The number of Japanese citizens residing in Shanghai plunged 17 percent last year, the first decline on record, amid worsening pollution, rising costs and the Senkaku sovereignty clash.

Japanese residents of the Chinese metropolis dropped to about 47,700 as of October, down from 57,458 a year earlier, the local Consulate General of Japan said earlier in the week, based on data from the Foreign Ministry in Tokyo.

Since comparable data began to be compiled in 1994, Shanghai had been a steady draw for Japanese. In 2011, it overtook New York as host of the second-largest Japanese expatriate community, behind Los Angeles, the data show.