Tracking Poll on Health Information and Trust: Use of Social Media and AI For Health Information and Advice | KFF

Findings

Key Takeaways

• Adults in the U.S. are turning to social media and AI for health advice. KFF’s latest Tracking Poll on Health Information and Trust finds three in ten adults (31%) using social media at least monthly for health information and advice. This is similar to the share (29%) who now say they use AI tools or chatbots for health information monthly, a number that has nearly doubled in the past two years – up from roughly one in six (17%). Still, majorities say they either “never” or only “occasionally” use AI tools (71%) or social media (69%) for health information.
• Although some people turn to both social media and AI for health information, the two audiences are demographically distinct. While younger adults are more likely than older adults to use social media and AI for health information, the youngest cohort is much more likely to rely on social media while 30 to 49 year olds are more likely to turn to AI. Additionally, social media tends to attract lower-income adults, while AI use is more common among those with higher incomes or more advanced education. Hispanic adults stand out as notable adopters of both platforms for health information, unlike White adults, who are less likely to use either as a source of information.
• Need for community and immediacy of information drives use of social media for health information and advice. Over a third of those who use social media for health information and advice report that wanting to learn from people with the same health condition or similar experiences is a “major reason” they turn to social media (36%). A similar share (35%) say it is because they want immediate information or support. While fewer (17%) say that not having a regular health care provider or not being able to afford the cost is a “major reason” for turning to social media, that number rises to a third among adults without insurance and LGBT adults. Notably, similar shares say not being able to afford the cost of seeing a provider (19%) or not having a regular health care provider (18%) are both a “major reason” why they used AI tools for health information in KFF’s March 2026 Tracking Poll on Health Information and Trust as said the same for a reason why they used social media in this poll.
• The majority of social media and AI users are confident in their ability to parse true or false information, which is perhaps why few take steps to validate the information either from a doctor or some other source. Less than four in ten adults who use social media for health information follow up with a doctor at least most of the time (36%), consult another online source like WebMD (35%), or check with health agency websites, like the CDC (21%).

Social Media and AI Use for Health Information

Three in ten adults report using social media for health information or advice at least once a month. This includes about one in six (16%) who say they use it “every day.” Similarly, three in ten (29%) adults now say they use artificial intelligence (AI) tools or chatbots like ChatGPT, Google Gemini, or Claude for health information and advice monthly, nearly doubling in the past two years, up from roughly one in six (17%) in June 2024. Though they provide health information in different ways, the growing use of these technologies suggests that adults are looking beyond traditional health care sources. Still, a majority of the public say they either “never” or only “occasionally” use AI tools (71%) or social media (69%) for this.

Younger adults (ages 18 to 29), Hispanic adults, Black adults, and those with lower incomes are among the most likely groups to use social media for health information. About four in ten Hispanic adults (42%), those with incomes of $40,000 or less a year (40%), adults under the age of 30 (40%), and Black adults (39%) say they use social media for health information at least monthly.

On the other hand, AI use for health information is common among the youngest cohort (ages 18 to 29) as well as those ages 30 to 49. While those with lower levels of education and income are more likely to go to social media for health information, there is less variation with reliance on AI with about three in ten across income and education groups reporting using it at least monthly. Notably, larger shares of Hispanic adults report using both social media and AI for health information, compared to White adults.

Reasons for Using Social Media

People report using social media for health information for a variety of different reasons. Among those who use social media for health information and advice (60% of total adults), over a third (36%) say that wanting to learn from people who have the same health condition or share similar experiences is a “major reason” why. A similar share (35%) says a “major reason” was wanting immediate information or support. Fewer (17%) say that not having a regular health care provider or not being able to afford the cost of seeing a provider is a “major reason” why they turned to social media for health information, though about four in ten (42%) say that it is a reason.

The use of social media for health information and advice because of a lack of a regular health care provider or not being able to afford the cost is higher among groups that have historically had a harder time accessing health care. Among social media users, roughly three in ten uninsured adults (32%) say this was a “major reason” and another four in ten (37%) say it is a “minor reason” they turned to social media. Adults with lower incomes are more likely than those with higher incomes to report that not having a regular provider is a “major reason” for using social media for health information, with a quarter of those with an income of less than $40,000 a year saying so, compared to two in ten (19%) of those with an income of $40,000 to $89,999, and less than one in ten (6%) of those with a yearly income of $90,000 or more. LGBT adults are also more likely to say this is a reason they used social media, with three in ten LGBT adults reporting this was a “major reason” and a quarter (24%) saying it’s a “minor reason.” LGBT adults are also more likely to have lower incomes generally, possibly explaining some of the access issues they report, though they may lack a provider due to stigma and discrimination related issues.  

Additionally, larger shares of Hispanic adults (29%) and Black adults (23%) report that not having a regular provider is a “major reason” for seeking advice through social media than White adults (12%).

Notably, similar shares said not being able to afford the cost of seeing a provider (19%) or not having a regular health care provider (18%) were both a “major reason” why they used AI tools for health information in KFF’s March 2026 Tracking Poll on Health Information and Trust as said the same for a reason why they used social mediain this poll (17%).

Women are more likely than men to say that they wanted to learn from people who have the same health condition or shared similar experiences (39% of women v. 32% of men). Young adults under the age of 30 are also among the most likely to say wanting to learn from people with the same condition or experiences is a “major reason” why they sought out health information on social media (44% of those ages 18 to 29 v. 21% of those ages 65 and older).

Confidence in Discerning True or False Information

Slim majorities of adults say they are confident in their ability to tell what is true or false when it comes to health information from social media (61%) or AI chatbots (56%). In fact, roughly four in ten adults overall say they are “not too” or “not at all” confident in their ability to tell whether health information from AI chatbots (44%) or social media (39%) is true or false. Larger shares are confident when the information comes from more personal sources, with eight in ten saying they are confident they can parse information from a doctor or other health care provider (80%) or their family and friends (77%).

Younger adults are more likely to express confidence in their ability to tell whether health advice is true or false on both social media and AI tools or chatbots than their older counterparts. In addition to young adults, adults with a college degree or higher education and those with incomes of $90,000 or more a year are more likely than their counterparts to say they are confident they can tell the difference between true and false health information from social media and AI chatbots.

People who use AI for health advice are more likely than those who do not use it to be confident in their ability to discern what is true when using these tools. However, the difference is less pronounced when it comes to social media. Roughly seven in ten (69%) of those who use AI at least monthly are confident in being able to decipher the truth from that source, compared to half (51%) of those who use AI for health information “occasionally” or “never.” Similarly, a slightly larger share of those who use social media at least monthly say they can tell what is true or not from the health information they find on social media – around two-thirds (65%), compared to six in ten (59%) who don’t use social media for health information.

KFF’s March 2026 Tracking Poll on Health Information and Trust found that trust in AI for reliable health information was largely predicated on use, with most users saying they trust AI for health information compared to few non-users.

Following Up With Other Sources

While not every health-related social media query requires a follow-up with a doctor or health care professional, few of those who seek health information on social media say they regularly consult any other source for information. Roughly a third of adults who use social media for health information and advice say they followed up with a doctor or other health care professional (36%) “every time” or “most of the time” to verify the accuracy of the information they see on social media. A similar share (35%) say they consulted another online source, such as health websites, like WebMD after using social media for information, and an even smaller share (21%) say they checked with health agency websites, like the CDC, “every” or “most of the time” after using social media for health information and advice in order to verify the accuracy of the information.

In fact, a majority of social media users say they either “some of the time,” “rarely,” or “never” followed up with a health care provider (64%), consulted another online source (65%), or checked a government health agency website (78%) after using social media for health information.

KFF Tracking Poll on Health Information and Trust: Use of Social Media and AI For Health Information and Advice | KFF

Chairman Cassidy Advances Legislation Im... | Senate Committee on Health, Education, Labor and Pensions

Chairman Cassidy Advances Legislation Im... | Senate Committee on Health, Education, Labor and Pensions

WASHINGTON – Today, the U.S. Senate Health, Education, Labor, and Pensions (HELP) Committee voted to favorably report several bills making health care more affordable and accessible to American families. During the markup, U.S. Senator Bill Cassidy, M.D. (R-LA), Chairman of the HELP Committee, led Republicans in rejecting Ranking Member Bernie Sanders’ (I-VT) attempt to sabotage the bipartisan bills with toxic poison pill amendments.

“I understand why Americans are frustrated with Congress. If we want Congress to work, we have to make it work,” said Dr. Cassidy. “I want part of my legacy [to be] he tried to preserve the institution. But that is a responsibility of us all.”

“I appreciate my colleagues’ efforts and will continue to work with Republicans and Democrats to enact a pro-patient, pro-family agenda,” continued Dr. Cassidy.

The Charlotte Woodward Organ Transplant Discrimination Prevention Act, Healthy Start Reauthorization Act, Stem Cell Therapeutic and Research Reauthorization Act, EARLY Act Reauthorization, Accelerating Access to Critical Therapies for ALS Act, and the Biosimilar Red Tape Elimination Act passed unanimously as amended in an en bloc vote. The Medication Affordability and Patent Integrity Act also passed in a 16-6 vote.

The bills approved include:

• Charlotte Woodward Organ Transplant Discrimination Protection Act

• Healthy Start Reauthorization Act of 2026

• Stem Cell Therapeutic and Research Reauthorization Act

• EARLY Act Reauthorization of 2025

• Accelerating Access to Critical Therapies for ALS Act of 2026

• Medication Affordability and Patent Integrity Act

• Biosimilar Red Tape Elimination Act

Click here to watch Cassidy’s opening remarks.

Click here to watch the full executive session.

A family member stood at the bedside asking why her son was on fentanyl, why he was on this particular antibiotic, whether she could see the cultures. She was treated as a nuisance. She was, in fact, the only unpaid second set of eyes in the room. That is not a story about one hospital. It is a story about who we let into the room when a patient cannot speak for themselves, and what we lose when we shut them out. Laura Buchman, MBA is a patient advocate and the author of NERVE: Surviving Medical Madness. Her son, healthy at 19, went to the hospital for chest pain and within days was paralyzed from the neck down and on a ventilator. She was kept out of rounds. When she questioned a strong antibiotic, she was told the physician had done the job for 25 years, and that ended the conversation. She went back through the medical records herself and reconstructed what she believes was a cascade of avoidable harm. For anyone who leads a clinical team, runs a safety program, or designs how families are handled at the bedside, her experience surfaces three things worth sitting with. First, an engaged family member is a free safety layer, not a threat to throughput. The questions she asked, why this drug, why now, can I see the culture results, are the same questions a good safety culture wants asked out loud. Second, "I have done this for 25 years" is a tell, not an answer. When seniority is used to close a question rather than satisfy it, the system has just lost information it needed. Third, the rate is the argument. One large study published in the New England Journal of Medicine found roughly one in four reviewed patients experienced an adverse event. At that rate, the family asking why is not paranoid. They are statistically reasonable. She is careful to credit the individual clinicians as kind and well meaning. Her critique is structural, which is exactly what makes it a leadership problem rather than a personnel one. The mechanism is simple and uncomfortable. Most of what she uncovered was already in the chart. The failure was not missing data. It was a default posture that treats the family as a visitor to be managed rather than a monitor to be debriefed. That posture is a design choice, and design choices are something leaders can change. Search "The Podcast by KevinMD" wherever you listen to podcasts What is one change a leader could make this quarter so that a family member's question at the bedside is captured as a safety signal rather than managed as an interruption? #PatientSafety #HealthcareLeadership #PatientExperience #ThePodcastbyKevinMD…

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10 Reasons Doctors Don't Care About Customer Service

Patient-customer service, to put it mildly, is an opportunity for improvement. Yet, most of the things that bug patients before, during, and after the visit can be fixed by the doctor and care team. Everyone knows that patients are angry when they have to wait, and sick-care billing and collection makes patients angry.

So, what is the etiology and treatment? If everyone knows there is a problem, why doesn't your doctor treat it?

1. They don't care because quality of care is their first priority, not quality of service or experience.

2. They don't always have control over dysfunctional systems that are the root cause.

3. They don't have customer-patient service knowledge, skills, and attitudes because they were not provided and measured during their training

4. They have role models and mentors that have bad customer-patient experience skills

5. They are not that empathic and rate low on other emotional intelligence parameters that are associated with excellent customer service professionals. It certainly is not a reason they were accepted to medical school.

6. There are few motivations or incentives to do it.

7. Particularly for those working as employees, the care team is stacked into care deliverers, nurses, and clerks, all answering to different bureaucracies.

8. Doctors don't want to spend the money to fix things and don't see the return on investment.

9. They have not made patient-customer service a habit.

10. They are increasingly disengaged.

The treatment to the problem is in changing physician behavior and making patient-customer service a habit. That takes some internal motivation to want to change, being sensitive to triggers, providing resources, education, tools, and metrics (on time arrival APP?), and rewarding the desired behavior as soon as possible after doing something positive, with a high likelihood that staff will be rewarded if they do the right thing with something they value. The reward might not always be money. It could be unlimited vacation time or concierge services.

Making customer-patient service a habit should be as commonplace as checking vital signs as part of a physical exam. It starts the first day of medical school.

Let's face it . Most medical customer/patient service/experience sucks. Fixing it has become a growth industry because a) organizations are getting rewarded and penalized on patient/customer service and 2) they have to to be competitive to grow market share. Since patients know little or nothing about the quality of care they are getting, they use customer service as a surrogate measure. One has nothing to do with the other, but that's the way the medical world seems to be turning. 

Like any service idustry, the patient-customer experience is about what happens before , during and after the service is rendered. Ask yourself:

1. Are providing the information and education patients want and need before the visit?

2. How easy is it for them to make an APPointment?

3. What is the pre-visit telephone experience like?

4. How convenient is getting to your office, maps, signage and parking?

5. How long does it take to get an appointment to see you?

6. How would you rate your office space or other physical plant?

7. Are you or your employees grumpy?

8. What is your on time arrival record and do you even measure it?

9. How would you rate your service after the service and ability of patients to follow up with questions or concerns?

10. Would you be happy if you were billed and expected to pay the way you bill and collect from your patients?

The patient experience can largely be controlled by doctors and the people who work with them. Most of the time, when the experience is painful, it is because doctors are unwilling to treat it. 

Should customer service be taught in medical school?

Customer service principles—such as empathy, active listening, and clear communication—should be integrated into medical school. While medicine prioritizes clinical outcomes, effective patient-facing interaction remains a core competency. Studies show that clinical customer service training significantly boosts patient satisfaction and lowers complaints. [1, 2, 3, 4, 5, 6]

Customer service features

• Empathy. ...
• Communication. ...
• Patience. ...
• Problem-solving. ...
• Active listening. ...
• Reframing ability. ...
• Time management. ...
• Adaptability.

That is a wrap.   Do you have other suggestions? Comment below.

10 Reasons Doctors Don't Care About Customer Service

Nearly 300 studies link the pesticide chlorpyrifos to multi-organ damage

Nearly 300 studies link the common pesticide chlorpyrifos to multi-organ damage, DNA disruption, and chronic disease 

Scientists tie chlorpyrifos to brain, liver, endocrine, and genetic damage, including at doses below current safety standards

Key findings:

• A review of nearly 300 studies summarizes evidence that chlorpyrifos may harm multiple systems throughout the body, including the brain, hormones, liver, gut microbiome, muscles, reproductive organs, and bones.
• The review describes DNA damage, chromosome instability, and epigenetic changes that may alter how genes function long after exposure.
• Some harmful effects appear at exposure levels below those considered safe under current pesticide exposure testing standards.

For decades, regulators viewed chlorpyrifos — a pesticide widely used in the U.S. and around the world — primarily as a neurotoxin that disrupts signaling in the brain and nervous system. But as the EPA reconsiders whether to continue to allow its use on foods like apples and soybeans, a new review indicates other insidious harms.

Published in April [2026] in the International Journal of Molecular Sciences, the review synthesizes findings from nearly 300 studies worldwide published up to this year. These include laboratory experiments, animal studies, epidemiological research, regulatory documents, and risk assessments.

Growing evidence suggests chlorpyrifos may damage the brain, hormones, liver, gut microbiome, muscles, reproductive organs, and bones. Studies also link the pesticide to DNA damage and lasting changes in gene activity that may increase the risk of chronic disease.

Together, the findings portray chlorpyrifos as what the reviewers call a “multi-system toxicant” that poses a more significant threat to public health than previously understood. It suggests the pesticide acts on the body in ways far beyond disrupted nerve signaling or obvious poisoning. Pregnancy and early childhood are especially sensitive periods for chemical exposure.

“What has genuinely evolved over time is our understanding that chlorpyrifos causes harm in ways that go beyond its effects on the nervous system including damage to DNA, changes in how genes are switched on or off, interference with hormones, and disruption of the healthy bacteria that live in the gut,” said Dr. Dana Boyd Barr, a professor at Emory University’s Rollins School of Public Health and past president of the International Society of Exposure Science.

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The authors warn that current regulatory systems may not fully capture the complexity of chlorpyrifos’ dangers to the body. Many occur at levels too low to be detected by current safety testing, which looks for the disruption of an enzyme involved in nerve cell communication. 

The review links chlorpyrifos exposure to:

• Biological changes associated with inflammation, chronic disease, and cancer 
• Brain and nervous system damage, including lower IQ and developmental harms in children, neurodegenerative disease, and disrupted cell growth, survival, and communication  
• DNA damage and altered gene regulation that hinders normal cell repair and changes how genes are switched on and off during development (epigenetics)
• Hormone disruption involving thyroid, estrogen, and testosterone pathways
• Liver injury, gut bacteria disruption, and metabolic dysfunction linked to obesity and type 2 diabetes
• Reproductive, muscular, and skeletal harm, including reduced sperm quality and bone loss

Industry pushback despite reported harms

The review comes as the EPA reassesses whether the pesticide’s remaining uses meet the statutory standard of “no unreasonable adverse effects.” The action follows years of official stalling, prior bans, policy reversals, and legal challenges. 

Meanwhile, agrichemical companies are lobbying federal and state lawmakers to shield pesticide manufacturers, including Bayer and its subsidiary Monsanto, from some lawsuits involving Roundup weedkiller. The suits allege their products cause non-Hodgkin lymphoma (NHL), among other cancers.  

In February 2020, Corteva Agriscience—then the world’s largest producer of chlorpyrifos — announced it would stop production, citing declining demand. But existing stocks continued to be used. The chemical remains approved for several major crops in the U.S., including apples, strawberries, soybeans, citrus, wheat and peaches.

Health concerns trigger restrictions and bans 

Chlorpyrifos — the active ingredient in Dursban^® and Lorsban^® — belongs to a class of chemicals known as organophosphates. Introduced in the U.S. in 1965, chlorpyrifos became one of the world’s most heavily used insecticides by the 1990s. 

Farmers use chlorpyrifos to control ticks on cattle and pests on crops. It is used on golf courses, in greenhouses, on wood products such as telephone poles, and in residential areas.

Chlorpyrifos poses a significant neurotoxic risk to humans, with developing fetuses and children being particularly vulnerable.

U.S. regulators banned chlorpyrifos for household use in 2001. The ban came after mounting evidence, including a prominent study by Columbia University, linked exposure to developmental brain harms in children.

Evidence that chlorpyrifos damages children’s brains later prompted bans or restrictions in more than 40 countries, including the European Union. The European Food Safety Authority concluded there was no safe exposure level, but it is still widely used elsewhere in the world. Several U.S. states, including California, New York, Hawaii, Oregon and Maryland, currently maintain restrictions or bans.

Yet chlorpyrifos persists in food (including fruits, cereals, and vegetables), the environment, and human tissue. The compound dissolves easily in fats and crosses cell membranes, allowing it to accumulate in tissues over time.

It can also travel long distances — in some cases more than 600 miles — from where it was applied. Researchers have detected residues in food, drinking water, soil, rain, snow, and wildlife. Samples range from the Mississippi River to remote Antarctica.

Children, pregnant women, farm workers face the highest risks

Health effects of chlorpyrifos depend on dose, duration, and route of exposure, the reviewers say. Genetic differences may also influence vulnerability.

For most people, exposure occurs through contaminated food, water, and air. Farmworkers often face the highest exposure levels. But researchers say chronic low-level exposure during pregnancy and childhood may also carry risks.

Infants and children remain especially vulnerable because their detoxification systems are still developing. They also consume more food relative to body weight and frequently put their hands in their mouths.

Chlorpyrifos risks extend beyond nerve damage

For years, scientists and regulators focused on one primary mechanism of harm. Chlorpyrifos becomes more toxic after the body converts it into a compound called chlorpyrifos-oxon. This blocks acetylcholinesterase (AChE), the enzyme that breaks down acetylcholine in the nervous system.

Acetylcholine is a neurotransmitter essential for communication between nerve cells. It also helps regulate attention, learning, memory, movement, breathing, and heart rate.

Without acetylcholinesterase, nerves fire uncontrollably. In insects, the effect causes paralysis and death. In humans, severe poisoning can cause seizures, respiratory failure, or death.

That effect on the single enzyme still matters. But the review argues it no longer explains the full scope of chlorpyrifos toxicity.

Chlorpyrifos affects the nervous system not only by blocking AChE activity, its well-known toxic mechanism, but also by disrupting fat balance in cells and interfering with other cell signaling pathways. These additional effects may worsen its harmful impacts on the brain and nervous system.

Chlorpyrifos is linked to cell damage throughout the body

Instead, researchers describe evidence that the pesticide may trigger widespread biological stress across organs and tissues. Studies point to several possible mechanisms, including inflammation and oxidative stress, when highly reactive oxygen-containing molecules build up, damage cells, and weaken the body’s defenses. Other ways include hormone disruption and altered gene regulation.

Chlorpyrifos may be especially harmful to mitochondria, the structures inside cells that produce most of the body’s energy. Damaged mitochondria can leak harmful, highly reactive molecules (mtROS) that can damage DNA, proteins, and cell structures.

The review also highlights how chlorpyrifos may cause genes to switch on and off. Scientists increasingly believe these changes may help explain how environmental exposures contribute to chronic disease years after exposure occurs.

“While traditionally characterized by its potent acetylcholinesterase-inhibitory properties, accumulating evidence now shows that chlorpyrifos and its bioactive metabolite, chlorpyrifos-oxon (CPO), exert far broader toxic effects, including the induction of oxidative stress, enhancement of neuroinflammatory processes, and the triggering of persistent epigenetic alterations,” the authors wrote.

Babies and children are more susceptible to the harms

The American Academy of Pediatrics warns that chlorpyrifos exposure poses risks to fetuses, infants, children, and pregnant women. Chlorpyrifos crosses the placenta and injures the developing nervous system before birth.

“Chlorpyrifos poses a significant neurotoxic risk to humans, with developing fetuses and children being particularly vulnerable,” they wrote. “Neurotoxic effects of the pesticide have been observed even at low doses.”

The body’s defenses against chlorpyrifos also depend heavily on an enzyme called paraoxonase-1 (PON1) that helps break it down. But PON1 activity varies widely among individuals due to genetics and age.

Infants and young children naturally have lower levels. This may also increase their susceptibility to toxicity, the authors say.

Prenatal exposure linked to lasting brain damage and lower IQ

Human studies link prenatal chlorpyrifos exposure to:

• Attention deficits
• Delayed motor development
• Lower birth weight
• Reduced IQ
• Structural brain abnormalities

For instance, an August 2025 study of New York City children found that prenatal exposure to chlorpyrifos was linked to widespread brain abnormalities and weaker motor skills years later. The researchers concluded prenatal exposure may cause lasting brain disruptions. The effects appeared to worsen with higher exposure.

What emerges is a troubling picture: the developing brain is being shaped by a toxic soup of chemicals acting on the same parts of the brain.

Meanwhile, animal studies show that chlorpyrifos disrupts nerve cell growth and alters brain signaling tied to learning and memory. It also damages connections between neurons during critical developmental periods, studies suggest. 

Perhaps most striking, chlorpyrifos appears in these studies to suppress brain-derived neurotrophic factor (BDNF). BPA, flame retardants, and other toxic chemicals also disrupt BDNF, which Dr. Bruce Lanphear describes as “fertilizer for the brain.” 

Brain-derived neurotrophic factor helps neurons survive and form synapses. It also helps them strengthen learning pathways and recover from injury.

“What emerges is a troubling picture: the developing brain is being shaped by a toxic soup of chemicals acting on the same parts of the brain,” said Lanphear, a preventive medicine physician and professor at Vancouver’s Simon Fraser University who studies how toxic chemicals impact human health. “Yet when the EPA evaluates chlorpyrifos, it largely considers the pesticide on its own—not alongside other chemicals that disrupt the same brain pathways.”

Studies investigate links between chlorpyrifos and cancer

The ways chlorpyrifos affects the body may contribute to the growth and rate of liver, breast, and ovarian tumors, studies indicate. One large 2015 study of more than 30,000 women—spouses of pesticide applicators—linked chlorpyrifos exposure to elevated breast cancer risk. While human evidence remains limited and inconsistent, the reviewers say, the combination of effects warrants closer investigation.

Additionally, 3D laboratory models suggest that chlorpyrifos may cause breast cancer cells to invade nearby tissues more actively. Epidemiological studies also report associations with hormone-related cancers, particularly more aggressive forms of hormone receptor-negative breast cancer. 

Animal studies done in living organisms also indicate that long-term, low-dose exposure to chlorpyrifos increases the risk of breast cancer, the reviewers say. The pesticide can make tumors appear sooner and increase their number, likely due to hormone disruption.

Parkinson’s, memory loss and other neurological impacts

The review cites evidence linking chlorpyrifos exposure to movement problems, memory impairment, anxiety-like behaviors, and damage to brain regions involved in emotion and cognition. One recent study reports that chlorpyrifos exposure may be associated with more than double the risk of Parkinson’s disease.

Researchers say chlorpyrifos-oxon (CPO) — produced when the body breaks down chlorpyrifos — may be especially dangerous. According to federal researchers, chlorpyrifos-oxon is about 1,000 times more toxic than chlorpyrifos itself.

Laboratory research indicates CPO may disrupt pathways tied to learning, memory, inflammation, and nerve cell survival. Studies also suggest that chlorpyrifos-oxon damages a structural protein called tubulin, potentially disrupting brain development. Tubulin helps nerve cells grow and form connections.

“Overall, the ability of CPO to interfere with normal developmental processes in the nervous system far exceeds that of its parent compound,” the authors wrote.

Hormone disruption linked to fertility and metabolic problems

The review finds substantial evidence that chlorpyrifos may interfere with multiple hormone systems (endocrine disruption) throughout the body. These include thyroid, estrogen, and testosterone pathways.

Research links exposure to abnormal reproductive cycles and tissue development, lower sperm counts, and reduced sperm quality. Some studies suggest it causes reduced prostate weight and disrupted hormone signaling in placental cells. Chlorpyrifos may also contribute to obesity, insulin resistance, and blood sugar problems, the review shows. 

Gut bacteria changes may fuel inflammation and disease

The review also tracks harms involving the gut microbiome — the ecosystem of microbes that supports digestion, metabolism, and immune function. Experimental studies indicate reductions in beneficial bacteria alongside increases in potentially harmful microbes after chlorpyrifos exposure. 

These changes may be tied to leaky gut syndrome, when bacterial toxins enter the bloodstream and trigger inflammation throughout the body. This type of gut-liver axis disruption may contribute to systemic inflammation and metabolic disease, the reviewers say.

Studies link chlorpyrifos  to liver, bone and muscle damage

The liver itself emerges as a major target of chlorpyrifos, experimental studies show. Researchers describe potential ties between chlorpyrifos and:

• Chronic liver inflammation
• Disrupted cholesterol, with higher levels of LDL  (“bad”) cholesterol and lower HDL (“good”) cholesterol
• Liver cell injury, including a form of cell death linked to iron buildup in liver cells (ferroptosis)

The review also links chlorpyrifos to musculoskeletal damage, including weaker bone formation, reduced bone density, and increased bone breakdown. Some bone changes occurred alongside neurological problems, suggesting broader developmental damage.

Studies show structural and functional changes involving both “slow-twitch” endurance muscles and “fast-twitch” muscles used for rapid movement. Some suggest chlorpyrifos may damage the diaphragm.

Chlorpyrifos DNA damage and altered gene activity raise alarm

The review highlights growing evidence that chlorpyrifos may damage DNA. Researchers describe chromosome damage and broken DNA strands. 

Studies also point to disruption of microRNAs, molecules that help regulate processes such as brain development, inflammation, and cell growth. And they suggest chlorpyrifos alters gene regulation in ways linked to neurodevelopmental disorders, metabolic disease, inflammation, and cancer.

“Collectively, the studies discussed above indicate that chlorpyrifos is a multifaceted genotoxic agent whose harmful effects extend far beyond acetylcholinesterase inhibition to include direct DNA strand breaks, chromosomal instability, and epigenetic reprogramming in various cell types, tissues, and species, detectable even at environmentally and clinically relevant concentrations,” they wrote.

Studies investigate links between chlorpyrifos and cancer

The ways chlorpyrifos affects the body may contribute to liver, breast, and ovarian tumors, studies indicate. These include changes in DNA damage and repair, cell growth control, and gene expression. 

Experimental studies in liver and breast cells found abnormal cell growth and altered tumor progression. Some epidemiological studies report associations with hormone-related cancers, particularly more aggressive forms of hormone receptor-negative breast cancer.

One large 2015 study of more than 30,000 women—spouses of pesticide applicators—linked chlorpyrifos exposure to elevated breast cancer risk. While human evidence remains limited and inconsistent, the reviewers say, the combination of effects warrants closer investigation.

Current safety standards fail to protect public health

Underlying the review is a larger challenge to how regulators evaluate the safety of chlorpyrifos and other pesticides. Current approaches, the authors say, do not adequately account for their effects, especially during fetal development and early childhood.

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“The regulatory system was designed to prevent obvious poisoning, but many pesticide-related diseases do not appear immediately. Exposures too low to cause symptoms today may impair fetal brain development or contribute to Parkinson’s disease decades later,” Lanphear added. “The science has moved ahead of the regulatory framework. That is the gap this review highlights.”

Epidemiological studies suggest that prenatal and early-life exposure, even at relatively low environmental levels, may be linked to impaired neurodevelopment and cognitive function. That means both the way exposure occurs and the amount of exposure should be considered important factors that influence toxic effects when evaluating health risks, they say.

They also revisit longstanding criticism of industry-funded chlorpyrifos studies that have been used to shape federal exposure limits for decades. They cite the so-called “Coulston study,” a 1972 safety evaluation funded by Dow Chemical. 

Later researchers questioned parts of the study, arguing that it was not peer-reviewed. They also found that some baseline data was excluded from the original analysis, understating the pesticide’s toxicity.

The review calls for an independent reassessment of industry-sponsored toxicology studies used in past safety evaluations. It also calls for stronger protections for children and pregnant women, expanded biomonitoring programs, and safer pesticide alternatives, the authors say.

They argue that academic research should play a larger role in regulatory decisions to provide a fuller picture of chlorpyrifos harms. Independent research indicates a potentially higher threat to human health, particularly for children, due to exposure to this pesticide, they say.

“The societal costs associated with these risks are substantial, highlighting the urgent need for stricter regulations on chlorpyrifos use,” the authors wrote.

How is it that industry carries so much weight in these decisions? Has the FDA been infiltrated by corporate executives?  Do they sign disclosure agreements?

HOW ARE THEY CHOSEN?

Reference

Kalenik S, Zaczek A, Rodacka A. Chlorpyrifos and Chlorpyrifos-Oxon: A Widening Spectrum of Toxicity. International Journal of Molecular Sciences. 2026; 27(9):3909. https://doi.org/10.3390/ijms27093909

Categories: Chemicals of Concern, Endocrine Disruptors, Healthwire, Pesticides Tags: Secondary Article

Nearly 300 studies link the pesticide chlorpyrifos to multi-organ damage