of the condition.These statistics matter because myopia is a leading cause of visual impairment, and it can precipitate serious diagnoses that range from detached retinas to glaucoma.On supporting science journalismIf you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.A search is now underway for tangible measures to stem this rising tide. An expert panel from the National Academies of Sciences, Engineering and Medicine (NASEM) released a report in September entitled Myopia: Causes, Prevention, and Treatment of an Increasingly Common Disease. It lays out a series of recommendations, one of which calls for the Centers for Medicare & Medicaid Services to reclassify myopia as a disease that necessitates a medical diagnosis—a step that would encourage federal and state agencies, along with professional associations, to devote resources to reversing the situation. Notably, the committee also recommended that children spend one to two hours outdoors each day.Terri L. Young, co-chair of the NASEM committee that produced the report and chair of the department of ophthalmology and visual sciences at the University of Wisconsin–Madison, talked with Scientific American about the implications of the myopia epidemic for people with myopia and policymakers.[An edited transcript of the interview follows.]I’d like to begin with the most basic of basics. Could you define what myopia, or nearsightedness, is?I’ll start off with what a person with myopia experiences. Myopia is a condition in which an individual sees an object up close clearly but cannot see it clearly at a distance without optical correction. They have natural blurred vision at a distance.Optically, there is a detailed definition that involves the very basics of how we see. Scattered light rays that enter the eye pass through multiple ocular components that reduce the scatter to focus the rays onto the retina, which converts the light into an electrical signal that is transferred through the optic nerve. The optic nerve is similar to a telephone cable that connects the eye to the occipital cortex at the very back of the brain, where what is viewed is then processed and interpreted.The focus of those wavelengths that enter the eye and travel through all its optical components needs to coincide on the retina. In the case of nearsightedness, or myopia, the focus of the light occurs in front of the retina.Myopia seems to be getting more attention lately, both in the U.S. and internationally. Why is that?Myopia prevalence rates are at epidemic levels, especially in urban Asian communities, where in recent times upward of 80 to 90 percent of young individuals have developed myopia. There are large, government-sponsored myopia research institutes in many parts of Asia, including Taiwan, Singapore, China, Hong Kong and Japan.Take Singapore, for example. All young men there are required to perform [two years] of military service after completing high school. Many of these military conscripts, and in particular the ones who are being prepared to go into battle or fly fighter planes, often need glasses or other corrective means for their myopia to fulfill those functions, causing concern for national security.And what about in the U.S.?It’s now certainly an issue in the U.S. as well. Research on myopia is conducted primarily in ophthalmologic and optometric training and research academic programs. But it hasn’t garnered, for whatever reasons, the same sense of urgency and funding as is the case for other parts of the world.In the U.S., we don’t have good prevalence data for myopia and other refractive errors, such as astigmatism and hyperopia [farsightedness]. Health care in this country is so varied in terms of everything from access to dissemination of vision care; because we don’t have a nationalized health system, we also don’t have a national database to provide standardized tracking and reporting.Aren’t there already simple ways to deal with myopia, such as getting a new prescription for glasses? Why is it perceived as becoming a global health problem?Myopia correction is not just an inconvenience of glasses or contact lenses. It predisposes a person to other eye conditions that can lead to blindness. Higher degrees of myopia are associated with eye conditions: premature cataracts, glaucoma, retinal tears and detachments and myopic macular degeneration.What’s happened in Asian communities is that the baseline level of refraction, the deflection of wavelengths as they pass through the eye, is trending toward nearsightedness. This shift is reflected in more individuals with high-grade myopia, with its increased ocular risks, as I described earlier. So instead of that group reflecting 3 to 5 percent of myopic individuals, it’s risen to 10 percent or more.Access to quality vision care, with proper and standardized dissemination for all children, is a major issue in [the U.S.] There are many children who don’t have steady access to care and the opportunity for continued changes in spectacle correction as they grow. If they can’t see, they can’t learn. If they don’t learn, they may get discouraged. If they get discouraged, they tend to act out or to not perform well in school—which has lifelong educational, vocational and economic impacts.Is there some idea why this myopia epidemic is happening?Nowadays, children are indoors more often, and they’re not getting as much outdoor play. Outdoor light enables the visual system to process a variety of spectral wavelengths of light for a certain duration of time, and that affects normal eye development and growth. Our report reaffirms what has been in the scientific literature for more than 15 years: increased childhood outdoor time appears to be protective for myopia onset and development.In urban Asia, education is highly regarded, and children undergo indoor schooling for relatively more hours per day—routinely with additional tutorial sessions on evenings and weekends. In Singapore, for example, there are fewer green spaces, and living situations are generally more vertical because of limited land mass. There are fewer nonclassroom hours and places for children to go outside to view the horizon for extended periods of time. That’s becoming more of the case in the urban U.S. as well.What does being outside do to promote healthy eyes?There are different and varied light wavelengths that enter the eye from outdoor versus indoor exposures. And there are differences in luminance—higher-intensity versus lower-intensity light levels. In the report, there is a lengthy discussion on what is called the “visual diet”—the environmental factors affecting the myopic eye—and there is a consensus that more research is needed.What about the role of electronic devices in promoting myopia?That’s certainly a trend that has exponentially grown in activity and use in our younger generations. I am a pediatric ophthalmologist. I see two- or three-year old children in my clinic who are comfortably playing with cell phones. This close-up activity is generally indoors. The limited research findings regarding electronic device impact on myopia development are inconclusive, however. Reflected in our report, studies could not support unequivocal evidence that using digital devices, especially electronic small devices, is an influencer for this shift toward myopia.What measures have countries implemented to try preventing or correcting myopia in young people?The Singapore Ministry of Health instituted outdoor playtime or recess during school hours. There are now programs in China and in Taiwan where classroom settings have been altered with the use of glass walls or colored light bulb use to increase outdoor daylight exposure. Children are undergoing treatment with atropine eye drops, which in some reports diminishes the shift toward myopia over time in the school-age years. The effect of the drops is not curative, however, and there are concerns regarding unknown long-term effects because we don’t quite understand the specific biochemical actions of atropine. Diagnosed children are also prescribed multifocal contact lenses or eyeglasses [progressive lenses that have different prescription zones to correct vision at different distances].One of the main findings of the report that you co-chaired is the recommendation that myopia be classified as a disease. Can you explain why the consensus of the panel felt that was important?The issue needs escalation to a recognized disease category to underscore its short- and long-term visual health consequences, and to attract attention and funding dollars on multiple and varied fronts for effective screening, treatment, prevention and research study.It takes a multipronged team to elevate this issue. That groundswell would have to come from parents, educators and educator societies, local to national health care systems, local to national policymakers, public health experts, researchers, funding agencies, insurance companies, etcetera. All [of these groups] need to recognize that continuous vision screening starting in early childhood is important. In addition to implementation, the data from those screening visits need to be collated for national database entry for improved monitoring in this country.What do you think should be the main takeaway from this report?In this country, if we elevate this condition to be considered a disease and recognize its impact on our children and ultimately on our future workforce, that would be monumental.

Is Wildfire Smoke Causing Birds to Tend to Empty Nests?

New studies suggest smoke from western megafires may be damaging bird health and leading to strange behavior

Hazy skies caused by smoke from Canadian wildfires blanketed Washington, D.C. on June 7, 2023. Win McNamee / Getty Images Early last summer, dull orange horizons replaced blue skies and hid city skylines in New York and Washington, D.C. Even the midday sun was dialed down to an ominously weak glow. People in the western half of North America have become all too familiar with the eerie scene that often accompanies a big wildfire. Thick smoke often blankets cities like Boise and Seattle. But the morning of June 7, 2023, was different. Smoke season had come east, heavier than many people there had ever seen before. But humans weren’t alone in dealing with that sudden smoke and its health effects. Wildlife across the Northeast, including millions of breeding birds, felt it, too. New research suggests the smoke may have more impact on birds than we ever realized, harming them both during their nesting season and throughout their lives. These studies are part of a new understanding of smoke, not just as a side effect of wildfire, but as a threat to wildlife and ecosystem health on its own. Just as that historic smoke was about to arrive in the White Mountains of New Hampshire last summer, two tiny songbirds were building their nest. A pair of black-throated blue warblers, striking birds with a blue back, a black mask and a bright white belly, had finished that season’s nest on June 4. The cup-like structure was constructed of bark, pine needles and other materials from around the forest. But just when the next cycle of life for these little birds was about to start, something unusual happened. The female of the pair started to sit in the nest vigilantly, as if incubating her eggs. But no eggs were there. She was incubating an empty nest, and nearby, someone was taking notes. A male black-throated blue warbler Gary Irwin via Wikipedia under CC By-SA 2.0 These warblers didn’t build their nest in just any woods, but in Hubbard Brook Experimental Forest, a 7,800-acre ecological research station that has hosted scientists and students of multiple fields for over 60 years. Hubbard Brook is well known in certain scientific circles and has produced a wealth of studies over the decades, but it is most famous as the site where acid rain was first discovered and studied in the 1960s. The only reason this nest was being monitored at all was because the male of the pair had previously been captured and marked with colored leg bands. A student named August Davidson-Onsgard noticed a nest being built in that banded bird’s territory and started watching it. Davidson-Onsgard happened to work for an ecologist and self-described naturalist with just the right experience and interest in the details of bird ecology to recognize how unusual, and potentially important, this observation could be. Ecologist Sara Kaiser is a research associate at the Smithsonian’s National Zoo and Conservation Biology Institute (NZCBI), and she directs the Cornell Lab of Ornithology’s field study program at Hubbard. When Davidson-Onsgard mentioned the empty nest incubator to Kaiser on her next visit to the site, it immediately got her attention. For a breeding bird, incubating a nest is always a gamble. Female black-throated blue warblers sit on their eggs for about 12 days straight, only leaving briefly to feed. During that time, they are more vulnerable to predators looking to make a meal of the bird, her eggs or both. Without the payoff of eggs and future offspring to keep her at the nest, the bird should not, theoretically, make the investment to stick to the nest so closely. “I said, you know, I haven’t really heard of anything like this before,” says Kaiser. She encouraged her student to follow up and search the scientific literature for examples of birds sitting on empty nests as if they had eggs. They found over 200 records of birds of 11 species, all in Europe, showing this strange behavior, and in over 80 percent of these accounts, the authors had noted environmental pollution as a possible cause. Researchers can’t say for sure if smoke is directly causing nesting birds like the warblers to fail in such a particular way, but the new observation as well as the literature review suggest a potential link. Kaiser and colleagues at Cornell and NZCBI recently published their findings in the Wilson Journal of Ornithology, with Davidson-Onsgard as the lead author. The study is the first systematic review of this particular kind of nest failure. We are in an age of megafires. Fire has always been an important part of the ecology of the West, but climate change and a century of forest mismanagement have amplified the scale and severity of wildfires beyond anything in modern history. A 2020 study showed that the average acreage burned in a wildfire almost tripled between 1950 and 2019. Through mid-September this year, over seven million acres have burned in the United States. Three times in the last decade, that number has topped seven million acres per year. In 2023, Canada’s fire season made even those numbers seem small. Forty-five million acres burned in Canada last year, an area larger than the entire state of Florida turned to smoke in one season. Wildfire smoke contains chemicals like carbon monoxide, sulfur dioxide and even lead. It also carries particles that scientists call PM2.5, meaning they are less than 2.5 microns, or 1/400th of a millimeter, in size—which makes them deadly. Because they’re so tiny, these particles can fit into the smallest crevices of the lung. A global study published in the Lancet found that four million people died as a result of PM2.5 pollution in 2019, more than twice the death toll of Covid-19 in 2020. According to Kaiser, the effects on birds could be even more severe. “It’s because of their respiratory system,” says Kaiser. “They’re moving a lot of air, much more volume of air than other animals. They have very efficient lungs, and so any air that has this particulate matter could be problematic for these birds.” In clean air, bird lungs have evolved to be incredibly efficient, but in smoky conditions, that same adaptation works against them. Nesting isn’t the only time that birds are susceptible to wildfire smoke. Until recently, smoke season rarely overlapped with the breeding season of most North American birds. But as fire seasons become longer and more severe, the chances increase of big smoke events like the one in 2023 that catch birds right as they are nesting. On the other side of the country from the woods of New Hampshire, another research team recently showed another set of effects from PM2.5 pollution and wildfire smoke on birds across the summer and fall, not just when they’re on the nest. Olivia Sanderfoot is an ecologist at the La Kretz Center for California Conservation Science at the University of California, Los Angeles. In a recent paper in Ornithology, Sanderfoot and colleagues found that birds in the San Francisco Bay Area lost body mass, a key measure of health that harms their ability to migrate, when they were exposed to wildfire smoke during the Bay Area’s July to November fire season. Scientists had theorized about that kind of effect but had not been able to establish and measure it before. “Knowing how big of a deal wildfire smoke is for people, it just made sense to me that birds would be similarly impacted,” says Sanderfoot, “because they are so highly sensitive to air pollution, and because, unlike people, they can’t take refuge indoors when the air is hazardous.” Like the New Hampshire warbler study, the San Francisco paper was led by a student, Anna Nihei, then an undergraduate majoring in computational and systems biology at the University of California, Los Angeles. Sanderfoot also helps oversee Project Phoenix, a community science effort that lets anyone in a study area in California, Oregon and Washington help monitor birds during wildfire season. She sees the warbler observations around the smoke event in 2023 as a meaningful development in understanding the effect of smoke on birds, and says the study is really important and powerful. “I think that considering smoke to be a disturbance in and of itself, outside the concept of fire, is a brand-new way of thinking about air pollution impacts on wildlife,” says Sanderfoot. Researchers are only now starting to understand some of the long-term effects of wildfire smoke on humans, and they still have a long way to go to measure its effect on birds and other wildlife as well. But evidence is mounting that smoke is another climate-related stressor, like heat and drought, that can have serious repercussions for birds, off and on the nest. As Sanderfoot explains, the warbler nesting observations around the smoke event in 2023 are a meaningful development in understanding the effect of smoke on birds. “It is not the norm that when we see these intense smoke events, the timing overlaps with the breeding season,” she says. “I have had conversations with many colleagues in which we have anticipated that should these two things align, the impact on bird populations would be big.” Get the latest Science stories in your inbox.

Study finds Central Valley residents continually exposed to 'toxic soup' of pesticides

A new study found that as Central Valley residents go about their day, they regularly breathe in pesticides, including one banned in California.

A recent UC Davis study found that as Central Valley residents go about their day, they regularly breathe in pesticides, including one that has been banned in California and another whose effects on people is unclear.The study, which was conducted in 2022 with the help of Central Valley residents, found that seven of 31 adults and one out of 11 children were exposed to detectable amounts of pesticides, including chlorpyrifos, which was banned by the state in 2020 after research showed it had a harmful neurodevelopmental effect on children.The researchers recruited volunteers to wear backpacks with air-collection tubes for at least eight hours a day. They found that the residents were exposed to five other pesticides including 1,3-dichloropropene, also known as 1,3-D, a pesticide used to eradicate parasitic worms that has been banned in more than 20 countries, and penthiopyrad, a fungicide used to prevent mold and mildew that has not yet been studied for its effect on mammals, so the human impact is unknown.It concluded that pesticide monitoring should be expanded because residents’ personal exposure included compounds not regularly measured in routine monitoring and that the pesticides should undergo additional toxicity testing.“It really highlights the need that we research the health impact of all these different pesticides that are being used because people are being exposed to a range of pesticides,” said Deborah Bennett, a scientist, UC Davis professor and lead author of the study, which was published Sept. 10 in the Journal of Exposure Science and Environmental Epidemiology.Bennett said she was surprised to find detectable amounts of chlorpyrifos because farmers were supposed to have stopped applying the pesticide. It was commonly used on alfalfa, almonds, citrus, cotton, grapes and walnuts. Before it was banned, more than 900,000 pounds of chlorpyrifos were used in 2017— more than in any other state. The primary manufacturer of the pesticide announced in 2020 that it would stop producing it due to reduced demand.It could be that a farmer was using the last of their reserves, or the individuals who tested for chlorpyrifos might have been exposed at home with products that use the pesticide, Bennett said, but researchers were ultimately unable to determine the cause.Leia Bailey, deputy director of communications and outreach for the state Department of Pesticide Regulation, said the agency did not have enough information to investigate the findings independently, but the department continues to enforce the ban on chlorpyrifos and maintains four air monitoring stations in areas where pesticides are used.She added that a preliminary review of the pesticide levels cited in the study found that they were “significantly below health screening levels.” Still, Bailey said, studies like this one complement the department’s work to inform their regulatory efforts. “Community-focused studies like this are key inputs to inform our continuous evaluation of pesticides,” Bailey said. She added that the department requires mammalian toxicology data for all pesticide evaluations, including penthiopyrad.Jane Sellen, co-director of the Californians for Pesticide Reform and co-author of the study, said she wasn’t surprised by the “toxic soup” of pesticides that they found through the study.“There’s not nearly enough pesticide monitoring happening in the state,” Sellen said.They recruited volunteers for the study in farmworking communities, and found that people were eager to participate because they wanted to know what they were being exposed to, she said. The volunteers were told to go about their regular day and wear the backpacks wherever they went, including to the grocery store, work and school. She said exposure to or illness from pesticides does not get reported as frequently as it occurs because people are afraid of being retaliated against or deported, as many farmworkers are in the U.S. without documentation.When the researchers were recruiting volunteers, the Tulare County Agricultural Commissioner Tom Tucker issued an advisory warning farmers to be “on the lookout for people trespassing onto orchards and farms” during or immediately after pesticide applications. The advisory asked residents to call Tucker’s office or the county sheriff.“We are concerned these individuals may attempt to enter a field or orchard during a pesticide application or immediately thereafter to utilize their air monitoring equipment in an attempt to detect pesticide spraying,” the advisory stated.The advisory, issued June 22, 2021, cited fliers that sought volunteers to wear backpacks. But those behind the study never asked participants to trespass or go near where pesticides were being applied, Sellen said.The state Environmental Protection Agency and Tucker later issued a joint statement clarifying the advisory and described the study as a project supported by the Air Resources Board and consistent with the Legislature’s intent to support community-led air monitoring.“The last thing we would ever do is send anyone into harm’s way,” she said. “It was really disheartening and disappointing that [the agricultural community] was threatened by the idea of monitoring air quality in these communities.”The communities, which were not named in the study, were in Kern, Fresno and Tulare counties, which have the highest pesticide applications in the state.

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