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Chemists invented PFAS in the 1930s to make life easier: Nonstick pans, waterproof clothing, grease-resistant food packaging and stain-resistant carpet were all made possible by PFAS. But in recent years, the growing number of health risks found to be connected to these chemicals has become increasingly alarming. PFAS – perfluoroalkyl and polyfluoroalkyl substances – are now either suspected or known to contribute to thyroid disease, elevated cholesterol, liver damage and cancer, among other health issues. They can be found in the blood of most Americans and in many drinking water systems, which is why the Environmental Protection Agency in April 2024 finalized the first enforceable federal limits for six types of PFAS in drinking water systems. The limits – between 4 and 10 parts per trillion for PFOS, PFOA, PFHxS, PFNA and GenX – are less than a drop of water in a thousand Olympic-sized swimming pools, which speaks to the chemicals’ toxicity. The...

The U.S. has a long record of extracting resources on Native lands and ignoring tribal opposition, but a decision by federal energy regulators to deny permits for seven proposed hydropower projects suggests that tide may be turning. As the U.S. shifts from fossil fuels to clean energy, developers are looking for sites to generate electricity from renewable sources. But in an unexpected move, the Federal Energy Regulatory Commission denied permits on Feb. 15, 2024, for seven proposed hydropower projects in Arizona and New Mexico. The reason: These projects were located within the Navajo Nation and were proposed without first consulting with the tribe. FERC said it was “establishing a new policy that the Commission will not issue preliminary permits for projects proposing to use Tribal lands if the Tribe on whose lands the project is to be located opposes the permit.” We are a cultural anthropologist and a water resource geographer who have studied tensions between...

In the wake of North America’s recent solar eclipse, another historic natural event is on the horizon. From late April through June 2024, the largest brood of 13-year cicadas, known as Brood XIX, will co-emerge with a midwestern brood of 17-year cicadas, Brood XIII. This event will affect 17 states, from Maryland west to Iowa and south into Arkansas, Alabama and northern Georgia, the Carolinas, Virginia and Maryland. A co-emergence like this of two specific broods with different life cycles happens only once every 221 years. The last time these two groups emerged together was in 1803, when Thomas Jefferson was president. For about four weeks, scattered wooded and suburban areas will ring with cicadas’ distinctive whistling, buzzing and chirping mating calls. After mating, each female will lay hundreds of eggs in pencil-size tree branches. Then the adult cicadas will die. Once the eggs hatch, new cicada nymphs will fall from the trees and burrow back underground, st...

The future of automobiles is electric, but many people worry about the safety of today’s electric vehicles. Public opinion about EV crash safety often hinges on a few high-profile fire incidents. Those safety concerns are arguably misplaced, and the actual safety of EVs is more nuanced. I’ve researched vehicle safety for more than two decades, focusing on the biomechanics of impact injuries in motor vehicle crashes. Here’s my take on how well the current crop of EVs protects people: The burning question EVs and internal combustion vehicles undergo the same crash-testing procedures to evaluate their crashworthiness and occupant protection. These tests are conducted by the National Highway Safety Administration’s New Car Assessment Program and the Insurance Institute for Highway Safety. These analyses use crash test dummies representing midsize male and small female occupants to evaluate the risk of injuries. The tests can evaluate fire hazard either ca...

Dozens of tornadoes hit the central U.S. April 26-28, 2024, tearing through suburbs and small towns and damaging hundreds of homes from Oklahoma to Nebraska and Iowa. Spring is tornado season in the U.S., but the tornadoes in Nebraska and Iowa were quite a bit farther north and east of what would be typical for tornadoes in late April, when tornado activity is more common in Oklahoma and Texas. The outbreak did fit another pattern for severe weather events, however, that occur as the atmosphere transitions out of El Niño. And this is exactly what was happening in late April. I study tornadoes and the conditions under which they form. Here’s how these storm systems develop and what El Niño has to do with it. Preliminary reports of tornadoes and hail during severe storms on April 26, 2024, collected by the National Oceanic and Atmospheric Administration’s Storm Prediction Center. NOAA...