Axios

In low- and middle-income nations, 98% of cities with populations exceeding 100,000 people do not meet the World Health Organization's air quality guidelines. Among high-income countries, the number falls to 56%.

The big picture: Together, the top ten most polluted cities have over 20 million residents. The 11th most polluted city in the world is Delhi, India, which has a population of 19 million and where spending one day outdoors is equivalent to smoking 44 cigarettes, per CNN.

Emerging markets roar back ... "America first? Not when it comes to world stocks," Barron's writes in its cover story:

• "[E]merging markets have outpaced an aging bull market in the U.S. over the last 12 months."
• Why it matters: "[E]merging markets ... were last this hot in 2009."
• "The MSCI Emerging Markets Index is up 34% so far this year, beating the 16% advance in the Standard & Poor's 500 index and last year's 9% gain, as emerging markets crawled out of a three-year slump."
• "China, Russia, and India found firmer fiscal footing and weathered developments that would have derailed them before."
• But, but, but: "[T]he prospect of Beijing wielding a heavier hand in Chinese companies and economic reforms in India potentially slowing near-term growth means that investors who take a closer look now will need to pick their spots carefully."

The Palestinian Liberation Office in Washington, D.C., will be allowed to stay open as long as it limits its activities to "achieving a lasting, comprehensive peace between the Israelis and Palestinians," the AP reports, in a reversal by the Trump administration. Those limits on activities could be lifted in 90 days.

Why it matters: Closure of the office threatened to derail U.S. mediated peace talks, as Barak Ravid Of Israel's Channel 10 News and Jonathan Swan of Axios reported earlier.