and rent-cost control was a primary motivating factor in city elections at the time, with the result that liberal candidates who had expressed the desire to close the airport, and/or develop new low-cost housing, were elected to 6 of the 7 city council seats. Battles between opponents and defenders of the airport have continued, with various court decisions and FAA legal opinions emerging, favoring one side or the other. However the airport has remained open throughout the rest of the 20th Century, and into the 21st. In 2009, with jet traffic increasing at SMO, studies by UCLA and the South Coast Air Quality Management District warned that SMO was a source of abnormally high air pollution in the area, particularly for ultrafine particles that threatened the health of children and the elderly, and those with respiratory and cardiovascular diseases. In neighborhoods downwind of the airport, ultrafine particles were measured at 2.5 to 10 times the normal amount. The FAA attempted remediation by controlling the timing of engine run-ups and positioning of aircraft, but some residents complained that the measures failed to resolve the problem. In 2017, the FAA agreed to let the city shorten the runway from to -- effectively blocking most jets from using the airport -- and allowing the city to completely close the airport by 2028. A legal challenge to the agreement, backed by the NBAA, failed in court. 21st Century political/social/cultural events The hangar in the airport hosted the 2022 Nickelodeon Kids' Choice Awards on April 9, 2022. Also in 2022, the Frieze Art Fair announced that its Los Angeles edition would move to the airport in 2023, occupying a massive temporary tent designed by Kulapat Yantrasast’s architecture firm WHY and hosting more than 100 exhibitors in addition to expanded programming and activations. U.S. Presidents Donald Trump (in 2019) and Joe Biden (in 2022) both landed at SMO during visits to the area -- arriving in their Marine One helicopter, after first arriving at Los Angeles International Airport aboard Air Force One. Operations The airport has a control tower. On average, it handled 296 operations a day (for the 12 months – ended July 2011. Traffic decreased to 83,381 annual operations in 2014. As the Santa Monica Airport is one of many general aviation airports in the nation that is surrounded on some sides by residential development, the City of Santa Monica aggressively enforces one of