Thursday’s top story: markets in turmoil amid signs of a global economic slowdown. Plus, how a sometime porn star is exposing the industry’s abuses

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Good morning, I’m Tim Walker with today’s essential stories.

Dow plunges 800 points as potential recession looms

The Dow Jones dropped by 800 points on Wednesday and shares in Asian markets continued to fall this morning, amid growing signs that the world economy is heading for a recession. Oil prices continue to fall, the yield on 30-year US treasuries have dipped below 2% for the first time, while the so-called US bond-yield curve inverted on Thursday for a second day running, suggesting investors have greater faith in long-term bonds than in other investments – historically, the harbinger of recession.

German wobble. Germany is on the brink of recession after the world’s fourth-largest economy contracted 0.1% in the second quarter.

Rate cut. Donald Trump continues to call for further cuts in US interest rates, tweeting that the Federal Reserve chair, Jerome Powell, had been “very very late” in cutting rates.

Philadelphia shooting suspect in custody after six cops wounded

Facebook Twitter Pinterest The suspected shooter was taken into police custody after a seven-hour standoff. Photograph: Mark Makela/Getty Images

A seven-hour armed standoff in Philadelphia has ended with six police officers wounded and a suspect in custody. At least one gunman opened fire on police as they served a drug warrant at a property in the Nicetown neighbourhood at about 4.30pm on Wednesday. Two other officers became trapped inside the house for about five hours after the shooting erupted. The suspect, named in reports as 36-year-old Maurice Hill, ultimately surrendered to police.

Heavy firepower. Philadelphia’s mayor, Jim Kenney, said he was grateful the officers’ injuries were not considered life-threatening. “I’m a little angry about someone having all that weaponry and all that firepower, but we’ll get to that another day,” he said.

Microplastics significantly contaminating air, say scientists

Facebook Twitter Pinterest Samples taken from ice floes on the ocean between Greenland and Svalbard contained an average of 1,760 microplastic particles per litre. Photograph: Mstyslav Chernov/AP

Microplastics are contaminating not just the oceans, but the air, according to a study that found high levels of microplastic pollution in snow from the Arctic to the Alps. Snow captures particles from the air as it falls, and samples from Europe contain an average of 24,600 microplastic particles per litre, according to scientists from Germany’s Alfred Wegener Institute for Polar and Marine Research, who warned of potential health impact, citing another study that found microplastic particles in cancerous human lung tissue.

Rocky Mountains. A US Geological Survey researcher has also discovered microplastics in rainwater samples collected from the Rocky Mountains, suggesting plastic waste is permeating the air, water, and soil almost everywhere.

US seeks to hold on to Iranian tanker seized by UK forces

Facebook Twitter Pinterest Grace 1 has been anchored in the strait of Gibraltar since it was seized in July by British Marines. Photograph: Jon Nazca/Reuters

The US has moved to block the release of an Iranian oil tanker that was commandeered by UK marines in the strait of Gibraltar in July, on suspicion of carrying oil to Syria in breach of an EU arms embargo. The US Department of Justice reportedly applied to hold on to the vessel, which otherwise “would have sailed” by now, Gibraltar’s chief justice told the Gibraltar Chronicle. The ship’s seizure has led to reprisals, specifically Iran’s capture of the British-flagged Stena Impero in the strait of Hormuz.

US-Iran tensions. Though the seizure of Grace 1 was ostensibly related to the EU’s Syria embargo, the incident was seen as an escalation of tensions between Iran and the US and its allies in the Gulf.

Crib sheet

South Korea’s president, Moon Jae-in, has promised to achieve the unification of the Korean peninsula by 2045, urging Trump and the North Korean leader, Kim Jong-un, to arrange a fourth summit on denuclearisation.

Imran Khan, the prime minister of Pakistan, has threatened to “teach Delhi a lesson” after the Indian government revoked the special status of Kashmir last week, raising fears of fresh violence in the long-disputed region.

Nepal has set new rules for anyone hoping to scale Mount Everest , demanding climbers have prior high-altitude mountaineering experience, after one of the deadliest and most crowded summers on the world’s highest peak.

Botanists have warned people in New Zealand not to consume a local species of “sexy pavement lichen” found on paths and rocks, after misleading stories about the stimulatory properties of the potentially toxic plant spread online.

Must-reads

Facebook Twitter Pinterest A couple walk through the grounds of the Boone Hill plantation in Mount Pleasant, South Carolina. Photograph: John Moore/Getty Images

Are southern plantations telling the story of slavery?

The plantation mansions of the south are grand memorials to the splendour of the antebellum era. But as the US marks 400 years since the beginning of slavery, Amanda Holpuch asks whether these monuments adequately explain the more sordid side of their history.

The safe house shielding patients from the abortion wars

Next door to the only abortion clinic in Montgomery, Alabama, is a single-storey building known as the Power House: a safe house where women can wait for the procedure, without being forced to face anti-abortion protesters. Khushbu Shah reports from inside, part of the Guardian’s series on abortion in the deep south.

Woodstock at 50 – in pictures

Half a century after the most celebrated music event of the most celebrated music decade, Woodstock’s founder, Michael Lang, recounts his memories of the festival in a new book. Here he tells the story through photos from those “three days of peace”.

The brutality of LA’s sheriff ‘gangs’

In early June, police officers across Los Angeles shot five people in five separate incidents in just over 24 hours, only one of whom survived. One of the victims was 24-year-old Ryan Twyman, who was shot 34 times despite being unarmed. Activists tell Sam Levin there are “gangs within the sheriff’s department”.

Opinion

Mia Khalifa was once the world’s most popular porn star, despite spending just three months as an adult performer – for which she earned a paltry $12,000. Now she is exposing exploitation in a business whose abuses often go unchallenged, says Yomi Adegoke.

A need to appear liberal and open-minded has left many modern feminists uncharacteristically quiet on the industry’s ethics. And because of this, it is held to a completely different standard to any other part of the entertainment industry.

Sport

World champion Alex Morgan says US Soccer’s heavily criticized pay-to-play youth model is “detrimental” to the game’s future. the MLS commissioner, Don Garber, told the Guardian he disagrees. Steve Brenner weighs up their arguments.

Liverpool’s keeper Adrián saved Tammy Abraham’s penalty to send his team to a 5-4 shootout victory over Chelsea in Wednesday’s Uefa Super Cup, after the game ended 2-2. Despite the defeat, Chelsea coach Frank Lampard can take comfort from strong performances by N’Golo Kanté and his new signing Christian Pulisic.

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