New York City subway stations that lie beneath the city's rivers may expose commuters to higher levels of harmful pollutants compared to other stations, according to a study published this month. Known as the "river-tunnel" effect by researchers, tunnels that are beneath water have limited ventilation, which ends up trapping harmful particles, according to scientists from New York University's Grossman School of Medicine. According to the research, stations neighboring river tunnels had 80 to 130 percent higher concentrations of potentially dangerous particles compared to stations only a few stops away.
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