A group of Chinese academics are calling for everyday English-language abbreviations to be struck from the country's top dictionary - claiming they are the biggest threat to the Chinese language in a century. A letter signed by more than 100 scholars condemned the inclusion of terms such as NBA (National Basketball Association) and WTO (World Trade Organisation) in the most recent Contemporary Chinese Dictionary. The latest edition of the country's most authoritative linguistic reference book included some 240 terms containing Latin letters, up from 39 in 1996. Chinese academics are not the only ones trying to hold back the tide of English. Similar campaigns have been waged in countries including France and Japan. Acronyms and other abbreviations derived from English are widely used on the mainland, where basketball fans refer to the league as the NBA, rather than mei zhi lan , the official translation. English abbreviations for international bodies such as the WTO are also commonplace, while PM2.5, a measure of air pollution, is now a familiar term among urban residents increasingly concerned about air quality. The academics claim the inclusion of English abbreviations threatens the Chinese language, and their presence in the dictionary violates Chinese laws governing language usage. "Replacing Chinese characters with letters in such a dictionary deals the most severe damage to the Chinese language in a century," said Li Mingsheng, a researcher at the Chinese Academy of Social Sciences. "If we don't make standards, more English expressions will become part of Chinese," said Fu Zhenguo of the Communist Party mouthpiece People's Daily and a signatory to the letter.