U.N. agencies on Friday called for two seven-day breaks in the fighting in Gaza to vaccinate more than 640,000 children against polio, which has been detected in the wastewater.

Swimming has been off-limits in the long-polluted Seine River in Paris for more than a century. So with Olympic swimming events on tap for the river, the city poured in $1.5 billion (1.4 billion euros) to try to clean it up.

With the Paris Games underway, officials are keeping a close eye on water quality. Athletes could feel health effects from swimming in a river with higher-than-accepted levels of E. coli or other bacteria.

A steady stream of miserable children and worried parents flowed into the dermatology office at Nasser Hospital in central Gaza.

A toddler with a blue hair bow sobbed as her mother showed how the red and white spots covering her face have spread to her neck and chest. Another woman lifted her little boy's clothes to reveal the rashes on his back, butt, thighs and stomach. On his wrists, he had open sores from scratching. A father stood his daughter on the desk so the doctor could examine the lesions on her calves.

Wildfire smoke may be worse for brain health than other types of air pollution, according to new research linking it to an increased risk of dementia.

The findings, reported Monday at the Alzheimer's Association International Conference in Philadelphia, come as millions spent the weekend under air quality warnings from wildfires spewing smoke across the western U.S.