TOKYO >> The operators of the Tokyo Dome unveiled coronavirus prevention measures last week, ahead of Tuesday’s professional baseball game at the stadium, the first played with fans in-house this season.

The stadium’s existing ventilation system was beefed up to increase airflow to seating areas, and 30 large ventilators have been installed in the concourse to improve air circulation.

Also, a new tracing system will allow spectators to be notified if someone seated in their vicinity later tests positive for the coronavirus.

Hiroyuki Kunishima, a professor at St. Marianna University of Medicine, and Toru Yoshikawa, a senior researcher at the National Institute of Occupational Safety and Health, oversaw the implementation of the measures.

“Our first priority is preventing the virus from entering the facility, but even if it enters, we’re implementing a three-step approach to prevent it from spreading,” said Yomiuri Giants owner Toshikazu Yamaguchi, who also serves as president of Yomiuri Shimbun Holding.

Yamaguchi said attendance for Giants games at the dome will be limited to 5,000 spectators. The government’s current guidelines for events is a maximum of 5,000 spectators or 50% of a venue’s capacity, whichever is lower. Attendance restrictions on professional sports were set to be eased by Aug. 1, but COVID-19 cases have been on the rise.

“The number of infections is increasing, especially in Tokyo. We had been aiming for about 19,000 spectators based on the government’s guidelines, but we’re not in a hurry to reach that number. We will start with 5,000, and if the situation permits, we hope to increase the number little by little,” Yamaguchi said.