The Brief

As gas-guzzling cars are replaced by their electric counterparts, tailpipe emissions are on the decline. But cars have other negative impacts on environmental health, beyond what comes out of their exhaust pipes.

One of the bigger, and lesser known, problems is tire pollution — or “tire and road wear particles,” in industry terminology.

Tires shed tiny particles with every rotation. Tire wear happens most dramatically during rapid acceleration, braking, and sharp turns, but even with the most conservative driving, particulate pollution is an unavoidable consequence of car use. And it’s a problem that’s poised to get worse as drivers transition to EVs.

“We’re pushing for decarbonization by going to battery electric vehicles, and in doing so we’re pushing up tire wear emissions … which is going to prove difficult to solve,” said Nick Molden, founder and CEO of Emissions Analytics, a London-based company that performs independent tests on cars’ real-world tailpipe and tire emissions. Molden pointed out that tailpipe exhaust is dramatically reduced by filters and catalytic converters, which use chemical reactions to reduce pollution. Meanwhile, tires are a fundamentally open system, so there is no viable way to capture the polluting particles that fly off of them.

Emissions Analytics found that a single car sheds almost nine pounds of tire weight per year, on average. Globally, that amounts to six million metric tons of tire pollution annually, with most of it coming from wealthier countries where personal car use is more prevalent.

The amount of tire pollution emitted per vehicle is increasing as more electric cars hit the road around the world — some 14 million of them this year, according to the International Energy Agency. EVs tend to be significantly heavier than gas-powered or hybrid cars due to their larger, heftier batteries. The average battery for an EV on the market today is roughly 1,000 pounds, with some outliers approaching 3,000 pounds — as much as an entire gasoline-powered compact car. Emissions Analytics has found that adding 1,000 pounds to a midsize vehicle increased tire wear by about 20%, and also that Tesla’s Model Y generated 26% more tire pollution than a similar Kia hybrid. EVs’ more aggressive torque, which translates into faster acceleration, is another factor that creates more tire particulate mile for mile, compared to similar internal combustion engine cars.

Due to its heavier battery and more aggressive torque, Tesla’s Model Y generated 26% more tire pollution than a similar Kia hybrid.

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Brandon Bell

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Tire particulate is a toxic slurry of microplastics, volatile organic compounds, and other chemical additives that enter the air, soil, and water around trafficked areas. The rubber, metals, and other compounds coming off tires settle along roads where rain washes them into waterways. Smaller bits of tire particulate linger in the air, where they can be inhaled, and the smallest of this particulate matter — known as PM 2.5, because each particle is 2.5 micrometers or less — can directly enter the bloodstream. A 2017 study estimated that tire wear is responsible for 5 to 10 percent of oceanic microplastic pollution, and 3 to 7 percent of airborne PM 2.5 pollution.

One particularly concerning chemical in tires is 6PPD, which is added to virtually all tires to prevent rubber from cracking. But in the environment, 6PPD reacts with ozone to become 6PPD-quinone, a substance that has been linked to salmon die-offs in the Pacific Northwest. A 2022 study confirmed the compound is also lethal to rainbow trout and brook trout.

Further research has shown that the chemical is absorbed by edible plants like lettuce and has the potential to accumulate in them. A study in South China found both 6PPD and 6PPD-quinone in human urine samples. The human health effects of the chemical are not yet understood, but other chemicals found in tires have been linked to problems ranging from skin irritation to respiratory problems to brain damage.

6PPD is added to virtually all tires to prevent rubber from cracking.

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Jakub Porzycki

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Given the intensifying realities of climate change, phasing out gas-powered vehicles rapidly is a must. But experts say the U.S. and other wealthy countries can accomplish this while also mitigating the environmental and health problems caused by EVs’ increased tire wear — namely by curbing car use overall.

Foremost, local policymakers can take steps to make U.S. cities less cripplingly car-dependent. Although that might sound like a daunting task, there’s historical precedent: The Netherlands used to be dominated by cars and experienced a higher rate of traffic fatalities than the U.S., until activist groups like Stop de Kindermoord (“Stop Child Murder”) mobilized in the 1970s to let policymakers know that they wanted less traffic on their streets. According to Chris Bruntlett, the co-author of Building the Cycling City, policymakers created the low-traffic, bike-friendly Dutch cities we know today by instituting traffic-calming measures. “Officials started with speed-limit reductions, parking restrictions, through-traffic limitations, and lane narrowings and removals,” Bruntlett told Grist.

David Zipper, a mobility expert and a visiting fellow at the Harvard Kennedy School, says that city leaders can also remove subsidies for car ownership, such as free residential parking on public streets. “Once car subsidies are removed, fewer people in cities will choose to buy and own them,” Zipper said.

Of course, measures to reduce car use only work in tandem with investments in alternative transportation. The Infrastructure Investment and Jobs Act of 2021 provided some federal funding for transit and pedestrian and bike infrastructure, but making the most of these funds will require political will from state and local lawmakers. Zipper said that policymakers in some U.S. cities have begun to take positive actions — like Boston Mayor Michelle Wu, who has committed to expanding her city’s bike lane network until 50 percent of the population lives within a three-minute walk of a bike lane.

Another way to reduce tire pollution is to trade big, heavy cars for smaller and lighter ones. Especially in the U.S., cars have grown significantly in size and weight in recent decades. Automakers began promoting SUVs in the 1980s, because a legal loophole allowed vehicles designated as “light trucks” to skirt fuel-efficiency regulations. Nine out of the 10 best-selling cars in the U.S. last year were trucks or SUVs, and the International Energy Agency has found that SUVs were the second largest cause of the global rise in CO2 emissions between 2010 and 2018.

Trading big, heavy cars for smaller and lighter ones could help reduce tire pollution.

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Marijan Murat

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One legislative solution to car bloat is introducing weight-based vehicle taxes, which encourage consumer interest in lighter cars and can be used to offset the cost of increased wear on roads caused by heavier vehicles. France implemented a weight-based car tax in 2021, charging consumers a penalty of 10 euros (about $10) for every kilogram above 1,800 (about 4,000 pounds) that their car weighs. This year, Norway also extended its weight-based vehicle tax to include EVs at a rate of a little more than a euro per kilogram above the first 500 kilograms (about 1,100 pounds) for EVs. Norway also taxes vehicles on their carbon dioxide and nitrogen oxides emissions. Taken together, these three taxes have the combined effect of dramatically incentivizing small electric vehicles.

In the U.S., some states already prorate vehicle registration fees based on weight, and Washington, D.C. recently overhauled its registration system to more heavily penalize larger cars. In D.C., owners of cars heavier than 6,000 pounds now have to pay $500 in annual fees. New York state lawmakers also recently introduced legislation that would similarly incentivize smaller cars.

Regulators can also take steps to minimize the harm caused by tire pollution — and in California, the process has already begun. In October, a new regulation implemented by the state’s Department of Toxic Substances Control, or DTSC, will require manufacturers of tires on the California market to research safer alternatives to 6PPD. Manufacturers that sell tires in the state are obligated to notify DTSC about products containing 6PPD by the end of November.

Karl Palmer, deputy director of safer consumer products at DTSC, believes that making tire makers conduct an “alternatives analysis” will ultimately result in products that are safer for the environment.

“We’re using California’s market strength to say, ‘If you want to park here, you’ve got to comply with our rules,’” Palmer told Grist.

More than 600,000 Californians are at risk of losing CalFresh food benefits after expanded work requirements imposed by the federal government go into effect next month, state and county officials warned Wednesday.

The “One Big Beautiful Bill,” signed into law by President Donald Trump last summer, included “multiple significant changes to CalFresh,” the state’s version of SNAP that serves about 5.4 million people, according to the Legislative Analyst’s Office.

They include requirements that some adults work, volunteer or participate in a school or job-training program for 20 hours a week.

People who don’t meet the expanded work requirements will be restricted to three months of CalFresh benefits every three years, according to the state Department of Social Services. CalFresh benefits can be used to buy almost any food, as well as seeds or plants that can grow food.

The new federal rules will now affect people experiencing homelessness, veterans and former foster youth, unless they are excused for other reasons.

About 260,000 people in L.A. County are at risk of losing CalFresh benefits under the new requirements, according to Hilda Solis, chair of the L.A. County Board of Supervisors.

“These expanded work requirements are going to create more barriers for people who are already struggling to meet ends,” she said at a briefing Wednesday. "It's not about creating opportunity, it's about making it harder for people to keep the benefits that they already qualify for.”

About 108,000 people in L.A. County have already lost their CalFresh benefits since the bill was passed last July, which Solis said is putting more pressure on local food banks and community-based organizations that are already operating at capacity to meet residents’ needs.

What are the changes to CalFresh?

Three main changes to CalFresh are planned for this year: expanded work requirements, disqualification of some people without U.S. citizenship and a new funding model that will pull more money from state and local sources instead of the federal government.

The work-requirement changes go into effect in June and are expected to affect about 665,000 Californians, according to the Legislative Analyst’s Office. The rules will be expanded to include people up to age 64. Previously, it applied to those up to 54 years old, according to officials.

There are some exemptions, including people who would be unable to meet the necessary hours because of a physical or mental illness and those caring for children under 14 years old.

Back in April, eligibility guidelines changed for certain Californians without U.S. citizenship. They disqualified some groups from being eligible for CalFresh, including refugees and victims of trafficking, according to the Legislative Analyst’s Office.

An estimated 72,000 people were expected to lose benefits because of limited eligibility.

In October, the way CalFresh is funded is expected to change, shifting more costs to states and counties. California could face roughly $480 million in new annual costs and $190 million for counties, according to the Legislative Analyst’s Office.

How could it affect LA County?

The roughly 260,000 Angelenos likely to be affected by the expanded work requirements may not lose their benefits immediately. People will be evaluated on the new rules when they apply or recertify to keep their CalFresh benefits, according to Jackie Contreras, director of the county’s Department of Public Social Services.

Contreras said people don’t need to take action today, and the department will notify Angelenos directly before any changes affect their case. She encouraged residents to keep their contact information up to date, carefully review all notices and contact the department for questions or assistance.

The Los Angeles Regional Food Bank is preparing to see people lose their benefits in the fall as recertifications roll in, according to CEO Michael Flood. The organization has been shoring up the supply through private donations from farmers and manufacturers, as well as purchasing food with funding from the county.

L.A. County committed $12 million to the Food Bank during the federal government shutdown last fall, which translated into about six million pounds of food, or roughly 5.5 million meals.

Flood said the organization was able to stretch those resources into this year, distributing some of the purchased food now and in the coming months to help offset the loss of CalFresh benefits. But the L.A. Regional Food Bank is already seeing an increased demand for food assistance, which he said has been driven primarily by higher prices and inflation.

“We all see it … shopping in a grocery store, those who, you know, need to fill up the gas tank to get to work,” Flood said. “That is something that's coming through loud and clear and really is causing ... challenges for people's budgets here locally.”

During a recent distribution in Baldwin Park, for example, food provided for about 2,000 households ran out half-an-hour before the event was slated to end, Flood said. He added that it’s likely the surge in demand will continue through the end of this year and into the next, and that the L.A. Regional Food Bank is “doing everything we can to try to increase resources.”

On the state level, $20 million has been deployed to help counties prepare for the expanded work requirements, according to Assemblymember Alex Lee, chair of the Assembly Human Services Committee.

Lee co-authored a bill that aims to exempt former foster youth from the expanded work requirements. The bill is pending in the state Legislature.

At least seven wildfires burning around Southern California are sending smoke across the region. The South Coast Air Quality Management District has extended a smoke advisory warning of unhealthy air through 10 p.m. Thursday.

What does a smoke advisory mean?

Local health officials send out warnings when the air quality is unhealthy. The advisories encourage people to avoid outdoor activities and take other steps to limit contact with smoky air.

Where are the wildfires?

Wildfires are burning in Ventura, San Diego, Riverside, Santa Barbara and L.A. counties. You can keep tabs on the fires on the CalFire website.

How bad is the air?

Wildfire smoke is generally worse for your health than the kind of “garden variety urban pollution” Angelenos are used to, said Suzanne Paulson, an atmospheric chemist at UCLA. But air quality depends on where you live, and might change from hour to hour. The good news is that low-cost air quality sensors have made it easier to find out just how bad the air is in your neck of the woods. You can check PurpleAir, Clarity, and IQAir for real-time data on pollution levels, often down to the neighborhood level.

How to avoid breathing bad air

Staying indoors in the best way to avoid bad air pollution, Paulson said. You can also try to avoid the worst areas. “So for example, I ride my bike to work. I regularly look at the map and see if the air quality is OK, and sometimes I even change my route,” Paulson said.

The city of Santa Ana is just $85 short of closing what started as a $13 million budget deficit. On the chopping block: after-school programming, park maintenance and more.

The city manager’s office presented another round of cuts to balance the budget at yesterday’s City Council meeting. Officials reported that the current proposal avoids layoffs and furloughs. Most of the cuts will come from the Public Works Department at more than $3 million.

Santa Ana's current budget proposal includes an estimated $85 deficit for the upcoming fiscal year.

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More on what’s being cut 

The Police Department is seeing a proposed $2 million in cuts, but could still be allocated $4 million more than last year, according to the budget draft.

The city is looking to cut 20 vacant full-time positions and reduce part-time spending.

Five non-mandated commissions will also be dissolved, including the youth, parks and recreation, and arts and culture commissions. The move will save the city nearly $28,000.

Ambulance services will be cut down from a 24-hour unit to a 12-hour unit, saving $250,000, and fees will increase.

How did we get here? 

At a City Council meeting earlier this month, officials reported that the city’s revenue increased by 3% compared to last year, but spending is up 6%, with hikes in labor and pension/liability costs.

What’s the deal with youth programming? 

The Santa Ana Police Athletic and Activity League, also known as PAAL, costs the city more than $877,000, about 80% of which goes toward salaries for its current fiscal budget.

PAAL costs the city about $5,400 per child, compared to youth programs run by the Parks and Recreation Department, which cost about $100 per kid.

PAAL’s after-school and summer programs serve 87 children, and more than 200 are mentored and coached through its sports programming. The program’s budget will be slashed by about half.

Councilmember Johnathan Ryan Hernandez said this move should not be seen as a cut to youth services.

“Through this new proposed recommendation, we’ll reinstate exercise instruction at four different elementary schools, and we will increase the services from 228 children to 2,200 children,” Hernandez said. “We are not cutting youth services, we're actually adding youth services while saving money for our city.”

Mayor Valerie Amezcua said the library and parks departments can do the same programs, but not the way PAAL does.

“I just want to make sure whatever cuts we're making, that we continue to include our Police Department. To me, that's very important for the public trust,” Amezcua said.

What’s next? 

The city isn’t completely in the clear when it comes to its finances. Measure X, a voter-approved sales tax, will be reduced in 2029, resulting in the loss of at least $30 million in annual revenue before completely expiring in 2039. The City Council, aside from Councilmembers David Penaloza and Jessie Lopez, has supported asking voters if the tax should be made permanent.

A public hearing to review the drafted budget will be held on June 2. Details will be posted on the city’s website.