Description: Woman waits for a car emission inspection in 1973.
Original caption: “A woman watches as her car goes through testing at an auto emission inspection station in downtown Cincinnati in September 1973. All light-duty, spark-ignition-powered motor vehicles were tested annually for carbon monoxide and hydrocarbon emissions and given a safety check. All other vehicles registered in the city received an annual safety check. The emissions test on an exhaust analyzer went into effect in January 1975; the safety test had been in effect since 1940.
Lyntha Scott Eiler/National Archives, Records of the Environmental Protection Agency