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Microplastics discovered in human and dog testes

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Microplastics discovered in human and dog testes

Researchers have located one more anatomical organ where microplastics — of all shapes and constituents — are found: human testes.

And although they can’t say for sure, they suspect the presence of these jagged bits and strands of polymers such as polyethylene, polyvinyl chloride and polystyrene could be — in part — behind a global trend in diminishing sperm quality and quantity.

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In 2022, a team of researchers published a paper showing that global sperm counts fell about 1.2% per year between 1973 and 2018. From the year 2000, that rate accelerated to more than 2.6% per year.

“What I think will grab people’s attention with this study is the fact that plastic is in the testicles and potentially contributing to disarray in the function of the testicles,” said Leonardo Trasande, a pediatrician and public policy expert at New York University’s Grossman School of Medicine and Wagner School of Public Service.

“What should have gotten people excited all along is the fact that we’ve known that the invisible chemicals — the phthalates, the bisphenols and the PFAS that are used in plastic materials — are already known to be problems,” he said. “And so if this is what it takes to get people’s attention, I’m a bit sad. Because we already had enough evidence that plastics were bad for testicular function.”

Others, including Philip Landrigan, director of the Program for Global Public Health and the Common Good at Boston College, said the study was “consistent with a whole series of papers that have come out now in the last few years” showing these particles in a variety of organs, including the heart, liver, lungs and brain.

“It’s no surprise that microplastics are in the testes. The plastic is ubiquitous in today’s world, the stuff breaks down, and the smaller the particle, the more easily it can move into and throughout the human body,” he said.

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Xiaozhong Yu, a professor of environmental health at the University of New Mexico — and an author on this latest research — said he’d been researching the effects of different chemicals on sperm production for years, and it was only recently that a colleague suggested he look for microplastics in testes.

“I said, ‘Are you joking?’,” he said, recalling the conversation, explaining he was pretty certain he wouldn’t find microplastics in tests because — like the brain — these sperm-generating factories are insulated by a protective barrier.

Nevertheless, they gave it a go.

They started by trying it out in dog testes. They were able to acquire 47 from neutering clinics. (The pet owners all provided permission.)

They found microplastics in small dogs, big dogs, young dogs and old dogs. The plastic bits were in every dog testis they examined. The number ranged from 2.36 micrograms per gram to 485.77 micrograms per gram. The average was 122.63 micrograms per gram, and 12 polymers were identified. The most abundant were polyethylene — the material found in plastic packaging, films and bottles — and polyvinyl chloride — a material found in most household water pipes.

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He said he immediately went back to investigate their quality control. Maybe the testes had become contaminated at some point during the procedure or testing?

He and his team were able to rule that out, although Landrigan noted that contamination was still possible — unless everything, from procurement to analysis had been done in a “clean” room devoid of all plastic.

Yu and his team then decided to look at human samples. In the end, they were able to examine 23 testes from men ages 16 to 88. The tissue was acquired from males who had died in accidents and whose testes had been preserved post-autopsy. He said all samples were from men who had died in 2016 — made available following a seven-year storage requirement, after which time such samples are usually discarded.

Once again, they found microplastics in every sample they examined, and as with the dog testes, there was wide variation — from 161.22 micrograms per gram to 695.94 micrograms per gram, with an average of 328.44 micrograms per gram — nearly three times greater than what they found in dogs.

The microplastics in human testes were also composed of a variety of polymers, with polyethylene being the most common, followed by ABS (acrylonitrile, butadiene and styrene monomers — which is used to make a variety of products, including toys, automotive parts, medical equipment and consumer electronics), N66 (a kind of nylon), polyvinyl chloride and others.

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The researchers also noted a correlation between the concentrations of PVC and polyethylene and testes weight: The higher the concentration, the lower the weight.

“Generally, a decreased testis weight is indicative of reduced spermatogenesis,” wrote the authors in the paper.

Yu said the difference in humans and dogs between polymer types — with dogs showing higher concentrations of PVC than men — likely has to do with lifestyle differences. He said consumer trends show a general aversion to eating or drinking out of bottles and foodware made from PVC, which contains bisphenol A — an additive that has been associated with health and developmental harm.

However, he began looking at dog toys, and noticed many of them are made from this kind of plastic.

“People are choosing to avoid it,” he said. But the market hasn’t budged in the same way for dogs.

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Asked what the major route of exposure was for dogs and people, he said “microplastics are everywhere — in the air, in the drinking water, in the food, in our clothes. We don’t exactly know what is the most probable route. But they are everywhere.”

He also noticed variation within the groups. Dog testes acquired from public veterinary clinics showed higher levels of microplastics than those from private clinics, “potentially reflecting the influence of socioeconomic differences on the living environments and lifestyles of dogs.”

The researchers were also not able to find a correlation between age and microplastic concentration — a finding that surprised them. (Although men over the age of 55 had the least amount).

“The absence of a distinct age-dependent accumulation of microplastics in human testes may be due to unique physiological and biological processes of spermatogenesis,” they wrote, noting the continual renewal and release of sperm, which could “help mitigate the buildup of microplastics over time.”

That hypothesis, they noted, was supported by the presence of microplastics in human seminal fluid.

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“The reality is that the petrochemical industry has gotten a pass all these years,” said Trasande, the NYU professor. “We know that plastics come from the petrochemical industry … and it’s no secret that we have paid as a society by letting the petrochemical industry pollute us. Now we’re paying the consequences. And if we don’t reverse course fairly quickly, we will have an even bigger problems before us because plastic consumption is growing, not slowing down.”

Landrigan agreed and noted that nations were currently in negotiations to sign a treaty that would curb the use of plastic and cap production.

“Plastic production is increasing exponentially,” he said noting that it’s increased more than 200-fold since the 1950s. He said plastic production is on a trajectory to double by 2040 and triple by 2060. There have been a total of about 8 billion tons of plastic produced since 1950, he said, and about 6 billion tons is “floating around us, most of it in the form of microplastics.”

He said the anatomical location of this latest microplastic discovery may hit close to home for lawmakers, who until this time, have not been too concerned.

He said he’d had to testify in the Senate several years ago about endocrine disruptors, and mentioned that sperm quantity was reduced in men who’d been exposed.

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“Two senators sat back and unconsciously crossed their legs,” he said. “The body language was amazing.”

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‘We’re not going away’: Rob Caughlan, fierce defender of the coastline and Surfrider leader, dies at the age of 82

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‘We’re not going away’: Rob Caughlan, fierce defender of the coastline and Surfrider leader, dies at the age of 82

Known by friends and colleagues as a “planetary patriot,” a “happy warrior” and the “Golden State Eco-Warrior,” Rob Caughlan, a political operative, savvy public relations specialist and one of the early leaders of the Surfrider Foundation, died at his home in San Mateo, on Jan. 17. He was 82.

His wife of nearly 62 years, Diana, died four days earlier, from lung cancer.

Environmentalists, political operatives and friends responded to his death with grief but also joy as they recalled his passion, talent and sense of humor — and his drive not only to make the world a better place, but to have fun doing it.

“He’d always say that the real winner in a surfing contest was the guy who had the most fun,” said Lennie Roberts, a conservationist in San Mateo County and longtime friend of Caughlan’s. “He was true to that. It’s the way he lived.”

“When he walked into a room, he’d have a big smile on his face. He was a great — a gifted — people person,” said Dan Young, one of the original five founders of the Surfrider Foundation. The organization was cobbled together in the early 1980s by a group of Southern California surfers who felt called to protect the coastline — and their waves.

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They also wanted to dispel the stereotype that surfers are lackadaisical stoners — and show the world that surfers could get organized and fight for just causes, said Roberts, citing Caughlan’s 2020 memoir, “The Surfer in the White House and Other Salty Yarns.”

Before joining Surfrider in 1986, Caughlan was a political operative who worked as an environmental adviser in the Carter administration. According to Warner Chabot, an old friend and recently retired executive director of the an Francisco Estuary Institute, Caughlan got his start during the early 1970s when he and his friend, David Oke, formed the Sam Ervin Fan Club, which supported the Southern senator’s efforts to lead the Watergate investigation of President Nixon.

According to Chabot, Caughlan organized the printing of T-shirts with Ervin’s face on them, underneath the text “I Trust Uncle Sam.”

“He was an early social influencer — par extraordinaire,” he said.

Glenn Hening, a surfer, former Jet Propulsion Laboratory space software engineer and another original founder of the Surfrider Foundation, said one of the group’s initial fights was against the city of Malibu, which in the early 1980s was periodically digging up sand in the lagoon right offshore and destroying the waves at one of their favorite surf spots.

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According to Hening, it was Caughlin’s unique ability to persuade and charm politicians and donors that put Surfrider’s efforts on the map.

Caughlan served as the foundation’s president from 1986 to 1992.

The foundation grabbed the national spotlight in 1989 when it went after two large paper mills in Humboldt Bay that were discharging toxic wastewater into an excellent surfspot in Northern California. The foundation took aim and in 1991 filed suit alongside the U.S. Environmental Protection Agency; the paper mills settled for $5.8 million.

Hening said the victory would never have happened without Caughlan.

The mills had tried to brush off the suit by offering a donation to the foundation, Hening said. But Caughlan and Mark Massara — an environmental lawyer with the organization — rebuffed the gesture.

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“The paper mill guys said, ‘Well, what can we do here? How can we make this go away?’” said Hening, recalling the conversation. “And Rob said, ‘It’s not going to go away. We’re not going away. We’re surfers.”

Roberts said Caughlan’s legacy can be felt by anyone who has ever spent time on the San Mateo County coastline. In the 1980s, the two spearheaded a successful ballot measure still protects the coast from non-agricultural development and ensured access to the beaches and bluffs. It also prohibits onshore oil facilities for off-shore facilities.

The two also worked on a county measure that led to the development of the Devil’s Slide tunnels on Highway 1 between Pacifica and Montara, designed to make that formerly treacherous path safer for travelers.

The state had wanted to build a six-lane highway over the steep hills in the area. “It would have been dangerous because of the steep slopes, and it would be going up into the fog bank and then back down out of the fog. So it was inherently dangerous,” Roberts said.

Chad Nelsen, the current president of the Surfrider Foundation, said he was first drawn into Caughlan’s orbit in 2010 when Surfrider got involved with a lawsuit pertaining to a beach in San Mateo County. Silicon Valley venture capitalist Vinod Khosla purchased 53 acres of Northern California coastline for $32.5 million and closed off access to the public — including a popular stretch known as Martin’s Beach — so Surfrider sued.

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Nelsen said that although Caughlan had left the organization about 20 years before, he reappeared with a “sort of unbridled enthusiasm and commitment to the cause,” and the organization ultimately prevailed — the public can once again access the beach “thanks to ‘Birdlegs.’”

Birdlegs was Caughlan’s nickname, and according to Nelsen, it was probably coined in the 1970s by his fellow surfers.

“He had notoriously spindly legs, I guess,” Nelsen said.

Robert Willis Caughlan was born in Alliance, Ohio, on Feb. 27, 1943. His father, who was a parachute instructor with the U.S. Army, died when Caughlan was 4. In 1950, Caughlan moved with his mother and younger brother to San Mateo, where he saw the ocean for the first time.

He rode his his first wave in 1959, at the age of 16, from the breakwater at Half Moon Bay.

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LAUSD says Pali High is safe for students to return to after fire. Some parents and experts have concerns

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LAUSD says Pali High is safe for students to return to after fire. Some parents and experts have concerns

The Los Angeles Unified School District released a litany of test results for the fire-damaged Palisades Charter High School ahead of the planned return of students next week, showing the district’s remediation efforts have removed much of the post-fire contamination.

However, some parents remain concerned with a perceived rush to repopulate the campus. And while experts commended the efforts as one of the most comprehensive post-fire school remediations in modern history, they warned the district failed to test for a key family of air contaminants that can increase cancer risk and cause illness.

“I think they jumped the gun,” said a parent of one Pali High sophomore, who asked not to be named because she feared backlash for her child. “I’m quite angry, and I’m very scared. My kid wants to go back. … I don’t want to give him too much information because he has a lot of anxiety around all of these changes.”

Nevertheless, she still plans to send her child back to school on Tuesday, because she doesn’t want to create yet another disruption to the student’s life. “These are kids that also lived through COVID,” she said.

The 2025 Palisades fire destroyed multiple buildings on Pali High’s campus and deposited soot and ash in others. Following the fire, the school operated virtually for several months and, in mid-April of 2025, moved into a former Sears department store in Santa Monica.

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Meanwhile, on campus, the U.S. Environmental Protection Agency and the U.S. Army Corps of Engineers cleared debris from the destroyed structures, and LAUSD hired certified environmental remediation and testing companies to restore the still-standing buildings to a safe condition.

LAUSD serves as the charter school’s landlord and took on post-fire remediation and testing for the school. The decision to move back to the campus was ultimately up to the charter school’s independent leadership.

The Los Angeles Department of Water and Power tested the drinking water for a slew of contaminants, and environmental consultants tested the soil, HVAC systems, indoor air and surfaces including floors, desks and lockers.

They tested for asbestos, toxic metals such as lead and potentially hazardous organic compounds often unleashed through combustion, called volatile organic compounds, or VOCs.

“The school is ready to occupy,” said Carlos Torres, director of LAUSD’s office of environmental health and safety. “This is really the most thorough testing that’s ever been done that I can recall — definitely after a fire.”

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Construction workers rebuild the Palisades Charter High School swimming pool.

(Allen J. Schaben / Los Angeles Times)

A handful of soil samples had metal concentrations slightly above typical post-fire cleanup standards, which are designed to protect at-risk individuals over many years of direct exposure to the soil — such as through yard work or playing sports. An analysis by the environmental consultants found the metals did not pose a health risk to students or staff.

On indoor surfaces, the consultants found two areas with lead and one with arsenic, spaces they recleaned and retested to make sure those metals were no longer present.

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The testing for contamination in the air, however, has become a matter of debate.

Some experts cautioned that LAUSD’s consultants tested the air for only a handful of mostly non-hazardous VOCs that are typically used to detect smoke from a wildfire that primarily burned plants. While those tests found no contamination, the consultants did not test for a more comprehensive panel of VOCs, including many hazardous contaminants commonly found in the smoke of urban fires that consume homes, cars, paints, detergents and plastics.

The most notorious of the group is benzene, a known carcinogen.

At a Wednesday webinar for parents and students, LAUSD’s consultants defended the decision, arguing their goal was only to determine whether smoke lingered in the air after remediation, not to complete more open-ended testing of hazardous chemicals that may or may not have come from the fire.

Andrew Whelton, a Purdue University professor who researches environmental disasters, didn’t find the explanation sufficient.

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“Benzene is known to be released from fire. It is known to be present in air. It is known to be released from ceilings and furniture and other things over time, after the fire is out,” Whelton said. “So, I do not understand why testing for benzene and some of the other fire-related chemicals was not done.”

For Whelton, it’s representative of a larger problem in the burn areas: With no decisive guidance on how to remediate indoor spaces after wildland-urban fires, different consultants are making significantly different decisions about what to test for.

LAUSD released the testing results and remediation reports in lengthy PDFs less than two weeks before students plan to return to campus, while the charter school’s leadership decided on a Jan. 27 return date before testing was completed.

At the webinar, school officials said two buildings near the outdoor pool have not yet been cleared through environmental testing and will remain closed. Four water fixtures are also awaiting final clearance from the Los Angeles Department of Water and Power, and the school’s food services are still awaiting certification from the L.A. County Department of Public Health.

For some parents — even those who are eager to ditch the department store campus — it amounts to a flurried rush to repopulate Pali High’s campus that is straining their decisions about how to keep their kids safe.

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Torres stressed that his team acted cautiously in the decision to authorize the school for occupancy, and that promising preliminary testing helped school administrators plan ahead. He also noted that the slow, cautious approach was a point of contention for other parents who hoped their students could return to the campus as quickly as possible.

Experts largely praised LAUSD’s efforts as thorough and comprehensive — with the exception of the VOC air testing.

Remediation personnel power washed the exterior of buildings, wiped down all surfaces and completed thorough vacuuming with filters to remove dangerous substances. Any soft objects such as carpet or clothing that could absorb and hold onto contamination were discarded. The school’s labyrinth of ducts and pipes making up the HVAC system was also thoroughly cleaned.

Crews tested throughout the process to confirm their remediation work was successful and isolated sections of buildings once the work was complete. They then completed another full round of testing to ensure isolated areas were not recontaminated by other work.

Environmental consultants even determined a few smaller buildings could not be effectively decontaminated and consequently had them demolished.

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Torres said LAUSD plans to conduct periodic testing to monitor air in the school, and that the district is open to parents’ suggestions.

For Whelton, the good news is that the school could easily complete comprehensive VOC testing within a week, if it wanted to.

“They are very close at giving the school a clean bill of health,” he said. “Going back and conducting this thorough VOC testing … would be the last action that they would need to take to determine whether or not health risks remain for the students, faculty and visitors.”

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A measles resurgence has put the U.S. at risk of losing its ‘elimination’ status

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A measles resurgence has put the U.S. at risk of losing its ‘elimination’ status

One year ago this week, a case of measles was recorded in Gaines County, Texas.

It was the start of an outbreak that killed two children and sickened at least 760 people. Thousands more in the U.S. have contracted measles since.

In April, the Pan American Health Organization, an offshoot of the World Health Organization, will determine whether the same virus strain first recorded in west Texas on Jan. 20, 2025, has been transmitted without interruption in the 12 months since.

If it has, the U.S. will officially lose the measles elimination status that the organization conferred in 2000.

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Meeting those requirements “took several decades of really hard work,” said Dr. John Swartzberg, an infectious disease specialist and emeritus professor at UC Berkeley. “Losing that distinction is an embarrassment for the United States. It’s another nail in the coffin for the credibility of this country.”

In public health terms, elimination means that a disease has become rare enough, and immunity to it widespread enough, that local transmission dwindles quickly if a case or two emerges.

Scientists from the U.S. Centers for Disease Control are studying virus sequences from multiple sites around the U.S. to determine whether more recent measles cases are descended from the original outbreak or were introduced from other locations, a distinction that could affect whether the U.S. keeps its status.

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Regardless of the international committee’s ultimate ruling, what is clear is that a highly contagious, vaccine-preventable disease kept largely in check for a quarter of a century is surging back.

There were 4,485 confirmed measles cases in the U.S. between Jan. 1, 2000, and Dec. 31, 2024, according to the Centers for Disease Control. In 2025 alone, there were 2,242 — the highest annual case count since the early 1990s.

“Measles is incredibly contagious, and it is the thing that comes first when you take your foot off the gas, in terms of trying to keep vaccination levels up,” said Dr. Adam Ratner, a New York-based pediatric infectious disease specialist and author of the book “Booster Shots: The Urgent Lessons of Measles and the Uncertain Future of Children’s Health.”

“It didn’t have to turn out this way,” he said. “It doesn’t help us that there haven’t been clear messages from HHS.”

In March, after the first child death from measles in more than a decade in the U.S., Health and Human Services Secretary Robert F. Kennedy Jr. issued a statement that noted vaccines’ effectiveness in preventing measles’ spread, but stopped short of outright recommending that parents vaccinate their children.

A month later, he posted on X: “The most effective way to prevent the spread of measles is the MMR vaccine,” outraging many of his anti-vaccine supporters.

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Yet as the year went on, Kennedy and the agencies he leads upended the nation’s vaccine delivery system, while publicly sharing misleading and inaccurate information about immunizations.

Kennedy dismissed the members of a key vaccine advisory committee to the CDC and replaced them all with handpicked appointees, many of whom have been openly critical of vaccines or have spread medical misinformation.

Late last year, the CDC altered its website on vaccines and autism to include inaccurate statements linking immunizations to the neurodevelopmental disorder. Earlier this month, the CDC abruptly slashed the number of diseases it recommends children be vaccinated against from 17 to 11.

While the CDC has not officially changed MMR vaccine recommendations, the agency’s conflicting actions and confusing statements have only further depressed vaccination rates, experts said.

“The messages that are coming out of this CDC are crazy. It’s hard for pediatricians. It’s hard for parents,” Ratner said. “Nothing has changed about how safe the MMR vaccines are … or how well they work. It is all the messaging. And I’m very concerned that that is speeding up, not slowing down.”

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Vaccination rates in the U.S. were already dipping before Kennedy’s appointment to Health and Human Services. Only 10 U.S. states — including California — meet the 95% vaccination threshold required to prevent community transmission of measles.

Forty-five states reported confirmed measles cases last year, and at least nine states have logged cases in January alone.

“If you go to cdc.gov, you would expect to see a huge banner saying, ‘Measles outbreak, get your vaccine now,’” said Dr. Jeff Goad, a Chapman University School of Pharmacy professor and president of the National Foundation for Infectious Diseases. “And it’s not there.”

The Pan American Health Organization will review data from the U.S. and Mexico on April 13 to determine whether those two countries will endure the same fate as Canada, which lost its measles elimination status in November.

“Whether or not we officially lose elimination status is an academic exercise at this point,” said Mathew Kiang, an assistant professor of epidemiology and population health at Stanford University. “The reality is that without concentrated efforts to ramp up vaccination, we will continue to have these long, extended outbreaks across the U.S. We’re witnessing the results of a years-long effort to disassemble the vaccine infrastructure in the U.S. that has been accelerated by the current administration.”

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