Venice Tourism May Never Be the Same. It Could Be Better.

A gondolier in Venice in February, when the Carnival period typically marked the start of peak tourist season.Credit...Francisco Seco/Associated Press
A gondolier in Venice in February, when the Carnival period typically marked the start of peak tourist season.Credit...Francisco Seco/Associated Press
TT

Venice Tourism May Never Be the Same. It Could Be Better.

A gondolier in Venice in February, when the Carnival period typically marked the start of peak tourist season.Credit...Francisco Seco/Associated Press
A gondolier in Venice in February, when the Carnival period typically marked the start of peak tourist season.Credit...Francisco Seco/Associated Press

Long before Venice became the destination of choice for millions of international holidaymakers, locals had a tradition of flânerie, an aimless stroll through the city’s calli, or walkways. They would bump into acquaintances for a chat and the occasional drink, an ombra de vin, a “shadow of wine,” as it’s called in the lagoon.

That tradition has been picked up again. The pandemic crushed the tourism industry, curtailing the hordes of annual visitors that made flânerie a near impossibility, and now many residents — particularly those furloughed or laid off — have more time and space to enjoy the city’s slow pace and faded beauty. But money is tight, for that sip of wine and everything else. Local taverns have begun accepting promises of future payments from regulars.

“People are like, I’ll pay you in September, when hopefully tourists will be back,” said Matteo Secchi, an unemployed hotel concierge. “If we don’t help each other, who will?”

Secchi, a native Venetian, started working in tourism when he was still in high school, 30 years ago. “My first job was to escort tourists from hotels to Murano’s glass shops,” he said. “Since I can remember, tourism has been our only economy, we thought it was a bottomless well."

Venice certainly wasn’t alone. The economies of other European cities — Barcelona, Prague and others — grew to rely heavily on tourism, leaving them now particularly exposed to the side effects of the Covid-19 pandemic.

But there’s a new feeling many residents and local travel operators share: The crisis creates an opportunity to make future travel to and in their cities and regions more sustainable. This crossroads is sparking conversations on how to make tourism less taxing and more beneficial on urban infrastructure and for its local inhabitants.

In Venice, residents and local leaders hope their city can develop an economy that doesn’t revolve entirely around tourism, one that would draw international investors, expand the footprint of the city’s two universities and turn its empty buildings into environmental research facilities.

Yes, the pandemic has shuttered Venice’s lodging industry, said Claudio Scarpa, the president of Associazione Veneziana Albergatori, a body representing 430 hotels in Venice, but “it is also a precious occasion to rethink tourism.”

“This is the time to reclaim this city,” he said, “Or in a couple of years we’ll get back to complaining about overtourism.”

Other Venetians echoed that sentiment.

“We have to act now, before mass tourism will be back at full capacity, because we won’t get a second chance,” said Paolo Costa, a former mayor of Venice and an economics professor who also served as the dean of Ca’ Foscari University of Venice.

An attraction for centuries
The uniqueness of this Italian city has made it a worldwide attraction for centuries. And, tellingly, Venice’s rise as a travel destination coincided with its decline as an economic powerhouse, said Ezio Micelli, an expert of urban transformation at Iuav University of Venice.

As a city-state, Venice thrived as a commercial and financial hub for much of the Middle Ages. Its location midway between Constantinople and Western Europe made it an ideal junction for the trade of spices, silk and salt. “It was the capital of capitalism,”Micelli said.

But as the center of trade moved from the Mediterranean to the Atlantic, Venice lost centrality and by the end of the 18th century, when it fell under foreign rule, its decline was unstoppable. It was then that wealthy Europeans started visiting Italy’s art-rich cities, including Venice, in a tradition known as “the Grand Tour.” Lord Byron and Stendhal were among the city’s earliest holidaymakers. By the 19th century, Venice’s Lido became the place of pilgrimage for Europe’s well-off bourgeoise (think of Thomas Mann’s “Death in Venice”).

But by the late 20th century, Venice became what economists describe as a “tourism monoculture,” borrowing the term from the risky agricultural practice of growing a single crop.

‘Too many of them’
Before Covid-19, hotels in and around Venice annually hosted 10.2 million mostly international guests, according to Italy’s bureau of statistics. But this figure — an estimate at best — does not account for day-trippers, who disembark from cruise ships, the train station and bus tours. One estimate puts the actual number of tourists around 20 million annually — largely concentrated in an area of two square miles and 50,000 residents. They contributed 3 billion euros, or about $3.3 billion, a year.

“Tourists grew gradually, year by year, and before we realized it, there were too many of them, just like a boiling frog,” Micelli said.

The mass tourism of recent decades was a result of globalization, home-sharing platforms, cheap airfares and emerging economies. Ryanair, easyJet and other low-cost carriers began flying into the Marco Polo airport, cruise ships alone brought in 1.6 million visitors each year, and the growing strength of the Chinese and other Asian economies allowed new tourists to join the crowds of Europeans and North Americans.

Especially in the high season between May and October, and during Carnival in February, Venice was impossibly crowded — particularly in its narrow calli, some just two meters, or six-and-a-half feet, wide.

When Dr. Micelli, the urban studies professor, would visit a brother who lives on one of the city’s most touristy streets, he sometimes could not get out of the door.

“It’s like a flood, literally. So I just have to wait,” Micelli said. Occasionally the local police would declare some calli one-way.

“I guess Venice is the only place in the world where you need one-way pedestrian streets.”

Cristina Giussani, a bookshop owner, often walked home with heavy groceries because the vaporetto, the water buses that serve as public transportation, would be swarmed with hordes of tourists. She considers the famous Rialto Bridge off-limits between 10 a.m. and 5 p.m., “because it’s impossible to cross it without throwing elbows.”

Tourism changed the soul of the lagoon. Grocery stores turned into souvenir shops, and rising housing costs and an increasing lack of services pushed residents out. With more than 8,000 apartments listed on Airbnb, Venice has Italy’s highest Airbnb-to-population ratio.

The city’s historical center, consisting of two islands, had at its peak in the 1950s, 175,000 residents.

In 2009, the population fell below 60,000, the conventional threshold to be considered a city in Italy. A mock funeral was organized, with a coffin wrapped in the city’s 1,500-year-old flag.

Today, the center of the city has some 50,000 residents.

“Being a resident in Venice feels like being part of the resistance,” Ms. Giussani said.

‘I knew it had to be tourism’

Approximately 25,000 Venetians are now directly employed in tourism. And even if the figure includes those who commute into the historical center from the city’s other areas, many other Venetians in the city center rely on the industry indirectly.

“If you sell groceries, if you are a lawyer or an accountant, your main clients are fellow Venetians who make money either directly from tourism or from other Venetians who make money from tourism,” said Stefano Croce, who heads the local association of tour guides.

It wasn’t a planned choice, as much as the result of a vicious cycle. The more touristy Venice became, the more residents were pushed out; the fewer the residents, the more those who remained struggled to find employment outside of tourism, thus reinforcing the pattern.

Before he became a guide five years ago, Croce commuted to Padua and worked in architecture. “When I decided I wanted to work in my own city, I knew it had to be tourism,” he said. His son, a neuroscientist, moved to Scotland.

Many Venetians found the situation unsustainable, but, until recently, few did anything to change it. “As long as mass tourism was there, there were ideas, but they never gained traction because the status quo was so convenient,” said Costa, the former mayor.

“The same people who complain that overtourism is making their lives impossible are renting their apartments to tourists on Airbnb,” said Guido Moltedo, editor of the Venice-based magazine Ytali.

“It’s a complicated place.”

Secchi, the hotel concierge, is also an activist fighting for the lagoon’s residents. Fifteen years ago, he founded the grassroots organization “Venessia” (Venice, in Venetian dialect), which keeps track of the declining local population.

But while his organization lobbies officials to create subsidized housing to locals, and “put some limits to the renting of the apartments to tourists,” Secchi also lists three rooms of his apartment on Airbnb. “I have to, if I want to pay my own rent.”

Secchi sees no contradiction in his livelihood and his passion for Venice.

“Tourism is a great resource, but residents shouldn’t be treated as second class,” he said.

“The longer a visitor stays, the smaller his impact on the territory,” said Magda Antonioli Corigliano, a tourism industry scholar at Milan’s Bocconi University. Day trippers tend to have a particularly harmful impact, she argues, because they are on a constant move, and always crowding the same spots around St. Mark’s and the Rialto.

“If you have only one day, you want to see as much as you can, so you run here and there, take a lot of vaporettos,” Ms. Antonioli Corigliano said. Overnight visitors can enjoy the lagoon at a slower pace, and venture beyond its most obvious spots, contributing less to pedestrian traffic jams.

Then there are the cruise ships, docking at the Marittima port and navigating through the Giudecca Canal and St. Mark’s basin. Though responsible for a fraction of day trippers, they unload a significant amount at a time, as well as causing a significant impact on the city’s environment because of the amount of fuel used.

“A cruise is a very energy-intensive way you can take a holiday,” said Jane Da Mosto, a scientist who heads the environmentalist group We Are Here Venice, which opposes the presence of cruise ships.

Cruise ships bring money, but not all goes to Venice’s historical center.

A 2013 study by Ca’ Foscari University estimated the overall business brought to the city from the cruise industry to be around 290 million euros annually. The study considered direct and indirect business with the government as well as privately owned companies, and included fuel, food supplies, laundry services and money spent by cruise day-trippers in the city (as little as 19 euros or around $21 per capita, if they didn’t spend the night).

The small amount of taxes paid to Venice’s Port Authority were included in that figure: Last year the authority, run by the central government’s transportation ministry, received 5.6 million euros from cruise vessels, a spokesman said. This money goes to the running the authority itself, and includes maintenance of the city’s canals.

In 2012, the central government approved a law banning cruise ships from the St. Mark’s basin and the Giudecca Canal, to lessen overcrowding in those areas, but it has yet to be enforced. And even if it were, Ms. Da Mosto said, it will do little to contain the damage.

Even if cruise ships were to dock in Marghera, the nearby port on the mainland, Ms. Da Mosto said that the vessels would cause the same environmental impact. The only difference is that they would do it a few miles away.

Six months ago, Venice’s overtourism came to a sudden halt.

The number of tourists in the city plummeted first in November, when a series of unusually high tides spurred cancellations. Tourism almost disappeared beginning in late February, when the Covid-19 pandemic prompted authorities to cancel the Carnival and, soon after, declare a nationwide lockdown.

Italy’s central government has vowed to help the tourism industry by providing aid packages and tax breaks for struggling hotels and restaurants, but other sectors have also been hit hard.

Tour guides are one such group. They are often self-employed and thus not eligible for long-term unemployment benefits; short-term subsidies for the self-employed, issued by the central government, ended when the lockdown was lifted but before international travelers were allowed back. In June, tour guides held protests in several Italian cities, including Venice.

“There are a lot of grievances in the profession,” said Croce, the tour guide. He pointed out that most guides work with international tourists. “When the lockdown was lifted, restaurants and cafes could go back to business, but we couldn’t. It’s not fair that we are getting the same treatment.

Since Italy lifted its restriction on movement in early June, the lagoon has seen few visitors, the vast majority of them day-trippers from the surrounding Veneto region.

Today’s Venice is more than its medieval origins in the lagoon. From an administrative point of view, it is a large city of more 250,000 inhabitants, consisting of neighborhoods on the mainland as well as several islands in the lagoon.

But historical Venice, which is what people mean when they use the word colloquially, is two islands. One large, fish-shaped island cut in half by the Grand Canal — technically, the “island of Venice,” but often just called “the fish”— and a smaller island, the Giudecca. Overtourism is largely concentrated within two of the larger island’s six neighborhoods.

“Venice is two cities, there’s the land, with their problems, and there’s the lagoon, with our problems,” said Moltedo, the editor. He noted that Venice’s past and present administrations are a reflection of the mainland population, which is larger and not as affected by overtourism.

Giussani, the bookstore owner, also noted that groups that have long opposed overtourism were disorganized, and rarely coordinated their approach. But she argued that now people seemed more open to “create a network.”

These groups are currently pressuring the City Council, which governs tourism decisions, together with the regional government, to limit access to the historical center with a system of quotas and bookings (residents and visitors with hotel reservations would be excluded). Mayor Luigi Brugnaro wrote in an email that his administration is working on the booking system “as a short-term goal.”

The government, he added, hopes “to regulate the tourists flows so that they can be compatible with the daily lives of the residents.”

In the meantime, the hotel industry plans to promote Venice as a Christmas destination for wealthy international holidaymakers, creating special cultural packages in partnership with museums, said Scarpa, the official at the local hotel group.

But most of all, Venice’s two universities are actively working on revitalizing the city’s population.

“People tend to think that everyone in Venice is either a tourist or a resident, but in the middle there’s another group, temporary residents, who are part of the social fabric and breathe new life into it,” said Michele Bugliesi, the dean of Ca’ Foscari, Venice’s largest university.

The school, he said, is already a pull factor for temporary residents — “It’s remarkable how easy we get visiting professors,” said Bugliesi — but later this year it plans to open a business incubator, with the goal of attracting forward-thinking entrepreneurs.

In late 2018, partnering with the Italian Institute of Technology, Ca’ Foscari launched a center for the application of technologies to the preservation of cultural heritage, which is now expanding. In 2018, the university also founded, in partnership with Italy’s National Research Council, a program on climate change. It is expected to expand; beginning next semester, it will offer a new English-language degree in environmental humanities, one that is targeted to international students.

Iuav, a small public-arts college, is converting empty bed-and-breakfasts into dorms for its 4,000 students, most of whom were commuters. Brugnaro, the current mayor, wrote that he is also planning some incentives to bring in new residents.

Taken alone, these three projects aren’t enough to repopulate Venice. But Bugliesi thinks they have the potential to create “a critical mass that would set off a chain reaction.”

Dreams of attracting multinational corporations, prestigious institutions and digital nomads, transforming Venice into something of a blend of Brussels and Berlin, have been discussed for years, and are a recurrent theme when one discusses the future of the city with educated Venetians.

“Arts foundations and research institutes from all over the world should have an interest to open a chapter here, but we have to offer them incentives,” said Camilla Seibezzi, an art curator.

Also frequently mentioned is that the city’s symbiotic relationship with the sea makes the place ideal for any private or public institution interested in climate change.

And locals love to argue that the city’s stunning beauty and its unique car-free lifestyle makes Venice an ideal place of residence for creative people and digital nomads.

“I really don’t understand why more people don’t move here, when one can simply work from remote and enjoy all this beauty and silence,” said Moltedo, the editor, who moved from Rome seven years ago.

And, for the first time, Venice may have the space to dedicate to new projects.

“Very soon, Venice will end up with lots of empty buildings, because some hotels will have to close. Now it’s the time to think about what to do with them,” Costa said.

“Before the pandemic, every project, every idea had to carve out space from overtourism. But now, there’s a whole world out there.”

The New York Times



Astronomers Spot White Dwarf Star Creating a Colorful Shockwave

The central square image, taken with the MUSE instrument on ESO's Very Large Telescope, shows shock waves around the dead star RXJ0528+2838. (European Southern Observatory (ESO)/K. Ilkiewicz and S. Scaringi et al./Handout via Reuters)
The central square image, taken with the MUSE instrument on ESO's Very Large Telescope, shows shock waves around the dead star RXJ0528+2838. (European Southern Observatory (ESO)/K. Ilkiewicz and S. Scaringi et al./Handout via Reuters)
TT

Astronomers Spot White Dwarf Star Creating a Colorful Shockwave

The central square image, taken with the MUSE instrument on ESO's Very Large Telescope, shows shock waves around the dead star RXJ0528+2838. (European Southern Observatory (ESO)/K. Ilkiewicz and S. Scaringi et al./Handout via Reuters)
The central square image, taken with the MUSE instrument on ESO's Very Large Telescope, shows shock waves around the dead star RXJ0528+2838. (European Southern Observatory (ESO)/K. Ilkiewicz and S. Scaringi et al./Handout via Reuters)

Astronomers have observed a white dwarf - a highly compact Earth-sized stellar ember - that is creating a colorful shockwave as it moves through space, leaving them searching for an explanation.

The highly magnetized white dwarf is gravitationally bound to another star in what is called a binary system. The white dwarf is siphoning gas from its companion as the two orbit close to each other. The system is located in the Milky Way about 730 light-years from Earth - relatively nearby in cosmic terms - in the constellation Auriga.

A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km).

The shockwave - more specifically a bow shock - caused by the white dwarf was observed using the European Southern Observatory's Chile-based Very Large Telescope. The shockwave was seen in an image released by the scientists glowing in various colors produced when material flowing outward from the white dwarf collided with interstellar gas.

"A shockwave ‌is created when ‌fast-moving material plows into surrounding gas, suddenly compressing and heating it. A ‌bow shock ⁠is the curved ‌shock front that forms when an object moves rapidly through space, similar to the wave in front of a boat moving through water," said astrophysicist Simone Scaringi of Durham University in England, co-lead author of the study published on Monday in the journal Nature Astronomy.

"The colors come from interstellar gas that is being heated and excited by the shock. Different chemical elements glow at specific colors when this happens," Scaringi added.

In this shockwave, a red hue represented hydrogen, green represented nitrogen and blue represented oxygen residing in interstellar space.

A handful of other white dwarfs have been observed creating shockwaves. But all of those were ⁠surrounded by disks of gas siphoned from a binary partner. Although this white dwarf is siphoning gas from its companion, it lacks any such disk and ‌is releasing gas into space for unknown reasons.

White dwarfs are among the ‍universe's most compact objects, though not as dense as ‍black holes.

Stars with up to eight times the mass of the sun appear destined to end up as ‍a white dwarf. They eventually burn up all the hydrogen they use as fuel. Gravity then causes them to collapse and blow off their outer layers in a "red giant" stage, eventually leaving behind a compact core - the white dwarf.

"There are plenty of white dwarfs out there, as these are the most common endpoints of stellar evolution," Scaringi said.

The sun appears fated to end its existence as a white dwarf, billions of years from now.

This white dwarf has a mass comparable to the sun contained in a body slightly larger than Earth. Its binary companion is ⁠a type of low-mass star called a red dwarf that is about a tenth the mass of the sun and thousands of times less luminous. It orbits the white dwarf every 80 minutes, with the two extremely close to each other - approximately the distance between the moon and Earth.

The gravitational strength of the white dwarf is pulling gas off the red dwarf. This siphoned material is being pulled into the white dwarf along its strong magnetic field, eventually landing at its magnetic poles. While this process releases energy and radiation, it cannot account for the outflow of material needed to produce the observed shockwave, Scaringi said.

"Every mechanism with outflowing gas we have considered does not explain our observation, and we still remain puzzled by this system, which is why this result is so interesting and exciting," Scaringi said.

"The shape and length of the (shockwave) structure show that this process has been ongoing for at least about 1,000 years, making it long-lived rather than a one-off event," Scaringi added.

The ‌researchers took note of the aesthetics of the colorful shockwave.

"Beyond the science, it's a striking reminder that space is not empty or static as we may naively imagine it: it's dynamic and sculpted by motion and energy," Scaringi said.


Australian Firefighters Warn of ‘High-Risk’ Bushfire Season

Country Fire Authority (CFA) crew fill up tankers in the bushfire affected town of Ruffy, Victoria, Australia, 12 January 2026. (EPA)
Country Fire Authority (CFA) crew fill up tankers in the bushfire affected town of Ruffy, Victoria, Australia, 12 January 2026. (EPA)
TT

Australian Firefighters Warn of ‘High-Risk’ Bushfire Season

Country Fire Authority (CFA) crew fill up tankers in the bushfire affected town of Ruffy, Victoria, Australia, 12 January 2026. (EPA)
Country Fire Authority (CFA) crew fill up tankers in the bushfire affected town of Ruffy, Victoria, Australia, 12 January 2026. (EPA)

Australian firefighters warned people on Monday to prepare for more bushfires in a "high-risk" summer, after blazes killed one person and incinerated more than 350 buildings in the southeast.

Weather conditions have eased since strong winds and temperatures topping 40C fed dozens of wildfires in southeastern Australia's Victoria, which declared a state of disaster on Saturday.

But officials said 12 major fires were still burning across the state.

Country Fire Authority chief officer Jason Heffernan said another "heating event" was expected towards the end of January, though its intensity was uncertain.

"We are early in the high-risk weather season," Heffernan told a news conference.

"There's been a lot of fire in the landscape. Much work will be done between now and then to contain these fires," he said.

"Whilst we join with community in the rebuilding and the relief and recovery of the fires that have been, we need to turn our minds to the fires that could be as the season continues."

More than 350 structures -- including over 65 homes -- have been lost so far in the state, officials said, with the number likely to rise as fire damage is assessed.

One person died in a fire near the town of Longwood, about two hours' drive north of state capital Melbourne, police say.

Emergency Management Commissioner Tim Wiebusch said weather conditions had become more favorable for firefighters.

"But that doesn't mean that the risk is over," he said.

"Whilst the conditions are easing in some parts of the state, even the slightest of winds are still causing those fires to move around."

High temperatures and dry winds combined last week to form some of the most dangerous bushfire conditions since the "Black Summer" blazes.

The Black Summer bushfires raged across Australia's eastern seaboard from late 2019 to early 2020, razing millions of hectares, destroying thousands of homes and blanketing cities in noxious smoke.

Australia's climate has warmed by an average of 1.51C since 1910, researchers have found, fueling increasingly frequent extreme weather patterns over both land and sea.


Some Supplements Can Make Your Medication Less Effective

Some vitamin and mineral supplements can interfere with absorption of medications (Oklahoma State University) 
Some vitamin and mineral supplements can interfere with absorption of medications (Oklahoma State University) 
TT

Some Supplements Can Make Your Medication Less Effective

Some vitamin and mineral supplements can interfere with absorption of medications (Oklahoma State University) 
Some vitamin and mineral supplements can interfere with absorption of medications (Oklahoma State University) 

Health experts warned that some supplements can interact with certain medications and reduce their effectiveness, according to Eating Well website.

While these supplements are usually sold over-the-counter, taking them without asking a health care provider can have dangerous impact on your health.

Naturopathic doctor Jacob Wolf said that for instance, some vitamin and mineral supplements can interfere with absorption of medications.

Other supplements can bind with medications, preventing the drug from being utilized in the body, or they may be metabolized by the same or similar pathways as medications, explains Wolf. That can have a dangerous impact on your health.

Top offenders include calcium, magnesium, iron, fiber, activated charcoal and vitamins C and K.

Minerals like calcium, magnesium and iron can bind with medications, especially levothyroxine, a drug used to treat hypothyroidism, said Wolf.

“This can impact how levothyroxine is utilized in the body, adversely affecting treatment,” he explained.

These minerals can also interact with antibiotics in the tetracycline and fluoroquinolone class, said pharmacist Amanda Corbett.

Taking these mineral supplements at the same time as antibiotics may reduce the bioavailability of the antibiotic, creating risks like bacterial resistance or ineffective treatment.

And while scientists affirm fiber is an important nutrient for digestive regularity, healthy cholesterol levels and blood sugar management, supplementing isn’t always a great idea, as large doses can impact the absorption of certain medications.

Fiber-rich foods are a cornerstone of blood sugar management, even for those taking blood sugar–lowering medications, like metformin.

Fiber may also impair the effectiveness of other drugs, including digoxin (which treats certain heart conditions) and levothyroxine for hypothyroidism, Wolf said.

Therefore, if you do choose to take a fiber supplement, Wolf recommended speaking with your health care provider about spacing out your fiber and medication doses.

As for activated charcoal, it is a form of carbon that is used in the emergency room to treat the ingestion of toxic drugs and poisons.

“Activated charcoal acts like a sponge and can bind to many medications. It is best to completely avoid activated charcoal if on any life-critical medication,” said Wolf.

For Vitamin C, it is an important antioxidant that protects cells from free radical damage and supports proper immune system function.

However, if you are undergoing chemotherapy treatment for cancer, experts strongly caution against taking vitamin C supplements.

“Vitamin C can lead to certain chemotherapies being less effective or ineffective in treating cancer,” said Corbett.

Vitamin E, another antioxidant, can also interfere with chemotherapy’s effectiveness.

If taking Vitamin K, which is a fat-soluble vitamin that helps blood clot and shores up bone health, you should know that it can reduce the effectiveness of a blood-thinning medication called warfarin (Coumadin).

That, in turn, can make blood more likely to clot, which can lead to a heart attack or stroke.

If you are taking warfarin, you don’t necessarily need to avoid vitamin K, but it is critical to keep the amount you consume—from both foods and supplements—consistent to avoid clotting problems.

Experts advise that to take supplements safely, consult with your health care provider.

Many supplements can interact with medications, and so it’s critical to connect with your prescribing health care provider to make sure that the supplements you’re taking play nice with your medications.

Also, look for those that have been independently tested in a laboratory, recommended Corbett.

Experts say you should also know how much to take. Supplement dosages are listed on the label, but they aren’t standardized.

That means they can vary from product to product, and may far exceed safe levels.