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Microplastics from the Magothy River are pictured at the laboratory of Dr. Lance Yonkos at the University of Maryland.

Microplastics collected from the Magothy River in Maryland.Credit: Will Parson/Chesapeake Bay Program

What’s the matter with microplastics?

Microscopic specks of plastic — called microplastics — are everywhere, from the deep oceans and Antarctic ice to table salt and beer. Researchers estimate that the worst-hit people might be ingesting around the mass of a credit card’s worth of microplastic each year. But we don’t know whether this is dangerous. Researchers are grappling with the challenge of studying the possible health effects of microplastics, which come in all shapes, sizes and chemical compositions.

Nature | 14 min read

MICROPLASTICS TO SCALE: infographic comparing sizes of microplastics to biological objects and the technology needed to study th

Source (tools and costs): S. Primpke et al. Appl. Spectrosc. 74, 1012–1047 (2020).

Arabian structures predate the pyramids

More than 1,000 ancient stone structures dating back 7,000 years have been located in the northwest corner of Saudi Arabia, more than twice the number thought to exist in the area. Mustatil monuments — named after the Arabic word for rectangle — were first identified in the 1970s, but received little academic attention at the time. The structures are between 20 and 600 metres long and might have been used for rituals. If so, the area is the oldest large-scale ritual landscape in the world, predating both Stonehenge and the Egyptian pyramids by thousands of years.

New Scientist | 3 min read

Reference: Antiquity paper

Flu numbers plummet worldwide

Influenza cases have dropped to rock-bottom levels — thanks, epidemiologists think, to the public-health measures taken to keep COVID-19 from spreading. For example, in the United States, there were about 600 deaths from influenza during the 2020–21 flu season, compared with 22,000 in the year before. “There’s just no flu circulating,” says physician and vaccinologist Greg Poland. The downside: fewer cases make it harder to plan the vaccine for next year’s flu season. And toddlers who evade a mild case of flu now could be more susceptible to the disease later in life, depending on what strains circulate in the future.

Scientific American | 3 min read

Nature Podcast

The Nature Podcast’s special three-part series, Stick to the Science: when science gets political, has been shortlisted for a Webby award. It’s well worth a listen — and, if you liked it, please consider casting your vote in our favour.

COVID-19 coronavirus update

The methods that might crack long COVID

Scientists are pursuing a host of possible causes for the debilitating long-term effects of SARS-CoV-2 infection. Theories include viral remnants in the brain, a lingering immune response and underlying genetic vulnerabilities. “We are only at the beginning of it,” says Nadia Rosenthal, a specialist in mammalian genetics. Given the urgency, “we are all collaborating like crazy”.

Nature Methods | 17 min read plus a series of related episodes on the Conversations with Scientists podcast.

Coronapod: inequality at the heart of the pandemic

Nature reporter Amy Maxmen spent eight months investigating how exploitation, poverty and discrimination drove COVID-19 in rural America. “Farmworkers told me that they felt their work was called essential, but their lives were treated as expendable,” she told the Briefing. “Scholars have connected these problems to disease over the past 150 years, so I’ve also been asking why so little has changed. This piece is about why change is so hard, and what can be done.”

Nature | 26 min listen

Read more: Will COVID force public health to confront America’s epic inequality? (Nature | 23 min read)

‘We are struggling’

“We are struggling to ensure our son completes the school year and our bills get paid on time. We please ask that the county consider families like ours, hardworking families, who are not asking for a handout, we are asking for help to get by during this pandemic.”

Lucia Salmeron Marroquin, Fresno resident

After the pandemic began, Fresno, California residents pleaded with county leadership to provide protection and financial support.Read more: Will COVID force public health to confront America’s epic inequality? (Nature | 23 min read)(Photo: Brian L. Frank for Nature)

Features & opinion

AI must learn to find common ground

To help humanity solve fundamental problems of cooperation, scientists need to recognize artificial intelligence as deeply social, argue six researchers in the field of artificial intelligence (AI). They outline the four ways that cooperative intelligence can help achieve mutually beneficial outcomes.

Nature | 11 min read

Undergraduates face curtailed opportunities

The pandemic has caused many of the university laboratories and government programmes that benefit aspiring researchers to be cancelled or reduced in size. Five undergraduates share how they dealt with reduced opportunities and increased competition.

Nature | 10 min read

Quote of the day

“I like rats better than I like people, it turns out.”

Pain researcher Geoffrey Bove quit academia, transferred his National Institutes of Health grant and built a lab in his garage to study whether massage can stem the development of fibrosis in rats. (The Scientist | 8 min read)