By Ysabelle Kempe for Smart Cities Dive.
Broadcast version by Suzanne Potter for California News Service reporting for the Solutions Journalism Network-Public News Service Collaboration

Reflective pavement coating helped cool down one of Los Angeles' hottest neighborhoods over a year-long period, according to a recently published study in Environmental Research Communications, but some researchers argue in favor of increasing shade as a better way to protect people from dangerously high temperatures.

The research on the installation in LA's Pacoima neighborhood is "probably the most comprehensive study on controlled cool pavement" due to the large amount of data and variables considered, said Haider Taha, an atmospheric modeler, president of the research company Altostratus and the study's author.

Over 700,000 square feet of dark asphalt surfaces in Pacoima were covered with solar-reflective pavement coating in the summer of 2022 through a partnership between local nonprofit Climate Resolve and roofing and waterproofing manufacturer GAF, which provided the coating.

Pavement that reflects, rather than absorbs sunlight, has emerged as a tool cities are considering to mitigate theincreasing danger of extreme heat.

GAF funded the recently released peer-reviewed study, although the company had no role in the study's design, data collection, modeling or analysis of the results. The research found that during an extreme heat event, the cool pavement-covered area saw ambient air temperatures that were as much as 3.5 degrees Fahrenheit cooler than those in the adjacent neighborhood. On sunny days, ambient air temperatures were reduced by up to 2.1 degrees Fahrenheit. During summer nights, they were reduced by up to 0.5 degrees Fahrenheit. The coating also lowered surface temperatures by up to around 10 degrees Fahrenheit.

What does that mean for the people who live in Pacoima? Melanie Torres, a resident and the Pacoima Beautiful's Cool Community Project organizing manager, said she's felt a difference. Pacoima Beautiful is a local environmental justice organization and helped GAF and Climate Resolve with community engagement for the reflective pavement project.

Torres often eats lunch in one of the parks where the coating is deployed. "I can just sit on the grass near the basketball court and feel just the breeze - and not necessarily a hot breeze," she said. A food vendor who frequents the neighborhood told Torres that "she feels the difference in the breeze more than anything.

Torres said she hasn't heard any complaints about the reflective pavement coating during her community engagement efforts. However, reflective pavement is not immune to criticism.

Some researchers have found that the solar energy reflected off cool pavement can actually increase how hot pedestrians feel. Taha, however, said that his study indicated an "improvement in thermal sensation," noting that every location within Pacoima has "its own dynamics" that could lead to slightly different results. Mean radiant temperature - a measurement of thermal comfort - "goes up and down. It's not always cooler," he said. "The overwhelming effect is the cooling."

But no matter how effective reflective coatings are, they can't beat shade, V. Kelly Turner, associate director of the University of California, Los Angeles' Luskin Center for Innovation and an associate professor of urban planning and geography, said in an email. Shade can cool people by up to 30 degrees Celsius, or 54 degrees Fahrenheit, in hot, dry environments, she said.

"No change in surface will protect the body from heat as effectively as preventing sunlight from hitting the body in the first place," she said. "Shade - blocking the sun with trees, canopies, and tall features like walls and buildings - is by far the most effective way to cool people outdoors."

She noted that reflective pavement doesn't have a large effect on air temperature unless it is deployed widely and, even when that happens, the cooling benefit is moderate. She believes that reflective pavement is an appropriate choice in locations where it would be difficult to replace surfaces that absorb a lot of heat with "something else like vegetation and where the goal of mitigating surface material contributions to heat is the priority as opposed to protecting people's bodies outdoors."

"I think cities should see reflective pavement as one tool among many, if deployed comprehensively, that could mitigate the regional urban heat island," Turner said. "They should see this goal as parsimonious from the public health goal of protecting people's bodies from the sun."


Ysabelle Kempe wrote this article for Smart Cities Dive.


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By Julieta Cardenas for Sentient.
Broadcast version by Freda Ross for Texas News Service reporting for the Sentient-Public News Service Collaboration

Microplastics are tiny pieces of plastic less than 5mm in size. Small and ubiquitous - they are only about as thick as a paperclip - microplastics have been detected in our water supply, agricultural soils and the farm animals we raise for food. One study suggests the presence of microplastics might be anywhere from 4 to 23 times higher in farm soils than in waterways. Whether in soils or water, plastic pollution flows throughout our food system, Brett Nadrich, communications officer for Break Free From Plastic, tells Sentient, and "we have to turn off the tap."

Break Free From Plastic is an international advocacy group working to combat plastic pollution. "More than 99 percent of plastics are made of fossil fuels that used to be mostly oil," Nadrich says. Now it is also made from fracked gas, he says. In the communities of West Pennsylvania, Appalachia, the Gulf, Louisiana and Texas, "you're already seeing toxic chemicals entering the water table." Pollution from fracking extraction sites settles on soil as particulate matter, Nadrich says, which is then absorbed by plants and animals, including crops and farm animals.

Plastic Pollution Begins at the Source, But Is Found Everywhere

In 2022, Break Free From Plastic released a brand audit to identify the top plastic polluting corporations for the past five years, naming Coca-Cola as the top contributor to the plastic problem, followed by Pepsi-Co and Nestlé, among others. These corporations produce a wide range of products, including packaged meats, dairy and also plant-based brands.

Foods packaged in plastic can end up in the food itself. In one example, researchers tested cuts of meat and found plastics that matched the surrounding wrapping and polystyrene trays.

How Microplastics End Up in the Food System

One of the more surprising ways plastics end up in the food system happens on livestock farms in a practice called garbage feeding. Legal in 27 states, the practice is shown in a 2022 video taken by a maintenance technician at a grain elevator owned by Smithfield, where bread in plastic wrappers was being processed into feed. The video went viral, and an executive from Smithfield responded to say most plastic is vacuumed out onsite. The technician disagreed, but there is no agency that inspects or oversees the process to tell for sure.

Garbage feeding sometimes results in wrapped food from schools, bakeries and markets thrown directly into a shredding machine, churned up, plastic and all, to be fed later to pigs. From there, the plastic ends up in the pigs, in turn slaughtered for pork for human consumption.

There are a host of other ways that plastics end up traveling through the food system. On farms, plastics break down into microplastics thanks to a variety of factors - exposure to sunlight, farm animals brushing up against on-farm plastic and from agricultural practices like adding compost that contains plastic, and fertilizer and using mulch film.

Mulch film, often used to prevent weeds and conserve water, ends up deteriorating, and need to be prelaced every one to two years, when the process starts all over again.

Researchers have also found that plants, including crops fed to farm animals, are capable of accumulating microplastics, absorbing them from the soil. Some farm animals like poultry are also fed feed derived from marine sources like fishmeal and seaweed, and these too can contain microplastics.

Microplastics have also been detected in the feces of various domestic animals, including sheep, dairy cows, poultry and pigs. The microplastics in animal waste re-enter the food system when applied to fields, and in turn can also leach into nearby water sources. Irrigation can also bring microplastics into agricultural soils, especially when it contains waste water, either from humans or from factory farms.

According to a 2022 report from the Center for International Environmental Law, another source are synthetic fertilizers and pesticides that are encapsulated in a plastic coating and marketed as "controlled-release." Much like slow release pills, they break down in the soil, releasing not only the pesticide or fertilizer, but the plastic into the ground.

What Can We Do About Microplastics?

Though the exact human health risks of microplastics are not known, some studies have found microplastics present in patients with adverse health outcomes, like cancer and cardiovascular disease. Another study found more microplastics in recent tissue samples as compared to those taken ten years earlier. As toxicology researcher Phoebe Stapleton told People magazine, "while it might not affect my health today, it may affect my health in 50 years."

While researchers and advocates have a variety of recommendations for reducing individual plastic use - like shifting to reusable bottles and filtered tap water rather than bottled - it will likely take a policy intervention to curb plastic pollution. The Biden administration issued a briefing on plastic pollution over the summer, but there are few signs the incoming Trump administration will carry on those policies.


Julieta Cardenas wrote this article for Sentient.


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Livestock being raised with antibiotics is on the rise in Iowa, the nation's number one hog producer.

Doctors say the trend increases the risk of antibiotic-resistant infections for people who consume drug-treated meat.

Scientists have described drug-resistant infections as a growing crisis. The National Institutes of Health say the drugs are overused.

The Food Animal Concerns Trust's Safe and Healthy Food Program Director and Senior Analyst, Steven Roach, said federal data show sales for antibiotics used in cattle and other animals is as high as it's been in nearly a decade.

That's especially important in Iowa.

"In pigs in the U.S. - it's up by 24%, and in cattle it's up by 10%," said Roach. "The chicken industry has continued to reduce their use, so it's possible for the animal ag industry to make changes - but we haven't seen that happen in cattle and pigs."

Data for 2024 show the use of antibiotics in chickens dropped by 50% over the last 7 years.

In Iowa, livestock, including hogs, are mostly raised in large corporate confinements - which are known to pollute the air and nearby ground and surface water.

Confinement operators say they are trying to keep up with consumer demand for a high-quality, consistent source of meat.

Roach said most of the meat available at grocery stores has been raised in confinements and treated with antibiotics.

The Centers for Disease Control and Prevention estimates antibiotic-resistant infections kill at least 35,000 Americans every year.

Roach said large-scale ag producers could help reduce that number by changing their philosophy of routinely using drugs in their operations.

"We know we're raising animals in unhealthy conditions," said Roach, "so then we're going to give them antibiotics independent of whether they've been diagnosed with an illness."

Roach said meat in the grocery store that has been raised without antibiotics is identified as such on the packaging.




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Low-income Latino communities often bear the brunt of wildfires, so the Hispanic Access Foundation offers a wildfire management toolkit and video series to help families and policymakers prepare.

So far this year, more than 1 million acres have burned in wildland fires in California, more than three times what was lost in 2023.

Hilda Berganza, climate manager for the Hispanic Access Foundation, said Latinos who work outside in agriculture or construction are at high risk from the smoke.

"When there's a wildfire near, they don't stop working, either because they're not allowed to or because they don't know," Berganza explained. "Lung cancer, asthma rates are going up. There are now links to neurological disease and cardiovascular diseases, all from the wildfire smoke and different air pollutants."

Latinos are also less likely than their white neighbors to have home or renter's insurance, so losses hit harder. They are less likely to have a car to make a quick escape, and may not be able to afford a hotel in case of an evacuation.

Berganza argued agencies should partner with trusted local community groups and Spanish-language radio stations to make sure the language barrier does not delay crucial information.

"The Red Cross has an application on the phones where they're sending out alerts," Berganza observed. "While that is a good thing to use technology, a lot of Latinos actually don't have access to internet and or don't have smartphones because they're more expensive."

The toolkit's authors encouraged lawmakers to fully fund programs to allow low-income communities to reduce wildfire risk and programs to help families recover after a natural disaster.