Soot from research bases and sightseeing cruises is melting millions of tonnes of Antarctic snow every summer
Low-cost air-ventilation systems have been installed in many classrooms across the U.S. to help reduce COVID-19 transmission.
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Air-ventilation upgrades have been badly needed in U.S. classrooms since long before the pandemic. Low-tech filtration systems that cost about the same as a textbook per student can make a big difference.
The number of substances emitted into the atmosphere is immense and growing, but some are particularly harmful to health and are subject to increased monitoring.